Re: WARNING: kernel stack frame pointer at ffff880156a5fea0 in bash:2103 has bad value 00007ffec7d87e50

Josh Poimboeuf
2017-09-27T14:14:33Z

On Wed, Sep 27, 2017 at 08:51:22AM +0200, Richard Weinberger wrote:
> Am Mittwoch, 27. September 2017, 00:42:46 CEST schrieb Josh Poimboeuf:
> > > Here is another variant of the warning, it matches the attached .config:
> > I can take a look at it. Unfortunately, for these types of issues I
> > often need the vmlinux file to be able to make sense of the unwinder
> > dump. So if you happen to have somewhere to copy the vmlinux to, that
> > would be helpful. Or if you give me your GCC version I can try to
> > rebuild it locally.
>
> There you go:
> http://git.infradead.org/~rw/bpf_splat/vmlinux.xz

Thanks. Can you test this fix?

diff --git a/arch/x86/kernel/kprobes/common.h b/arch/x86/kernel/kprobes/common.h
index db2182d63ed0..3fc0f9a794cb 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" \