Commit 0a1eb2d474ed ("fs/proc: Stop reporting eip and esp in /proc/PID/stat") stopped reporting eip/esp and commit fd7d56270b52 ("fs/proc: Report eip/esp in /prod/PID/stat for coredumping") reintroduced the feature to fix a regression with userspace core dump handlers (such as minicoredumper).

Because PF_DUMPCORE is only set for the primary thread, this didn't fix the original problem for secondary threads. Allow reporting the eip/esp for all threads by checking for PF_EXITING as well. This is set for all the other threads when they are killed. coredump_wait() waits for all the tasks to become inactive before proceeding to invoke a core dumper.

Fixes: fd7d56270b526ca3 ("fs/proc: Report eip/esp in /prod/PID/stat for coredumping") Reported-by: Jan Luebbe jlu@pengutronix.de Signed-off-by: John Ogness john.ogness@linutronix.de --- This is a rework of Jan's v1 patch that allows accessing eip/esp of all the threads without risk of the task still executing on a CPU.

The code chagnes are the same as v2. With v3 I included a "Fixes" tag, fixed a typo in the commit message, and Cc'd stable.

fs/proc/array.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/proc/array.c b/fs/proc/array.c index 2edbb657f859..55180501b915 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -462,7 +462,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns, * a program is not able to use ptrace(2) in that case. It is * safe because the task has stopped executing permanently. */ - if (permitted && (task->flags & PF_DUMPCORE)) { + if (permitted && (task->flags & (PF_EXITING|PF_DUMPCORE))) { if (try_get_task_stack(task)) { eip = KSTK_EIP(task); esp = KSTK_ESP(task);