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-rw-r--r--arch/x86/kernel/Makefile1
-rw-r--r--arch/x86/kernel/static_call.c31
2 files changed, 32 insertions, 0 deletions
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index e77261db2391..de09af019e23 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -68,6 +68,7 @@ obj-y += tsc.o tsc_msr.o io_delay.o rtc.o
obj-y += pci-iommu_table.o
obj-y += resource.o
obj-y += irqflags.o
+obj-y += static_call.o
obj-y += process.o
obj-y += fpu/
diff --git a/arch/x86/kernel/static_call.c b/arch/x86/kernel/static_call.c
new file mode 100644
index 000000000000..0565825970af
--- /dev/null
+++ b/arch/x86/kernel/static_call.c
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/static_call.h>
+#include <linux/memory.h>
+#include <linux/bug.h>
+#include <asm/text-patching.h>
+
+static void __static_call_transform(void *insn, u8 opcode, void *func)
+{
+ const void *code = text_gen_insn(opcode, insn, func);
+
+ if (WARN_ONCE(*(u8 *)insn != opcode,
+ "unexpected static call insn opcode 0x%x at %pS\n",
+ opcode, insn))
+ return;
+
+ if (memcmp(insn, code, CALL_INSN_SIZE) == 0)
+ return;
+
+ text_poke_bp(insn, code, CALL_INSN_SIZE, NULL);
+}
+
+void arch_static_call_transform(void *site, void *tramp, void *func)
+{
+ mutex_lock(&text_mutex);
+
+ if (tramp)
+ __static_call_transform(tramp, JMP32_INSN_OPCODE, func);
+
+ mutex_unlock(&text_mutex);
+}
+EXPORT_SYMBOL_GPL(arch_static_call_transform);