From da68933e0a999fb13636653c710cca701b457ad2 Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Thu, 7 Dec 2006 02:14:02 +0100 Subject: [PATCH] [PATCH] x86-64: dump_trace() atomicity fix Fix BUG: using smp_processor_id() in preemptible [00000001] code: in backtracer on preemptible debug kernels. Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Andi Kleen --- arch/x86_64/kernel/traps.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c index eedd4e759c3a..e37b4d77d5a8 100644 --- a/arch/x86_64/kernel/traps.c +++ b/arch/x86_64/kernel/traps.c @@ -254,7 +254,7 @@ void dump_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long *stack, struct stacktrace_ops *ops, void *data) { - const unsigned cpu = smp_processor_id(); + const unsigned cpu = get_cpu(); unsigned long *irqstack_end = (unsigned long*)cpu_pda(cpu)->irqstackptr; unsigned used = 0; struct thread_info *tinfo; @@ -286,11 +286,11 @@ void dump_trace(struct task_struct *tsk, struct pt_regs *regs, MSG("Leftover inexact backtrace:"); stack = (unsigned long *)UNW_SP(&info); if (!stack) - return; + goto out; } else MSG("Full inexact backtrace again:"); } else if (call_trace >= 1) - return; + goto out; else MSG("Full inexact backtrace again:"); } else @@ -385,6 +385,8 @@ void dump_trace(struct task_struct *tsk, struct pt_regs *regs, tinfo = current_thread_info(); HANDLE_STACK (valid_stack_ptr(tinfo, stack)); #undef HANDLE_STACK +out: + put_cpu(); } EXPORT_SYMBOL(dump_trace); -- 2.20.1