From 4f9b514b765a3057341f3236c94877d9413babc7 Mon Sep 17 00:00:00 2001 From: Thadeu Lima de Souza Cascardo Date: Mon, 27 Mar 2017 16:32:33 -0300 Subject: [PATCH] powerpc: Make /proc/self/stack always print the current stack For the current task, the kernel stack would only tell the last time the process was rescheduled, if ever. Use the current stack pointer for the current task. Otherwise, every once in a while, the stacktrace printed when reading /proc/self/stack would look like the process is running in userspace, while it's not, which some may consider as a bug. This is also consistent with some other architectures, like x86 and arm, at least. Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/stacktrace.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/stacktrace.c b/arch/powerpc/kernel/stacktrace.c index 66711958493c..d534ed901538 100644 --- a/arch/powerpc/kernel/stacktrace.c +++ b/arch/powerpc/kernel/stacktrace.c @@ -59,7 +59,14 @@ EXPORT_SYMBOL_GPL(save_stack_trace); void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) { - save_context_stack(trace, tsk->thread.ksp, tsk, 0); + unsigned long sp; + + if (tsk == current) + sp = current_stack_pointer(); + else + sp = tsk->thread.ksp; + + save_context_stack(trace, sp, tsk, 0); } EXPORT_SYMBOL_GPL(save_stack_trace_tsk);