diff options
| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2021-06-17 14:17:29 +0900 |
|---|---|---|
| committer | Masami Hiramatsu <mhiramat@kernel.org> | 2021-07-11 21:51:21 +0900 |
| commit | e4d6ef1b03f84257031acd58c208dd0ffa92548c (patch) | |
| tree | 9807b98d32be318cb1aa5316adb8f252b00076d7 | |
| parent | e62f9c5992b9176e023a28f7dc4927b234049810 (diff) | |
| download | linux-e4d6ef1b03f84257031acd58c208dd0ffa92548c.tar.gz | |
x86/kprobes: Add UNWIND_HINT_FUNC on kretprobe_trampoline()
Add UNWIND_HINT_FUNC on __kretprobe_trampoline() code so that ORC
information is generated on the __kretprobe_trampoline() correctly.
Also, this uses STACK_FRAME_NON_STANDARD_FP(), CONFIG_FRAME_POINTER-
-specific version of STACK_FRAME_NON_STANDARD().
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Andrii Nakryiko <andrii@kernel.org>
---
Changes in v9:
- Update changelog and fix comment.
- Use STACK_FRAME_NON_STANDARD_FP().
Changes in v4:
- Apply UNWIND_HINT_FUNC only if CONFIG_FRAME_POINTER=n.
| -rw-r--r-- | arch/x86/include/asm/unwind_hints.h | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/kprobes/core.c | 13 |
2 files changed, 16 insertions, 2 deletions
diff --git a/arch/x86/include/asm/unwind_hints.h b/arch/x86/include/asm/unwind_hints.h index 8e574c0afef80..8b33674288ea7 100644 --- a/arch/x86/include/asm/unwind_hints.h +++ b/arch/x86/include/asm/unwind_hints.h @@ -52,6 +52,11 @@ UNWIND_HINT sp_reg=ORC_REG_SP sp_offset=8 type=UNWIND_HINT_TYPE_FUNC .endm +#else + +#define UNWIND_HINT_FUNC \ + UNWIND_HINT(ORC_REG_SP, 8, UNWIND_HINT_TYPE_FUNC, 0) + #endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_UNWIND_HINTS_H */ diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 79cd23dba5b53..d1436d7463fd5 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -1025,6 +1025,7 @@ asm( /* We don't bother saving the ss register */ #ifdef CONFIG_X86_64 " pushq %rsp\n" + UNWIND_HINT_FUNC " pushfq\n" SAVE_REGS_STRING " movq %rsp, %rdi\n" @@ -1035,6 +1036,7 @@ asm( " popfq\n" #else " pushl %esp\n" + UNWIND_HINT_FUNC " pushfl\n" SAVE_REGS_STRING " movl %esp, %eax\n" @@ -1048,8 +1050,15 @@ asm( ".size __kretprobe_trampoline, .-__kretprobe_trampoline\n" ); NOKPROBE_SYMBOL(__kretprobe_trampoline); -STACK_FRAME_NON_STANDARD(__kretprobe_trampoline); - +/* + * __kretprobe_trampoline() skips updating frame pointer. The frame pointer + * saved in trampoline_handler() points to the real caller function's + * frame pointer. Thus the __kretprobe_trampoline() doesn't have a + * standard stack frame with CONFIG_FRAME_POINTER=y. + * Let's mark it non-standard function. Anyway, FP unwinder can correctly + * unwind without the hint. + */ +STACK_FRAME_NON_STANDARD_FP(__kretprobe_trampoline); /* * Called from __kretprobe_trampoline |