From: Glauber Costa Date: Thu, 14 Aug 2008 20:33:12 +0000 (-0300) Subject: x86: set bp field in pt_regs properly X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=097a0788df71b0f3328c70ab5f4e41c27ee66817;p=linux-beck.git x86: set bp field in pt_regs properly Save rbp twice: One is for marking the stack frame, as usual (already there), and the other, to fill pt_regs properly. This is because bx comes right before the last saved register in that structure, and not bp. If the base pointer were in the place bx is today, this would not be needed. Signed-off-by: Glauber Costa Signed-off-by: Ingo Molnar --- diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index cf3a0b2d0059..25bb3f9b2552 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -667,6 +667,13 @@ END(stub_rt_sigreturn) SAVE_ARGS leaq -ARGOFFSET(%rsp),%rdi # arg1 for handler pushq %rbp + /* + * Save rbp twice: One is for marking the stack frame, as usual, and the + * other, to fill pt_regs properly. This is because bx comes right + * before the last saved register in that structure, and not bp. If the + * base pointer were in the place bx is today, this would not be needed. + */ + movq %rbp, -8(%rsp) CFI_ADJUST_CFA_OFFSET 8 CFI_REL_OFFSET rbp, 0 movq %rsp,%rbp