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-rw-r--r--arch/x86/kernel/stacktrace.c16
1 files changed, 12 insertions, 4 deletions
diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index f9dacf6d4667..6acf1d5ca832 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -89,21 +89,24 @@ __save_stack_trace_reliable(struct stack_trace *trace,
struct pt_regs *regs;
unsigned long addr;
- for (unwind_start(&state, task, NULL, NULL); !unwind_done(&state);
+ for (unwind_start(&state, task, NULL, NULL);
+ !unwind_done(&state) && !unwind_error(&state);
unwind_next_frame(&state)) {
regs = unwind_get_entry_regs(&state, NULL);
if (regs) {
+ /* Success path for user tasks */
+ if (user_mode(regs))
+ goto success;
+
/*
* Kernel mode registers on the stack indicate an
* in-kernel interrupt or exception (e.g., preemption
* or a page fault), which can make frame pointers
* unreliable.
*/
- if (!user_mode(regs))
- return -EINVAL;
- break;
+ return -EINVAL;
}
addr = unwind_get_return_address(&state);
@@ -124,6 +127,11 @@ __save_stack_trace_reliable(struct stack_trace *trace,
if (unwind_error(&state))
return -EINVAL;
+ /* Success path for non-user tasks, i.e. kthreads and idle tasks */
+ if (!(task->flags & (PF_KTHREAD | PF_IDLE)))
+ return -EINVAL;
+
+success:
if (trace->nr_entries < trace->max_entries)
trace->entries[trace->nr_entries++] = ULONG_MAX;
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