Return an error from __copy_instruction and use printk to give us more productive message, since this is just an error case which we can handle it and also the BUG_ON() never tell us why and what happened,
This is related to the below bug-report. https://bugzilla.redhat.com/show_bug.cgi?id=910649 Note, this patch is for help to analyze what happened. Signed-off-by: Masami Hiramatsu <masami.hiramatsu...@hitachi.com> Cc: Frank Ch. Eigler <f...@redhat.com> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Ingo Molnar <mi...@redhat.com> Cc: "H. Peter Anvin" <h...@zytor.com> Cc: Steven Rostedt <rost...@goodmis.org> --- arch/x86/kernel/kprobes/core.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 7bfe318..a86f83d 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -353,7 +353,11 @@ int __kprobes __copy_instruction(u8 *dest, u8 *src) * have given. */ newdisp = (u8 *) src + (s64) insn.displacement.value - (u8 *) dest; - BUG_ON((s64) (s32) newdisp != newdisp); /* Sanity check. */ + if ((s64) (s32) newdisp != newdisp) { + pr_err("Kprobes error: new displacement is not fit in s32 (%llx)\n", newdisp); + pr_err("\tSrc: %p, Dest: %p, old disp: %x\n", src, dest, insn.displacement.value); + return 0; + } disp = (u8 *) dest + insn_offset_displacement(&insn); *(s32 *) disp = (s32) newdisp; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
