Update Linux to v5.10.109
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz
Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/tools/objtool/.gitignore b/tools/objtool/.gitignore
index 914cff1..45cefda 100644
--- a/tools/objtool/.gitignore
+++ b/tools/objtool/.gitignore
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
arch/x86/lib/inat-tables.c
objtool
fixdep
diff --git a/tools/objtool/Build b/tools/objtool/Build
index 8dc4f08..b7222d5 100644
--- a/tools/objtool/Build
+++ b/tools/objtool/Build
@@ -1,16 +1,22 @@
objtool-y += arch/$(SRCARCH)/
+
+objtool-y += weak.o
+
+objtool-$(SUBCMD_CHECK) += check.o
+objtool-$(SUBCMD_CHECK) += special.o
+objtool-$(SUBCMD_ORC) += check.o
+objtool-$(SUBCMD_ORC) += orc_gen.o
+objtool-$(SUBCMD_ORC) += orc_dump.o
+
objtool-y += builtin-check.o
objtool-y += builtin-orc.o
-objtool-y += check.o
-objtool-y += orc_gen.o
-objtool-y += orc_dump.o
objtool-y += elf.o
-objtool-y += special.o
objtool-y += objtool.o
objtool-y += libstring.o
objtool-y += libctype.o
objtool-y += str_error_r.o
+objtool-y += librbtree.o
CFLAGS += -I$(srctree)/tools/lib
@@ -25,3 +31,7 @@
$(OUTPUT)str_error_r.o: ../lib/str_error_r.c FORCE
$(call rule_mkdir)
$(call if_changed_dep,cc_o_c)
+
+$(OUTPUT)librbtree.o: ../lib/rbtree.c FORCE
+ $(call rule_mkdir)
+ $(call if_changed_dep,cc_o_c)
diff --git a/tools/objtool/Documentation/stack-validation.txt b/tools/objtool/Documentation/stack-validation.txt
index de09467..0542e46 100644
--- a/tools/objtool/Documentation/stack-validation.txt
+++ b/tools/objtool/Documentation/stack-validation.txt
@@ -289,6 +289,47 @@
might be corrupt due to a gcc bug. For more details, see:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70646
+9. file.o: warning: objtool: funcA() call to funcB() with UACCESS enabled
+
+ This means that an unexpected call to a non-whitelisted function exists
+ outside of arch-specific guards.
+ X86: SMAP (stac/clac): __uaccess_begin()/__uaccess_end()
+ ARM: PAN: uaccess_enable()/uaccess_disable()
+
+ These functions should be called to denote a minimal critical section around
+ access to __user variables. See also: https://lwn.net/Articles/517475/
+
+ The intention of the warning is to prevent calls to funcB() from eventually
+ calling schedule(), potentially leaking the AC flags state, and not
+ restoring them correctly.
+
+ It also helps verify that there are no unexpected calls to funcB() which may
+ access user space pages with protections against doing so disabled.
+
+ To fix, either:
+ 1) remove explicit calls to funcB() from funcA().
+ 2) add the correct guards before and after calls to low level functions like
+ __get_user_size()/__put_user_size().
+ 3) add funcB to uaccess_safe_builtin whitelist in tools/objtool/check.c, if
+ funcB obviously does not call schedule(), and is marked notrace (since
+ function tracing inserts additional calls, which is not obvious from the
+ sources).
+
+10. file.o: warning: func()+0x5c: alternative modifies stack
+
+ This means that an alternative includes instructions that modify the
+ stack. The problem is that there is only one ORC unwind table, this means
+ that the ORC unwind entries must be valid for each of the alternatives.
+ The easiest way to enforce this is to ensure alternatives do not contain
+ any ORC entries, which in turn implies the above constraint.
+
+11. file.o: warning: unannotated intra-function call
+
+ This warning means that a direct call is done to a destination which
+ is not at the beginning of a function. If this is a legit call, you
+ can remove this warning by putting the ANNOTATE_INTRA_FUNCTION_CALL
+ directive right before the call.
+
If the error doesn't seem to make sense, it could be a bug in objtool.
Feel free to ask the objtool maintainer for help.
diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
index 9ae4a10..5cdb190 100644
--- a/tools/objtool/Makefile
+++ b/tools/objtool/Makefile
@@ -26,8 +26,9 @@
INCLUDES := -I$(srctree)/tools/include \
-I$(srctree)/tools/arch/$(HOSTARCH)/include/uapi \
- -I$(srctree)/tools/arch/$(SRCARCH)/include
-WARNINGS := $(EXTRA_WARNINGS) -Wno-switch-default -Wno-switch-enum -Wno-packed
+ -I$(srctree)/tools/arch/$(SRCARCH)/include \
+ -I$(srctree)/tools/objtool/arch/$(SRCARCH)/include
+WARNINGS := $(EXTRA_WARNINGS) -Wno-switch-default -Wno-switch-enum -Wno-packed -Wno-nested-externs
CFLAGS := -Werror $(WARNINGS) $(KBUILD_HOSTCFLAGS) -g $(INCLUDES) $(LIBELF_FLAGS)
LDFLAGS += $(LIBELF_LIBS) $(LIBSUBCMD) $(KBUILD_HOSTLDFLAGS)
@@ -36,14 +37,28 @@
CFLAGS += $(if $(elfshdr),,-DLIBELF_USE_DEPRECATED)
AWK = awk
+
+SUBCMD_CHECK := n
+SUBCMD_ORC := n
+
+ifeq ($(SRCARCH),x86)
+ SUBCMD_CHECK := y
+ SUBCMD_ORC := y
+endif
+
+ifeq ($(SUBCMD_ORC),y)
+ CFLAGS += -DINSN_USE_ORC
+endif
+
+export SUBCMD_CHECK SUBCMD_ORC
export srctree OUTPUT CFLAGS SRCARCH AWK
include $(srctree)/tools/build/Makefile.include
$(OBJTOOL_IN): fixdep FORCE
+ @$(CONFIG_SHELL) ./sync-check.sh
@$(MAKE) $(build)=objtool
$(OBJTOOL): $(LIBSUBCMD) $(OBJTOOL_IN)
- @$(CONFIG_SHELL) ./sync-check.sh
$(QUIET_LINK)$(CC) $(OBJTOOL_IN) $(LDFLAGS) -o $@
diff --git a/tools/objtool/arch.h b/tools/objtool/arch.h
index ced3765..4a84c30 100644
--- a/tools/objtool/arch.h
+++ b/tools/objtool/arch.h
@@ -8,9 +8,13 @@
#include <stdbool.h>
#include <linux/list.h>
-#include "elf.h"
+#include "objtool.h"
#include "cfi.h"
+#ifdef INSN_USE_ORC
+#include <asm/orc_types.h>
+#endif
+
enum insn_type {
INSN_JUMP_CONDITIONAL,
INSN_JUMP_UNCONDITIONAL,
@@ -20,7 +24,6 @@
INSN_CALL_DYNAMIC,
INSN_RETURN,
INSN_CONTEXT_SWITCH,
- INSN_STACK,
INSN_BUG,
INSN_NOP,
INSN_STAC,
@@ -64,15 +67,27 @@
struct stack_op {
struct op_dest dest;
struct op_src src;
+ struct list_head list;
};
-void arch_initial_func_cfi_state(struct cfi_state *state);
+struct instruction;
-int arch_decode_instruction(struct elf *elf, struct section *sec,
+void arch_initial_func_cfi_state(struct cfi_init_state *state);
+
+int arch_decode_instruction(const struct elf *elf, const struct section *sec,
unsigned long offset, unsigned int maxlen,
unsigned int *len, enum insn_type *type,
- unsigned long *immediate, struct stack_op *op);
+ unsigned long *immediate,
+ struct list_head *ops_list);
bool arch_callee_saved_reg(unsigned char reg);
+unsigned long arch_jump_destination(struct instruction *insn);
+
+unsigned long arch_dest_reloc_offset(int addend);
+
+const char *arch_nop_insn(int len);
+
+int arch_decode_hint_reg(struct instruction *insn, u8 sp_reg);
+
#endif /* _ARCH_H */
diff --git a/tools/objtool/arch/x86/Build b/tools/objtool/arch/x86/Build
index 7c50040..9f7869b 100644
--- a/tools/objtool/arch/x86/Build
+++ b/tools/objtool/arch/x86/Build
@@ -1,3 +1,4 @@
+objtool-y += special.o
objtool-y += decode.o
inat_tables_script = ../arch/x86/tools/gen-insn-attr-x86.awk
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index a62e032..cde9c36 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -11,9 +11,11 @@
#include "../../../arch/x86/lib/inat.c"
#include "../../../arch/x86/lib/insn.c"
+#include "../../check.h"
#include "../../elf.h"
#include "../../arch.h"
#include "../../warn.h"
+#include <asm/orc_types.h>
static unsigned char op_to_cfi_reg[][2] = {
{CFI_AX, CFI_R8},
@@ -26,7 +28,7 @@
{CFI_DI, CFI_R15},
};
-static int is_x86_64(struct elf *elf)
+static int is_x86_64(const struct elf *elf)
{
switch (elf->ehdr.e_machine) {
case EM_X86_64:
@@ -66,16 +68,34 @@
}
}
-int arch_decode_instruction(struct elf *elf, struct section *sec,
+unsigned long arch_dest_reloc_offset(int addend)
+{
+ return addend + 4;
+}
+
+unsigned long arch_jump_destination(struct instruction *insn)
+{
+ return insn->offset + insn->len + insn->immediate;
+}
+
+#define ADD_OP(op) \
+ if (!(op = calloc(1, sizeof(*op)))) \
+ return -1; \
+ else for (list_add_tail(&op->list, ops_list); op; op = NULL)
+
+int arch_decode_instruction(const struct elf *elf, const struct section *sec,
unsigned long offset, unsigned int maxlen,
unsigned int *len, enum insn_type *type,
- unsigned long *immediate, struct stack_op *op)
+ unsigned long *immediate,
+ struct list_head *ops_list)
{
struct insn insn;
int x86_64, sign;
unsigned char op1, op2, rex = 0, rex_b = 0, rex_r = 0, rex_w = 0,
rex_x = 0, modrm = 0, modrm_mod = 0, modrm_rm = 0,
modrm_reg = 0, sib = 0;
+ struct stack_op *op = NULL;
+ struct symbol *sym;
x86_64 = is_x86_64(elf);
if (x86_64 == -1)
@@ -85,7 +105,7 @@
insn_get_length(&insn);
if (!insn_complete(&insn)) {
- WARN_FUNC("can't decode instruction", sec, offset);
+ WARN("can't decode instruction at %s:0x%lx", sec->name, offset);
return -1;
}
@@ -123,40 +143,44 @@
if (rex_w && !rex_b && modrm_mod == 3 && modrm_rm == 4) {
/* add/sub reg, %rsp */
- *type = INSN_STACK;
- op->src.type = OP_SRC_ADD;
- op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
- op->dest.type = OP_DEST_REG;
- op->dest.reg = CFI_SP;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_ADD;
+ op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = CFI_SP;
+ }
}
break;
case 0x50 ... 0x57:
/* push reg */
- *type = INSN_STACK;
- op->src.type = OP_SRC_REG;
- op->src.reg = op_to_cfi_reg[op1 & 0x7][rex_b];
- op->dest.type = OP_DEST_PUSH;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_REG;
+ op->src.reg = op_to_cfi_reg[op1 & 0x7][rex_b];
+ op->dest.type = OP_DEST_PUSH;
+ }
break;
case 0x58 ... 0x5f:
/* pop reg */
- *type = INSN_STACK;
- op->src.type = OP_SRC_POP;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = op_to_cfi_reg[op1 & 0x7][rex_b];
+ ADD_OP(op) {
+ op->src.type = OP_SRC_POP;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = op_to_cfi_reg[op1 & 0x7][rex_b];
+ }
break;
case 0x68:
case 0x6a:
/* push immediate */
- *type = INSN_STACK;
- op->src.type = OP_SRC_CONST;
- op->dest.type = OP_DEST_PUSH;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_CONST;
+ op->dest.type = OP_DEST_PUSH;
+ }
break;
case 0x70 ... 0x7f:
@@ -170,12 +194,13 @@
if (modrm == 0xe4) {
/* and imm, %rsp */
- *type = INSN_STACK;
- op->src.type = OP_SRC_AND;
- op->src.reg = CFI_SP;
- op->src.offset = insn.immediate.value;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = CFI_SP;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_AND;
+ op->src.reg = CFI_SP;
+ op->src.offset = insn.immediate.value;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = CFI_SP;
+ }
break;
}
@@ -187,34 +212,37 @@
break;
/* add/sub imm, %rsp */
- *type = INSN_STACK;
- op->src.type = OP_SRC_ADD;
- op->src.reg = CFI_SP;
- op->src.offset = insn.immediate.value * sign;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = CFI_SP;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_ADD;
+ op->src.reg = CFI_SP;
+ op->src.offset = insn.immediate.value * sign;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = CFI_SP;
+ }
break;
case 0x89:
if (rex_w && !rex_r && modrm_mod == 3 && modrm_reg == 4) {
/* mov %rsp, reg */
- *type = INSN_STACK;
- op->src.type = OP_SRC_REG;
- op->src.reg = CFI_SP;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = op_to_cfi_reg[modrm_rm][rex_b];
+ ADD_OP(op) {
+ op->src.type = OP_SRC_REG;
+ op->src.reg = CFI_SP;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = op_to_cfi_reg[modrm_rm][rex_b];
+ }
break;
}
if (rex_w && !rex_b && modrm_mod == 3 && modrm_rm == 4) {
/* mov reg, %rsp */
- *type = INSN_STACK;
- op->src.type = OP_SRC_REG;
- op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
- op->dest.type = OP_DEST_REG;
- op->dest.reg = CFI_SP;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_REG;
+ op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = CFI_SP;
+ }
break;
}
@@ -224,22 +252,24 @@
(modrm_mod == 1 || modrm_mod == 2) && modrm_rm == 5) {
/* mov reg, disp(%rbp) */
- *type = INSN_STACK;
- op->src.type = OP_SRC_REG;
- op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
- op->dest.type = OP_DEST_REG_INDIRECT;
- op->dest.reg = CFI_BP;
- op->dest.offset = insn.displacement.value;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_REG;
+ op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
+ op->dest.type = OP_DEST_REG_INDIRECT;
+ op->dest.reg = CFI_BP;
+ op->dest.offset = insn.displacement.value;
+ }
} else if (rex_w && !rex_b && modrm_rm == 4 && sib == 0x24) {
/* mov reg, disp(%rsp) */
- *type = INSN_STACK;
- op->src.type = OP_SRC_REG;
- op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
- op->dest.type = OP_DEST_REG_INDIRECT;
- op->dest.reg = CFI_SP;
- op->dest.offset = insn.displacement.value;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_REG;
+ op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
+ op->dest.type = OP_DEST_REG_INDIRECT;
+ op->dest.reg = CFI_SP;
+ op->dest.offset = insn.displacement.value;
+ }
}
break;
@@ -248,23 +278,25 @@
if (rex_w && !rex_b && modrm_mod == 1 && modrm_rm == 5) {
/* mov disp(%rbp), reg */
- *type = INSN_STACK;
- op->src.type = OP_SRC_REG_INDIRECT;
- op->src.reg = CFI_BP;
- op->src.offset = insn.displacement.value;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];
+ ADD_OP(op) {
+ op->src.type = OP_SRC_REG_INDIRECT;
+ op->src.reg = CFI_BP;
+ op->src.offset = insn.displacement.value;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];
+ }
} else if (rex_w && !rex_b && sib == 0x24 &&
modrm_mod != 3 && modrm_rm == 4) {
/* mov disp(%rsp), reg */
- *type = INSN_STACK;
- op->src.type = OP_SRC_REG_INDIRECT;
- op->src.reg = CFI_SP;
- op->src.offset = insn.displacement.value;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];
+ ADD_OP(op) {
+ op->src.type = OP_SRC_REG_INDIRECT;
+ op->src.reg = CFI_SP;
+ op->src.offset = insn.displacement.value;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];
+ }
}
break;
@@ -272,28 +304,30 @@
case 0x8d:
if (sib == 0x24 && rex_w && !rex_b && !rex_x) {
- *type = INSN_STACK;
- if (!insn.displacement.value) {
- /* lea (%rsp), reg */
- op->src.type = OP_SRC_REG;
- } else {
- /* lea disp(%rsp), reg */
- op->src.type = OP_SRC_ADD;
- op->src.offset = insn.displacement.value;
+ ADD_OP(op) {
+ if (!insn.displacement.value) {
+ /* lea (%rsp), reg */
+ op->src.type = OP_SRC_REG;
+ } else {
+ /* lea disp(%rsp), reg */
+ op->src.type = OP_SRC_ADD;
+ op->src.offset = insn.displacement.value;
+ }
+ op->src.reg = CFI_SP;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];
}
- op->src.reg = CFI_SP;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];
} else if (rex == 0x48 && modrm == 0x65) {
/* lea disp(%rbp), %rsp */
- *type = INSN_STACK;
- op->src.type = OP_SRC_ADD;
- op->src.reg = CFI_BP;
- op->src.offset = insn.displacement.value;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = CFI_SP;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_ADD;
+ op->src.reg = CFI_BP;
+ op->src.offset = insn.displacement.value;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = CFI_SP;
+ }
} else if (rex == 0x49 && modrm == 0x62 &&
insn.displacement.value == -8) {
@@ -304,12 +338,13 @@
* Restoring rsp back to its original value after a
* stack realignment.
*/
- *type = INSN_STACK;
- op->src.type = OP_SRC_ADD;
- op->src.reg = CFI_R10;
- op->src.offset = -8;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = CFI_SP;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_ADD;
+ op->src.reg = CFI_R10;
+ op->src.offset = -8;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = CFI_SP;
+ }
} else if (rex == 0x49 && modrm == 0x65 &&
insn.displacement.value == -16) {
@@ -320,21 +355,23 @@
* Restoring rsp back to its original value after a
* stack realignment.
*/
- *type = INSN_STACK;
- op->src.type = OP_SRC_ADD;
- op->src.reg = CFI_R13;
- op->src.offset = -16;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = CFI_SP;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_ADD;
+ op->src.reg = CFI_R13;
+ op->src.offset = -16;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = CFI_SP;
+ }
}
break;
case 0x8f:
/* pop to mem */
- *type = INSN_STACK;
- op->src.type = OP_SRC_POP;
- op->dest.type = OP_DEST_MEM;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_POP;
+ op->dest.type = OP_DEST_MEM;
+ }
break;
case 0x90:
@@ -343,16 +380,18 @@
case 0x9c:
/* pushf */
- *type = INSN_STACK;
- op->src.type = OP_SRC_CONST;
- op->dest.type = OP_DEST_PUSHF;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_CONST;
+ op->dest.type = OP_DEST_PUSHF;
+ }
break;
case 0x9d:
/* popf */
- *type = INSN_STACK;
- op->src.type = OP_SRC_POPF;
- op->dest.type = OP_DEST_MEM;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_POPF;
+ op->dest.type = OP_DEST_MEM;
+ }
break;
case 0x0f:
@@ -387,16 +426,18 @@
} else if (op2 == 0xa0 || op2 == 0xa8) {
/* push fs/gs */
- *type = INSN_STACK;
- op->src.type = OP_SRC_CONST;
- op->dest.type = OP_DEST_PUSH;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_CONST;
+ op->dest.type = OP_DEST_PUSH;
+ }
} else if (op2 == 0xa1 || op2 == 0xa9) {
/* pop fs/gs */
- *type = INSN_STACK;
- op->src.type = OP_SRC_POP;
- op->dest.type = OP_DEST_MEM;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_POP;
+ op->dest.type = OP_DEST_MEM;
+ }
}
break;
@@ -409,8 +450,8 @@
* mov bp, sp
* pop bp
*/
- *type = INSN_STACK;
- op->dest.type = OP_DEST_LEAVE;
+ ADD_OP(op)
+ op->dest.type = OP_DEST_LEAVE;
break;
@@ -429,14 +470,41 @@
*type = INSN_RETURN;
break;
+ case 0xcf: /* iret */
+ /*
+ * Handle sync_core(), which has an IRET to self.
+ * All other IRET are in STT_NONE entry code.
+ */
+ sym = find_symbol_containing(sec, offset);
+ if (sym && sym->type == STT_FUNC) {
+ ADD_OP(op) {
+ /* add $40, %rsp */
+ op->src.type = OP_SRC_ADD;
+ op->src.reg = CFI_SP;
+ op->src.offset = 5*8;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = CFI_SP;
+ }
+ break;
+ }
+
+ /* fallthrough */
+
case 0xca: /* retf */
case 0xcb: /* retf */
- case 0xcf: /* iret */
*type = INSN_CONTEXT_SWITCH;
break;
case 0xe8:
*type = INSN_CALL;
+ /*
+ * For the impact on the stack, a CALL behaves like
+ * a PUSH of an immediate value (the return address).
+ */
+ ADD_OP(op) {
+ op->src.type = OP_SRC_CONST;
+ op->dest.type = OP_DEST_PUSH;
+ }
break;
case 0xfc:
@@ -464,9 +532,10 @@
else if (modrm_reg == 6) {
/* push from mem */
- *type = INSN_STACK;
- op->src.type = OP_SRC_CONST;
- op->dest.type = OP_DEST_PUSH;
+ ADD_OP(op) {
+ op->src.type = OP_SRC_CONST;
+ op->dest.type = OP_DEST_PUSH;
+ }
}
break;
@@ -480,7 +549,7 @@
return 0;
}
-void arch_initial_func_cfi_state(struct cfi_state *state)
+void arch_initial_func_cfi_state(struct cfi_init_state *state)
{
int i;
@@ -497,3 +566,57 @@
state->regs[16].base = CFI_CFA;
state->regs[16].offset = -8;
}
+
+const char *arch_nop_insn(int len)
+{
+ static const char nops[5][5] = {
+ /* 1 */ { 0x90 },
+ /* 2 */ { 0x66, 0x90 },
+ /* 3 */ { 0x0f, 0x1f, 0x00 },
+ /* 4 */ { 0x0f, 0x1f, 0x40, 0x00 },
+ /* 5 */ { 0x0f, 0x1f, 0x44, 0x00, 0x00 },
+ };
+
+ if (len < 1 || len > 5) {
+ WARN("invalid NOP size: %d\n", len);
+ return NULL;
+ }
+
+ return nops[len-1];
+}
+
+int arch_decode_hint_reg(struct instruction *insn, u8 sp_reg)
+{
+ struct cfi_reg *cfa = &insn->cfi.cfa;
+
+ switch (sp_reg) {
+ case ORC_REG_UNDEFINED:
+ cfa->base = CFI_UNDEFINED;
+ break;
+ case ORC_REG_SP:
+ cfa->base = CFI_SP;
+ break;
+ case ORC_REG_BP:
+ cfa->base = CFI_BP;
+ break;
+ case ORC_REG_SP_INDIRECT:
+ cfa->base = CFI_SP_INDIRECT;
+ break;
+ case ORC_REG_R10:
+ cfa->base = CFI_R10;
+ break;
+ case ORC_REG_R13:
+ cfa->base = CFI_R13;
+ break;
+ case ORC_REG_DI:
+ cfa->base = CFI_DI;
+ break;
+ case ORC_REG_DX:
+ cfa->base = CFI_DX;
+ break;
+ default:
+ return -1;
+ }
+
+ return 0;
+}
diff --git a/tools/objtool/arch/x86/include/arch_elf.h b/tools/objtool/arch/x86/include/arch_elf.h
new file mode 100644
index 0000000..69cc426
--- /dev/null
+++ b/tools/objtool/arch/x86/include/arch_elf.h
@@ -0,0 +1,6 @@
+#ifndef _OBJTOOL_ARCH_ELF
+#define _OBJTOOL_ARCH_ELF
+
+#define R_NONE R_X86_64_NONE
+
+#endif /* _OBJTOOL_ARCH_ELF */
diff --git a/tools/objtool/arch/x86/include/arch_special.h b/tools/objtool/arch/x86/include/arch_special.h
new file mode 100644
index 0000000..d818b2b
--- /dev/null
+++ b/tools/objtool/arch/x86/include/arch_special.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _X86_ARCH_SPECIAL_H
+#define _X86_ARCH_SPECIAL_H
+
+#define EX_ENTRY_SIZE 12
+#define EX_ORIG_OFFSET 0
+#define EX_NEW_OFFSET 4
+
+#define JUMP_ENTRY_SIZE 16
+#define JUMP_ORIG_OFFSET 0
+#define JUMP_NEW_OFFSET 4
+
+#define ALT_ENTRY_SIZE 13
+#define ALT_ORIG_OFFSET 0
+#define ALT_NEW_OFFSET 4
+#define ALT_FEATURE_OFFSET 8
+#define ALT_ORIG_LEN_OFFSET 10
+#define ALT_NEW_LEN_OFFSET 11
+
+#endif /* _X86_ARCH_SPECIAL_H */
diff --git a/tools/objtool/arch/x86/include/cfi_regs.h b/tools/objtool/arch/x86/include/cfi_regs.h
new file mode 100644
index 0000000..79bc517
--- /dev/null
+++ b/tools/objtool/arch/x86/include/cfi_regs.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef _OBJTOOL_CFI_REGS_H
+#define _OBJTOOL_CFI_REGS_H
+
+#define CFI_AX 0
+#define CFI_DX 1
+#define CFI_CX 2
+#define CFI_BX 3
+#define CFI_SI 4
+#define CFI_DI 5
+#define CFI_BP 6
+#define CFI_SP 7
+#define CFI_R8 8
+#define CFI_R9 9
+#define CFI_R10 10
+#define CFI_R11 11
+#define CFI_R12 12
+#define CFI_R13 13
+#define CFI_R14 14
+#define CFI_R15 15
+#define CFI_RA 16
+#define CFI_NUM_REGS 17
+
+#endif /* _OBJTOOL_CFI_REGS_H */
diff --git a/tools/objtool/arch/x86/special.c b/tools/objtool/arch/x86/special.c
new file mode 100644
index 0000000..151b13d
--- /dev/null
+++ b/tools/objtool/arch/x86/special.c
@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <string.h>
+
+#include "../../special.h"
+#include "../../builtin.h"
+
+#define X86_FEATURE_POPCNT (4 * 32 + 23)
+#define X86_FEATURE_SMAP (9 * 32 + 20)
+
+void arch_handle_alternative(unsigned short feature, struct special_alt *alt)
+{
+ switch (feature) {
+ case X86_FEATURE_SMAP:
+ /*
+ * If UACCESS validation is enabled; force that alternative;
+ * otherwise force it the other way.
+ *
+ * What we want to avoid is having both the original and the
+ * alternative code flow at the same time, in that case we can
+ * find paths that see the STAC but take the NOP instead of
+ * CLAC and the other way around.
+ */
+ if (uaccess)
+ alt->skip_orig = true;
+ else
+ alt->skip_alt = true;
+ break;
+ case X86_FEATURE_POPCNT:
+ /*
+ * It has been requested that we don't validate the !POPCNT
+ * feature path which is a "very very small percentage of
+ * machines".
+ */
+ alt->skip_orig = true;
+ break;
+ default:
+ break;
+ }
+}
+
+bool arch_support_alt_relocation(struct special_alt *special_alt,
+ struct instruction *insn,
+ struct reloc *reloc)
+{
+ /*
+ * The x86 alternatives code adjusts the offsets only when it
+ * encounters a branch instruction at the very beginning of the
+ * replacement group.
+ */
+ return insn->offset == special_alt->new_off &&
+ (insn->type == INSN_CALL || is_jump(insn));
+}
+
+/*
+ * There are 3 basic jump table patterns:
+ *
+ * 1. jmpq *[rodata addr](,%reg,8)
+ *
+ * This is the most common case by far. It jumps to an address in a simple
+ * jump table which is stored in .rodata.
+ *
+ * 2. jmpq *[rodata addr](%rip)
+ *
+ * This is caused by a rare GCC quirk, currently only seen in three driver
+ * functions in the kernel, only with certain obscure non-distro configs.
+ *
+ * As part of an optimization, GCC makes a copy of an existing switch jump
+ * table, modifies it, and then hard-codes the jump (albeit with an indirect
+ * jump) to use a single entry in the table. The rest of the jump table and
+ * some of its jump targets remain as dead code.
+ *
+ * In such a case we can just crudely ignore all unreachable instruction
+ * warnings for the entire object file. Ideally we would just ignore them
+ * for the function, but that would require redesigning the code quite a
+ * bit. And honestly that's just not worth doing: unreachable instruction
+ * warnings are of questionable value anyway, and this is such a rare issue.
+ *
+ * 3. mov [rodata addr],%reg1
+ * ... some instructions ...
+ * jmpq *(%reg1,%reg2,8)
+ *
+ * This is a fairly uncommon pattern which is new for GCC 6. As of this
+ * writing, there are 11 occurrences of it in the allmodconfig kernel.
+ *
+ * As of GCC 7 there are quite a few more of these and the 'in between' code
+ * is significant. Esp. with KASAN enabled some of the code between the mov
+ * and jmpq uses .rodata itself, which can confuse things.
+ *
+ * TODO: Once we have DWARF CFI and smarter instruction decoding logic,
+ * ensure the same register is used in the mov and jump instructions.
+ *
+ * NOTE: RETPOLINE made it harder still to decode dynamic jumps.
+ */
+struct reloc *arch_find_switch_table(struct objtool_file *file,
+ struct instruction *insn)
+{
+ struct reloc *text_reloc, *rodata_reloc;
+ struct section *table_sec;
+ unsigned long table_offset;
+
+ /* look for a relocation which references .rodata */
+ text_reloc = find_reloc_by_dest_range(file->elf, insn->sec,
+ insn->offset, insn->len);
+ if (!text_reloc || text_reloc->sym->type != STT_SECTION ||
+ !text_reloc->sym->sec->rodata)
+ return NULL;
+
+ table_offset = text_reloc->addend;
+ table_sec = text_reloc->sym->sec;
+
+ if (text_reloc->type == R_X86_64_PC32)
+ table_offset += 4;
+
+ /*
+ * Make sure the .rodata address isn't associated with a
+ * symbol. GCC jump tables are anonymous data.
+ *
+ * Also support C jump tables which are in the same format as
+ * switch jump tables. For objtool to recognize them, they
+ * need to be placed in the C_JUMP_TABLE_SECTION section. They
+ * have symbols associated with them.
+ */
+ if (find_symbol_containing(table_sec, table_offset) &&
+ strcmp(table_sec->name, C_JUMP_TABLE_SECTION))
+ return NULL;
+
+ /*
+ * Each table entry has a rela associated with it. The rela
+ * should reference text in the same function as the original
+ * instruction.
+ */
+ rodata_reloc = find_reloc_by_dest(file->elf, table_sec, table_offset);
+ if (!rodata_reloc)
+ return NULL;
+
+ /*
+ * Use of RIP-relative switch jumps is quite rare, and
+ * indicates a rare GCC quirk/bug which can leave dead
+ * code behind.
+ */
+ if (text_reloc->type == R_X86_64_PC32)
+ file->ignore_unreachables = true;
+
+ return rodata_reloc;
+}
diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c
index c807984..c6d199b 100644
--- a/tools/objtool/builtin-check.c
+++ b/tools/objtool/builtin-check.c
@@ -14,10 +14,11 @@
*/
#include <subcmd/parse-options.h>
+#include <string.h>
#include "builtin.h"
-#include "check.h"
+#include "objtool.h"
-bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess;
+bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats, validate_dup, vmlinux;
static const char * const check_usage[] = {
"objtool check [<options>] file.o",
@@ -31,12 +32,17 @@
OPT_BOOLEAN('m', "module", &module, "Indicates the object will be part of a kernel module"),
OPT_BOOLEAN('b', "backtrace", &backtrace, "unwind on error"),
OPT_BOOLEAN('a', "uaccess", &uaccess, "enable uaccess checking"),
+ OPT_BOOLEAN('s', "stats", &stats, "print statistics"),
+ OPT_BOOLEAN('d', "duplicate", &validate_dup, "duplicate validation for vmlinux.o"),
+ OPT_BOOLEAN('l', "vmlinux", &vmlinux, "vmlinux.o validation"),
OPT_END(),
};
int cmd_check(int argc, const char **argv)
{
- const char *objname;
+ const char *objname, *s;
+ struct objtool_file *file;
+ int ret;
argc = parse_options(argc, argv, check_options, check_usage, 0);
@@ -45,5 +51,20 @@
objname = argv[0];
- return check(objname, false);
+ s = strstr(objname, "vmlinux.o");
+ if (s && !s[9])
+ vmlinux = true;
+
+ file = objtool_open_read(objname);
+ if (!file)
+ return 1;
+
+ ret = check(file);
+ if (ret)
+ return ret;
+
+ if (file->elf->changed)
+ return elf_write(file->elf);
+
+ return 0;
}
diff --git a/tools/objtool/builtin-orc.c b/tools/objtool/builtin-orc.c
index 5f7cc61..7b31121 100644
--- a/tools/objtool/builtin-orc.c
+++ b/tools/objtool/builtin-orc.c
@@ -14,8 +14,7 @@
#include <string.h>
#include "builtin.h"
-#include "check.h"
-
+#include "objtool.h"
static const char *orc_usage[] = {
"objtool orc generate [<options>] file.o",
@@ -32,13 +31,38 @@
usage_with_options(orc_usage, check_options);
if (!strncmp(argv[0], "gen", 3)) {
+ struct objtool_file *file;
+ int ret;
+
argc = parse_options(argc, argv, check_options, orc_usage, 0);
if (argc != 1)
usage_with_options(orc_usage, check_options);
objname = argv[0];
- return check(objname, true);
+ file = objtool_open_read(objname);
+ if (!file)
+ return 1;
+
+ ret = check(file);
+ if (ret)
+ return ret;
+
+ if (list_empty(&file->insn_list))
+ return 0;
+
+ ret = create_orc(file);
+ if (ret)
+ return ret;
+
+ ret = create_orc_sections(file);
+ if (ret)
+ return ret;
+
+ if (!file->elf->changed)
+ return 0;
+
+ return elf_write(file->elf);
}
if (!strcmp(argv[0], "dump")) {
diff --git a/tools/objtool/builtin.h b/tools/objtool/builtin.h
index a32736f..85c979c 100644
--- a/tools/objtool/builtin.h
+++ b/tools/objtool/builtin.h
@@ -8,7 +8,7 @@
#include <subcmd/parse-options.h>
extern const struct option check_options[];
-extern bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess;
+extern bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats, validate_dup, vmlinux;
extern int cmd_check(int argc, const char **argv);
extern int cmd_orc(int argc, const char **argv);
diff --git a/tools/objtool/cfi.h b/tools/objtool/cfi.h
index 4427bf8..c7c59c6 100644
--- a/tools/objtool/cfi.h
+++ b/tools/objtool/cfi.h
@@ -6,38 +6,33 @@
#ifndef _OBJTOOL_CFI_H
#define _OBJTOOL_CFI_H
+#include "cfi_regs.h"
+
#define CFI_UNDEFINED -1
#define CFI_CFA -2
#define CFI_SP_INDIRECT -3
#define CFI_BP_INDIRECT -4
-#define CFI_AX 0
-#define CFI_DX 1
-#define CFI_CX 2
-#define CFI_BX 3
-#define CFI_SI 4
-#define CFI_DI 5
-#define CFI_BP 6
-#define CFI_SP 7
-#define CFI_R8 8
-#define CFI_R9 9
-#define CFI_R10 10
-#define CFI_R11 11
-#define CFI_R12 12
-#define CFI_R13 13
-#define CFI_R14 14
-#define CFI_R15 15
-#define CFI_RA 16
-#define CFI_NUM_REGS 17
-
struct cfi_reg {
int base;
int offset;
};
-struct cfi_state {
- struct cfi_reg cfa;
+struct cfi_init_state {
struct cfi_reg regs[CFI_NUM_REGS];
+ struct cfi_reg cfa;
+};
+
+struct cfi_state {
+ struct cfi_reg regs[CFI_NUM_REGS];
+ struct cfi_reg vals[CFI_NUM_REGS];
+ struct cfi_reg cfa;
+ int stack_size;
+ int drap_reg, drap_offset;
+ unsigned char type;
+ bool bp_scratch;
+ bool drap;
+ bool end;
};
#endif /* _OBJTOOL_CFI_H */
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 06aaf04..8932f41 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -7,36 +7,37 @@
#include <stdlib.h>
#include "builtin.h"
-#include "check.h"
-#include "elf.h"
-#include "special.h"
+#include "cfi.h"
#include "arch.h"
+#include "check.h"
+#include "special.h"
#include "warn.h"
+#include "arch_elf.h"
+#include <linux/objtool.h>
#include <linux/hashtable.h>
#include <linux/kernel.h>
+#include <linux/static_call_types.h>
#define FAKE_JUMP_OFFSET -1
-#define C_JUMP_TABLE_SECTION ".rodata..c_jump_table"
-
struct alternative {
struct list_head list;
struct instruction *insn;
bool skip_orig;
};
-const char *objname;
-struct cfi_state initial_func_cfi;
+struct cfi_init_state initial_func_cfi;
struct instruction *find_insn(struct objtool_file *file,
struct section *sec, unsigned long offset)
{
struct instruction *insn;
- hash_for_each_possible(file->insn_hash, insn, hash, offset)
+ hash_for_each_possible(file->insn_hash, insn, hash, sec_offset_hash(sec, offset)) {
if (insn->sec == sec && insn->offset == offset)
return insn;
+ }
return NULL;
}
@@ -72,22 +73,33 @@
return find_insn(file, func->cfunc->sec, func->cfunc->offset);
}
-#define func_for_each_insn_all(file, func, insn) \
+static struct instruction *prev_insn_same_sym(struct objtool_file *file,
+ struct instruction *insn)
+{
+ struct instruction *prev = list_prev_entry(insn, list);
+
+ if (&prev->list != &file->insn_list && prev->func == insn->func)
+ return prev;
+
+ return NULL;
+}
+
+#define func_for_each_insn(file, func, insn) \
for (insn = find_insn(file, func->sec, func->offset); \
insn; \
insn = next_insn_same_func(file, insn))
-#define func_for_each_insn(file, func, insn) \
- for (insn = find_insn(file, func->sec, func->offset); \
+#define sym_for_each_insn(file, sym, insn) \
+ for (insn = find_insn(file, sym->sec, sym->offset); \
insn && &insn->list != &file->insn_list && \
- insn->sec == func->sec && \
- insn->offset < func->offset + func->len; \
+ insn->sec == sym->sec && \
+ insn->offset < sym->offset + sym->len; \
insn = list_next_entry(insn, list))
-#define func_for_each_insn_continue_reverse(file, func, insn) \
+#define sym_for_each_insn_continue_reverse(file, sym, insn) \
for (insn = list_prev_entry(insn, list); \
&insn->list != &file->insn_list && \
- insn->sec == func->sec && insn->offset >= func->offset; \
+ insn->sec == sym->sec && insn->offset >= sym->offset; \
insn = list_prev_entry(insn, list))
#define sec_for_each_insn_from(file, insn) \
@@ -103,8 +115,7 @@
if (insn->type == INSN_JUMP_DYNAMIC)
return list_empty(&insn->alts);
- if (insn->type != INSN_JUMP_CONDITIONAL &&
- insn->type != INSN_JUMP_UNCONDITIONAL)
+ if (!is_static_jump(insn))
return false;
/* add_jump_destinations() sets insn->call_dest for sibling calls. */
@@ -144,6 +155,9 @@
"usercopy_abort",
"machine_real_restart",
"rewind_stack_do_exit",
+ "kunit_try_catch_throw",
+ "xen_start_kernel",
+ "cpu_bringup_and_idle",
};
if (!func)
@@ -164,7 +178,7 @@
if (!insn->func)
return false;
- func_for_each_insn_all(file, func, insn) {
+ func_for_each_insn(file, func, insn) {
empty = false;
if (insn->type == INSN_RETURN)
@@ -179,7 +193,7 @@
* case, the function's dead-end status depends on whether the target
* of the sibling call returns.
*/
- func_for_each_insn_all(file, func, insn) {
+ func_for_each_insn(file, func, insn) {
if (is_sibling_call(insn)) {
struct instruction *dest = insn->jump_dest;
@@ -209,18 +223,31 @@
return __dead_end_function(file, func, 0);
}
-static void clear_insn_state(struct insn_state *state)
+static void init_cfi_state(struct cfi_state *cfi)
{
int i;
- memset(state, 0, sizeof(*state));
- state->cfa.base = CFI_UNDEFINED;
for (i = 0; i < CFI_NUM_REGS; i++) {
- state->regs[i].base = CFI_UNDEFINED;
- state->vals[i].base = CFI_UNDEFINED;
+ cfi->regs[i].base = CFI_UNDEFINED;
+ cfi->vals[i].base = CFI_UNDEFINED;
}
- state->drap_reg = CFI_UNDEFINED;
- state->drap_offset = -1;
+ cfi->cfa.base = CFI_UNDEFINED;
+ cfi->drap_reg = CFI_UNDEFINED;
+ cfi->drap_offset = -1;
+}
+
+static void init_insn_state(struct insn_state *state, struct section *sec)
+{
+ memset(state, 0, sizeof(*state));
+ init_cfi_state(&state->cfi);
+
+ /*
+ * We need the full vmlinux for noinstr validation, otherwise we can
+ * not correctly determine insn->call_dest->sec (external symbols do
+ * not have a section).
+ */
+ if (vmlinux && sec)
+ state->noinstr = sec->noinstr;
}
/*
@@ -233,6 +260,7 @@
struct symbol *func;
unsigned long offset;
struct instruction *insn;
+ unsigned long nr_insns = 0;
int ret;
for_each_sec(file, sec) {
@@ -245,6 +273,10 @@
strncmp(sec->name, ".discard.", 9))
sec->text = true;
+ if (!strcmp(sec->name, ".noinstr.text") ||
+ !strcmp(sec->name, ".entry.text"))
+ sec->noinstr = true;
+
for (offset = 0; offset < sec->len; offset += insn->len) {
insn = malloc(sizeof(*insn));
if (!insn) {
@@ -253,7 +285,8 @@
}
memset(insn, 0, sizeof(*insn));
INIT_LIST_HEAD(&insn->alts);
- clear_insn_state(&insn->state);
+ INIT_LIST_HEAD(&insn->stack_ops);
+ init_cfi_state(&insn->cfi);
insn->sec = sec;
insn->offset = offset;
@@ -262,12 +295,13 @@
sec->len - offset,
&insn->len, &insn->type,
&insn->immediate,
- &insn->stack_op);
+ &insn->stack_ops);
if (ret)
goto err;
- hash_add(file->insn_hash, &insn->hash, insn->offset);
+ hash_add(file->insn_hash, &insn->hash, sec_offset_hash(sec, insn->offset));
list_add_tail(&insn->list, &file->insn_list);
+ nr_insns++;
}
list_for_each_entry(func, &sec->symbol_list, list) {
@@ -280,11 +314,14 @@
return -1;
}
- func_for_each_insn(file, func, insn)
+ sym_for_each_insn(file, func, insn)
insn->func = func;
}
}
+ if (stats)
+ printf("nr_insns: %lu\n", nr_insns);
+
return 0;
err:
@@ -292,15 +329,27 @@
return ret;
}
+static struct instruction *find_last_insn(struct objtool_file *file,
+ struct section *sec)
+{
+ struct instruction *insn = NULL;
+ unsigned int offset;
+ unsigned int end = (sec->len > 10) ? sec->len - 10 : 0;
+
+ for (offset = sec->len - 1; offset >= end && !insn; offset--)
+ insn = find_insn(file, sec, offset);
+
+ return insn;
+}
+
/*
* Mark "ud2" instructions and manually annotated dead ends.
*/
static int add_dead_ends(struct objtool_file *file)
{
struct section *sec;
- struct rela *rela;
+ struct reloc *reloc;
struct instruction *insn;
- bool found;
/*
* By default, "ud2" is a dead end unless otherwise annotated, because
@@ -317,31 +366,24 @@
if (!sec)
goto reachable;
- list_for_each_entry(rela, &sec->rela_list, list) {
- if (rela->sym->type != STT_SECTION) {
+ list_for_each_entry(reloc, &sec->reloc_list, list) {
+ if (reloc->sym->type != STT_SECTION) {
WARN("unexpected relocation symbol type in %s", sec->name);
return -1;
}
- insn = find_insn(file, rela->sym->sec, rela->addend);
+ insn = find_insn(file, reloc->sym->sec, reloc->addend);
if (insn)
insn = list_prev_entry(insn, list);
- else if (rela->addend == rela->sym->sec->len) {
- found = false;
- list_for_each_entry_reverse(insn, &file->insn_list, list) {
- if (insn->sec == rela->sym->sec) {
- found = true;
- break;
- }
- }
-
- if (!found) {
+ else if (reloc->addend == reloc->sym->sec->len) {
+ insn = find_last_insn(file, reloc->sym->sec);
+ if (!insn) {
WARN("can't find unreachable insn at %s+0x%x",
- rela->sym->sec->name, rela->addend);
+ reloc->sym->sec->name, reloc->addend);
return -1;
}
} else {
WARN("can't find unreachable insn at %s+0x%x",
- rela->sym->sec->name, rela->addend);
+ reloc->sym->sec->name, reloc->addend);
return -1;
}
@@ -359,31 +401,24 @@
if (!sec)
return 0;
- list_for_each_entry(rela, &sec->rela_list, list) {
- if (rela->sym->type != STT_SECTION) {
+ list_for_each_entry(reloc, &sec->reloc_list, list) {
+ if (reloc->sym->type != STT_SECTION) {
WARN("unexpected relocation symbol type in %s", sec->name);
return -1;
}
- insn = find_insn(file, rela->sym->sec, rela->addend);
+ insn = find_insn(file, reloc->sym->sec, reloc->addend);
if (insn)
insn = list_prev_entry(insn, list);
- else if (rela->addend == rela->sym->sec->len) {
- found = false;
- list_for_each_entry_reverse(insn, &file->insn_list, list) {
- if (insn->sec == rela->sym->sec) {
- found = true;
- break;
- }
- }
-
- if (!found) {
+ else if (reloc->addend == reloc->sym->sec->len) {
+ insn = find_last_insn(file, reloc->sym->sec);
+ if (!insn) {
WARN("can't find reachable insn at %s+0x%x",
- rela->sym->sec->name, rela->addend);
+ reloc->sym->sec->name, reloc->addend);
return -1;
}
} else {
WARN("can't find reachable insn at %s+0x%x",
- rela->sym->sec->name, rela->addend);
+ reloc->sym->sec->name, reloc->addend);
return -1;
}
@@ -393,6 +428,123 @@
return 0;
}
+static int create_static_call_sections(struct objtool_file *file)
+{
+ struct section *sec, *reloc_sec;
+ struct reloc *reloc;
+ struct static_call_site *site;
+ struct instruction *insn;
+ struct symbol *key_sym;
+ char *key_name, *tmp;
+ int idx;
+
+ sec = find_section_by_name(file->elf, ".static_call_sites");
+ if (sec) {
+ INIT_LIST_HEAD(&file->static_call_list);
+ WARN("file already has .static_call_sites section, skipping");
+ return 0;
+ }
+
+ if (list_empty(&file->static_call_list))
+ return 0;
+
+ idx = 0;
+ list_for_each_entry(insn, &file->static_call_list, static_call_node)
+ idx++;
+
+ sec = elf_create_section(file->elf, ".static_call_sites", SHF_WRITE,
+ sizeof(struct static_call_site), idx);
+ if (!sec)
+ return -1;
+
+ reloc_sec = elf_create_reloc_section(file->elf, sec, SHT_RELA);
+ if (!reloc_sec)
+ return -1;
+
+ idx = 0;
+ list_for_each_entry(insn, &file->static_call_list, static_call_node) {
+
+ site = (struct static_call_site *)sec->data->d_buf + idx;
+ memset(site, 0, sizeof(struct static_call_site));
+
+ /* populate reloc for 'addr' */
+ reloc = malloc(sizeof(*reloc));
+
+ if (!reloc) {
+ perror("malloc");
+ return -1;
+ }
+ memset(reloc, 0, sizeof(*reloc));
+
+ insn_to_reloc_sym_addend(insn->sec, insn->offset, reloc);
+ if (!reloc->sym) {
+ WARN_FUNC("static call tramp: missing containing symbol",
+ insn->sec, insn->offset);
+ return -1;
+ }
+
+ reloc->type = R_X86_64_PC32;
+ reloc->offset = idx * sizeof(struct static_call_site);
+ reloc->sec = reloc_sec;
+ elf_add_reloc(file->elf, reloc);
+
+ /* find key symbol */
+ key_name = strdup(insn->call_dest->name);
+ if (!key_name) {
+ perror("strdup");
+ return -1;
+ }
+ if (strncmp(key_name, STATIC_CALL_TRAMP_PREFIX_STR,
+ STATIC_CALL_TRAMP_PREFIX_LEN)) {
+ WARN("static_call: trampoline name malformed: %s", key_name);
+ return -1;
+ }
+ tmp = key_name + STATIC_CALL_TRAMP_PREFIX_LEN - STATIC_CALL_KEY_PREFIX_LEN;
+ memcpy(tmp, STATIC_CALL_KEY_PREFIX_STR, STATIC_CALL_KEY_PREFIX_LEN);
+
+ key_sym = find_symbol_by_name(file->elf, tmp);
+ if (!key_sym) {
+ if (!module) {
+ WARN("static_call: can't find static_call_key symbol: %s", tmp);
+ return -1;
+ }
+
+ /*
+ * For modules(), the key might not be exported, which
+ * means the module can make static calls but isn't
+ * allowed to change them.
+ *
+ * In that case we temporarily set the key to be the
+ * trampoline address. This is fixed up in
+ * static_call_add_module().
+ */
+ key_sym = insn->call_dest;
+ }
+ free(key_name);
+
+ /* populate reloc for 'key' */
+ reloc = malloc(sizeof(*reloc));
+ if (!reloc) {
+ perror("malloc");
+ return -1;
+ }
+ memset(reloc, 0, sizeof(*reloc));
+ reloc->sym = key_sym;
+ reloc->addend = is_sibling_call(insn) ? STATIC_CALL_SITE_TAIL : 0;
+ reloc->type = R_X86_64_PC32;
+ reloc->offset = idx * sizeof(struct static_call_site) + 4;
+ reloc->sec = reloc_sec;
+ elf_add_reloc(file->elf, reloc);
+
+ idx++;
+ }
+
+ if (elf_rebuild_reloc_section(file->elf, reloc_sec))
+ return -1;
+
+ return 0;
+}
+
/*
* Warnings shouldn't be reported for ignored functions.
*/
@@ -401,30 +553,30 @@
struct instruction *insn;
struct section *sec;
struct symbol *func;
- struct rela *rela;
+ struct reloc *reloc;
sec = find_section_by_name(file->elf, ".rela.discard.func_stack_frame_non_standard");
if (!sec)
return;
- list_for_each_entry(rela, &sec->rela_list, list) {
- switch (rela->sym->type) {
+ list_for_each_entry(reloc, &sec->reloc_list, list) {
+ switch (reloc->sym->type) {
case STT_FUNC:
- func = rela->sym;
+ func = reloc->sym;
break;
case STT_SECTION:
- func = find_symbol_by_offset(rela->sym->sec, rela->addend);
- if (!func || func->type != STT_FUNC)
+ func = find_func_by_offset(reloc->sym->sec, reloc->addend);
+ if (!func)
continue;
break;
default:
- WARN("unexpected relocation symbol type in %s: %d", sec->name, rela->sym->type);
+ WARN("unexpected relocation symbol type in %s: %d", sec->name, reloc->sym->type);
continue;
}
- func_for_each_insn_all(file, func, insn)
+ func_for_each_insn(file, func, insn)
insn->ignore = true;
}
}
@@ -453,6 +605,8 @@
"__asan_store4_noabort",
"__asan_store8_noabort",
"__asan_store16_noabort",
+ "__kasan_check_read",
+ "__kasan_check_write",
/* KASAN in-line */
"__asan_report_load_n_noabort",
"__asan_report_load1_noabort",
@@ -466,8 +620,86 @@
"__asan_report_store4_noabort",
"__asan_report_store8_noabort",
"__asan_report_store16_noabort",
+ /* KCSAN */
+ "__kcsan_check_access",
+ "kcsan_found_watchpoint",
+ "kcsan_setup_watchpoint",
+ "kcsan_check_scoped_accesses",
+ "kcsan_disable_current",
+ "kcsan_enable_current_nowarn",
+ /* KCSAN/TSAN */
+ "__tsan_func_entry",
+ "__tsan_func_exit",
+ "__tsan_read_range",
+ "__tsan_write_range",
+ "__tsan_read1",
+ "__tsan_read2",
+ "__tsan_read4",
+ "__tsan_read8",
+ "__tsan_read16",
+ "__tsan_write1",
+ "__tsan_write2",
+ "__tsan_write4",
+ "__tsan_write8",
+ "__tsan_write16",
+ "__tsan_read_write1",
+ "__tsan_read_write2",
+ "__tsan_read_write4",
+ "__tsan_read_write8",
+ "__tsan_read_write16",
+ "__tsan_atomic8_load",
+ "__tsan_atomic16_load",
+ "__tsan_atomic32_load",
+ "__tsan_atomic64_load",
+ "__tsan_atomic8_store",
+ "__tsan_atomic16_store",
+ "__tsan_atomic32_store",
+ "__tsan_atomic64_store",
+ "__tsan_atomic8_exchange",
+ "__tsan_atomic16_exchange",
+ "__tsan_atomic32_exchange",
+ "__tsan_atomic64_exchange",
+ "__tsan_atomic8_fetch_add",
+ "__tsan_atomic16_fetch_add",
+ "__tsan_atomic32_fetch_add",
+ "__tsan_atomic64_fetch_add",
+ "__tsan_atomic8_fetch_sub",
+ "__tsan_atomic16_fetch_sub",
+ "__tsan_atomic32_fetch_sub",
+ "__tsan_atomic64_fetch_sub",
+ "__tsan_atomic8_fetch_and",
+ "__tsan_atomic16_fetch_and",
+ "__tsan_atomic32_fetch_and",
+ "__tsan_atomic64_fetch_and",
+ "__tsan_atomic8_fetch_or",
+ "__tsan_atomic16_fetch_or",
+ "__tsan_atomic32_fetch_or",
+ "__tsan_atomic64_fetch_or",
+ "__tsan_atomic8_fetch_xor",
+ "__tsan_atomic16_fetch_xor",
+ "__tsan_atomic32_fetch_xor",
+ "__tsan_atomic64_fetch_xor",
+ "__tsan_atomic8_fetch_nand",
+ "__tsan_atomic16_fetch_nand",
+ "__tsan_atomic32_fetch_nand",
+ "__tsan_atomic64_fetch_nand",
+ "__tsan_atomic8_compare_exchange_strong",
+ "__tsan_atomic16_compare_exchange_strong",
+ "__tsan_atomic32_compare_exchange_strong",
+ "__tsan_atomic64_compare_exchange_strong",
+ "__tsan_atomic8_compare_exchange_weak",
+ "__tsan_atomic16_compare_exchange_weak",
+ "__tsan_atomic32_compare_exchange_weak",
+ "__tsan_atomic64_compare_exchange_weak",
+ "__tsan_atomic8_compare_exchange_val",
+ "__tsan_atomic16_compare_exchange_val",
+ "__tsan_atomic32_compare_exchange_val",
+ "__tsan_atomic64_compare_exchange_val",
+ "__tsan_atomic_thread_fence",
+ "__tsan_atomic_signal_fence",
/* KCOV */
"write_comp_data",
+ "check_kcov_mode",
"__sanitizer_cov_trace_pc",
"__sanitizer_cov_trace_const_cmp1",
"__sanitizer_cov_trace_const_cmp2",
@@ -477,6 +709,7 @@
"__sanitizer_cov_trace_cmp2",
"__sanitizer_cov_trace_cmp4",
"__sanitizer_cov_trace_cmp8",
+ "__sanitizer_cov_trace_switch",
/* UBSAN */
"ubsan_type_mismatch_common",
"__ubsan_handle_type_mismatch",
@@ -484,8 +717,9 @@
"__ubsan_handle_shift_out_of_bounds",
/* misc */
"csum_partial_copy_generic",
- "__memcpy_mcsafe",
- "mcsafe_handle_tail",
+ "copy_mc_fragile",
+ "copy_mc_fragile_handle_tail",
+ "copy_mc_enhanced_fast_string",
"ftrace_likely_update", /* CONFIG_TRACE_BRANCH_PROFILING */
NULL
};
@@ -516,20 +750,20 @@
static int add_ignore_alternatives(struct objtool_file *file)
{
struct section *sec;
- struct rela *rela;
+ struct reloc *reloc;
struct instruction *insn;
sec = find_section_by_name(file->elf, ".rela.discard.ignore_alts");
if (!sec)
return 0;
- list_for_each_entry(rela, &sec->rela_list, list) {
- if (rela->sym->type != STT_SECTION) {
+ list_for_each_entry(reloc, &sec->reloc_list, list) {
+ if (reloc->sym->type != STT_SECTION) {
WARN("unexpected relocation symbol type in %s", sec->name);
return -1;
}
- insn = find_insn(file, rela->sym->sec, rela->addend);
+ insn = find_insn(file, reloc->sym->sec, reloc->addend);
if (!insn) {
WARN("bad .discard.ignore_alts entry");
return -1;
@@ -547,30 +781,31 @@
static int add_jump_destinations(struct objtool_file *file)
{
struct instruction *insn;
- struct rela *rela;
+ struct reloc *reloc;
struct section *dest_sec;
unsigned long dest_off;
for_each_insn(file, insn) {
- if (insn->type != INSN_JUMP_CONDITIONAL &&
- insn->type != INSN_JUMP_UNCONDITIONAL)
+ if (!is_static_jump(insn))
continue;
if (insn->offset == FAKE_JUMP_OFFSET)
continue;
- rela = find_rela_by_dest_range(insn->sec, insn->offset,
- insn->len);
- if (!rela) {
+ reloc = find_reloc_by_dest_range(file->elf, insn->sec,
+ insn->offset, insn->len);
+ if (!reloc) {
dest_sec = insn->sec;
- dest_off = insn->offset + insn->len + insn->immediate;
- } else if (rela->sym->type == STT_SECTION) {
- dest_sec = rela->sym->sec;
- dest_off = rela->addend + 4;
- } else if (rela->sym->sec->idx) {
- dest_sec = rela->sym->sec;
- dest_off = rela->sym->sym.st_value + rela->addend + 4;
- } else if (strstr(rela->sym->name, "_indirect_thunk_")) {
+ dest_off = arch_jump_destination(insn);
+ } else if (reloc->sym->type == STT_SECTION) {
+ dest_sec = reloc->sym->sec;
+ dest_off = arch_dest_reloc_offset(reloc->addend);
+ } else if (reloc->sym->sec->idx) {
+ dest_sec = reloc->sym->sec;
+ dest_off = reloc->sym->sym.st_value +
+ arch_dest_reloc_offset(reloc->addend);
+ } else if (!strncmp(reloc->sym->name, "__x86_indirect_thunk_", 21) ||
+ !strncmp(reloc->sym->name, "__x86_retpoline_", 16)) {
/*
* Retpoline jumps are really dynamic jumps in
* disguise, so convert them accordingly.
@@ -584,7 +819,11 @@
continue;
} else {
/* external sibling call */
- insn->call_dest = rela->sym;
+ insn->call_dest = reloc->sym;
+ if (insn->call_dest->static_call_tramp) {
+ list_add_tail(&insn->static_call_node,
+ &file->static_call_list);
+ }
continue;
}
@@ -636,6 +875,10 @@
/* internal sibling call */
insn->call_dest = insn->jump_dest->func;
+ if (insn->call_dest->static_call_tramp) {
+ list_add_tail(&insn->static_call_node,
+ &file->static_call_list);
+ }
}
}
}
@@ -643,6 +886,27 @@
return 0;
}
+static void remove_insn_ops(struct instruction *insn)
+{
+ struct stack_op *op, *tmp;
+
+ list_for_each_entry_safe(op, tmp, &insn->stack_ops, list) {
+ list_del(&op->list);
+ free(op);
+ }
+}
+
+static struct symbol *find_call_destination(struct section *sec, unsigned long offset)
+{
+ struct symbol *call_dest;
+
+ call_dest = find_func_by_offset(sec, offset);
+ if (!call_dest)
+ call_dest = find_symbol_by_offset(sec, offset);
+
+ return call_dest;
+}
+
/*
* Find the destination instructions for all calls.
*/
@@ -650,40 +914,77 @@
{
struct instruction *insn;
unsigned long dest_off;
- struct rela *rela;
+ struct reloc *reloc;
for_each_insn(file, insn) {
if (insn->type != INSN_CALL)
continue;
- rela = find_rela_by_dest_range(insn->sec, insn->offset,
- insn->len);
- if (!rela) {
- dest_off = insn->offset + insn->len + insn->immediate;
- insn->call_dest = find_symbol_by_offset(insn->sec,
- dest_off);
+ reloc = find_reloc_by_dest_range(file->elf, insn->sec,
+ insn->offset, insn->len);
+ if (!reloc) {
+ dest_off = arch_jump_destination(insn);
+ insn->call_dest = find_call_destination(insn->sec, dest_off);
- if (!insn->call_dest && !insn->ignore) {
- WARN_FUNC("unsupported intra-function call",
- insn->sec, insn->offset);
- if (retpoline)
- WARN("If this is a retpoline, please patch it in with alternatives and annotate it with ANNOTATE_NOSPEC_ALTERNATIVE.");
+ if (insn->ignore)
+ continue;
+
+ if (!insn->call_dest) {
+ WARN_FUNC("unannotated intra-function call", insn->sec, insn->offset);
return -1;
}
- } else if (rela->sym->type == STT_SECTION) {
- insn->call_dest = find_symbol_by_offset(rela->sym->sec,
- rela->addend+4);
- if (!insn->call_dest ||
- insn->call_dest->type != STT_FUNC) {
- WARN_FUNC("can't find call dest symbol at %s+0x%x",
+ if (insn->func && insn->call_dest->type != STT_FUNC) {
+ WARN_FUNC("unsupported call to non-function",
+ insn->sec, insn->offset);
+ return -1;
+ }
+
+ } else if (reloc->sym->type == STT_SECTION) {
+ dest_off = arch_dest_reloc_offset(reloc->addend);
+ insn->call_dest = find_call_destination(reloc->sym->sec,
+ dest_off);
+ if (!insn->call_dest) {
+ WARN_FUNC("can't find call dest symbol at %s+0x%lx",
insn->sec, insn->offset,
- rela->sym->sec->name,
- rela->addend + 4);
+ reloc->sym->sec->name,
+ dest_off);
return -1;
}
} else
- insn->call_dest = rela->sym;
+ insn->call_dest = reloc->sym;
+
+ if (insn->call_dest && insn->call_dest->static_call_tramp) {
+ list_add_tail(&insn->static_call_node,
+ &file->static_call_list);
+ }
+
+ /*
+ * Many compilers cannot disable KCOV with a function attribute
+ * so they need a little help, NOP out any KCOV calls from noinstr
+ * text.
+ */
+ if (insn->sec->noinstr &&
+ !strncmp(insn->call_dest->name, "__sanitizer_cov_", 16)) {
+ if (reloc) {
+ reloc->type = R_NONE;
+ elf_write_reloc(file->elf, reloc);
+ }
+
+ elf_write_insn(file->elf, insn->sec,
+ insn->offset, insn->len,
+ arch_nop_insn(insn->len));
+ insn->type = INSN_NOP;
+ }
+
+ /*
+ * Whatever stack impact regular CALLs have, should be undone
+ * by the RETURN of the called function.
+ *
+ * Annotated intra-function calls retain the stack_ops but
+ * are converted to JUMP, see read_intra_function_calls().
+ */
+ remove_insn_ops(insn);
}
return 0;
@@ -711,7 +1012,9 @@
struct instruction *orig_insn,
struct instruction **new_insn)
{
+ static unsigned int alt_group_next_index = 1;
struct instruction *last_orig_insn, *last_new_insn, *insn, *fake_jump = NULL;
+ unsigned int alt_group = alt_group_next_index++;
unsigned long dest_off;
last_orig_insn = NULL;
@@ -720,7 +1023,7 @@
if (insn->offset >= special_alt->orig_off + special_alt->orig_len)
break;
- insn->alt_group = true;
+ insn->alt_group = alt_group;
last_orig_insn = insn;
}
@@ -732,7 +1035,8 @@
}
memset(fake_jump, 0, sizeof(*fake_jump));
INIT_LIST_HEAD(&fake_jump->alts);
- clear_insn_state(&fake_jump->state);
+ INIT_LIST_HEAD(&fake_jump->stack_ops);
+ init_cfi_state(&fake_jump->cfi);
fake_jump->sec = special_alt->new_sec;
fake_jump->offset = FAKE_JUMP_OFFSET;
@@ -753,8 +1057,11 @@
}
last_new_insn = NULL;
+ alt_group = alt_group_next_index++;
insn = *new_insn;
sec_for_each_insn_from(file, insn) {
+ struct reloc *alt_reloc;
+
if (insn->offset >= special_alt->new_off + special_alt->new_len)
break;
@@ -762,15 +1069,33 @@
insn->ignore = orig_insn->ignore_alts;
insn->func = orig_insn->func;
+ insn->alt_group = alt_group;
- if (insn->type != INSN_JUMP_CONDITIONAL &&
- insn->type != INSN_JUMP_UNCONDITIONAL)
+ /*
+ * Since alternative replacement code is copy/pasted by the
+ * kernel after applying relocations, generally such code can't
+ * have relative-address relocation references to outside the
+ * .altinstr_replacement section, unless the arch's
+ * alternatives code can adjust the relative offsets
+ * accordingly.
+ */
+ alt_reloc = find_reloc_by_dest_range(file->elf, insn->sec,
+ insn->offset, insn->len);
+ if (alt_reloc &&
+ !arch_support_alt_relocation(special_alt, insn, alt_reloc)) {
+
+ WARN_FUNC("unsupported relocation in alternatives section",
+ insn->sec, insn->offset);
+ return -1;
+ }
+
+ if (!is_static_jump(insn))
continue;
if (!insn->immediate)
continue;
- dest_off = insn->offset + insn->len + insn->immediate;
+ dest_off = arch_jump_destination(insn);
if (dest_off == special_alt->new_off + special_alt->new_len) {
if (!fake_jump) {
WARN("%s: alternative jump to end of section",
@@ -903,34 +1228,34 @@
}
static int add_jump_table(struct objtool_file *file, struct instruction *insn,
- struct rela *table)
+ struct reloc *table)
{
- struct rela *rela = table;
+ struct reloc *reloc = table;
struct instruction *dest_insn;
struct alternative *alt;
struct symbol *pfunc = insn->func->pfunc;
unsigned int prev_offset = 0;
/*
- * Each @rela is a switch table relocation which points to the target
+ * Each @reloc is a switch table relocation which points to the target
* instruction.
*/
- list_for_each_entry_from(rela, &table->sec->rela_list, list) {
+ list_for_each_entry_from(reloc, &table->sec->reloc_list, list) {
/* Check for the end of the table: */
- if (rela != table && rela->jump_table_start)
+ if (reloc != table && reloc->jump_table_start)
break;
/* Make sure the table entries are consecutive: */
- if (prev_offset && rela->offset != prev_offset + 8)
+ if (prev_offset && reloc->offset != prev_offset + 8)
break;
/* Detect function pointers from contiguous objects: */
- if (rela->sym->sec == pfunc->sec &&
- rela->addend == pfunc->offset)
+ if (reloc->sym->sec == pfunc->sec &&
+ reloc->addend == pfunc->offset)
break;
- dest_insn = find_insn(file, rela->sym->sec, rela->addend);
+ dest_insn = find_insn(file, reloc->sym->sec, reloc->addend);
if (!dest_insn)
break;
@@ -946,7 +1271,7 @@
alt->insn = dest_insn;
list_add_tail(&alt->list, &insn->alts);
- prev_offset = rela->offset;
+ prev_offset = reloc->offset;
}
if (!prev_offset) {
@@ -959,56 +1284,15 @@
}
/*
- * find_jump_table() - Given a dynamic jump, find the switch jump table in
- * .rodata associated with it.
- *
- * There are 3 basic patterns:
- *
- * 1. jmpq *[rodata addr](,%reg,8)
- *
- * This is the most common case by far. It jumps to an address in a simple
- * jump table which is stored in .rodata.
- *
- * 2. jmpq *[rodata addr](%rip)
- *
- * This is caused by a rare GCC quirk, currently only seen in three driver
- * functions in the kernel, only with certain obscure non-distro configs.
- *
- * As part of an optimization, GCC makes a copy of an existing switch jump
- * table, modifies it, and then hard-codes the jump (albeit with an indirect
- * jump) to use a single entry in the table. The rest of the jump table and
- * some of its jump targets remain as dead code.
- *
- * In such a case we can just crudely ignore all unreachable instruction
- * warnings for the entire object file. Ideally we would just ignore them
- * for the function, but that would require redesigning the code quite a
- * bit. And honestly that's just not worth doing: unreachable instruction
- * warnings are of questionable value anyway, and this is such a rare issue.
- *
- * 3. mov [rodata addr],%reg1
- * ... some instructions ...
- * jmpq *(%reg1,%reg2,8)
- *
- * This is a fairly uncommon pattern which is new for GCC 6. As of this
- * writing, there are 11 occurrences of it in the allmodconfig kernel.
- *
- * As of GCC 7 there are quite a few more of these and the 'in between' code
- * is significant. Esp. with KASAN enabled some of the code between the mov
- * and jmpq uses .rodata itself, which can confuse things.
- *
- * TODO: Once we have DWARF CFI and smarter instruction decoding logic,
- * ensure the same register is used in the mov and jump instructions.
- *
- * NOTE: RETPOLINE made it harder still to decode dynamic jumps.
+ * find_jump_table() - Given a dynamic jump, find the switch jump table
+ * associated with it.
*/
-static struct rela *find_jump_table(struct objtool_file *file,
+static struct reloc *find_jump_table(struct objtool_file *file,
struct symbol *func,
struct instruction *insn)
{
- struct rela *text_rela, *table_rela;
- struct instruction *orig_insn = insn;
- struct section *table_sec;
- unsigned long table_offset;
+ struct reloc *table_reloc;
+ struct instruction *dest_insn, *orig_insn = insn;
/*
* Backward search using the @first_jump_src links, these help avoid
@@ -1016,8 +1300,8 @@
* it.
*/
for (;
- &insn->list != &file->insn_list && insn->func && insn->func->pfunc == func;
- insn = insn->first_jump_src ?: list_prev_entry(insn, list)) {
+ insn && insn->func && insn->func->pfunc == func;
+ insn = insn->first_jump_src ?: prev_insn_same_sym(file, insn)) {
if (insn != orig_insn && insn->type == INSN_JUMP_DYNAMIC)
break;
@@ -1029,46 +1313,14 @@
insn->jump_dest->offset > orig_insn->offset))
break;
- /* look for a relocation which references .rodata */
- text_rela = find_rela_by_dest_range(insn->sec, insn->offset,
- insn->len);
- if (!text_rela || text_rela->sym->type != STT_SECTION ||
- !text_rela->sym->sec->rodata)
+ table_reloc = arch_find_switch_table(file, insn);
+ if (!table_reloc)
+ continue;
+ dest_insn = find_insn(file, table_reloc->sym->sec, table_reloc->addend);
+ if (!dest_insn || !dest_insn->func || dest_insn->func->pfunc != func)
continue;
- table_offset = text_rela->addend;
- table_sec = text_rela->sym->sec;
-
- if (text_rela->type == R_X86_64_PC32)
- table_offset += 4;
-
- /*
- * Make sure the .rodata address isn't associated with a
- * symbol. GCC jump tables are anonymous data.
- *
- * Also support C jump tables which are in the same format as
- * switch jump tables. For objtool to recognize them, they
- * need to be placed in the C_JUMP_TABLE_SECTION section. They
- * have symbols associated with them.
- */
- if (find_symbol_containing(table_sec, table_offset) &&
- strcmp(table_sec->name, C_JUMP_TABLE_SECTION))
- continue;
-
- /* Each table entry has a rela associated with it. */
- table_rela = find_rela_by_dest(table_sec, table_offset);
- if (!table_rela)
- continue;
-
- /*
- * Use of RIP-relative switch jumps is quite rare, and
- * indicates a rare GCC quirk/bug which can leave dead code
- * behind.
- */
- if (text_rela->type == R_X86_64_PC32)
- file->ignore_unreachables = true;
-
- return table_rela;
+ return table_reloc;
}
return NULL;
@@ -1082,9 +1334,9 @@
struct symbol *func)
{
struct instruction *insn, *last = NULL;
- struct rela *rela;
+ struct reloc *reloc;
- func_for_each_insn_all(file, func, insn) {
+ func_for_each_insn(file, func, insn) {
if (!last)
last = insn;
@@ -1105,10 +1357,10 @@
if (insn->type != INSN_JUMP_DYNAMIC)
continue;
- rela = find_jump_table(file, func, insn);
- if (rela) {
- rela->jump_table_start = true;
- insn->jump_table = rela;
+ reloc = find_jump_table(file, func, insn);
+ if (reloc) {
+ reloc->jump_table_start = true;
+ insn->jump_table = reloc;
}
}
}
@@ -1119,7 +1371,7 @@
struct instruction *insn;
int ret;
- func_for_each_insn_all(file, func, insn) {
+ func_for_each_insn(file, func, insn) {
if (!insn->jump_table)
continue;
@@ -1162,8 +1414,8 @@
static int read_unwind_hints(struct objtool_file *file)
{
- struct section *sec, *relasec;
- struct rela *rela;
+ struct section *sec, *relocsec;
+ struct reloc *reloc;
struct unwind_hint *hint;
struct instruction *insn;
struct cfi_reg *cfa;
@@ -1173,8 +1425,8 @@
if (!sec)
return 0;
- relasec = sec->rela;
- if (!relasec) {
+ relocsec = sec->reloc;
+ if (!relocsec) {
WARN("missing .rela.discard.unwind_hints section");
return -1;
}
@@ -1189,66 +1441,36 @@
for (i = 0; i < sec->len / sizeof(struct unwind_hint); i++) {
hint = (struct unwind_hint *)sec->data->d_buf + i;
- rela = find_rela_by_dest(sec, i * sizeof(*hint));
- if (!rela) {
- WARN("can't find rela for unwind_hints[%d]", i);
+ reloc = find_reloc_by_dest(file->elf, sec, i * sizeof(*hint));
+ if (!reloc) {
+ WARN("can't find reloc for unwind_hints[%d]", i);
return -1;
}
- insn = find_insn(file, rela->sym->sec, rela->addend);
+ insn = find_insn(file, reloc->sym->sec, reloc->addend);
if (!insn) {
WARN("can't find insn for unwind_hints[%d]", i);
return -1;
}
- cfa = &insn->state.cfa;
+ cfa = &insn->cfi.cfa;
- if (hint->type == UNWIND_HINT_TYPE_SAVE) {
- insn->save = true;
- continue;
-
- } else if (hint->type == UNWIND_HINT_TYPE_RESTORE) {
- insn->restore = true;
- insn->hint = true;
+ if (hint->type == UNWIND_HINT_TYPE_RET_OFFSET) {
+ insn->ret_offset = hint->sp_offset;
continue;
}
insn->hint = true;
- switch (hint->sp_reg) {
- case ORC_REG_UNDEFINED:
- cfa->base = CFI_UNDEFINED;
- break;
- case ORC_REG_SP:
- cfa->base = CFI_SP;
- break;
- case ORC_REG_BP:
- cfa->base = CFI_BP;
- break;
- case ORC_REG_SP_INDIRECT:
- cfa->base = CFI_SP_INDIRECT;
- break;
- case ORC_REG_R10:
- cfa->base = CFI_R10;
- break;
- case ORC_REG_R13:
- cfa->base = CFI_R13;
- break;
- case ORC_REG_DI:
- cfa->base = CFI_DI;
- break;
- case ORC_REG_DX:
- cfa->base = CFI_DX;
- break;
- default:
+ if (arch_decode_hint_reg(insn, hint->sp_reg)) {
WARN_FUNC("unsupported unwind_hint sp base reg %d",
insn->sec, insn->offset, hint->sp_reg);
return -1;
}
cfa->offset = hint->sp_offset;
- insn->state.type = hint->type;
- insn->state.end = hint->end;
+ insn->cfi.type = hint->type;
+ insn->cfi.end = hint->end;
}
return 0;
@@ -1258,19 +1480,19 @@
{
struct section *sec;
struct instruction *insn;
- struct rela *rela;
+ struct reloc *reloc;
sec = find_section_by_name(file->elf, ".rela.discard.retpoline_safe");
if (!sec)
return 0;
- list_for_each_entry(rela, &sec->rela_list, list) {
- if (rela->sym->type != STT_SECTION) {
+ list_for_each_entry(reloc, &sec->reloc_list, list) {
+ if (reloc->sym->type != STT_SECTION) {
WARN("unexpected relocation symbol type in %s", sec->name);
return -1;
}
- insn = find_insn(file, rela->sym->sec, rela->addend);
+ insn = find_insn(file, reloc->sym->sec, reloc->addend);
if (!insn) {
WARN("bad .discard.retpoline_safe entry");
return -1;
@@ -1289,6 +1511,121 @@
return 0;
}
+static int read_instr_hints(struct objtool_file *file)
+{
+ struct section *sec;
+ struct instruction *insn;
+ struct reloc *reloc;
+
+ sec = find_section_by_name(file->elf, ".rela.discard.instr_end");
+ if (!sec)
+ return 0;
+
+ list_for_each_entry(reloc, &sec->reloc_list, list) {
+ if (reloc->sym->type != STT_SECTION) {
+ WARN("unexpected relocation symbol type in %s", sec->name);
+ return -1;
+ }
+
+ insn = find_insn(file, reloc->sym->sec, reloc->addend);
+ if (!insn) {
+ WARN("bad .discard.instr_end entry");
+ return -1;
+ }
+
+ insn->instr--;
+ }
+
+ sec = find_section_by_name(file->elf, ".rela.discard.instr_begin");
+ if (!sec)
+ return 0;
+
+ list_for_each_entry(reloc, &sec->reloc_list, list) {
+ if (reloc->sym->type != STT_SECTION) {
+ WARN("unexpected relocation symbol type in %s", sec->name);
+ return -1;
+ }
+
+ insn = find_insn(file, reloc->sym->sec, reloc->addend);
+ if (!insn) {
+ WARN("bad .discard.instr_begin entry");
+ return -1;
+ }
+
+ insn->instr++;
+ }
+
+ return 0;
+}
+
+static int read_intra_function_calls(struct objtool_file *file)
+{
+ struct instruction *insn;
+ struct section *sec;
+ struct reloc *reloc;
+
+ sec = find_section_by_name(file->elf, ".rela.discard.intra_function_calls");
+ if (!sec)
+ return 0;
+
+ list_for_each_entry(reloc, &sec->reloc_list, list) {
+ unsigned long dest_off;
+
+ if (reloc->sym->type != STT_SECTION) {
+ WARN("unexpected relocation symbol type in %s",
+ sec->name);
+ return -1;
+ }
+
+ insn = find_insn(file, reloc->sym->sec, reloc->addend);
+ if (!insn) {
+ WARN("bad .discard.intra_function_call entry");
+ return -1;
+ }
+
+ if (insn->type != INSN_CALL) {
+ WARN_FUNC("intra_function_call not a direct call",
+ insn->sec, insn->offset);
+ return -1;
+ }
+
+ /*
+ * Treat intra-function CALLs as JMPs, but with a stack_op.
+ * See add_call_destinations(), which strips stack_ops from
+ * normal CALLs.
+ */
+ insn->type = INSN_JUMP_UNCONDITIONAL;
+
+ dest_off = insn->offset + insn->len + insn->immediate;
+ insn->jump_dest = find_insn(file, insn->sec, dest_off);
+ if (!insn->jump_dest) {
+ WARN_FUNC("can't find call dest at %s+0x%lx",
+ insn->sec, insn->offset,
+ insn->sec->name, dest_off);
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+static int read_static_call_tramps(struct objtool_file *file)
+{
+ struct section *sec;
+ struct symbol *func;
+
+ for_each_sec(file, sec) {
+ list_for_each_entry(func, &sec->symbol_list, list) {
+ if (func->bind == STB_GLOBAL &&
+ !strncmp(func->name, STATIC_CALL_TRAMP_PREFIX_STR,
+ strlen(STATIC_CALL_TRAMP_PREFIX_STR)))
+ func->static_call_tramp = true;
+ }
+ }
+
+ return 0;
+}
+
static void mark_rodata(struct objtool_file *file)
{
struct section *sec;
@@ -1305,8 +1642,8 @@
* .rodata.str1.* sections are ignored; they don't contain jump tables.
*/
for_each_sec(file, sec) {
- if ((!strncmp(sec->name, ".rodata", 7) && !strstr(sec->name, ".str1.")) ||
- !strcmp(sec->name, C_JUMP_TABLE_SECTION)) {
+ if (!strncmp(sec->name, ".rodata", 7) &&
+ !strstr(sec->name, ".str1.")) {
sec->rodata = true;
found = true;
}
@@ -1336,6 +1673,13 @@
if (ret)
return ret;
+ /*
+ * Must be before add_{jump_call}_destination.
+ */
+ ret = read_static_call_tramps(file);
+ if (ret)
+ return ret;
+
ret = add_jump_destinations(file);
if (ret)
return ret;
@@ -1344,6 +1688,14 @@
if (ret)
return ret;
+ /*
+ * Must be before add_call_destination(); it changes INSN_CALL to
+ * INSN_JUMP.
+ */
+ ret = read_intra_function_calls(file);
+ if (ret)
+ return ret;
+
ret = add_call_destinations(file);
if (ret)
return ret;
@@ -1360,12 +1712,16 @@
if (ret)
return ret;
+ ret = read_instr_hints(file);
+ if (ret)
+ return ret;
+
return 0;
}
static bool is_fentry_call(struct instruction *insn)
{
- if (insn->type == INSN_CALL &&
+ if (insn->type == INSN_CALL && insn->call_dest &&
insn->call_dest->type == STT_NOTYPE &&
!strcmp(insn->call_dest->name, "__fentry__"))
return true;
@@ -1373,40 +1729,57 @@
return false;
}
-static bool has_modified_stack_frame(struct insn_state *state)
+static bool has_modified_stack_frame(struct instruction *insn, struct insn_state *state)
{
+ u8 ret_offset = insn->ret_offset;
+ struct cfi_state *cfi = &state->cfi;
int i;
- if (state->cfa.base != initial_func_cfi.cfa.base ||
- state->cfa.offset != initial_func_cfi.cfa.offset ||
- state->stack_size != initial_func_cfi.cfa.offset ||
- state->drap)
+ if (cfi->cfa.base != initial_func_cfi.cfa.base || cfi->drap)
return true;
- for (i = 0; i < CFI_NUM_REGS; i++)
- if (state->regs[i].base != initial_func_cfi.regs[i].base ||
- state->regs[i].offset != initial_func_cfi.regs[i].offset)
+ if (cfi->cfa.offset != initial_func_cfi.cfa.offset + ret_offset)
+ return true;
+
+ if (cfi->stack_size != initial_func_cfi.cfa.offset + ret_offset)
+ return true;
+
+ /*
+ * If there is a ret offset hint then don't check registers
+ * because a callee-saved register might have been pushed on
+ * the stack.
+ */
+ if (ret_offset)
+ return false;
+
+ for (i = 0; i < CFI_NUM_REGS; i++) {
+ if (cfi->regs[i].base != initial_func_cfi.regs[i].base ||
+ cfi->regs[i].offset != initial_func_cfi.regs[i].offset)
return true;
+ }
return false;
}
static bool has_valid_stack_frame(struct insn_state *state)
{
- if (state->cfa.base == CFI_BP && state->regs[CFI_BP].base == CFI_CFA &&
- state->regs[CFI_BP].offset == -16)
+ struct cfi_state *cfi = &state->cfi;
+
+ if (cfi->cfa.base == CFI_BP && cfi->regs[CFI_BP].base == CFI_CFA &&
+ cfi->regs[CFI_BP].offset == -16)
return true;
- if (state->drap && state->regs[CFI_BP].base == CFI_BP)
+ if (cfi->drap && cfi->regs[CFI_BP].base == CFI_BP)
return true;
return false;
}
-static int update_insn_state_regs(struct instruction *insn, struct insn_state *state)
+static int update_cfi_state_regs(struct instruction *insn,
+ struct cfi_state *cfi,
+ struct stack_op *op)
{
- struct cfi_reg *cfa = &state->cfa;
- struct stack_op *op = &insn->stack_op;
+ struct cfi_reg *cfa = &cfi->cfa;
if (cfa->base != CFI_SP && cfa->base != CFI_SP_INDIRECT)
return 0;
@@ -1427,20 +1800,19 @@
return 0;
}
-static void save_reg(struct insn_state *state, unsigned char reg, int base,
- int offset)
+static void save_reg(struct cfi_state *cfi, unsigned char reg, int base, int offset)
{
if (arch_callee_saved_reg(reg) &&
- state->regs[reg].base == CFI_UNDEFINED) {
- state->regs[reg].base = base;
- state->regs[reg].offset = offset;
+ cfi->regs[reg].base == CFI_UNDEFINED) {
+ cfi->regs[reg].base = base;
+ cfi->regs[reg].offset = offset;
}
}
-static void restore_reg(struct insn_state *state, unsigned char reg)
+static void restore_reg(struct cfi_state *cfi, unsigned char reg)
{
- state->regs[reg].base = CFI_UNDEFINED;
- state->regs[reg].offset = 0;
+ cfi->regs[reg].base = initial_func_cfi.regs[reg].base;
+ cfi->regs[reg].offset = initial_func_cfi.regs[reg].offset;
}
/*
@@ -1496,11 +1868,11 @@
* 41 5d pop %r13
* c3 retq
*/
-static int update_insn_state(struct instruction *insn, struct insn_state *state)
+static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
+ struct stack_op *op)
{
- struct stack_op *op = &insn->stack_op;
- struct cfi_reg *cfa = &state->cfa;
- struct cfi_reg *regs = state->regs;
+ struct cfi_reg *cfa = &cfi->cfa;
+ struct cfi_reg *regs = cfi->regs;
/* stack operations don't make sense with an undefined CFA */
if (cfa->base == CFI_UNDEFINED) {
@@ -1511,8 +1883,9 @@
return 0;
}
- if (state->type == ORC_TYPE_REGS || state->type == ORC_TYPE_REGS_IRET)
- return update_insn_state_regs(insn, state);
+ if (cfi->type == UNWIND_HINT_TYPE_REGS ||
+ cfi->type == UNWIND_HINT_TYPE_REGS_PARTIAL)
+ return update_cfi_state_regs(insn, cfi, op);
switch (op->dest.type) {
@@ -1527,16 +1900,16 @@
/* mov %rsp, %rbp */
cfa->base = op->dest.reg;
- state->bp_scratch = false;
+ cfi->bp_scratch = false;
}
else if (op->src.reg == CFI_SP &&
- op->dest.reg == CFI_BP && state->drap) {
+ op->dest.reg == CFI_BP && cfi->drap) {
/* drap: mov %rsp, %rbp */
regs[CFI_BP].base = CFI_BP;
- regs[CFI_BP].offset = -state->stack_size;
- state->bp_scratch = false;
+ regs[CFI_BP].offset = -cfi->stack_size;
+ cfi->bp_scratch = false;
}
else if (op->src.reg == CFI_SP && cfa->base == CFI_SP) {
@@ -1551,8 +1924,8 @@
* ...
* mov %rax, %rsp
*/
- state->vals[op->dest.reg].base = CFI_CFA;
- state->vals[op->dest.reg].offset = -state->stack_size;
+ cfi->vals[op->dest.reg].base = CFI_CFA;
+ cfi->vals[op->dest.reg].offset = -cfi->stack_size;
}
else if (op->src.reg == CFI_BP && op->dest.reg == CFI_SP &&
@@ -1563,14 +1936,14 @@
*
* Restore the original stack pointer (Clang).
*/
- state->stack_size = -state->regs[CFI_BP].offset;
+ cfi->stack_size = -cfi->regs[CFI_BP].offset;
}
else if (op->dest.reg == cfa->base) {
/* mov %reg, %rsp */
if (cfa->base == CFI_SP &&
- state->vals[op->src.reg].base == CFI_CFA) {
+ cfi->vals[op->src.reg].base == CFI_CFA) {
/*
* This is needed for the rare case
@@ -1580,8 +1953,8 @@
* ...
* mov %rcx, %rsp
*/
- cfa->offset = -state->vals[op->src.reg].offset;
- state->stack_size = cfa->offset;
+ cfa->offset = -cfi->vals[op->src.reg].offset;
+ cfi->stack_size = cfa->offset;
} else {
cfa->base = CFI_UNDEFINED;
@@ -1595,7 +1968,7 @@
if (op->dest.reg == CFI_SP && op->src.reg == CFI_SP) {
/* add imm, %rsp */
- state->stack_size -= op->src.offset;
+ cfi->stack_size -= op->src.offset;
if (cfa->base == CFI_SP)
cfa->offset -= op->src.offset;
break;
@@ -1604,14 +1977,14 @@
if (op->dest.reg == CFI_SP && op->src.reg == CFI_BP) {
/* lea disp(%rbp), %rsp */
- state->stack_size = -(op->src.offset + regs[CFI_BP].offset);
+ cfi->stack_size = -(op->src.offset + regs[CFI_BP].offset);
break;
}
if (op->src.reg == CFI_SP && cfa->base == CFI_SP) {
/* drap: lea disp(%rsp), %drap */
- state->drap_reg = op->dest.reg;
+ cfi->drap_reg = op->dest.reg;
/*
* lea disp(%rsp), %reg
@@ -1623,25 +1996,25 @@
* ...
* mov %rcx, %rsp
*/
- state->vals[op->dest.reg].base = CFI_CFA;
- state->vals[op->dest.reg].offset = \
- -state->stack_size + op->src.offset;
+ cfi->vals[op->dest.reg].base = CFI_CFA;
+ cfi->vals[op->dest.reg].offset = \
+ -cfi->stack_size + op->src.offset;
break;
}
- if (state->drap && op->dest.reg == CFI_SP &&
- op->src.reg == state->drap_reg) {
+ if (cfi->drap && op->dest.reg == CFI_SP &&
+ op->src.reg == cfi->drap_reg) {
/* drap: lea disp(%drap), %rsp */
cfa->base = CFI_SP;
- cfa->offset = state->stack_size = -op->src.offset;
- state->drap_reg = CFI_UNDEFINED;
- state->drap = false;
+ cfa->offset = cfi->stack_size = -op->src.offset;
+ cfi->drap_reg = CFI_UNDEFINED;
+ cfi->drap = false;
break;
}
- if (op->dest.reg == state->cfa.base) {
+ if (op->dest.reg == cfi->cfa.base) {
WARN_FUNC("unsupported stack register modification",
insn->sec, insn->offset);
return -1;
@@ -1651,18 +2024,18 @@
case OP_SRC_AND:
if (op->dest.reg != CFI_SP ||
- (state->drap_reg != CFI_UNDEFINED && cfa->base != CFI_SP) ||
- (state->drap_reg == CFI_UNDEFINED && cfa->base != CFI_BP)) {
+ (cfi->drap_reg != CFI_UNDEFINED && cfa->base != CFI_SP) ||
+ (cfi->drap_reg == CFI_UNDEFINED && cfa->base != CFI_BP)) {
WARN_FUNC("unsupported stack pointer realignment",
insn->sec, insn->offset);
return -1;
}
- if (state->drap_reg != CFI_UNDEFINED) {
+ if (cfi->drap_reg != CFI_UNDEFINED) {
/* drap: and imm, %rsp */
- cfa->base = state->drap_reg;
- cfa->offset = state->stack_size = 0;
- state->drap = true;
+ cfa->base = cfi->drap_reg;
+ cfa->offset = cfi->stack_size = 0;
+ cfi->drap = true;
}
/*
@@ -1674,57 +2047,55 @@
case OP_SRC_POP:
case OP_SRC_POPF:
- if (!state->drap && op->dest.type == OP_DEST_REG &&
- op->dest.reg == cfa->base) {
+ if (!cfi->drap && op->dest.reg == cfa->base) {
/* pop %rbp */
cfa->base = CFI_SP;
}
- if (state->drap && cfa->base == CFI_BP_INDIRECT &&
- op->dest.type == OP_DEST_REG &&
- op->dest.reg == state->drap_reg &&
- state->drap_offset == -state->stack_size) {
+ if (cfi->drap && cfa->base == CFI_BP_INDIRECT &&
+ op->dest.reg == cfi->drap_reg &&
+ cfi->drap_offset == -cfi->stack_size) {
/* drap: pop %drap */
- cfa->base = state->drap_reg;
+ cfa->base = cfi->drap_reg;
cfa->offset = 0;
- state->drap_offset = -1;
+ cfi->drap_offset = -1;
- } else if (regs[op->dest.reg].offset == -state->stack_size) {
+ } else if (regs[op->dest.reg].offset == -cfi->stack_size) {
/* pop %reg */
- restore_reg(state, op->dest.reg);
+ restore_reg(cfi, op->dest.reg);
}
- state->stack_size -= 8;
+ cfi->stack_size -= 8;
if (cfa->base == CFI_SP)
cfa->offset -= 8;
break;
case OP_SRC_REG_INDIRECT:
- if (state->drap && op->src.reg == CFI_BP &&
- op->src.offset == state->drap_offset) {
+ if (cfi->drap && op->src.reg == CFI_BP &&
+ op->src.offset == cfi->drap_offset) {
/* drap: mov disp(%rbp), %drap */
- cfa->base = state->drap_reg;
+ cfa->base = cfi->drap_reg;
cfa->offset = 0;
- state->drap_offset = -1;
+ cfi->drap_offset = -1;
}
- if (state->drap && op->src.reg == CFI_BP &&
+ if (cfi->drap && op->src.reg == CFI_BP &&
op->src.offset == regs[op->dest.reg].offset) {
/* drap: mov disp(%rbp), %reg */
- restore_reg(state, op->dest.reg);
+ restore_reg(cfi, op->dest.reg);
} else if (op->src.reg == cfa->base &&
op->src.offset == regs[op->dest.reg].offset + cfa->offset) {
/* mov disp(%rbp), %reg */
/* mov disp(%rsp), %reg */
- restore_reg(state, op->dest.reg);
+ restore_reg(cfi, op->dest.reg);
}
break;
@@ -1739,78 +2110,76 @@
case OP_DEST_PUSH:
case OP_DEST_PUSHF:
- state->stack_size += 8;
+ cfi->stack_size += 8;
if (cfa->base == CFI_SP)
cfa->offset += 8;
if (op->src.type != OP_SRC_REG)
break;
- if (state->drap) {
- if (op->src.reg == cfa->base && op->src.reg == state->drap_reg) {
+ if (cfi->drap) {
+ if (op->src.reg == cfa->base && op->src.reg == cfi->drap_reg) {
/* drap: push %drap */
cfa->base = CFI_BP_INDIRECT;
- cfa->offset = -state->stack_size;
+ cfa->offset = -cfi->stack_size;
/* save drap so we know when to restore it */
- state->drap_offset = -state->stack_size;
+ cfi->drap_offset = -cfi->stack_size;
- } else if (op->src.reg == CFI_BP && cfa->base == state->drap_reg) {
+ } else if (op->src.reg == CFI_BP && cfa->base == cfi->drap_reg) {
/* drap: push %rbp */
- state->stack_size = 0;
+ cfi->stack_size = 0;
- } else if (regs[op->src.reg].base == CFI_UNDEFINED) {
+ } else {
/* drap: push %reg */
- save_reg(state, op->src.reg, CFI_BP, -state->stack_size);
+ save_reg(cfi, op->src.reg, CFI_BP, -cfi->stack_size);
}
} else {
/* push %reg */
- save_reg(state, op->src.reg, CFI_CFA, -state->stack_size);
+ save_reg(cfi, op->src.reg, CFI_CFA, -cfi->stack_size);
}
/* detect when asm code uses rbp as a scratch register */
if (!no_fp && insn->func && op->src.reg == CFI_BP &&
cfa->base != CFI_BP)
- state->bp_scratch = true;
+ cfi->bp_scratch = true;
break;
case OP_DEST_REG_INDIRECT:
- if (state->drap) {
- if (op->src.reg == cfa->base && op->src.reg == state->drap_reg) {
+ if (cfi->drap) {
+ if (op->src.reg == cfa->base && op->src.reg == cfi->drap_reg) {
/* drap: mov %drap, disp(%rbp) */
cfa->base = CFI_BP_INDIRECT;
cfa->offset = op->dest.offset;
/* save drap offset so we know when to restore it */
- state->drap_offset = op->dest.offset;
- }
-
- else if (regs[op->src.reg].base == CFI_UNDEFINED) {
+ cfi->drap_offset = op->dest.offset;
+ } else {
/* drap: mov reg, disp(%rbp) */
- save_reg(state, op->src.reg, CFI_BP, op->dest.offset);
+ save_reg(cfi, op->src.reg, CFI_BP, op->dest.offset);
}
} else if (op->dest.reg == cfa->base) {
/* mov reg, disp(%rbp) */
/* mov reg, disp(%rsp) */
- save_reg(state, op->src.reg, CFI_CFA,
- op->dest.offset - state->cfa.offset);
+ save_reg(cfi, op->src.reg, CFI_CFA,
+ op->dest.offset - cfi->cfa.offset);
}
break;
case OP_DEST_LEAVE:
- if ((!state->drap && cfa->base != CFI_BP) ||
- (state->drap && cfa->base != state->drap_reg)) {
+ if ((!cfi->drap && cfa->base != CFI_BP) ||
+ (cfi->drap && cfa->base != cfi->drap_reg)) {
WARN_FUNC("leave instruction with modified stack frame",
insn->sec, insn->offset);
return -1;
@@ -1818,10 +2187,10 @@
/* leave (mov %rbp, %rsp; pop %rbp) */
- state->stack_size = -state->regs[CFI_BP].offset - 8;
- restore_reg(state, CFI_BP);
+ cfi->stack_size = -cfi->regs[CFI_BP].offset - 8;
+ restore_reg(cfi, CFI_BP);
- if (!state->drap) {
+ if (!cfi->drap) {
cfa->base = CFI_SP;
cfa->offset -= 8;
}
@@ -1836,7 +2205,7 @@
}
/* pop mem */
- state->stack_size -= 8;
+ cfi->stack_size -= 8;
if (cfa->base == CFI_SP)
cfa->offset -= 8;
@@ -1851,41 +2220,86 @@
return 0;
}
-static bool insn_state_match(struct instruction *insn, struct insn_state *state)
+static int handle_insn_ops(struct instruction *insn, struct insn_state *state)
{
- struct insn_state *state1 = &insn->state, *state2 = state;
+ struct stack_op *op;
+
+ list_for_each_entry(op, &insn->stack_ops, list) {
+ struct cfi_state old_cfi = state->cfi;
+ int res;
+
+ res = update_cfi_state(insn, &state->cfi, op);
+ if (res)
+ return res;
+
+ if (insn->alt_group && memcmp(&state->cfi, &old_cfi, sizeof(struct cfi_state))) {
+ WARN_FUNC("alternative modifies stack", insn->sec, insn->offset);
+ return -1;
+ }
+
+ if (op->dest.type == OP_DEST_PUSHF) {
+ if (!state->uaccess_stack) {
+ state->uaccess_stack = 1;
+ } else if (state->uaccess_stack >> 31) {
+ WARN_FUNC("PUSHF stack exhausted",
+ insn->sec, insn->offset);
+ return 1;
+ }
+ state->uaccess_stack <<= 1;
+ state->uaccess_stack |= state->uaccess;
+ }
+
+ if (op->src.type == OP_SRC_POPF) {
+ if (state->uaccess_stack) {
+ state->uaccess = state->uaccess_stack & 1;
+ state->uaccess_stack >>= 1;
+ if (state->uaccess_stack == 1)
+ state->uaccess_stack = 0;
+ }
+ }
+ }
+
+ return 0;
+}
+
+static bool insn_cfi_match(struct instruction *insn, struct cfi_state *cfi2)
+{
+ struct cfi_state *cfi1 = &insn->cfi;
int i;
- if (memcmp(&state1->cfa, &state2->cfa, sizeof(state1->cfa))) {
+ if (memcmp(&cfi1->cfa, &cfi2->cfa, sizeof(cfi1->cfa))) {
+
WARN_FUNC("stack state mismatch: cfa1=%d%+d cfa2=%d%+d",
insn->sec, insn->offset,
- state1->cfa.base, state1->cfa.offset,
- state2->cfa.base, state2->cfa.offset);
+ cfi1->cfa.base, cfi1->cfa.offset,
+ cfi2->cfa.base, cfi2->cfa.offset);
- } else if (memcmp(&state1->regs, &state2->regs, sizeof(state1->regs))) {
+ } else if (memcmp(&cfi1->regs, &cfi2->regs, sizeof(cfi1->regs))) {
for (i = 0; i < CFI_NUM_REGS; i++) {
- if (!memcmp(&state1->regs[i], &state2->regs[i],
+ if (!memcmp(&cfi1->regs[i], &cfi2->regs[i],
sizeof(struct cfi_reg)))
continue;
WARN_FUNC("stack state mismatch: reg1[%d]=%d%+d reg2[%d]=%d%+d",
insn->sec, insn->offset,
- i, state1->regs[i].base, state1->regs[i].offset,
- i, state2->regs[i].base, state2->regs[i].offset);
+ i, cfi1->regs[i].base, cfi1->regs[i].offset,
+ i, cfi2->regs[i].base, cfi2->regs[i].offset);
break;
}
- } else if (state1->type != state2->type) {
- WARN_FUNC("stack state mismatch: type1=%d type2=%d",
- insn->sec, insn->offset, state1->type, state2->type);
+ } else if (cfi1->type != cfi2->type) {
- } else if (state1->drap != state2->drap ||
- (state1->drap && state1->drap_reg != state2->drap_reg) ||
- (state1->drap && state1->drap_offset != state2->drap_offset)) {
+ WARN_FUNC("stack state mismatch: type1=%d type2=%d",
+ insn->sec, insn->offset, cfi1->type, cfi2->type);
+
+ } else if (cfi1->drap != cfi2->drap ||
+ (cfi1->drap && cfi1->drap_reg != cfi2->drap_reg) ||
+ (cfi1->drap && cfi1->drap_offset != cfi2->drap_offset)) {
+
WARN_FUNC("stack state mismatch: drap1=%d(%d,%d) drap2=%d(%d,%d)",
insn->sec, insn->offset,
- state1->drap, state1->drap_reg, state1->drap_offset,
- state2->drap, state2->drap_reg, state2->drap_offset);
+ cfi1->drap, cfi1->drap_reg, cfi1->drap_offset,
+ cfi2->drap, cfi2->drap_reg, cfi2->drap_offset);
} else
return true;
@@ -1909,8 +2323,41 @@
return "{dynamic}";
}
+static inline bool noinstr_call_dest(struct symbol *func)
+{
+ /*
+ * We can't deal with indirect function calls at present;
+ * assume they're instrumented.
+ */
+ if (!func)
+ return false;
+
+ /*
+ * If the symbol is from a noinstr section; we good.
+ */
+ if (func->sec->noinstr)
+ return true;
+
+ /*
+ * The __ubsan_handle_*() calls are like WARN(), they only happen when
+ * something 'BAD' happened. At the risk of taking the machine down,
+ * let them proceed to get the message out.
+ */
+ if (!strncmp(func->name, "__ubsan_handle_", 15))
+ return true;
+
+ return false;
+}
+
static int validate_call(struct instruction *insn, struct insn_state *state)
{
+ if (state->noinstr && state->instr <= 0 &&
+ !noinstr_call_dest(insn->call_dest)) {
+ WARN_FUNC("call to %s() leaves .noinstr.text section",
+ insn->sec, insn->offset, call_dest_name(insn));
+ return 1;
+ }
+
if (state->uaccess && !func_uaccess_safe(insn->call_dest)) {
WARN_FUNC("call to %s() with UACCESS enabled",
insn->sec, insn->offset, call_dest_name(insn));
@@ -1928,7 +2375,7 @@
static int validate_sibling_call(struct instruction *insn, struct insn_state *state)
{
- if (has_modified_stack_frame(state)) {
+ if (has_modified_stack_frame(insn, state)) {
WARN_FUNC("sibling call from callable instruction with modified stack frame",
insn->sec, insn->offset);
return 1;
@@ -1937,6 +2384,71 @@
return validate_call(insn, state);
}
+static int validate_return(struct symbol *func, struct instruction *insn, struct insn_state *state)
+{
+ if (state->noinstr && state->instr > 0) {
+ WARN_FUNC("return with instrumentation enabled",
+ insn->sec, insn->offset);
+ return 1;
+ }
+
+ if (state->uaccess && !func_uaccess_safe(func)) {
+ WARN_FUNC("return with UACCESS enabled",
+ insn->sec, insn->offset);
+ return 1;
+ }
+
+ if (!state->uaccess && func_uaccess_safe(func)) {
+ WARN_FUNC("return with UACCESS disabled from a UACCESS-safe function",
+ insn->sec, insn->offset);
+ return 1;
+ }
+
+ if (state->df) {
+ WARN_FUNC("return with DF set",
+ insn->sec, insn->offset);
+ return 1;
+ }
+
+ if (func && has_modified_stack_frame(insn, state)) {
+ WARN_FUNC("return with modified stack frame",
+ insn->sec, insn->offset);
+ return 1;
+ }
+
+ if (state->cfi.bp_scratch) {
+ WARN_FUNC("BP used as a scratch register",
+ insn->sec, insn->offset);
+ return 1;
+ }
+
+ return 0;
+}
+
+/*
+ * Alternatives should not contain any ORC entries, this in turn means they
+ * should not contain any CFI ops, which implies all instructions should have
+ * the same same CFI state.
+ *
+ * It is possible to constuct alternatives that have unreachable holes that go
+ * unreported (because they're NOPs), such holes would result in CFI_UNDEFINED
+ * states which then results in ORC entries, which we just said we didn't want.
+ *
+ * Avoid them by copying the CFI entry of the first instruction into the whole
+ * alternative.
+ */
+static void fill_alternative_cfi(struct objtool_file *file, struct instruction *insn)
+{
+ struct instruction *first_insn = insn;
+ int alt_group = insn->alt_group;
+
+ sec_for_each_insn_continue(file, insn) {
+ if (insn->alt_group != alt_group)
+ break;
+ insn->cfi = first_insn->cfi;
+ }
+}
+
/*
* Follow the branch starting at the given instruction, and recursively follow
* any other branches (jumps). Meanwhile, track the frame pointer state at
@@ -1944,23 +2456,16 @@
* tools/objtool/Documentation/stack-validation.txt.
*/
static int validate_branch(struct objtool_file *file, struct symbol *func,
- struct instruction *first, struct insn_state state)
+ struct instruction *insn, struct insn_state state)
{
struct alternative *alt;
- struct instruction *insn, *next_insn;
+ struct instruction *next_insn;
struct section *sec;
u8 visited;
int ret;
- insn = first;
sec = insn->sec;
- if (insn->alt_group && list_empty(&insn->alts)) {
- WARN_FUNC("don't know how to handle branch to middle of alternative instruction group",
- sec, insn->offset);
- return 1;
- }
-
while (1) {
next_insn = next_insn_same_sec(file, insn);
@@ -1978,59 +2483,24 @@
visited = 1 << state.uaccess;
if (insn->visited) {
- if (!insn->hint && !insn_state_match(insn, &state))
+ if (!insn->hint && !insn_cfi_match(insn, &state.cfi))
return 1;
if (insn->visited & visited)
return 0;
}
- if (insn->hint) {
- if (insn->restore) {
- struct instruction *save_insn, *i;
+ if (state.noinstr)
+ state.instr += insn->instr;
- i = insn;
- save_insn = NULL;
- func_for_each_insn_continue_reverse(file, func, i) {
- if (i->save) {
- save_insn = i;
- break;
- }
- }
-
- if (!save_insn) {
- WARN_FUNC("no corresponding CFI save for CFI restore",
- sec, insn->offset);
- return 1;
- }
-
- if (!save_insn->visited) {
- /*
- * Oops, no state to copy yet.
- * Hopefully we can reach this
- * instruction from another branch
- * after the save insn has been
- * visited.
- */
- if (insn == first)
- return 0;
-
- WARN_FUNC("objtool isn't smart enough to handle this CFI save/restore combo",
- sec, insn->offset);
- return 1;
- }
-
- insn->state = save_insn->state;
- }
-
- state = insn->state;
-
- } else
- insn->state = state;
+ if (insn->hint)
+ state.cfi = insn->cfi;
+ else
+ insn->cfi = state.cfi;
insn->visited |= visited;
- if (!insn->ignore_alts) {
+ if (!insn->ignore_alts && !list_empty(&insn->alts)) {
bool skip_orig = false;
list_for_each_entry(alt, &insn->alts, list) {
@@ -2045,41 +2515,20 @@
}
}
+ if (insn->alt_group)
+ fill_alternative_cfi(file, insn);
+
if (skip_orig)
return 0;
}
+ if (handle_insn_ops(insn, &state))
+ return 1;
+
switch (insn->type) {
case INSN_RETURN:
- if (state.uaccess && !func_uaccess_safe(func)) {
- WARN_FUNC("return with UACCESS enabled", sec, insn->offset);
- return 1;
- }
-
- if (!state.uaccess && func_uaccess_safe(func)) {
- WARN_FUNC("return with UACCESS disabled from a UACCESS-safe function", sec, insn->offset);
- return 1;
- }
-
- if (state.df) {
- WARN_FUNC("return with DF set", sec, insn->offset);
- return 1;
- }
-
- if (func && has_modified_stack_frame(&state)) {
- WARN_FUNC("return with modified stack frame",
- sec, insn->offset);
- return 1;
- }
-
- if (state.bp_scratch) {
- WARN("%s uses BP as a scratch register",
- func->name);
- return 1;
- }
-
- return 0;
+ return validate_return(func, insn, &state);
case INSN_CALL:
case INSN_CALL_DYNAMIC:
@@ -2142,32 +2591,6 @@
}
return 0;
- case INSN_STACK:
- if (update_insn_state(insn, &state))
- return 1;
-
- if (insn->stack_op.dest.type == OP_DEST_PUSHF) {
- if (!state.uaccess_stack) {
- state.uaccess_stack = 1;
- } else if (state.uaccess_stack >> 31) {
- WARN_FUNC("PUSHF stack exhausted", sec, insn->offset);
- return 1;
- }
- state.uaccess_stack <<= 1;
- state.uaccess_stack |= state.uaccess;
- }
-
- if (insn->stack_op.src.type == OP_SRC_POPF) {
- if (state.uaccess_stack) {
- state.uaccess = state.uaccess_stack & 1;
- state.uaccess_stack >>= 1;
- if (state.uaccess_stack == 1)
- state.uaccess_stack = 0;
- }
- }
-
- break;
-
case INSN_STAC:
if (state.uaccess) {
WARN_FUNC("recursive UACCESS enable", sec, insn->offset);
@@ -2217,7 +2640,7 @@
return 0;
if (!next_insn) {
- if (state.cfa.base == CFI_UNDEFINED)
+ if (state.cfi.cfa.base == CFI_UNDEFINED)
return 0;
WARN("%s: unexpected end of section", sec->name);
return 1;
@@ -2229,24 +2652,34 @@
return 0;
}
-static int validate_unwind_hints(struct objtool_file *file)
+static int validate_unwind_hints(struct objtool_file *file, struct section *sec)
{
struct instruction *insn;
- int ret, warnings = 0;
struct insn_state state;
+ int ret, warnings = 0;
if (!file->hints)
return 0;
- clear_insn_state(&state);
+ init_insn_state(&state, sec);
- for_each_insn(file, insn) {
+ if (sec) {
+ insn = find_insn(file, sec, 0);
+ if (!insn)
+ return 0;
+ } else {
+ insn = list_first_entry(&file->insn_list, typeof(*insn), list);
+ }
+
+ while (&insn->list != &file->insn_list && (!sec || insn->sec == sec)) {
if (insn->hint && !insn->visited) {
ret = validate_branch(file, insn->func, insn, state);
if (ret && backtrace)
BT_FUNC("<=== (hint)", insn);
warnings += ret;
}
+
+ insn = list_next_entry(insn, list);
}
return warnings;
@@ -2297,9 +2730,10 @@
"__ubsan_handle_builtin_unreachable"));
}
-static bool ignore_unreachable_insn(struct instruction *insn)
+static bool ignore_unreachable_insn(struct objtool_file *file, struct instruction *insn)
{
int i;
+ struct instruction *prev_insn;
if (insn->ignore || insn->type == INSN_NOP)
return true;
@@ -2316,6 +2750,9 @@
!strcmp(insn->sec->name, ".altinstr_aux"))
return true;
+ if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->offset == FAKE_JUMP_OFFSET)
+ return true;
+
if (!insn->func)
return false;
@@ -2324,8 +2761,11 @@
* __builtin_unreachable(). The BUG() macro has an unreachable() after
* the UD2, which causes GCC's undefined trap logic to emit another UD2
* (or occasionally a JMP to UD2).
+ *
+ * It may also insert a UD2 after calling a __noreturn function.
*/
- if (list_prev_entry(insn, list)->dead_end &&
+ prev_insn = list_prev_entry(insn, list);
+ if ((prev_insn->dead_end || dead_end_function(file, prev_insn->call_dest)) &&
(insn->type == INSN_BUG ||
(insn->type == INSN_JUMP_UNCONDITIONAL &&
insn->jump_dest && insn->jump_dest->type == INSN_BUG)))
@@ -2361,46 +2801,84 @@
return false;
}
+static int validate_symbol(struct objtool_file *file, struct section *sec,
+ struct symbol *sym, struct insn_state *state)
+{
+ struct instruction *insn;
+ int ret;
+
+ if (!sym->len) {
+ WARN("%s() is missing an ELF size annotation", sym->name);
+ return 1;
+ }
+
+ if (sym->pfunc != sym || sym->alias != sym)
+ return 0;
+
+ insn = find_insn(file, sec, sym->offset);
+ if (!insn || insn->ignore || insn->visited)
+ return 0;
+
+ state->uaccess = sym->uaccess_safe;
+
+ ret = validate_branch(file, insn->func, insn, *state);
+ if (ret && backtrace)
+ BT_FUNC("<=== (sym)", insn);
+ return ret;
+}
+
+static int validate_section(struct objtool_file *file, struct section *sec)
+{
+ struct insn_state state;
+ struct symbol *func;
+ int warnings = 0;
+
+ list_for_each_entry(func, &sec->symbol_list, list) {
+ if (func->type != STT_FUNC)
+ continue;
+
+ init_insn_state(&state, sec);
+ state.cfi.cfa = initial_func_cfi.cfa;
+ memcpy(&state.cfi.regs, &initial_func_cfi.regs,
+ CFI_NUM_REGS * sizeof(struct cfi_reg));
+ state.cfi.stack_size = initial_func_cfi.cfa.offset;
+
+ warnings += validate_symbol(file, sec, func, &state);
+ }
+
+ return warnings;
+}
+
+static int validate_vmlinux_functions(struct objtool_file *file)
+{
+ struct section *sec;
+ int warnings = 0;
+
+ sec = find_section_by_name(file->elf, ".noinstr.text");
+ if (sec) {
+ warnings += validate_section(file, sec);
+ warnings += validate_unwind_hints(file, sec);
+ }
+
+ sec = find_section_by_name(file->elf, ".entry.text");
+ if (sec) {
+ warnings += validate_section(file, sec);
+ warnings += validate_unwind_hints(file, sec);
+ }
+
+ return warnings;
+}
+
static int validate_functions(struct objtool_file *file)
{
struct section *sec;
- struct symbol *func;
- struct instruction *insn;
- struct insn_state state;
- int ret, warnings = 0;
-
- clear_insn_state(&state);
-
- state.cfa = initial_func_cfi.cfa;
- memcpy(&state.regs, &initial_func_cfi.regs,
- CFI_NUM_REGS * sizeof(struct cfi_reg));
- state.stack_size = initial_func_cfi.cfa.offset;
+ int warnings = 0;
for_each_sec(file, sec) {
- list_for_each_entry(func, &sec->symbol_list, list) {
- if (func->type != STT_FUNC)
- continue;
+ if (!(sec->sh.sh_flags & SHF_EXECINSTR))
+ continue;
- if (!func->len) {
- WARN("%s() is missing an ELF size annotation",
- func->name);
- warnings++;
- }
-
- if (func->pfunc != func || func->alias != func)
- continue;
-
- insn = find_insn(file, sec, func->offset);
- if (!insn || insn->ignore || insn->visited)
- continue;
-
- state.uaccess = func->uaccess_safe;
-
- ret = validate_branch(file, func, insn, state);
- if (ret && backtrace)
- BT_FUNC("<=== (func)", insn);
- warnings += ret;
- }
+ warnings += validate_section(file, sec);
}
return warnings;
@@ -2414,7 +2892,7 @@
return 0;
for_each_insn(file, insn) {
- if (insn->visited || ignore_unreachable_insn(insn))
+ if (insn->visited || ignore_unreachable_insn(file, insn))
continue;
WARN_FUNC("unreachable instruction", insn->sec, insn->offset);
@@ -2424,94 +2902,63 @@
return 0;
}
-static void cleanup(struct objtool_file *file)
-{
- struct instruction *insn, *tmpinsn;
- struct alternative *alt, *tmpalt;
-
- list_for_each_entry_safe(insn, tmpinsn, &file->insn_list, list) {
- list_for_each_entry_safe(alt, tmpalt, &insn->alts, list) {
- list_del(&alt->list);
- free(alt);
- }
- list_del(&insn->list);
- hash_del(&insn->hash);
- free(insn);
- }
- elf_close(file->elf);
-}
-
-static struct objtool_file file;
-
-int check(const char *_objname, bool orc)
+int check(struct objtool_file *file)
{
int ret, warnings = 0;
- objname = _objname;
-
- file.elf = elf_read(objname, orc ? O_RDWR : O_RDONLY);
- if (!file.elf)
- return 1;
-
- INIT_LIST_HEAD(&file.insn_list);
- hash_init(file.insn_hash);
- file.c_file = find_section_by_name(file.elf, ".comment");
- file.ignore_unreachables = no_unreachable;
- file.hints = false;
-
arch_initial_func_cfi_state(&initial_func_cfi);
- ret = decode_sections(&file);
+ ret = decode_sections(file);
if (ret < 0)
goto out;
warnings += ret;
- if (list_empty(&file.insn_list))
+ if (list_empty(&file->insn_list))
goto out;
+ if (vmlinux && !validate_dup) {
+ ret = validate_vmlinux_functions(file);
+ if (ret < 0)
+ goto out;
+
+ warnings += ret;
+ goto out;
+ }
+
if (retpoline) {
- ret = validate_retpoline(&file);
+ ret = validate_retpoline(file);
if (ret < 0)
return ret;
warnings += ret;
}
- ret = validate_functions(&file);
+ ret = validate_functions(file);
if (ret < 0)
goto out;
warnings += ret;
- ret = validate_unwind_hints(&file);
+ ret = validate_unwind_hints(file, NULL);
if (ret < 0)
goto out;
warnings += ret;
if (!warnings) {
- ret = validate_reachable_instructions(&file);
+ ret = validate_reachable_instructions(file);
if (ret < 0)
goto out;
warnings += ret;
}
- if (orc) {
- ret = create_orc(&file);
- if (ret < 0)
- goto out;
-
- ret = create_orc_sections(&file);
- if (ret < 0)
- goto out;
-
- ret = elf_write(file.elf);
- if (ret < 0)
- goto out;
- }
+ ret = create_static_call_sections(file);
+ if (ret < 0)
+ goto out;
+ warnings += ret;
out:
- cleanup(&file);
-
- /* ignore warnings for now until we get all the code cleaned up */
- if (ret || warnings)
- return 0;
+ /*
+ * For now, don't fail the kernel build on fatal warnings. These
+ * errors are still fairly common due to the growing matrix of
+ * supported toolchains and their recent pace of change.
+ */
return 0;
}
diff --git a/tools/objtool/check.h b/tools/objtool/check.h
index 6d875ca..2804848 100644
--- a/tools/objtool/check.h
+++ b/tools/objtool/check.h
@@ -7,54 +7,63 @@
#define _CHECK_H
#include <stdbool.h>
-#include "elf.h"
#include "cfi.h"
#include "arch.h"
-#include "orc.h"
-#include <linux/hashtable.h>
struct insn_state {
- struct cfi_reg cfa;
- struct cfi_reg regs[CFI_NUM_REGS];
- int stack_size;
- unsigned char type;
- bool bp_scratch;
- bool drap, end, uaccess, df;
+ struct cfi_state cfi;
unsigned int uaccess_stack;
- int drap_reg, drap_offset;
- struct cfi_reg vals[CFI_NUM_REGS];
+ bool uaccess;
+ bool df;
+ bool noinstr;
+ s8 instr;
};
struct instruction {
struct list_head list;
struct hlist_node hash;
+ struct list_head static_call_node;
struct section *sec;
unsigned long offset;
unsigned int len;
enum insn_type type;
unsigned long immediate;
- bool alt_group, dead_end, ignore, hint, save, restore, ignore_alts;
+ bool dead_end, ignore, ignore_alts;
+ bool hint;
bool retpoline_safe;
+ s8 instr;
u8 visited;
+ u8 ret_offset;
+ int alt_group;
struct symbol *call_dest;
struct instruction *jump_dest;
struct instruction *first_jump_src;
- struct rela *jump_table;
+ struct reloc *jump_table;
struct list_head alts;
struct symbol *func;
- struct stack_op stack_op;
- struct insn_state state;
+ struct list_head stack_ops;
+ struct cfi_state cfi;
+#ifdef INSN_USE_ORC
struct orc_entry orc;
+#endif
};
-struct objtool_file {
- struct elf *elf;
- struct list_head insn_list;
- DECLARE_HASHTABLE(insn_hash, 16);
- bool ignore_unreachables, c_file, hints, rodata;
-};
+static inline bool is_static_jump(struct instruction *insn)
+{
+ return insn->type == INSN_JUMP_CONDITIONAL ||
+ insn->type == INSN_JUMP_UNCONDITIONAL;
+}
-int check(const char *objname, bool orc);
+static inline bool is_dynamic_jump(struct instruction *insn)
+{
+ return insn->type == INSN_JUMP_DYNAMIC ||
+ insn->type == INSN_JUMP_DYNAMIC_CONDITIONAL;
+}
+
+static inline bool is_jump(struct instruction *insn)
+{
+ return is_static_jump(insn) || is_dynamic_jump(insn);
+}
struct instruction *find_insn(struct objtool_file *file,
struct section *sec, unsigned long offset);
@@ -68,5 +77,4 @@
insn->sec == sec; \
insn = list_next_entry(insn, list))
-
#endif /* _CHECK_H */
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 693d740..d8421e1 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -15,17 +15,123 @@
#include <string.h>
#include <unistd.h>
#include <errno.h>
+#include "builtin.h"
#include "elf.h"
#include "warn.h"
#define MAX_NAME_LEN 128
-struct section *find_section_by_name(struct elf *elf, const char *name)
+static inline u32 str_hash(const char *str)
+{
+ return jhash(str, strlen(str), 0);
+}
+
+static inline int elf_hash_bits(void)
+{
+ return vmlinux ? ELF_HASH_BITS : 16;
+}
+
+#define elf_hash_add(hashtable, node, key) \
+ hlist_add_head(node, &hashtable[hash_min(key, elf_hash_bits())])
+
+static void elf_hash_init(struct hlist_head *table)
+{
+ __hash_init(table, 1U << elf_hash_bits());
+}
+
+#define elf_hash_for_each_possible(name, obj, member, key) \
+ hlist_for_each_entry(obj, &name[hash_min(key, elf_hash_bits())], member)
+
+static void rb_add(struct rb_root *tree, struct rb_node *node,
+ int (*cmp)(struct rb_node *, const struct rb_node *))
+{
+ struct rb_node **link = &tree->rb_node;
+ struct rb_node *parent = NULL;
+
+ while (*link) {
+ parent = *link;
+ if (cmp(node, parent) < 0)
+ link = &parent->rb_left;
+ else
+ link = &parent->rb_right;
+ }
+
+ rb_link_node(node, parent, link);
+ rb_insert_color(node, tree);
+}
+
+static struct rb_node *rb_find_first(const struct rb_root *tree, const void *key,
+ int (*cmp)(const void *key, const struct rb_node *))
+{
+ struct rb_node *node = tree->rb_node;
+ struct rb_node *match = NULL;
+
+ while (node) {
+ int c = cmp(key, node);
+ if (c <= 0) {
+ if (!c)
+ match = node;
+ node = node->rb_left;
+ } else if (c > 0) {
+ node = node->rb_right;
+ }
+ }
+
+ return match;
+}
+
+static struct rb_node *rb_next_match(struct rb_node *node, const void *key,
+ int (*cmp)(const void *key, const struct rb_node *))
+{
+ node = rb_next(node);
+ if (node && cmp(key, node))
+ node = NULL;
+ return node;
+}
+
+#define rb_for_each(tree, node, key, cmp) \
+ for ((node) = rb_find_first((tree), (key), (cmp)); \
+ (node); (node) = rb_next_match((node), (key), (cmp)))
+
+static int symbol_to_offset(struct rb_node *a, const struct rb_node *b)
+{
+ struct symbol *sa = rb_entry(a, struct symbol, node);
+ struct symbol *sb = rb_entry(b, struct symbol, node);
+
+ if (sa->offset < sb->offset)
+ return -1;
+ if (sa->offset > sb->offset)
+ return 1;
+
+ if (sa->len < sb->len)
+ return -1;
+ if (sa->len > sb->len)
+ return 1;
+
+ sa->alias = sb;
+
+ return 0;
+}
+
+static int symbol_by_offset(const void *key, const struct rb_node *node)
+{
+ const struct symbol *s = rb_entry(node, struct symbol, node);
+ const unsigned long *o = key;
+
+ if (*o < s->offset)
+ return -1;
+ if (*o >= s->offset + s->len)
+ return 1;
+
+ return 0;
+}
+
+struct section *find_section_by_name(const struct elf *elf, const char *name)
{
struct section *sec;
- list_for_each_entry(sec, &elf->sections, list)
+ elf_hash_for_each_possible(elf->section_name_hash, sec, name_hash, str_hash(name))
if (!strcmp(sec->name, name))
return sec;
@@ -37,7 +143,7 @@
{
struct section *sec;
- list_for_each_entry(sec, &elf->sections, list)
+ elf_hash_for_each_possible(elf->section_hash, sec, hash, idx)
if (sec->idx == idx)
return sec;
@@ -46,86 +152,140 @@
static struct symbol *find_symbol_by_index(struct elf *elf, unsigned int idx)
{
- struct section *sec;
struct symbol *sym;
- list_for_each_entry(sec, &elf->sections, list)
- hash_for_each_possible(sec->symbol_hash, sym, hash, idx)
- if (sym->idx == idx)
- return sym;
+ elf_hash_for_each_possible(elf->symbol_hash, sym, hash, idx)
+ if (sym->idx == idx)
+ return sym;
return NULL;
}
struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset)
{
+ struct rb_node *node;
+
+ rb_for_each(&sec->symbol_tree, node, &offset, symbol_by_offset) {
+ struct symbol *s = rb_entry(node, struct symbol, node);
+
+ if (s->offset == offset && s->type != STT_SECTION)
+ return s;
+ }
+
+ return NULL;
+}
+
+struct symbol *find_func_by_offset(struct section *sec, unsigned long offset)
+{
+ struct rb_node *node;
+
+ rb_for_each(&sec->symbol_tree, node, &offset, symbol_by_offset) {
+ struct symbol *s = rb_entry(node, struct symbol, node);
+
+ if (s->offset == offset && s->type == STT_FUNC)
+ return s;
+ }
+
+ return NULL;
+}
+
+struct symbol *find_symbol_containing(const struct section *sec, unsigned long offset)
+{
+ struct rb_node *node;
+
+ rb_for_each(&sec->symbol_tree, node, &offset, symbol_by_offset) {
+ struct symbol *s = rb_entry(node, struct symbol, node);
+
+ if (s->type != STT_SECTION)
+ return s;
+ }
+
+ return NULL;
+}
+
+struct symbol *find_func_containing(struct section *sec, unsigned long offset)
+{
+ struct rb_node *node;
+
+ rb_for_each(&sec->symbol_tree, node, &offset, symbol_by_offset) {
+ struct symbol *s = rb_entry(node, struct symbol, node);
+
+ if (s->type == STT_FUNC)
+ return s;
+ }
+
+ return NULL;
+}
+
+struct symbol *find_symbol_by_name(const struct elf *elf, const char *name)
+{
struct symbol *sym;
- list_for_each_entry(sym, &sec->symbol_list, list)
- if (sym->type != STT_SECTION &&
- sym->offset == offset)
+ elf_hash_for_each_possible(elf->symbol_name_hash, sym, name_hash, str_hash(name))
+ if (!strcmp(sym->name, name))
return sym;
return NULL;
}
-struct symbol *find_symbol_by_name(struct elf *elf, const char *name)
+struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *sec,
+ unsigned long offset, unsigned int len)
{
- struct section *sec;
- struct symbol *sym;
-
- list_for_each_entry(sec, &elf->sections, list)
- list_for_each_entry(sym, &sec->symbol_list, list)
- if (!strcmp(sym->name, name))
- return sym;
-
- return NULL;
-}
-
-struct symbol *find_symbol_containing(struct section *sec, unsigned long offset)
-{
- struct symbol *sym;
-
- list_for_each_entry(sym, &sec->symbol_list, list)
- if (sym->type != STT_SECTION &&
- offset >= sym->offset && offset < sym->offset + sym->len)
- return sym;
-
- return NULL;
-}
-
-struct rela *find_rela_by_dest_range(struct section *sec, unsigned long offset,
- unsigned int len)
-{
- struct rela *rela;
+ struct reloc *reloc, *r = NULL;
unsigned long o;
- if (!sec->rela)
+ if (!sec->reloc)
return NULL;
- for (o = offset; o < offset + len; o++)
- hash_for_each_possible(sec->rela->rela_hash, rela, hash, o)
- if (rela->offset == o)
- return rela;
+ sec = sec->reloc;
+
+ for_offset_range(o, offset, offset + len) {
+ elf_hash_for_each_possible(elf->reloc_hash, reloc, hash,
+ sec_offset_hash(sec, o)) {
+ if (reloc->sec != sec)
+ continue;
+
+ if (reloc->offset >= offset && reloc->offset < offset + len) {
+ if (!r || reloc->offset < r->offset)
+ r = reloc;
+ }
+ }
+ if (r)
+ return r;
+ }
return NULL;
}
-struct rela *find_rela_by_dest(struct section *sec, unsigned long offset)
+struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, unsigned long offset)
{
- return find_rela_by_dest_range(sec, offset, 1);
+ return find_reloc_by_dest_range(elf, sec, offset, 1);
}
-struct symbol *find_containing_func(struct section *sec, unsigned long offset)
+void insn_to_reloc_sym_addend(struct section *sec, unsigned long offset,
+ struct reloc *reloc)
{
- struct symbol *func;
+ if (sec->sym) {
+ reloc->sym = sec->sym;
+ reloc->addend = offset;
+ return;
+ }
- list_for_each_entry(func, &sec->symbol_list, list)
- if (func->type == STT_FUNC && offset >= func->offset &&
- offset < func->offset + func->len)
- return func;
+ /*
+ * The Clang assembler strips section symbols, so we have to reference
+ * the function symbol instead:
+ */
+ reloc->sym = find_symbol_containing(sec, offset);
+ if (!reloc->sym) {
+ /*
+ * Hack alert. This happens when we need to reference the NOP
+ * pad insn immediately after the function.
+ */
+ reloc->sym = find_symbol_containing(sec, offset - 1);
+ }
- return NULL;
+ if (reloc->sym)
+ reloc->addend = offset - reloc->sym->offset;
}
static int read_sections(struct elf *elf)
@@ -154,11 +314,7 @@
memset(sec, 0, sizeof(*sec));
INIT_LIST_HEAD(&sec->symbol_list);
- INIT_LIST_HEAD(&sec->rela_list);
- hash_init(sec->rela_hash);
- hash_init(sec->symbol_hash);
-
- list_add_tail(&sec->list, &elf->sections);
+ INIT_LIST_HEAD(&sec->reloc_list);
s = elf_getscn(elf->elf, i);
if (!s) {
@@ -193,8 +349,15 @@
}
}
sec->len = sec->sh.sh_size;
+
+ list_add_tail(&sec->list, &elf->sections);
+ elf_hash_add(elf->section_hash, &sec->hash, sec->idx);
+ elf_hash_add(elf->section_name_hash, &sec->name_hash, str_hash(sec->name));
}
+ if (stats)
+ printf("nr_sections: %lu\n", (unsigned long)sections_nr);
+
/* sanity check, one more call to elf_nextscn() should return NULL */
if (elf_nextscn(elf->elf, s)) {
WARN("section entry mismatch");
@@ -206,11 +369,14 @@
static int read_symbols(struct elf *elf)
{
- struct section *symtab, *sec;
- struct symbol *sym, *pfunc, *alias;
- struct list_head *entry, *tmp;
+ struct section *symtab, *symtab_shndx, *sec;
+ struct symbol *sym, *pfunc;
+ struct list_head *entry;
+ struct rb_node *pnode;
int symbols_nr, i;
char *coldstr;
+ Elf_Data *shndx_data = NULL;
+ Elf32_Word shndx;
symtab = find_section_by_name(elf, ".symtab");
if (!symtab) {
@@ -221,6 +387,10 @@
return 0;
}
+ symtab_shndx = find_section_by_name(elf, ".symtab_shndx");
+ if (symtab_shndx)
+ shndx_data = symtab_shndx->data;
+
symbols_nr = symtab->sh.sh_size / symtab->sh.sh_entsize;
for (i = 0; i < symbols_nr; i++) {
@@ -230,12 +400,13 @@
return -1;
}
memset(sym, 0, sizeof(*sym));
- alias = sym;
+ sym->alias = sym;
sym->idx = i;
- if (!gelf_getsym(symtab->data, i, &sym->sym)) {
- WARN_ELF("gelf_getsym");
+ if (!gelf_getsymshndx(symtab->data, shndx_data, i, &sym->sym,
+ &shndx)) {
+ WARN_ELF("gelf_getsymshndx");
goto err;
}
@@ -249,10 +420,13 @@
sym->type = GELF_ST_TYPE(sym->sym.st_info);
sym->bind = GELF_ST_BIND(sym->sym.st_info);
- if (sym->sym.st_shndx > SHN_UNDEF &&
- sym->sym.st_shndx < SHN_LORESERVE) {
- sym->sec = find_section_by_index(elf,
- sym->sym.st_shndx);
+ if ((sym->sym.st_shndx > SHN_UNDEF &&
+ sym->sym.st_shndx < SHN_LORESERVE) ||
+ (shndx_data && sym->sym.st_shndx == SHN_XINDEX)) {
+ if (sym->sym.st_shndx != SHN_XINDEX)
+ shndx = sym->sym.st_shndx;
+
+ sym->sec = find_section_by_index(elf, shndx);
if (!sym->sec) {
WARN("couldn't find section for symbol %s",
sym->name);
@@ -268,33 +442,27 @@
sym->offset = sym->sym.st_value;
sym->len = sym->sym.st_size;
- /* sorted insert into a per-section list */
- entry = &sym->sec->symbol_list;
- list_for_each_prev(tmp, &sym->sec->symbol_list) {
- struct symbol *s;
-
- s = list_entry(tmp, struct symbol, list);
-
- if (sym->offset > s->offset) {
- entry = tmp;
- break;
- }
-
- if (sym->offset == s->offset) {
- if (sym->len && sym->len == s->len && alias == sym)
- alias = s;
-
- if (sym->len >= s->len) {
- entry = tmp;
- break;
- }
- }
- }
- sym->alias = alias;
+ rb_add(&sym->sec->symbol_tree, &sym->node, symbol_to_offset);
+ pnode = rb_prev(&sym->node);
+ if (pnode)
+ entry = &rb_entry(pnode, struct symbol, node)->list;
+ else
+ entry = &sym->sec->symbol_list;
list_add(&sym->list, entry);
- hash_add(sym->sec->symbol_hash, &sym->hash, sym->idx);
+ elf_hash_add(elf->symbol_hash, &sym->hash, sym->idx);
+ elf_hash_add(elf->symbol_name_hash, &sym->name_hash, str_hash(sym->name));
+
+ /*
+ * Don't store empty STT_NOTYPE symbols in the rbtree. They
+ * can exist within a function, confusing the sorting.
+ */
+ if (!sym->len)
+ rb_erase(&sym->node, &sym->sec->symbol_tree);
}
+ if (stats)
+ printf("nr_symbols: %lu\n", (unsigned long)symbols_nr);
+
/* Create parent/child links for any cold subfunctions */
list_for_each_entry(sec, &elf->sections, list) {
list_for_each_entry(sym, &sec->symbol_list, list) {
@@ -302,7 +470,13 @@
size_t pnamelen;
if (sym->type != STT_FUNC)
continue;
- sym->pfunc = sym->cfunc = sym;
+
+ if (sym->pfunc == NULL)
+ sym->pfunc = sym;
+
+ if (sym->cfunc == NULL)
+ sym->cfunc = sym;
+
coldstr = strstr(sym->name, ".cold");
if (!coldstr)
continue;
@@ -350,61 +524,107 @@
return -1;
}
-static int read_relas(struct elf *elf)
+void elf_add_reloc(struct elf *elf, struct reloc *reloc)
+{
+ struct section *sec = reloc->sec;
+
+ list_add_tail(&reloc->list, &sec->reloc_list);
+ elf_hash_add(elf->reloc_hash, &reloc->hash, reloc_hash(reloc));
+}
+
+static int read_rel_reloc(struct section *sec, int i, struct reloc *reloc, unsigned int *symndx)
+{
+ if (!gelf_getrel(sec->data, i, &reloc->rel)) {
+ WARN_ELF("gelf_getrel");
+ return -1;
+ }
+ reloc->type = GELF_R_TYPE(reloc->rel.r_info);
+ reloc->addend = 0;
+ reloc->offset = reloc->rel.r_offset;
+ *symndx = GELF_R_SYM(reloc->rel.r_info);
+ return 0;
+}
+
+static int read_rela_reloc(struct section *sec, int i, struct reloc *reloc, unsigned int *symndx)
+{
+ if (!gelf_getrela(sec->data, i, &reloc->rela)) {
+ WARN_ELF("gelf_getrela");
+ return -1;
+ }
+ reloc->type = GELF_R_TYPE(reloc->rela.r_info);
+ reloc->addend = reloc->rela.r_addend;
+ reloc->offset = reloc->rela.r_offset;
+ *symndx = GELF_R_SYM(reloc->rela.r_info);
+ return 0;
+}
+
+static int read_relocs(struct elf *elf)
{
struct section *sec;
- struct rela *rela;
+ struct reloc *reloc;
int i;
unsigned int symndx;
+ unsigned long nr_reloc, max_reloc = 0, tot_reloc = 0;
list_for_each_entry(sec, &elf->sections, list) {
- if (sec->sh.sh_type != SHT_RELA)
+ if ((sec->sh.sh_type != SHT_RELA) &&
+ (sec->sh.sh_type != SHT_REL))
continue;
- sec->base = find_section_by_name(elf, sec->name + 5);
+ sec->base = find_section_by_index(elf, sec->sh.sh_info);
if (!sec->base) {
- WARN("can't find base section for rela section %s",
+ WARN("can't find base section for reloc section %s",
sec->name);
return -1;
}
- sec->base->rela = sec;
+ sec->base->reloc = sec;
+ nr_reloc = 0;
for (i = 0; i < sec->sh.sh_size / sec->sh.sh_entsize; i++) {
- rela = malloc(sizeof(*rela));
- if (!rela) {
+ reloc = malloc(sizeof(*reloc));
+ if (!reloc) {
perror("malloc");
return -1;
}
- memset(rela, 0, sizeof(*rela));
-
- if (!gelf_getrela(sec->data, i, &rela->rela)) {
- WARN_ELF("gelf_getrela");
- return -1;
+ memset(reloc, 0, sizeof(*reloc));
+ switch (sec->sh.sh_type) {
+ case SHT_REL:
+ if (read_rel_reloc(sec, i, reloc, &symndx))
+ return -1;
+ break;
+ case SHT_RELA:
+ if (read_rela_reloc(sec, i, reloc, &symndx))
+ return -1;
+ break;
+ default: return -1;
}
- rela->type = GELF_R_TYPE(rela->rela.r_info);
- rela->addend = rela->rela.r_addend;
- rela->offset = rela->rela.r_offset;
- symndx = GELF_R_SYM(rela->rela.r_info);
- rela->sym = find_symbol_by_index(elf, symndx);
- rela->sec = sec;
- if (!rela->sym) {
- WARN("can't find rela entry symbol %d for %s",
+ reloc->sec = sec;
+ reloc->idx = i;
+ reloc->sym = find_symbol_by_index(elf, symndx);
+ if (!reloc->sym) {
+ WARN("can't find reloc entry symbol %d for %s",
symndx, sec->name);
return -1;
}
- list_add_tail(&rela->list, &sec->rela_list);
- hash_add(sec->rela_hash, &rela->hash, rela->offset);
-
+ elf_add_reloc(elf, reloc);
+ nr_reloc++;
}
+ max_reloc = max(max_reloc, nr_reloc);
+ tot_reloc += nr_reloc;
+ }
+
+ if (stats) {
+ printf("max_reloc: %lu\n", max_reloc);
+ printf("tot_reloc: %lu\n", tot_reloc);
}
return 0;
}
-struct elf *elf_read(const char *name, int flags)
+struct elf *elf_open_read(const char *name, int flags)
{
struct elf *elf;
Elf_Cmd cmd;
@@ -416,10 +636,16 @@
perror("malloc");
return NULL;
}
- memset(elf, 0, sizeof(*elf));
+ memset(elf, 0, offsetof(struct elf, sections));
INIT_LIST_HEAD(&elf->sections);
+ elf_hash_init(elf->symbol_hash);
+ elf_hash_init(elf->symbol_name_hash);
+ elf_hash_init(elf->section_hash);
+ elf_hash_init(elf->section_name_hash);
+ elf_hash_init(elf->reloc_hash);
+
elf->fd = open(name, flags);
if (elf->fd == -1) {
fprintf(stderr, "objtool: Can't open '%s': %s\n",
@@ -451,7 +677,7 @@
if (read_symbols(elf))
goto err;
- if (read_relas(elf))
+ if (read_relocs(elf))
goto err;
return elf;
@@ -462,7 +688,7 @@
}
struct section *elf_create_section(struct elf *elf, const char *name,
- size_t entsize, int nr)
+ unsigned int sh_flags, size_t entsize, int nr)
{
struct section *sec, *shstrtab;
size_t size = entsize * nr;
@@ -477,11 +703,7 @@
memset(sec, 0, sizeof(*sec));
INIT_LIST_HEAD(&sec->symbol_list);
- INIT_LIST_HEAD(&sec->rela_list);
- hash_init(sec->rela_hash);
- hash_init(sec->symbol_hash);
-
- list_add_tail(&sec->list, &elf->sections);
+ INIT_LIST_HEAD(&sec->reloc_list);
s = elf_newscn(elf->elf);
if (!s) {
@@ -526,7 +748,7 @@
sec->sh.sh_entsize = entsize;
sec->sh.sh_type = SHT_PROGBITS;
sec->sh.sh_addralign = 1;
- sec->sh.sh_flags = SHF_ALLOC;
+ sec->sh.sh_flags = SHF_ALLOC | sh_flags;
/* Add section name to .shstrtab (or .strtab for Clang) */
@@ -559,28 +781,64 @@
shstrtab->len += strlen(name) + 1;
shstrtab->changed = true;
+ list_add_tail(&sec->list, &elf->sections);
+ elf_hash_add(elf->section_hash, &sec->hash, sec->idx);
+ elf_hash_add(elf->section_name_hash, &sec->name_hash, str_hash(sec->name));
+
+ elf->changed = true;
+
return sec;
}
-struct section *elf_create_rela_section(struct elf *elf, struct section *base)
+static struct section *elf_create_rel_reloc_section(struct elf *elf, struct section *base)
{
- char *relaname;
+ char *relocname;
struct section *sec;
- relaname = malloc(strlen(base->name) + strlen(".rela") + 1);
- if (!relaname) {
+ relocname = malloc(strlen(base->name) + strlen(".rel") + 1);
+ if (!relocname) {
perror("malloc");
return NULL;
}
- strcpy(relaname, ".rela");
- strcat(relaname, base->name);
+ strcpy(relocname, ".rel");
+ strcat(relocname, base->name);
- sec = elf_create_section(elf, relaname, sizeof(GElf_Rela), 0);
- free(relaname);
+ sec = elf_create_section(elf, relocname, 0, sizeof(GElf_Rel), 0);
+ free(relocname);
if (!sec)
return NULL;
- base->rela = sec;
+ base->reloc = sec;
+ sec->base = base;
+
+ sec->sh.sh_type = SHT_REL;
+ sec->sh.sh_addralign = 8;
+ sec->sh.sh_link = find_section_by_name(elf, ".symtab")->idx;
+ sec->sh.sh_info = base->idx;
+ sec->sh.sh_flags = SHF_INFO_LINK;
+
+ return sec;
+}
+
+static struct section *elf_create_rela_reloc_section(struct elf *elf, struct section *base)
+{
+ char *relocname;
+ struct section *sec;
+
+ relocname = malloc(strlen(base->name) + strlen(".rela") + 1);
+ if (!relocname) {
+ perror("malloc");
+ return NULL;
+ }
+ strcpy(relocname, ".rela");
+ strcat(relocname, base->name);
+
+ sec = elf_create_section(elf, relocname, 0, sizeof(GElf_Rela), 0);
+ free(relocname);
+ if (!sec)
+ return NULL;
+
+ base->reloc = sec;
sec->base = base;
sec->sh.sh_type = SHT_RELA;
@@ -592,39 +850,142 @@
return sec;
}
-int elf_rebuild_rela_section(struct section *sec)
+struct section *elf_create_reloc_section(struct elf *elf,
+ struct section *base,
+ int reltype)
{
- struct rela *rela;
- int nr, idx = 0, size;
- GElf_Rela *relas;
+ switch (reltype) {
+ case SHT_REL: return elf_create_rel_reloc_section(elf, base);
+ case SHT_RELA: return elf_create_rela_reloc_section(elf, base);
+ default: return NULL;
+ }
+}
- nr = 0;
- list_for_each_entry(rela, &sec->rela_list, list)
- nr++;
+static int elf_rebuild_rel_reloc_section(struct section *sec, int nr)
+{
+ struct reloc *reloc;
+ int idx = 0, size;
+ GElf_Rel *relocs;
- size = nr * sizeof(*relas);
- relas = malloc(size);
- if (!relas) {
+ /* Allocate a buffer for relocations */
+ size = nr * sizeof(*relocs);
+ relocs = malloc(size);
+ if (!relocs) {
perror("malloc");
return -1;
}
- sec->data->d_buf = relas;
+ sec->data->d_buf = relocs;
sec->data->d_size = size;
sec->sh.sh_size = size;
idx = 0;
- list_for_each_entry(rela, &sec->rela_list, list) {
- relas[idx].r_offset = rela->offset;
- relas[idx].r_addend = rela->addend;
- relas[idx].r_info = GELF_R_INFO(rela->sym->idx, rela->type);
+ list_for_each_entry(reloc, &sec->reloc_list, list) {
+ relocs[idx].r_offset = reloc->offset;
+ relocs[idx].r_info = GELF_R_INFO(reloc->sym->idx, reloc->type);
idx++;
}
return 0;
}
+static int elf_rebuild_rela_reloc_section(struct section *sec, int nr)
+{
+ struct reloc *reloc;
+ int idx = 0, size;
+ GElf_Rela *relocs;
+
+ /* Allocate a buffer for relocations with addends */
+ size = nr * sizeof(*relocs);
+ relocs = malloc(size);
+ if (!relocs) {
+ perror("malloc");
+ return -1;
+ }
+
+ sec->data->d_buf = relocs;
+ sec->data->d_size = size;
+
+ sec->sh.sh_size = size;
+
+ idx = 0;
+ list_for_each_entry(reloc, &sec->reloc_list, list) {
+ relocs[idx].r_offset = reloc->offset;
+ relocs[idx].r_addend = reloc->addend;
+ relocs[idx].r_info = GELF_R_INFO(reloc->sym->idx, reloc->type);
+ idx++;
+ }
+
+ return 0;
+}
+
+int elf_rebuild_reloc_section(struct elf *elf, struct section *sec)
+{
+ struct reloc *reloc;
+ int nr;
+
+ sec->changed = true;
+ elf->changed = true;
+
+ nr = 0;
+ list_for_each_entry(reloc, &sec->reloc_list, list)
+ nr++;
+
+ switch (sec->sh.sh_type) {
+ case SHT_REL: return elf_rebuild_rel_reloc_section(sec, nr);
+ case SHT_RELA: return elf_rebuild_rela_reloc_section(sec, nr);
+ default: return -1;
+ }
+}
+
+int elf_write_insn(struct elf *elf, struct section *sec,
+ unsigned long offset, unsigned int len,
+ const char *insn)
+{
+ Elf_Data *data = sec->data;
+
+ if (data->d_type != ELF_T_BYTE || data->d_off) {
+ WARN("write to unexpected data for section: %s", sec->name);
+ return -1;
+ }
+
+ memcpy(data->d_buf + offset, insn, len);
+ elf_flagdata(data, ELF_C_SET, ELF_F_DIRTY);
+
+ elf->changed = true;
+
+ return 0;
+}
+
+int elf_write_reloc(struct elf *elf, struct reloc *reloc)
+{
+ struct section *sec = reloc->sec;
+
+ if (sec->sh.sh_type == SHT_REL) {
+ reloc->rel.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type);
+ reloc->rel.r_offset = reloc->offset;
+
+ if (!gelf_update_rel(sec->data, reloc->idx, &reloc->rel)) {
+ WARN_ELF("gelf_update_rel");
+ return -1;
+ }
+ } else {
+ reloc->rela.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type);
+ reloc->rela.r_addend = reloc->addend;
+ reloc->rela.r_offset = reloc->offset;
+
+ if (!gelf_update_rela(sec->data, reloc->idx, &reloc->rela)) {
+ WARN_ELF("gelf_update_rela");
+ return -1;
+ }
+ }
+
+ elf->changed = true;
+
+ return 0;
+}
+
int elf_write(struct elf *elf)
{
struct section *sec;
@@ -642,6 +1003,8 @@
WARN_ELF("gelf_update_shdr");
return -1;
}
+
+ sec->changed = false;
}
}
@@ -654,6 +1017,8 @@
return -1;
}
+ elf->changed = false;
+
return 0;
}
@@ -661,7 +1026,7 @@
{
struct section *sec, *tmpsec;
struct symbol *sym, *tmpsym;
- struct rela *rela, *tmprela;
+ struct reloc *reloc, *tmpreloc;
if (elf->elf)
elf_end(elf->elf);
@@ -675,10 +1040,10 @@
hash_del(&sym->hash);
free(sym);
}
- list_for_each_entry_safe(rela, tmprela, &sec->rela_list, list) {
- list_del(&rela->list);
- hash_del(&rela->hash);
- free(rela);
+ list_for_each_entry_safe(reloc, tmpreloc, &sec->reloc_list, list) {
+ list_del(&reloc->list);
+ hash_del(&reloc->hash);
+ free(reloc);
}
list_del(&sec->list);
free(sec);
diff --git a/tools/objtool/elf.h b/tools/objtool/elf.h
index 4415020..e6890cc 100644
--- a/tools/objtool/elf.h
+++ b/tools/objtool/elf.h
@@ -10,6 +10,8 @@
#include <gelf.h>
#include <linux/list.h>
#include <linux/hashtable.h>
+#include <linux/rbtree.h>
+#include <linux/jhash.h>
#ifdef LIBELF_USE_DEPRECATED
# define elf_getshdrnum elf_getshnum
@@ -25,23 +27,26 @@
struct section {
struct list_head list;
+ struct hlist_node hash;
+ struct hlist_node name_hash;
GElf_Shdr sh;
+ struct rb_root symbol_tree;
struct list_head symbol_list;
- DECLARE_HASHTABLE(symbol_hash, 8);
- struct list_head rela_list;
- DECLARE_HASHTABLE(rela_hash, 16);
- struct section *base, *rela;
+ struct list_head reloc_list;
+ struct section *base, *reloc;
struct symbol *sym;
Elf_Data *data;
char *name;
int idx;
unsigned int len;
- bool changed, text, rodata;
+ bool changed, text, rodata, noinstr;
};
struct symbol {
struct list_head list;
+ struct rb_node node;
struct hlist_node hash;
+ struct hlist_node name_hash;
GElf_Sym sym;
struct section *sec;
char *name;
@@ -51,46 +56,94 @@
unsigned int len;
struct symbol *pfunc, *cfunc, *alias;
bool uaccess_safe;
+ bool static_call_tramp;
};
-struct rela {
+struct reloc {
struct list_head list;
struct hlist_node hash;
- GElf_Rela rela;
+ union {
+ GElf_Rela rela;
+ GElf_Rel rel;
+ };
struct section *sec;
struct symbol *sym;
- unsigned int type;
unsigned long offset;
+ unsigned int type;
int addend;
+ int idx;
bool jump_table_start;
};
+#define ELF_HASH_BITS 20
+
struct elf {
Elf *elf;
GElf_Ehdr ehdr;
int fd;
+ bool changed;
char *name;
struct list_head sections;
- DECLARE_HASHTABLE(rela_hash, 16);
+ DECLARE_HASHTABLE(symbol_hash, ELF_HASH_BITS);
+ DECLARE_HASHTABLE(symbol_name_hash, ELF_HASH_BITS);
+ DECLARE_HASHTABLE(section_hash, ELF_HASH_BITS);
+ DECLARE_HASHTABLE(section_name_hash, ELF_HASH_BITS);
+ DECLARE_HASHTABLE(reloc_hash, ELF_HASH_BITS);
};
+#define OFFSET_STRIDE_BITS 4
+#define OFFSET_STRIDE (1UL << OFFSET_STRIDE_BITS)
+#define OFFSET_STRIDE_MASK (~(OFFSET_STRIDE - 1))
-struct elf *elf_read(const char *name, int flags);
-struct section *find_section_by_name(struct elf *elf, const char *name);
-struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset);
-struct symbol *find_symbol_by_name(struct elf *elf, const char *name);
-struct symbol *find_symbol_containing(struct section *sec, unsigned long offset);
-struct rela *find_rela_by_dest(struct section *sec, unsigned long offset);
-struct rela *find_rela_by_dest_range(struct section *sec, unsigned long offset,
- unsigned int len);
-struct symbol *find_containing_func(struct section *sec, unsigned long offset);
-struct section *elf_create_section(struct elf *elf, const char *name, size_t
- entsize, int nr);
-struct section *elf_create_rela_section(struct elf *elf, struct section *base);
-int elf_rebuild_rela_section(struct section *sec);
+#define for_offset_range(_offset, _start, _end) \
+ for (_offset = ((_start) & OFFSET_STRIDE_MASK); \
+ _offset >= ((_start) & OFFSET_STRIDE_MASK) && \
+ _offset <= ((_end) & OFFSET_STRIDE_MASK); \
+ _offset += OFFSET_STRIDE)
+
+static inline u32 sec_offset_hash(struct section *sec, unsigned long offset)
+{
+ u32 ol, oh, idx = sec->idx;
+
+ offset &= OFFSET_STRIDE_MASK;
+
+ ol = offset;
+ oh = (offset >> 16) >> 16;
+
+ __jhash_mix(ol, oh, idx);
+
+ return ol;
+}
+
+static inline u32 reloc_hash(struct reloc *reloc)
+{
+ return sec_offset_hash(reloc->sec, reloc->offset);
+}
+
+struct elf *elf_open_read(const char *name, int flags);
+struct section *elf_create_section(struct elf *elf, const char *name, unsigned int sh_flags, size_t entsize, int nr);
+struct section *elf_create_reloc_section(struct elf *elf, struct section *base, int reltype);
+void elf_add_reloc(struct elf *elf, struct reloc *reloc);
+int elf_write_insn(struct elf *elf, struct section *sec,
+ unsigned long offset, unsigned int len,
+ const char *insn);
+int elf_write_reloc(struct elf *elf, struct reloc *reloc);
int elf_write(struct elf *elf);
void elf_close(struct elf *elf);
+struct section *find_section_by_name(const struct elf *elf, const char *name);
+struct symbol *find_func_by_offset(struct section *sec, unsigned long offset);
+struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset);
+struct symbol *find_symbol_by_name(const struct elf *elf, const char *name);
+struct symbol *find_symbol_containing(const struct section *sec, unsigned long offset);
+struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, unsigned long offset);
+struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *sec,
+ unsigned long offset, unsigned int len);
+struct symbol *find_func_containing(struct section *sec, unsigned long offset);
+void insn_to_reloc_sym_addend(struct section *sec, unsigned long offset,
+ struct reloc *reloc);
+int elf_rebuild_reloc_section(struct elf *elf, struct section *sec);
+
#define for_each_sec(file, sec) \
list_for_each_entry(sec, &file->elf->sections, list)
diff --git a/tools/objtool/objtool.c b/tools/objtool/objtool.c
index 0b3528f..9df0cd8 100644
--- a/tools/objtool/objtool.c
+++ b/tools/objtool/objtool.c
@@ -22,6 +22,8 @@
#include <linux/kernel.h>
#include "builtin.h"
+#include "objtool.h"
+#include "warn.h"
struct cmd_struct {
const char *name;
@@ -39,6 +41,34 @@
bool help;
+const char *objname;
+static struct objtool_file file;
+
+struct objtool_file *objtool_open_read(const char *_objname)
+{
+ if (objname) {
+ if (strcmp(objname, _objname)) {
+ WARN("won't handle more than one file at a time");
+ return NULL;
+ }
+ return &file;
+ }
+ objname = _objname;
+
+ file.elf = elf_open_read(objname, O_RDWR);
+ if (!file.elf)
+ return NULL;
+
+ INIT_LIST_HEAD(&file.insn_list);
+ hash_init(file.insn_hash);
+ INIT_LIST_HEAD(&file.static_call_list);
+ file.c_file = !vmlinux && find_section_by_name(file.elf, ".comment");
+ file.ignore_unreachables = no_unreachable;
+ file.hints = false;
+
+ return &file;
+}
+
static void cmd_usage(void)
{
unsigned int i, longest = 0;
@@ -58,7 +88,9 @@
printf("\n");
- exit(129);
+ if (!help)
+ exit(129);
+ exit(0);
}
static void handle_options(int *argc, const char ***argv)
diff --git a/tools/objtool/objtool.h b/tools/objtool/objtool.h
new file mode 100644
index 0000000..4125d45
--- /dev/null
+++ b/tools/objtool/objtool.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2020 Matt Helsley <mhelsley@vmware.com>
+ */
+
+#ifndef _OBJTOOL_H
+#define _OBJTOOL_H
+
+#include <stdbool.h>
+#include <linux/list.h>
+#include <linux/hashtable.h>
+
+#include "elf.h"
+
+#define __weak __attribute__((weak))
+
+struct objtool_file {
+ struct elf *elf;
+ struct list_head insn_list;
+ DECLARE_HASHTABLE(insn_hash, 20);
+ struct list_head static_call_list;
+ bool ignore_unreachables, c_file, hints, rodata;
+};
+
+struct objtool_file *objtool_open_read(const char *_objname);
+
+int check(struct objtool_file *file);
+int orc_dump(const char *objname);
+int create_orc(struct objtool_file *file);
+int create_orc_sections(struct objtool_file *file);
+
+#endif /* _OBJTOOL_H */
diff --git a/tools/objtool/orc.h b/tools/objtool/orc.h
deleted file mode 100644
index ee28322..0000000
--- a/tools/objtool/orc.h
+++ /dev/null
@@ -1,18 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later */
-/*
- * Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com>
- */
-
-#ifndef _ORC_H
-#define _ORC_H
-
-#include <asm/orc_types.h>
-
-struct objtool_file;
-
-int create_orc(struct objtool_file *file);
-int create_orc_sections(struct objtool_file *file);
-
-int orc_dump(const char *objname);
-
-#endif /* _ORC_H */
diff --git a/tools/objtool/orc_dump.c b/tools/objtool/orc_dump.c
index ba4cbb1..5e6a953 100644
--- a/tools/objtool/orc_dump.c
+++ b/tools/objtool/orc_dump.c
@@ -4,7 +4,9 @@
*/
#include <unistd.h>
-#include "orc.h"
+#include <linux/objtool.h>
+#include <asm/orc_types.h>
+#include "objtool.h"
#include "warn.h"
static const char *reg_name(unsigned int reg)
@@ -36,12 +38,12 @@
static const char *orc_type_name(unsigned int type)
{
switch (type) {
- case ORC_TYPE_CALL:
+ case UNWIND_HINT_TYPE_CALL:
return "call";
- case ORC_TYPE_REGS:
+ case UNWIND_HINT_TYPE_REGS:
return "regs";
- case ORC_TYPE_REGS_IRET:
- return "iret";
+ case UNWIND_HINT_TYPE_REGS_PARTIAL:
+ return "regs (partial)";
default:
return "?";
}
diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c
index e8c34b0..9ce68b3 100644
--- a/tools/objtool/orc_gen.c
+++ b/tools/objtool/orc_gen.c
@@ -6,7 +6,9 @@
#include <stdlib.h>
#include <string.h>
-#include "orc.h"
+#include <linux/objtool.h>
+#include <asm/orc_types.h>
+
#include "check.h"
#include "warn.h"
@@ -16,10 +18,13 @@
for_each_insn(file, insn) {
struct orc_entry *orc = &insn->orc;
- struct cfi_reg *cfa = &insn->state.cfa;
- struct cfi_reg *bp = &insn->state.regs[CFI_BP];
+ struct cfi_reg *cfa = &insn->cfi.cfa;
+ struct cfi_reg *bp = &insn->cfi.regs[CFI_BP];
- orc->end = insn->state.end;
+ if (!insn->sec->text)
+ continue;
+
+ orc->end = insn->cfi.end;
if (cfa->base == CFI_UNDEFINED) {
orc->sp_reg = ORC_REG_UNDEFINED;
@@ -75,62 +80,43 @@
orc->sp_offset = cfa->offset;
orc->bp_offset = bp->offset;
- orc->type = insn->state.type;
+ orc->type = insn->cfi.type;
}
return 0;
}
-static int create_orc_entry(struct section *u_sec, struct section *ip_relasec,
+static int create_orc_entry(struct elf *elf, struct section *u_sec, struct section *ip_relocsec,
unsigned int idx, struct section *insn_sec,
unsigned long insn_off, struct orc_entry *o)
{
struct orc_entry *orc;
- struct rela *rela;
+ struct reloc *reloc;
/* populate ORC data */
orc = (struct orc_entry *)u_sec->data->d_buf + idx;
memcpy(orc, o, sizeof(*orc));
- /* populate rela for ip */
- rela = malloc(sizeof(*rela));
- if (!rela) {
+ /* populate reloc for ip */
+ reloc = malloc(sizeof(*reloc));
+ if (!reloc) {
perror("malloc");
return -1;
}
- memset(rela, 0, sizeof(*rela));
+ memset(reloc, 0, sizeof(*reloc));
- if (insn_sec->sym) {
- rela->sym = insn_sec->sym;
- rela->addend = insn_off;
- } else {
- /*
- * The Clang assembler doesn't produce section symbols, so we
- * have to reference the function symbol instead:
- */
- rela->sym = find_symbol_containing(insn_sec, insn_off);
- if (!rela->sym) {
- /*
- * Hack alert. This happens when we need to reference
- * the NOP pad insn immediately after the function.
- */
- rela->sym = find_symbol_containing(insn_sec,
- insn_off - 1);
- }
- if (!rela->sym) {
- WARN("missing symbol for insn at offset 0x%lx\n",
- insn_off);
- return -1;
- }
-
- rela->addend = insn_off - rela->sym->offset;
+ insn_to_reloc_sym_addend(insn_sec, insn_off, reloc);
+ if (!reloc->sym) {
+ WARN("missing symbol for insn at offset 0x%lx",
+ insn_off);
+ return -1;
}
- rela->type = R_X86_64_PC32;
- rela->offset = idx * sizeof(int);
+ reloc->type = R_X86_64_PC32;
+ reloc->offset = idx * sizeof(int);
+ reloc->sec = ip_relocsec;
- list_add_tail(&rela->list, &ip_relasec->rela_list);
- hash_add(ip_relasec->rela_hash, &rela->hash, rela->offset);
+ elf_add_reloc(elf, reloc);
return 0;
}
@@ -138,13 +124,13 @@
int create_orc_sections(struct objtool_file *file)
{
struct instruction *insn, *prev_insn;
- struct section *sec, *u_sec, *ip_relasec;
+ struct section *sec, *u_sec, *ip_relocsec;
unsigned int idx;
struct orc_entry empty = {
.sp_reg = ORC_REG_UNDEFINED,
.bp_reg = ORC_REG_UNDEFINED,
- .type = ORC_TYPE_CALL,
+ .type = UNWIND_HINT_TYPE_CALL,
};
sec = find_section_by_name(file->elf, ".orc_unwind");
@@ -178,16 +164,16 @@
/* create .orc_unwind_ip and .rela.orc_unwind_ip sections */
- sec = elf_create_section(file->elf, ".orc_unwind_ip", sizeof(int), idx);
+ sec = elf_create_section(file->elf, ".orc_unwind_ip", 0, sizeof(int), idx);
if (!sec)
return -1;
- ip_relasec = elf_create_rela_section(file->elf, sec);
- if (!ip_relasec)
+ ip_relocsec = elf_create_reloc_section(file->elf, sec, SHT_RELA);
+ if (!ip_relocsec)
return -1;
/* create .orc_unwind section */
- u_sec = elf_create_section(file->elf, ".orc_unwind",
+ u_sec = elf_create_section(file->elf, ".orc_unwind", 0,
sizeof(struct orc_entry), idx);
/* populate sections */
@@ -201,7 +187,7 @@
if (!prev_insn || memcmp(&insn->orc, &prev_insn->orc,
sizeof(struct orc_entry))) {
- if (create_orc_entry(u_sec, ip_relasec, idx,
+ if (create_orc_entry(file->elf, u_sec, ip_relocsec, idx,
insn->sec, insn->offset,
&insn->orc))
return -1;
@@ -213,7 +199,7 @@
/* section terminator */
if (prev_insn) {
- if (create_orc_entry(u_sec, ip_relasec, idx,
+ if (create_orc_entry(file->elf, u_sec, ip_relocsec, idx,
prev_insn->sec,
prev_insn->offset + prev_insn->len,
&empty))
@@ -223,7 +209,7 @@
}
}
- if (elf_rebuild_rela_section(ip_relasec))
+ if (elf_rebuild_reloc_section(file->elf, ip_relocsec))
return -1;
return 0;
diff --git a/tools/objtool/special.c b/tools/objtool/special.c
index fdbaa61..1a2420f 100644
--- a/tools/objtool/special.c
+++ b/tools/objtool/special.c
@@ -14,24 +14,7 @@
#include "builtin.h"
#include "special.h"
#include "warn.h"
-
-#define EX_ENTRY_SIZE 12
-#define EX_ORIG_OFFSET 0
-#define EX_NEW_OFFSET 4
-
-#define JUMP_ENTRY_SIZE 16
-#define JUMP_ORIG_OFFSET 0
-#define JUMP_NEW_OFFSET 4
-
-#define ALT_ENTRY_SIZE 13
-#define ALT_ORIG_OFFSET 0
-#define ALT_NEW_OFFSET 4
-#define ALT_FEATURE_OFFSET 8
-#define ALT_ORIG_LEN_OFFSET 10
-#define ALT_NEW_LEN_OFFSET 11
-
-#define X86_FEATURE_POPCNT (4*32+23)
-#define X86_FEATURE_SMAP (9*32+20)
+#include "arch_special.h"
struct special_entry {
const char *sec;
@@ -68,11 +51,15 @@
{},
};
+void __weak arch_handle_alternative(unsigned short feature, struct special_alt *alt)
+{
+}
+
static int get_alt_entry(struct elf *elf, struct special_entry *entry,
struct section *sec, int idx,
struct special_alt *alt)
{
- struct rela *orig_rela, *new_rela;
+ struct reloc *orig_reloc, *new_reloc;
unsigned long offset;
offset = idx * entry->size;
@@ -92,56 +79,33 @@
feature = *(unsigned short *)(sec->data->d_buf + offset +
entry->feature);
-
- /*
- * It has been requested that we don't validate the !POPCNT
- * feature path which is a "very very small percentage of
- * machines".
- */
- if (feature == X86_FEATURE_POPCNT)
- alt->skip_orig = true;
-
- /*
- * If UACCESS validation is enabled; force that alternative;
- * otherwise force it the other way.
- *
- * What we want to avoid is having both the original and the
- * alternative code flow at the same time, in that case we can
- * find paths that see the STAC but take the NOP instead of
- * CLAC and the other way around.
- */
- if (feature == X86_FEATURE_SMAP) {
- if (uaccess)
- alt->skip_orig = true;
- else
- alt->skip_alt = true;
- }
+ arch_handle_alternative(feature, alt);
}
- orig_rela = find_rela_by_dest(sec, offset + entry->orig);
- if (!orig_rela) {
- WARN_FUNC("can't find orig rela", sec, offset + entry->orig);
+ orig_reloc = find_reloc_by_dest(elf, sec, offset + entry->orig);
+ if (!orig_reloc) {
+ WARN_FUNC("can't find orig reloc", sec, offset + entry->orig);
return -1;
}
- if (orig_rela->sym->type != STT_SECTION) {
- WARN_FUNC("don't know how to handle non-section rela symbol %s",
- sec, offset + entry->orig, orig_rela->sym->name);
+ if (orig_reloc->sym->type != STT_SECTION) {
+ WARN_FUNC("don't know how to handle non-section reloc symbol %s",
+ sec, offset + entry->orig, orig_reloc->sym->name);
return -1;
}
- alt->orig_sec = orig_rela->sym->sec;
- alt->orig_off = orig_rela->addend;
+ alt->orig_sec = orig_reloc->sym->sec;
+ alt->orig_off = orig_reloc->addend;
if (!entry->group || alt->new_len) {
- new_rela = find_rela_by_dest(sec, offset + entry->new);
- if (!new_rela) {
- WARN_FUNC("can't find new rela",
+ new_reloc = find_reloc_by_dest(elf, sec, offset + entry->new);
+ if (!new_reloc) {
+ WARN_FUNC("can't find new reloc",
sec, offset + entry->new);
return -1;
}
- alt->new_sec = new_rela->sym->sec;
- alt->new_off = (unsigned int)new_rela->addend;
+ alt->new_sec = new_reloc->sym->sec;
+ alt->new_off = (unsigned int)new_reloc->addend;
/* _ASM_EXTABLE_EX hack */
if (alt->new_off >= 0x7ffffff0)
diff --git a/tools/objtool/special.h b/tools/objtool/special.h
index 3506153..abddf38 100644
--- a/tools/objtool/special.h
+++ b/tools/objtool/special.h
@@ -7,8 +7,11 @@
#define _SPECIAL_H
#include <stdbool.h>
+#include "check.h"
#include "elf.h"
+#define C_JUMP_TABLE_SECTION ".rodata..c_jump_table"
+
struct special_alt {
struct list_head list;
@@ -28,4 +31,11 @@
int special_get_alts(struct elf *elf, struct list_head *alts);
+void arch_handle_alternative(unsigned short feature, struct special_alt *alt);
+
+bool arch_support_alt_relocation(struct special_alt *special_alt,
+ struct instruction *insn,
+ struct reloc *reloc);
+struct reloc *arch_find_switch_table(struct objtool_file *file,
+ struct instruction *insn);
#endif /* _SPECIAL_H */
diff --git a/tools/objtool/sync-check.sh b/tools/objtool/sync-check.sh
index c3ae1e8..606a4b5 100755
--- a/tools/objtool/sync-check.sh
+++ b/tools/objtool/sync-check.sh
@@ -1,12 +1,27 @@
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
-FILES='
+if [ -z "$SRCARCH" ]; then
+ echo 'sync-check.sh: error: missing $SRCARCH environment variable' >&2
+ exit 1
+fi
+
+FILES="include/linux/objtool.h"
+
+if [ "$SRCARCH" = "x86" ]; then
+FILES="$FILES
arch/x86/include/asm/inat_types.h
arch/x86/include/asm/orc_types.h
+arch/x86/include/asm/emulate_prefix.h
arch/x86/lib/x86-opcode-map.txt
arch/x86/tools/gen-insn-attr-x86.awk
-'
+include/linux/static_call_types.h
+arch/x86/include/asm/inat.h -I '^#include [\"<]\(asm/\)*inat_types.h[\">]'
+arch/x86/include/asm/insn.h -I '^#include [\"<]\(asm/\)*inat.h[\">]'
+arch/x86/lib/inat.c -I '^#include [\"<]\(../include/\)*asm/insn.h[\">]'
+arch/x86/lib/insn.c -I '^#include [\"<]\(../include/\)*asm/in\(at\|sn\).h[\">]' -I '^#include [\"<]\(../include/\)*asm/emulate_prefix.h[\">]'
+"
+fi
check_2 () {
file1=$1
@@ -39,11 +54,12 @@
cd ../..
-for i in $FILES; do
- check $i
-done
+while read -r file_entry; do
+ if [ -z "$file_entry" ]; then
+ continue
+ fi
-check arch/x86/include/asm/inat.h '-I "^#include [\"<]\(asm/\)*inat_types.h[\">]"'
-check arch/x86/include/asm/insn.h '-I "^#include [\"<]\(asm/\)*inat.h[\">]"'
-check arch/x86/lib/inat.c '-I "^#include [\"<]\(../include/\)*asm/insn.h[\">]"'
-check arch/x86/lib/insn.c '-I "^#include [\"<]\(../include/\)*asm/in\(at\|sn\).h[\">]"'
+ check $file_entry
+done <<EOF
+$FILES
+EOF
diff --git a/tools/objtool/warn.h b/tools/objtool/warn.h
index cbb0a02..7799f60 100644
--- a/tools/objtool/warn.h
+++ b/tools/objtool/warn.h
@@ -21,7 +21,7 @@
char *name, *str;
unsigned long name_off;
- func = find_containing_func(sec, offset);
+ func = find_func_containing(sec, offset);
if (func) {
name = func->name;
name_off = offset - func->offset;
diff --git a/tools/objtool/weak.c b/tools/objtool/weak.c
new file mode 100644
index 0000000..7843e9a
--- /dev/null
+++ b/tools/objtool/weak.c
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2020 Matt Helsley <mhelsley@vmware.com>
+ * Weak definitions necessary to compile objtool without
+ * some subcommands (e.g. check, orc).
+ */
+
+#include <stdbool.h>
+#include <errno.h>
+#include "objtool.h"
+
+#define UNSUPPORTED(name) \
+({ \
+ fprintf(stderr, "error: objtool: " name " not implemented\n"); \
+ return ENOSYS; \
+})
+
+int __weak check(struct objtool_file *file)
+{
+ UNSUPPORTED("check subcommand");
+}
+
+int __weak orc_dump(const char *_objname)
+{
+ UNSUPPORTED("orc");
+}
+
+int __weak create_orc(struct objtool_file *file)
+{
+ UNSUPPORTED("orc");
+}
+
+int __weak create_orc_sections(struct objtool_file *file)
+{
+ UNSUPPORTED("orc");
+}