diff options
| author | Jiri Slaby <jslaby@suse.cz> | 2019-10-30 08:25:45 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-11-04 21:19:25 +0100 |
| commit | b0c51f158455e31d5024100cf3580fcd88214b0e (patch) | |
| tree | 91ad1228a374988275c24f2c3f31063a1faa6610 /kernel/stacktrace.c | |
| parent | a99d8080aaf358d5d23581244e5da23b35e340b9 (diff) | |
stacktrace: Don't skip first entry on noncurrent tasks
When doing cat /proc/<PID>/stack, the output is missing the first entry.
When the current code walks the stack starting in stack_trace_save_tsk,
it skips all scheduler functions (that's OK) plus one more function. But
this one function should be skipped only for the 'current' task as it is
stack_trace_save_tsk proper.
The original code (before the common infrastructure) skipped one
function only for the 'current' task -- see save_stack_trace_tsk before
3599fe12a125. So do so also in the new infrastructure now.
Fixes: 214d8ca6ee85 ("stacktrace: Provide common infrastructure")
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michal Suchanek <msuchanek@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20191030072545.19462-1-jslaby@suse.cz
Diffstat (limited to 'kernel/stacktrace.c')
| -rw-r--r-- | kernel/stacktrace.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c index 6d1f68b7e528..c9ea7eb2cb1a 100644 --- a/kernel/stacktrace.c +++ b/kernel/stacktrace.c @@ -141,7 +141,8 @@ unsigned int stack_trace_save_tsk(struct task_struct *tsk, unsigned long *store, struct stacktrace_cookie c = { .store = store, .size = size, - .skip = skipnr + 1, + /* skip this function if they are tracing us */ + .skip = skipnr + !!(current == tsk), }; if (!try_get_task_stack(tsk)) @@ -298,7 +299,8 @@ unsigned int stack_trace_save_tsk(struct task_struct *task, struct stack_trace trace = { .entries = store, .max_entries = size, - .skip = skipnr + 1, + /* skip this function if they are tracing us */ + .skip = skipnr + !!(current == task), }; save_stack_trace_tsk(task, &trace); |