From: John Ogness <john.ogness@linutronix.de>
To: Jan Luebbe <jlu@pengutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Alexey Dobriyan <adobriyan@gmail.com>,
Andy Lutomirski <luto@kernel.org>,
kernel@pengutronix.de, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org
Subject: [PATCHv2] fs/proc: allow reporting eip/esp for all coredumping threads
Date: Wed, 29 May 2019 10:55:53 +0200 [thread overview]
Message-ID: <87y32p7i7a.fsf@linutronix.de> (raw)
In-Reply-To: 87d0k5f1g7.fsf@linutronix.de
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 the core the
core dumper.
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.
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);
--
2.11.0
next prev parent reply other threads:[~2019-05-29 8:56 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-22 16:16 [PATCH] proc: report eip and esp for all threads when coredumping Jan Luebbe
2019-05-22 17:13 ` Alexey Dobriyan
2019-05-22 18:00 ` Andrew Morton
2019-05-23 8:15 ` Jan Lübbe
2019-05-24 23:50 ` John Ogness
[not found] ` <20190525143220.e771b7915d17f22dad1438fa@linux-foundation.org>
2019-05-26 19:41 ` John Ogness
2019-05-29 8:55 ` John Ogness [this message]
2019-05-29 21:55 ` [PATCHv2] fs/proc: allow reporting eip/esp for all coredumping threads Andrew Morton
2019-05-30 0:58 ` [PATCHv3] " John Ogness
2019-05-30 1:14 ` Andrew Morton
2019-06-03 19:54 ` Jan Lübbe
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