This will prevent a crash if the target task dies before or while
dumping its stack once we start freeing task stacks early.
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
---
arch/x86/kernel/stacktrace.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index 9ee98eefc44d..cc0826409a21 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -79,9 +79,14 @@ void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
{
+ if (!try_get_task_stack(tsk))
+ return;
+
dump_trace(tsk, NULL, NULL, 0, &save_stack_ops_nosched, trace);
if (trace->nr_entries < trace->max_entries)
trace->entries[trace->nr_entries++] = ULONG_MAX;
+
+ put_task_stack(tsk);
}
EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
--
2.7.4
--
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