Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 3b2490b..3f8e226 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -1,7 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* common.c - C code for kernel entry and exit
* Copyright (c) 2015 Andrew Lutomirski
- * GPL v2
*
* Based on asm and ptrace code by many authors. The code here originated
* in ptrace.c and signal.c.
@@ -25,12 +25,14 @@
#include <linux/uprobes.h>
#include <linux/livepatch.h>
#include <linux/syscalls.h>
+#include <linux/uaccess.h>
#include <asm/desc.h>
#include <asm/traps.h>
#include <asm/vdso.h>
-#include <linux/uaccess.h>
#include <asm/cpufeature.h>
+#include <asm/fpu/api.h>
+#include <asm/nospec-branch.h>
#define CREATE_TRACE_POINTS
#include <trace/events/syscalls.h>
@@ -70,23 +72,18 @@
struct thread_info *ti = current_thread_info();
unsigned long ret = 0;
- bool emulated = false;
u32 work;
if (IS_ENABLED(CONFIG_DEBUG_ENTRY))
BUG_ON(regs != task_pt_regs(current));
- work = READ_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY;
+ work = READ_ONCE(ti->flags);
- if (unlikely(work & _TIF_SYSCALL_EMU))
- emulated = true;
-
- if ((emulated || (work & _TIF_SYSCALL_TRACE)) &&
- tracehook_report_syscall_entry(regs))
- return -1L;
-
- if (emulated)
- return -1L;
+ if (work & (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU)) {
+ ret = tracehook_report_syscall_entry(regs);
+ if (ret || (work & _TIF_SYSCALL_EMU))
+ return -1L;
+ }
#ifdef CONFIG_SECCOMP
/*
@@ -140,7 +137,7 @@
/*
* In order to return to user mode, we need to have IRQs off with
* none of EXIT_TO_USERMODE_LOOP_FLAGS set. Several of these flags
- * can be set at any time on preemptable kernels if we have IRQs on,
+ * can be set at any time on preemptible kernels if we have IRQs on,
* so we need to loop. Disabling preemption wouldn't help: doing the
* work to clear some of the flags can sleep.
*/
@@ -196,6 +193,13 @@
if (unlikely(cached_flags & EXIT_TO_USERMODE_LOOP_FLAGS))
exit_to_usermode_loop(regs, cached_flags);
+ /* Reload ti->flags; we may have rescheduled above. */
+ cached_flags = READ_ONCE(ti->flags);
+
+ fpregs_assert_state_consistent();
+ if (unlikely(cached_flags & _TIF_NEED_FPU_LOAD))
+ switch_fpu_return();
+
#ifdef CONFIG_COMPAT
/*
* Compat syscalls set TS_COMPAT. Make sure we clear it before
@@ -212,6 +216,8 @@
#endif
user_enter_irqoff();
+
+ mds_user_clear_cpu_buffers();
}
#define SYSCALL_EXIT_WORK_FLAGS \
@@ -279,15 +285,16 @@
if (READ_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY)
nr = syscall_trace_enter(regs);
- /*
- * NB: Native and x32 syscalls are dispatched from the same
- * table. The only functional difference is the x32 bit in
- * regs->orig_ax, which changes the behavior of some syscalls.
- */
- nr &= __SYSCALL_MASK;
if (likely(nr < NR_syscalls)) {
nr = array_index_nospec(nr, NR_syscalls);
regs->ax = sys_call_table[nr](regs);
+#ifdef CONFIG_X86_X32_ABI
+ } else if (likely((nr & __X32_SYSCALL_BIT) &&
+ (nr & ~__X32_SYSCALL_BIT) < X32_NR_syscalls)) {
+ nr = array_index_nospec(nr & ~__X32_SYSCALL_BIT,
+ X32_NR_syscalls);
+ regs->ax = x32_sys_call_table[nr](regs);
+#endif
}
syscall_return_slowpath(regs);