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/arch/x86/kernel/static_call.c b/arch/x86/kernel/static_call.c
new file mode 100644
index 0000000..ca9a380
--- /dev/null
+++ b/arch/x86/kernel/static_call.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/static_call.h>
+#include <linux/memory.h>
+#include <linux/bug.h>
+#include <asm/text-patching.h>
+
+enum insn_type {
+ CALL = 0, /* site call */
+ NOP = 1, /* site cond-call */
+ JMP = 2, /* tramp / site tail-call */
+ RET = 3, /* tramp / site cond-tail-call */
+};
+
+static void __ref __static_call_transform(void *insn, enum insn_type type, void *func)
+{
+ int size = CALL_INSN_SIZE;
+ const void *code;
+
+ switch (type) {
+ case CALL:
+ code = text_gen_insn(CALL_INSN_OPCODE, insn, func);
+ break;
+
+ case NOP:
+ code = ideal_nops[NOP_ATOMIC5];
+ break;
+
+ case JMP:
+ code = text_gen_insn(JMP32_INSN_OPCODE, insn, func);
+ break;
+
+ case RET:
+ code = text_gen_insn(RET_INSN_OPCODE, insn, func);
+ size = RET_INSN_SIZE;
+ break;
+ }
+
+ if (memcmp(insn, code, size) == 0)
+ return;
+
+ if (unlikely(system_state == SYSTEM_BOOTING))
+ return text_poke_early(insn, code, size);
+
+ text_poke_bp(insn, code, size, NULL);
+}
+
+static void __static_call_validate(void *insn, bool tail)
+{
+ u8 opcode = *(u8 *)insn;
+
+ if (tail) {
+ if (opcode == JMP32_INSN_OPCODE ||
+ opcode == RET_INSN_OPCODE)
+ return;
+ } else {
+ if (opcode == CALL_INSN_OPCODE ||
+ !memcmp(insn, ideal_nops[NOP_ATOMIC5], 5))
+ return;
+ }
+
+ /*
+ * If we ever trigger this, our text is corrupt, we'll probably not live long.
+ */
+ WARN_ONCE(1, "unexpected static_call insn opcode 0x%x at %pS\n", opcode, insn);
+}
+
+static inline enum insn_type __sc_insn(bool null, bool tail)
+{
+ /*
+ * Encode the following table without branches:
+ *
+ * tail null insn
+ * -----+-------+------
+ * 0 | 0 | CALL
+ * 0 | 1 | NOP
+ * 1 | 0 | JMP
+ * 1 | 1 | RET
+ */
+ return 2*tail + null;
+}
+
+void arch_static_call_transform(void *site, void *tramp, void *func, bool tail)
+{
+ mutex_lock(&text_mutex);
+
+ if (tramp) {
+ __static_call_validate(tramp, true);
+ __static_call_transform(tramp, __sc_insn(!func, true), func);
+ }
+
+ if (IS_ENABLED(CONFIG_HAVE_STATIC_CALL_INLINE) && site) {
+ __static_call_validate(site, tail);
+ __static_call_transform(site, __sc_insn(!func, tail), func);
+ }
+
+ mutex_unlock(&text_mutex);
+}
+EXPORT_SYMBOL_GPL(arch_static_call_transform);