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Diffstat (limited to 'arch/x86/kernel/stacktrace.c')
-rw-r--r--arch/x86/kernel/stacktrace.c18
1 files changed, 13 insertions, 5 deletions
diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index 8dabd7bf1673..093f2ea5dd56 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -30,7 +30,7 @@ static int save_stack_address(struct stack_trace *trace, unsigned long addr,
return 0;
}
-static void __save_stack_trace(struct stack_trace *trace,
+static void noinline __save_stack_trace(struct stack_trace *trace,
struct task_struct *task, struct pt_regs *regs,
bool nosched)
{
@@ -56,6 +56,7 @@ static void __save_stack_trace(struct stack_trace *trace,
*/
void save_stack_trace(struct stack_trace *trace)
{
+ trace->skip++;
__save_stack_trace(trace, current, NULL, false);
}
EXPORT_SYMBOL_GPL(save_stack_trace);
@@ -70,6 +71,8 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
if (!try_get_task_stack(tsk))
return;
+ if (tsk == current)
+ trace->skip++;
__save_stack_trace(trace, tsk, NULL, true);
put_task_stack(tsk);
@@ -88,8 +91,9 @@ EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
} \
})
-static int __save_stack_trace_reliable(struct stack_trace *trace,
- struct task_struct *task)
+static int __always_inline
+__save_stack_trace_reliable(struct stack_trace *trace,
+ struct task_struct *task)
{
struct unwind_state state;
struct pt_regs *regs;
@@ -98,7 +102,7 @@ static int __save_stack_trace_reliable(struct stack_trace *trace,
for (unwind_start(&state, task, NULL, NULL); !unwind_done(&state);
unwind_next_frame(&state)) {
- regs = unwind_get_entry_regs(&state);
+ regs = unwind_get_entry_regs(&state, NULL);
if (regs) {
/*
* Kernel mode registers on the stack indicate an
@@ -160,8 +164,12 @@ int save_stack_trace_tsk_reliable(struct task_struct *tsk,
{
int ret;
+ /*
+ * If the task doesn't have a stack (e.g., a zombie), the stack is
+ * "reliably" empty.
+ */
if (!try_get_task_stack(tsk))
- return -EINVAL;
+ return 0;
ret = __save_stack_trace_reliable(trace, tsk);