Commit-ID: ee213fc72fd67d0988525af501534f4cb924d1e9 Gitweb: https://git.kernel.org/tip/ee213fc72fd67d0988525af501534f4cb924d1e9 Author: Josh Poimboeuf <[email protected]> AuthorDate: Tue, 3 Oct 2017 08:51:43 -0500 Committer: Ingo Molnar <[email protected]> CommitDate: Tue, 3 Oct 2017 19:11:27 +0200
kprobes/x86: Set up frame pointer in kprobe trampoline Richard Weinberger saw an unwinder warning when running bcc's opensnoop: WARNING: kernel stack frame pointer at ffff99ef4076bea0 in opensnoop:2008 has bad value 0000000000000008 unwind stack type:0 next_sp: (null) mask:0x2 graph_idx:0 ... ffff99ef4076be88: ffff99ef4076bea0 (0xffff99ef4076bea0) ffff99ef4076be90: ffffffffac442721 (optimized_callback +0x81/0x90) ... A lockdep stack trace was initiated from inside a kprobe handler, when the unwinder noticed a bad frame pointer on the stack. The bad frame pointer is related to the fact that the kprobe optprobe trampoline doesn't save the frame pointer before calling into optimized_callback(). Reported-and-tested-by: Richard Weinberger <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Acked-by: Masami Hiramatsu <[email protected]> Cc: Ananth N Mavinakayanahalli <[email protected]> Cc: Anil S Keshavamurthy <[email protected]> Cc: David S . Miller <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/7aef2f8ecd75c2f505ef9b80490412262cf4a44c.1507038547.git.jpoim...@redhat.com Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/kernel/kprobes/common.h | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/kprobes/common.h b/arch/x86/kernel/kprobes/common.h index db2182d..3fc0f9a 100644 --- a/arch/x86/kernel/kprobes/common.h +++ b/arch/x86/kernel/kprobes/common.h @@ -3,6 +3,15 @@ /* Kprobes and Optprobes common header */ +#include <asm/asm.h> + +#ifdef CONFIG_FRAME_POINTER +# define SAVE_RBP_STRING " push %" _ASM_BP "\n" \ + " mov %" _ASM_SP ", %" _ASM_BP "\n" +#else +# define SAVE_RBP_STRING " push %" _ASM_BP "\n" +#endif + #ifdef CONFIG_X86_64 #define SAVE_REGS_STRING \ /* Skip cs, ip, orig_ax. */ \ @@ -17,7 +26,7 @@ " pushq %r10\n" \ " pushq %r11\n" \ " pushq %rbx\n" \ - " pushq %rbp\n" \ + SAVE_RBP_STRING \ " pushq %r12\n" \ " pushq %r13\n" \ " pushq %r14\n" \ @@ -48,7 +57,7 @@ " pushl %es\n" \ " pushl %ds\n" \ " pushl %eax\n" \ - " pushl %ebp\n" \ + SAVE_RBP_STRING \ " pushl %edi\n" \ " pushl %esi\n" \ " pushl %edx\n" \
