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authorTiezhu Yang <yangtiezhu@loongson.cn>2023-02-25 15:52:57 +0800
committerHuacai Chen <chenhuacai@loongson.cn>2023-02-25 22:12:17 +0800
commitfcf77d016216ae75a19078e1079c2511a6319a49 (patch)
tree23eedd8b706bcec957e3b86f20412aa3b101ca30
parent09e679c28a4def4ea8d4f618503c1d55c355ae5c (diff)
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LoongArch: Mark some assembler symbols as non-kprobe-able
Some assembler symbols are not kprobe safe, such as handle_syscall (used as syscall exception handler), *memset*/*memcpy*/*memmove* (may cause recursive exceptions), they can not be instrumented, just blacklist them for kprobing. Here is a related problem and discussion: Link: https://lore.kernel.org/lkml/20230114143859.7ccc45c1c5d9ce302113ab0a@kernel.org/ Tested-by: Jeff Xie <xiehuan09@gmail.com> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
-rw-r--r--arch/loongarch/include/asm/asm.h10
-rw-r--r--arch/loongarch/kernel/entry.S1
-rw-r--r--arch/loongarch/lib/memcpy.S3
-rw-r--r--arch/loongarch/lib/memmove.S4
-rw-r--r--arch/loongarch/lib/memset.S3
5 files changed, 21 insertions, 0 deletions
diff --git a/arch/loongarch/include/asm/asm.h b/arch/loongarch/include/asm/asm.h
index 40eea6aa469e..f591b3245def 100644
--- a/arch/loongarch/include/asm/asm.h
+++ b/arch/loongarch/include/asm/asm.h
@@ -188,4 +188,14 @@
#define PTRLOG 3
#endif
+/* Annotate a function as being unsuitable for kprobes. */
+#ifdef CONFIG_KPROBES
+#define _ASM_NOKPROBE(name) \
+ .pushsection "_kprobe_blacklist", "aw"; \
+ .quad name; \
+ .popsection
+#else
+#define _ASM_NOKPROBE(name)
+#endif
+
#endif /* __ASM_ASM_H */
diff --git a/arch/loongarch/kernel/entry.S b/arch/loongarch/kernel/entry.S
index f14ab6a0e0b0..d737e3cf42d3 100644
--- a/arch/loongarch/kernel/entry.S
+++ b/arch/loongarch/kernel/entry.S
@@ -67,6 +67,7 @@ SYM_FUNC_START(handle_syscall)
RESTORE_ALL_AND_RET
SYM_FUNC_END(handle_syscall)
+_ASM_NOKPROBE(handle_syscall)
SYM_CODE_START(ret_from_fork)
bl schedule_tail # a0 = struct task_struct *prev
diff --git a/arch/loongarch/lib/memcpy.S b/arch/loongarch/lib/memcpy.S
index 7c07d595ee89..3b7e1dec7109 100644
--- a/arch/loongarch/lib/memcpy.S
+++ b/arch/loongarch/lib/memcpy.S
@@ -17,6 +17,7 @@ SYM_FUNC_START(memcpy)
ALTERNATIVE "b __memcpy_generic", \
"b __memcpy_fast", CPU_FEATURE_UAL
SYM_FUNC_END(memcpy)
+_ASM_NOKPROBE(memcpy)
EXPORT_SYMBOL(memcpy)
@@ -41,6 +42,7 @@ SYM_FUNC_START(__memcpy_generic)
2: move a0, a3
jr ra
SYM_FUNC_END(__memcpy_generic)
+_ASM_NOKPROBE(__memcpy_generic)
/*
* void *__memcpy_fast(void *dst, const void *src, size_t n)
@@ -93,3 +95,4 @@ SYM_FUNC_START(__memcpy_fast)
3: move a0, a3
jr ra
SYM_FUNC_END(__memcpy_fast)
+_ASM_NOKPROBE(__memcpy_fast)
diff --git a/arch/loongarch/lib/memmove.S b/arch/loongarch/lib/memmove.S
index 6ffdb46da78f..b796c3d6da05 100644
--- a/arch/loongarch/lib/memmove.S
+++ b/arch/loongarch/lib/memmove.S
@@ -29,6 +29,7 @@ SYM_FUNC_START(memmove)
b rmemcpy
4: b __rmemcpy_generic
SYM_FUNC_END(memmove)
+_ASM_NOKPROBE(memmove)
EXPORT_SYMBOL(memmove)
@@ -39,6 +40,7 @@ SYM_FUNC_START(rmemcpy)
ALTERNATIVE "b __rmemcpy_generic", \
"b __rmemcpy_fast", CPU_FEATURE_UAL
SYM_FUNC_END(rmemcpy)
+_ASM_NOKPROBE(rmemcpy)
/*
* void *__rmemcpy_generic(void *dst, const void *src, size_t n)
@@ -64,6 +66,7 @@ SYM_FUNC_START(__rmemcpy_generic)
2: move a0, a3
jr ra
SYM_FUNC_END(__rmemcpy_generic)
+_ASM_NOKPROBE(__rmemcpy_generic)
/*
* void *__rmemcpy_fast(void *dst, const void *src, size_t n)
@@ -119,3 +122,4 @@ SYM_FUNC_START(__rmemcpy_fast)
3: move a0, a3
jr ra
SYM_FUNC_END(__rmemcpy_fast)
+_ASM_NOKPROBE(__rmemcpy_fast)
diff --git a/arch/loongarch/lib/memset.S b/arch/loongarch/lib/memset.S
index e7cb4ea3747d..a9eb732ab2ad 100644
--- a/arch/loongarch/lib/memset.S
+++ b/arch/loongarch/lib/memset.S
@@ -23,6 +23,7 @@ SYM_FUNC_START(memset)
ALTERNATIVE "b __memset_generic", \
"b __memset_fast", CPU_FEATURE_UAL
SYM_FUNC_END(memset)
+_ASM_NOKPROBE(memset)
EXPORT_SYMBOL(memset)
@@ -45,6 +46,7 @@ SYM_FUNC_START(__memset_generic)
2: move a0, a3
jr ra
SYM_FUNC_END(__memset_generic)
+_ASM_NOKPROBE(__memset_generic)
/*
* void *__memset_fast(void *s, int c, size_t n)
@@ -89,3 +91,4 @@ SYM_FUNC_START(__memset_fast)
3: move a0, a3
jr ra
SYM_FUNC_END(__memset_fast)
+_ASM_NOKPROBE(__memset_fast)