From: ebiederm@xmission.com (Eric W. Biederman)
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
Michael Schmitz <schmitzmic@gmail.com>,
linux-arch <linux-arch@vger.kernel.org>,
Jens Axboe <axboe@kernel.dk>, Oleg Nesterov <oleg@redhat.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Richard Henderson <rth@twiddle.net>,
Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
Matt Turner <mattst88@gmail.com>,
alpha <linux-alpha@vger.kernel.org>,
Geert Uytterhoeven <geert@linux-m68k.org>,
linux-m68k <linux-m68k@lists.linux-m68k.org>,
Arnd Bergmann <arnd@kernel.org>,
Ley Foon Tan <ley.foon.tan@intel.com>, Tejun Heo <tj@kernel.org>,
Kees Cook <keescook@chromium.org>
Subject: [PATCH 6/9] signal: Fold do_group_exit into get_signal fixing io_uring threads
Date: Thu, 24 Jun 2021 14:02:16 -0500 [thread overview]
Message-ID: <874kdn6q87.fsf_-_@disp2133> (raw)
In-Reply-To: <875yy3850g.fsf_-_@disp2133> (Eric W. Biederman's message of "Thu, 24 Jun 2021 13:57:35 -0500")
Forld do_group_exit into get_signal as it is the last caller.
Move the group_exit logic above the PF_IO_WORKER exit, ensuring
that if an PF_IO_WORKER catches SIGKILL every thread in
the thread group will exit not just the the PF_IO_WORKER.
Now that the information is easily available only set PF_SIGNALED
when it was a signal that caused the exit.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
include/linux/sched/task.h | 1 -
kernel/exit.c | 31 -------------------------------
kernel/signal.c | 35 +++++++++++++++++++++++++----------
3 files changed, 25 insertions(+), 42 deletions(-)
diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index ef02be869cf2..45525512e3d0 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -77,7 +77,6 @@ static inline void exit_thread(struct task_struct *tsk)
{
}
#endif
-extern void do_group_exit(int);
extern void exit_files(struct task_struct *);
extern void exit_itimers(struct signal_struct *);
diff --git a/kernel/exit.c b/kernel/exit.c
index 921519d80b56..635f434122b7 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -892,37 +892,6 @@ SYSCALL_DEFINE1(exit, int, error_code)
do_exit((error_code&0xff)<<8);
}
-/*
- * Take down every thread in the group. This is called by fatal signals
- * as well as by sys_exit_group (below).
- */
-void
-do_group_exit(int exit_code)
-{
- struct signal_struct *sig = current->signal;
-
- BUG_ON(exit_code & 0x80); /* core dumps don't get here */
-
- if (signal_group_exit(sig))
- exit_code = sig->group_exit_code;
- else if (!thread_group_empty(current)) {
- struct sighand_struct *const sighand = current->sighand;
-
- spin_lock_irq(&sighand->siglock);
- if (signal_group_exit(sig))
- /* Another thread got here before we took the lock. */
- exit_code = sig->group_exit_code;
- else {
- sig->group_exit_code = exit_code;
- sig->flags = SIGNAL_GROUP_EXIT;
- zap_other_threads(current);
- }
- spin_unlock_irq(&sighand->siglock);
- }
-
- do_exit(exit_code);
- /* NOTREACHED */
-}
/*
* this kills every thread in the thread group. Note that any externally
diff --git a/kernel/signal.c b/kernel/signal.c
index c79c010ca5f3..95a076af600a 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2646,6 +2646,7 @@ bool get_signal(struct ksignal *ksig)
{
struct sighand_struct *sighand = current->sighand;
struct signal_struct *signal = current->signal;
+ int exit_code;
int signr;
if (unlikely(current->task_works))
@@ -2848,8 +2849,6 @@ bool get_signal(struct ksignal *ksig)
/*
* Anything else is fatal, maybe with a core dump.
*/
- current->flags |= PF_SIGNALED;
-
if (sig_kernel_coredump(signr)) {
if (print_fatal_signals)
print_fatal_signal(ksig->info.si_signo);
@@ -2857,14 +2856,33 @@ bool get_signal(struct ksignal *ksig)
/*
* If it was able to dump core, this kills all
* other threads in the group and synchronizes with
- * their demise. If we lost the race with another
- * thread getting here, it set group_exit_code
- * first and our do_group_exit call below will use
- * that value and ignore the one we pass it.
+ * their demise. If another thread makes it
+ * to do_coredump first, it will set group_exit_code
+ * which will be passed to do_exit.
*/
do_coredump(&ksig->info);
}
+ /*
+ * Death signals, no core dump.
+ */
+ exit_code = signr;
+ if (signal_group_exit(signal)) {
+ exit_code = signal->group_exit_code;
+ } else {
+ spin_lock_irq(&sighand->siglock);
+ if (signal_group_exit(signal)) {
+ /* Another thread got here before we took the lock. */
+ exit_code = signal->group_exit_code;
+ } else {
+ start_group_exit_locked(signal, exit_code);
+ }
+ spin_unlock_irq(&sighand->siglock);
+ }
+
+ if (exit_code & 0x7f)
+ current->flags |= PF_SIGNALED;
+
/*
* PF_IO_WORKER threads will catch and exit on fatal signals
* themselves. They have cleanup that must be performed, so
@@ -2873,10 +2891,7 @@ bool get_signal(struct ksignal *ksig)
if (current->flags & PF_IO_WORKER)
goto out;
- /*
- * Death signals, no core dump.
- */
- do_group_exit(ksig->info.si_signo);
+ do_exit(exit_code);
/* NOTREACHED */
}
spin_unlock_irq(&sighand->siglock);
--
2.20.1
next prev parent reply other threads:[~2021-06-24 19:02 UTC|newest]
Thread overview: 112+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-10 20:57 Kernel stack read with PTRACE_EVENT_EXIT and io_uring threads Eric W. Biederman
2021-06-10 22:04 ` Linus Torvalds
2021-06-11 21:39 ` Eric W. Biederman
2021-06-11 23:26 ` Linus Torvalds
2021-06-13 21:54 ` Eric W. Biederman
2021-06-13 22:18 ` Linus Torvalds
2021-06-14 2:05 ` Michael Schmitz
2021-06-14 5:03 ` Michael Schmitz
2021-06-14 16:26 ` Eric W. Biederman
2021-06-14 22:26 ` Michael Schmitz
2021-06-15 19:30 ` Eric W. Biederman
2021-06-15 19:36 ` [PATCH] alpha: Add extra switch_stack frames in exit, exec, and kernel threads Eric W. Biederman
2021-06-15 22:02 ` Linus Torvalds
2021-06-16 16:32 ` Eric W. Biederman
2021-06-16 18:29 ` [PATCH 0/2] alpha/ptrace: Improved switch_stack handling Eric W. Biederman
2021-06-16 18:31 ` [PATCH 1/2] alpha/ptrace: Record and handle the absence of switch_stack Eric W. Biederman
2021-06-16 20:00 ` Linus Torvalds
2021-06-16 20:37 ` Linus Torvalds
2021-06-16 20:57 ` Eric W. Biederman
2021-06-16 21:02 ` Al Viro
2021-06-16 21:08 ` Linus Torvalds
2021-06-16 20:42 ` Eric W. Biederman
2021-06-16 20:17 ` Al Viro
2021-06-21 2:01 ` Michael Schmitz
2021-06-21 2:17 ` Linus Torvalds
2021-06-21 3:18 ` Michael Schmitz
2021-06-21 3:37 ` Linus Torvalds
2021-06-21 4:08 ` Michael Schmitz
2021-06-21 3:44 ` Al Viro
2021-06-21 5:31 ` Michael Schmitz
2021-06-21 2:27 ` Al Viro
2021-06-21 3:36 ` Michael Schmitz
2021-06-16 18:32 ` [PATCH 2/2] alpha/ptrace: Add missing switch_stack frames Eric W. Biederman
2021-06-16 20:25 ` Al Viro
2021-06-16 20:28 ` Al Viro
2021-06-16 20:49 ` Eric W. Biederman
2021-06-16 20:54 ` Al Viro
2021-06-16 20:47 ` Eric W. Biederman
2021-06-16 20:55 ` Al Viro
2021-06-16 20:50 ` [PATCH] alpha: Add extra switch_stack frames in exit, exec, and kernel threads Al Viro
2021-06-15 20:56 ` Kernel stack read with PTRACE_EVENT_EXIT and io_uring threads Michael Schmitz
2021-06-16 0:23 ` Finn Thain
2021-06-15 21:58 ` Linus Torvalds
2021-06-16 15:06 ` Eric W. Biederman
2021-06-21 13:54 ` Al Viro
2021-06-21 14:16 ` Al Viro
2021-06-21 16:50 ` Eric W. Biederman
2021-06-21 23:05 ` Al Viro
2021-06-22 16:39 ` Eric W. Biederman
2021-06-21 15:38 ` Linus Torvalds
2021-06-21 18:59 ` Al Viro
2021-06-21 19:22 ` Linus Torvalds
2021-06-21 19:45 ` Al Viro
2021-06-21 23:14 ` Linus Torvalds
2021-06-21 23:23 ` Al Viro
2021-06-21 23:36 ` Linus Torvalds
2021-06-22 21:02 ` Eric W. Biederman
2021-06-22 21:48 ` Michael Schmitz
2021-06-23 5:26 ` Michael Schmitz
2021-06-23 14:36 ` Eric W. Biederman
2021-06-22 0:01 ` Michael Schmitz
2021-06-22 20:04 ` Michael Schmitz
2021-06-22 20:18 ` Al Viro
2021-06-22 21:57 ` Michael Schmitz
2021-06-21 20:03 ` Eric W. Biederman
2021-06-21 23:15 ` Linus Torvalds
2021-06-22 20:52 ` Eric W. Biederman
2021-06-23 0:41 ` Linus Torvalds
2021-06-23 14:33 ` Eric W. Biederman
2021-06-24 18:57 ` [PATCH 0/9] Refactoring exit Eric W. Biederman
2021-06-24 18:59 ` [PATCH 1/9] signal/sh: Use force_sig(SIGKILL) instead of do_group_exit(SIGKILL) Eric W. Biederman
2021-06-24 18:59 ` [PATCH 2/9] signal/seccomp: Refactor seccomp signal and coredump generation Eric W. Biederman
2021-06-26 3:17 ` Kees Cook
2021-06-28 19:21 ` Eric W. Biederman
2021-06-28 14:34 ` [signal/seccomp] 3fdd8c68c2: kernel-selftests.seccomp.seccomp_bpf.fail kernel test robot
2021-06-24 19:00 ` [PATCH 3/9] signal/seccomp: Dump core when there is only one live thread Eric W. Biederman
2021-06-26 3:20 ` Kees Cook
2021-06-24 19:01 ` [PATCH 4/9] signal: Factor start_group_exit out of complete_signal Eric W. Biederman
2021-06-24 20:04 ` Linus Torvalds
2021-06-25 8:47 ` kernel test robot
2021-06-26 3:24 ` Kees Cook
2021-06-24 19:01 ` [PATCH 5/9] signal/group_exit: Use start_group_exit in place of do_group_exit Eric W. Biederman
2021-06-26 3:35 ` Kees Cook
2021-06-24 19:02 ` Eric W. Biederman [this message]
2021-06-26 3:42 ` [PATCH 6/9] signal: Fold do_group_exit into get_signal fixing io_uring threads Kees Cook
2021-06-28 19:25 ` Eric W. Biederman
2021-06-24 19:02 ` [PATCH 7/9] signal: Make individual tasks exiting a first class concept Eric W. Biederman
2021-06-24 20:11 ` Linus Torvalds
2021-06-24 21:37 ` Eric W. Biederman
2021-06-24 19:03 ` [PATCH 8/9] signal/task_exit: Use start_task_exit in place of do_exit Eric W. Biederman
2021-06-26 5:56 ` Kees Cook
2021-06-24 19:03 ` [PATCH 9/9] signal: Move PTRACE_EVENT_EXIT into get_signal Eric W. Biederman
2021-06-24 22:45 ` [PATCH 0/9] Refactoring exit Al Viro
2021-06-27 22:13 ` Al Viro
2021-06-27 22:59 ` Michael Schmitz
2021-06-28 7:31 ` Geert Uytterhoeven
2021-06-28 16:20 ` Eric W. Biederman
2021-06-28 17:14 ` Michael Schmitz
2021-06-28 19:17 ` Geert Uytterhoeven
2021-06-28 20:13 ` Michael Schmitz
2021-06-28 21:18 ` Geert Uytterhoeven
2021-06-28 23:42 ` Michael Schmitz
2021-06-29 20:28 ` [CFT][PATCH] exit/bdflush: Remove the deprecated bdflush system call Eric W. Biederman
2021-06-29 21:45 ` Michael Schmitz
2021-06-30 8:24 ` Geert Uytterhoeven
2021-06-30 8:37 ` Arnd Bergmann
2021-06-30 12:30 ` Cyril Hrubis
2021-06-28 19:02 ` [PATCH 0/9] Refactoring exit Eric W. Biederman
2021-06-21 19:24 ` Kernel stack read with PTRACE_EVENT_EXIT and io_uring threads Al Viro
2021-06-21 23:24 ` Michael Schmitz
2021-06-16 7:38 ` Geert Uytterhoeven
2021-06-16 19:40 ` Michael Schmitz
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