[PATCH 1/2] arm64: patching: Make text-poke src pointer const.

Dylan Hatch dylanbhatch at google.com
Thu Apr 10 13:06:05 PDT 2025


Match the signature of memcpy() and enforce this envariant. Allows this
API to be interchangeable with memcpy().

Signed-off-by: Dylan Hatch <dylanbhatch at google.com>
---
 arch/arm64/include/asm/text-patching.h |  2 +-
 arch/arm64/kernel/patching.c           | 10 +++++-----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/include/asm/text-patching.h b/arch/arm64/include/asm/text-patching.h
index 587bdb91ab7a6..d61280238c81d 100644
--- a/arch/arm64/include/asm/text-patching.h
+++ b/arch/arm64/include/asm/text-patching.h
@@ -9,7 +9,7 @@ int aarch64_insn_write(void *addr, u32 insn);
 
 int aarch64_insn_write_literal_u64(void *addr, u64 val);
 void *aarch64_insn_set(void *dst, u32 insn, size_t len);
-void *aarch64_insn_copy(void *dst, void *src, size_t len);
+void *aarch64_insn_copy(void *dst, const void *src, size_t len);
 
 int aarch64_insn_patch_text_nosync(void *addr, u32 insn);
 int aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt);
diff --git a/arch/arm64/kernel/patching.c b/arch/arm64/kernel/patching.c
index 1041bc67a3eee..69494db3a578e 100644
--- a/arch/arm64/kernel/patching.c
+++ b/arch/arm64/kernel/patching.c
@@ -102,9 +102,9 @@ noinstr int aarch64_insn_write_literal_u64(void *addr, u64 val)
 	return ret;
 }
 
-typedef void text_poke_f(void *dst, void *src, size_t patched, size_t len);
+typedef void text_poke_f(void *dst, const void *src, size_t patched, size_t len);
 
-static void *__text_poke(text_poke_f func, void *addr, void *src, size_t len)
+static void *__text_poke(text_poke_f func, void *addr, const void *src, size_t len)
 {
 	unsigned long flags;
 	size_t patched = 0;
@@ -132,12 +132,12 @@ static void *__text_poke(text_poke_f func, void *addr, void *src, size_t len)
 	return addr;
 }
 
-static void text_poke_memcpy(void *dst, void *src, size_t patched, size_t len)
+static void text_poke_memcpy(void *dst, const void *src, size_t patched, size_t len)
 {
 	copy_to_kernel_nofault(dst, src + patched, len);
 }
 
-static void text_poke_memset(void *dst, void *src, size_t patched, size_t len)
+static void text_poke_memset(void *dst, const void *src, size_t patched, size_t len)
 {
 	u32 c = *(u32 *)src;
 
@@ -152,7 +152,7 @@ static void text_poke_memset(void *dst, void *src, size_t patched, size_t len)
  *
  * Useful for JITs to dump new code blocks into unused regions of RX memory.
  */
-noinstr void *aarch64_insn_copy(void *dst, void *src, size_t len)
+noinstr void *aarch64_insn_copy(void *dst, const void *src, size_t len)
 {
 	/* A64 instructions must be word aligned */
 	if ((uintptr_t)dst & 0x3)
-- 
2.49.0.604.gff1f9ca942-goog




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