diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c index 0ca4815a2938..e2095cba409f 100644 --- a/arch/x86/oprofile/backtrace.c +++ b/arch/x86/oprofile/backtrace.c @@ -77,7 +77,7 @@ void x86_backtrace(struct pt_regs * const regs, unsigned int depth) { struct frame_head *head = (struct frame_head *)frame_pointer(regs); - unsigned long stack = stack_pointer(regs); + unsigned long stack = kernel_trap_sp(regs); if (!user_mode_vm(regs)) { if (depth) diff --git a/include/asm-x86/ptrace.h b/include/asm-x86/ptrace.h index 79d5b8fcd7b1..d9e04b46a440 100644 --- a/include/asm-x86/ptrace.h +++ b/include/asm-x86/ptrace.h @@ -182,7 +182,13 @@ static inline int v8086_mode(struct pt_regs *regs) #endif } -static inline unsigned long stack_pointer(struct pt_regs *regs) +/* + * X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode + * when it traps. So regs will be the current sp. + * + * This is valid only for kernel mode traps. + */ +static inline unsigned long kernel_trap_sp(struct pt_regs *regs) { #ifdef CONFIG_X86_32 return (unsigned long)regs;