On Wed, May 08, 2019 at 09:49:03AM +0200, Peter Zijlstra wrote:
The kprobe trampolines have a FRAME_POINTER annotation that makes no sense. It marks the frame in the middle of pt_regs, at the place of saving BP.
Change it to mark the pt_regs frame as per the ENCODE_FRAME_POINTER from the respective entry_*.S.
Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org
arch/x86/kernel/kprobes/common.h | 32 +++++++++++++++++++++++--------- 1 file changed, 23 insertions(+), 9 deletions(-)
--- a/arch/x86/kernel/kprobes/common.h +++ b/arch/x86/kernel/kprobes/common.h @@ -6,14 +6,15 @@ #include <asm/asm.h> +#ifdef CONFIG_X86_64
#ifdef CONFIG_FRAME_POINTER -# define SAVE_RBP_STRING " push %" _ASM_BP "\n" \
" mov %" _ASM_SP ", %" _ASM_BP "\n"+#define ENCODE_FRAME_POINTER \
- " leaq 1(%rsp), %rbp\n"
#else -# define SAVE_RBP_STRING " push %" _ASM_BP "\n" +#define ENCODE_FRAME_POINTER #endif
+#ifdef CONFIG_FRAME_POINTER +#define ENCODE_FRAME_POINTER \
- " movl %esp, %ebp\n" \
- " andl $0x7fffffff, %ebp\n"
+#else +#define ENCODE_FRAME_POINTER +#endif
We should put these macros in a header file somewhere (including stringified versions).