From: Al Viro <viro@zeniv.linux.org.uk>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Alexey Gladkov <legion@kernel.org>, Kyle Huey <me@kylehuey.com>,
Oleg Nesterov <oleg@redhat.com>,
Kees Cook <keescook@chromium.org>,
Heiko Carstens <hca@linux.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Christian Borntraeger <borntraeger@de.ibm.com>,
Alexander Gordeev <agordeev@linux.ibm.com>,
Martin Schwidefsky <schwidefsky@de.ibm.com>
Subject: Re: [PATCH 03/10] exit: Move oops specific logic from do_exit into make_task_dead
Date: Thu, 6 Jan 2022 07:08:17 +0000 [thread overview]
Message-ID: <YdaVYeHWIjAR7mhp@zeniv-ca.linux.org.uk> (raw)
In-Reply-To: <YdUxGKRcSiDy8jGg@zeniv-ca.linux.org.uk>
On Wed, Jan 05, 2022 at 05:48:08AM +0000, Al Viro wrote:
> On Wed, Dec 08, 2021 at 02:25:25PM -0600, Eric W. Biederman wrote:
> > The beginning of do_exit has become cluttered and difficult to read as
> > it is filled with checks to handle things that can only happen when
> > the kernel is operating improperly.
> >
> > Now that we have a dedicated function for cleaning up a task when the
> > kernel is operating improperly move the checks there.
>
> Umm... I would probably take profile_task_exit() crap out before that
> point.
> 1) the damn thing is dead - nothing registers notifiers there
> 2) blocking_notifier_call_chain() is not a nice thing to do on oops...
>
> I'll post a patch ripping the dead parts of kernel/profile.c out tomorrow
> morning (there's also profile_handoff_task(), equally useless these days
> and complicating things for __put_task_struct()).
Ugh... Forgot to post, sorry.
[PATCH] get rid of dead machinery in kernel/profile.c
Nothing is placed on the call chains in there, now that oprofile is
gone. Remove them, along with the hooks for calling them.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
diff --git a/include/linux/profile.h b/include/linux/profile.h
index fd18ca96f5574..88dfb0543ea63 100644
--- a/include/linux/profile.h
+++ b/include/linux/profile.h
@@ -63,26 +63,6 @@ static inline void profile_hit(int type, void *ip)
profile_hits(type, ip, 1);
}
-struct task_struct;
-struct mm_struct;
-
-/* task is in do_exit() */
-void profile_task_exit(struct task_struct * task);
-
-/* task is dead, free task struct ? Returns 1 if
- * the task was taken, 0 if the task should be freed.
- */
-int profile_handoff_task(struct task_struct * task);
-
-/* sys_munmap */
-void profile_munmap(unsigned long addr);
-
-int task_handoff_register(struct notifier_block * n);
-int task_handoff_unregister(struct notifier_block * n);
-
-int profile_event_register(enum profile_type, struct notifier_block * n);
-int profile_event_unregister(enum profile_type, struct notifier_block * n);
-
#else
#define prof_on 0
@@ -107,30 +87,6 @@ static inline void profile_hit(int type, void *ip)
return;
}
-static inline int task_handoff_register(struct notifier_block * n)
-{
- return -ENOSYS;
-}
-
-static inline int task_handoff_unregister(struct notifier_block * n)
-{
- return -ENOSYS;
-}
-
-static inline int profile_event_register(enum profile_type t, struct notifier_block * n)
-{
- return -ENOSYS;
-}
-
-static inline int profile_event_unregister(enum profile_type t, struct notifier_block * n)
-{
- return -ENOSYS;
-}
-
-#define profile_task_exit(a) do { } while (0)
-#define profile_handoff_task(a) (0)
-#define profile_munmap(a) do { } while (0)
-
#endif /* CONFIG_PROFILING */
#endif /* _LINUX_PROFILE_H */
diff --git a/kernel/exit.c b/kernel/exit.c
index f702a6a63686e..5086a5e9d02de 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -765,7 +765,6 @@ void __noreturn do_exit(long code)
preempt_count_set(PREEMPT_ENABLED);
}
- profile_task_exit(tsk);
kcov_task_exit(tsk);
coredump_task_exit(tsk);
diff --git a/kernel/fork.c b/kernel/fork.c
index 3244cc56b697d..496c0b6c8cb83 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -754,9 +754,7 @@ void __put_task_struct(struct task_struct *tsk)
delayacct_tsk_free(tsk);
put_signal_struct(tsk->signal);
sched_core_free(tsk);
-
- if (!profile_handoff_task(tsk))
- free_task(tsk);
+ free_task(tsk);
}
EXPORT_SYMBOL_GPL(__put_task_struct);
diff --git a/kernel/profile.c b/kernel/profile.c
index eb9c7f0f5ac52..37640a0bd8a3c 100644
--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -133,79 +133,6 @@ int __ref profile_init(void)
return -ENOMEM;
}
-/* Profile event notifications */
-
-static BLOCKING_NOTIFIER_HEAD(task_exit_notifier);
-static ATOMIC_NOTIFIER_HEAD(task_free_notifier);
-static BLOCKING_NOTIFIER_HEAD(munmap_notifier);
-
-void profile_task_exit(struct task_struct *task)
-{
- blocking_notifier_call_chain(&task_exit_notifier, 0, task);
-}
-
-int profile_handoff_task(struct task_struct *task)
-{
- int ret;
- ret = atomic_notifier_call_chain(&task_free_notifier, 0, task);
- return (ret == NOTIFY_OK) ? 1 : 0;
-}
-
-void profile_munmap(unsigned long addr)
-{
- blocking_notifier_call_chain(&munmap_notifier, 0, (void *)addr);
-}
-
-int task_handoff_register(struct notifier_block *n)
-{
- return atomic_notifier_chain_register(&task_free_notifier, n);
-}
-EXPORT_SYMBOL_GPL(task_handoff_register);
-
-int task_handoff_unregister(struct notifier_block *n)
-{
- return atomic_notifier_chain_unregister(&task_free_notifier, n);
-}
-EXPORT_SYMBOL_GPL(task_handoff_unregister);
-
-int profile_event_register(enum profile_type type, struct notifier_block *n)
-{
- int err = -EINVAL;
-
- switch (type) {
- case PROFILE_TASK_EXIT:
- err = blocking_notifier_chain_register(
- &task_exit_notifier, n);
- break;
- case PROFILE_MUNMAP:
- err = blocking_notifier_chain_register(
- &munmap_notifier, n);
- break;
- }
-
- return err;
-}
-EXPORT_SYMBOL_GPL(profile_event_register);
-
-int profile_event_unregister(enum profile_type type, struct notifier_block *n)
-{
- int err = -EINVAL;
-
- switch (type) {
- case PROFILE_TASK_EXIT:
- err = blocking_notifier_chain_unregister(
- &task_exit_notifier, n);
- break;
- case PROFILE_MUNMAP:
- err = blocking_notifier_chain_unregister(
- &munmap_notifier, n);
- break;
- }
-
- return err;
-}
-EXPORT_SYMBOL_GPL(profile_event_unregister);
-
#if defined(CONFIG_SMP) && defined(CONFIG_PROC_FS)
/*
* Each cpu has a pair of open-addressed hashtables for pending
diff --git a/mm/mmap.c b/mm/mmap.c
index bfb0ea164a90a..70318c2a47c39 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2928,7 +2928,6 @@ EXPORT_SYMBOL(vm_munmap);
SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len)
{
addr = untagged_addr(addr);
- profile_munmap(addr);
return __vm_munmap(addr, len, true);
}
next prev parent reply other threads:[~2022-01-06 7:08 UTC|newest]
Thread overview: 137+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-08 20:17 [PATCH 00/10] Removal of most do_exit calls Eric W. Biederman
2021-12-08 20:25 ` [PATCH 01/10] exit/s390: Remove dead reference to do_exit from copy_thread Eric W. Biederman
2021-12-12 17:48 ` Heiko Carstens
2021-12-13 14:50 ` Eric W. Biederman
2022-01-05 4:25 ` Al Viro
2021-12-08 20:25 ` [PATCH 02/10] exit: Add and use make_task_dead Eric W. Biederman
2022-01-05 5:01 ` Al Viro
2022-01-05 20:46 ` Eric W. Biederman
2022-01-05 21:53 ` Al Viro
2022-01-05 22:51 ` Linus Torvalds
2022-01-05 23:34 ` Al Viro
2021-12-08 20:25 ` [PATCH 03/10] exit: Move oops specific logic from do_exit into make_task_dead Eric W. Biederman
2022-01-05 5:48 ` Al Viro
2022-01-06 7:08 ` Al Viro [this message]
2022-01-07 3:42 ` Al Viro
2022-01-07 19:02 ` Eric W. Biederman
2022-01-07 18:59 ` Eric W. Biederman
2022-01-17 8:05 ` Christoph Hellwig
2022-01-17 12:15 ` Heiko Carstens
2022-01-17 13:17 ` Christoph Hellwig
2022-01-17 13:24 ` Arnd Bergmann
2022-01-17 13:27 ` [PATCH] microblaze: remove CONFIG_SET_FS Arnd Bergmann
2022-02-09 13:50 ` Michal Simek
2022-02-09 13:52 ` Christoph Hellwig
2022-02-09 14:03 ` Michal Simek
2022-02-09 14:40 ` Arnd Bergmann
2022-02-09 14:44 ` Michal Simek
2022-02-09 14:54 ` Arnd Bergmann
2022-02-09 23:31 ` Stafford Horne
2022-02-11 0:17 ` Stafford Horne
2022-02-11 16:59 ` Arnd Bergmann
2022-02-11 17:46 ` Linus Torvalds
2022-02-11 20:57 ` Arnd Bergmann
2022-02-11 21:10 ` Eric W. Biederman
2022-02-11 22:21 ` Stafford Horne
2022-02-14 7:41 ` Christoph Hellwig
2022-02-14 7:50 ` Christoph Hellwig
2022-02-14 16:20 ` Arnd Bergmann
2021-12-08 20:25 ` [PATCH 04/10] exit: Stop poorly open coding do_task_dead in make_task_dead Eric W. Biederman
2022-01-05 5:58 ` Al Viro
2022-01-05 22:33 ` Eric W. Biederman
2021-12-08 20:25 ` [PATCH 05/10] exit: Stop exporting do_exit Eric W. Biederman
2022-01-05 6:02 ` Al Viro
2022-01-05 22:36 ` Eric W. Biederman
2021-12-08 20:25 ` [PATCH 06/10] exit: Implement kthread_exit Eric W. Biederman
2022-01-07 2:27 ` Al Viro
2022-01-08 18:35 ` Eric W. Biederman
2022-01-08 22:44 ` David Laight
2022-01-10 15:00 ` Eric W. Biederman
2022-01-09 3:27 ` Al Viro
2022-01-10 15:05 ` Eric W. Biederman
2021-12-08 20:25 ` [PATCH 07/10] exit: Rename module_put_and_exit to module_put_and_kthread_exit Eric W. Biederman
2021-12-08 20:25 ` [PATCH 08/10] exit: Rename complete_and_exit to kthread_complete_and_exit Eric W. Biederman
2021-12-08 20:25 ` [PATCH 09/10] kthread: Ensure struct kthread is present for all kthreads Eric W. Biederman
2021-12-22 18:19 ` Nathan Chancellor
2021-12-22 18:30 ` Eric W. Biederman
2021-12-22 18:46 ` Nathan Chancellor
2021-12-22 23:22 ` Eric W. Biederman
2021-12-23 0:37 ` Nathan Chancellor
2021-12-23 1:44 ` Linus Torvalds
2021-12-23 3:34 ` Eric W. Biederman
2021-12-23 5:19 ` [PATCH] kthread: Generalize pf_io_worker so it can point to struct kthread Eric W. Biederman
2021-12-23 17:20 ` Linus Torvalds
2022-01-07 3:59 ` [PATCH 09/10] kthread: Ensure struct kthread is present for all kthreads Al Viro
2022-01-08 18:20 ` Eric W. Biederman
2021-12-08 20:25 ` [PATCH 10/10] exit/kthread: Move the exit code for kernel threads into struct kthread Eric W. Biederman
2022-01-07 3:22 ` Al Viro
2021-12-13 22:50 ` [PATCH 0/8] signal: Cleanup of the signal->flags Eric W. Biederman
2022-01-03 21:30 ` [PATCH 00/17] exit: Making task exiting a first class concept Eric W. Biederman
2022-01-03 21:32 ` [PATCH 01/17] exit: Remove profile_task_exit & profile_munmap Eric W. Biederman
2022-01-04 7:38 ` Christoph Hellwig
2022-01-07 3:48 ` Al Viro
2022-01-08 16:10 ` Eric W. Biederman
2022-01-03 21:32 ` [PATCH 02/17] exit: Coredumps reach do_group_exit Eric W. Biederman
2022-01-03 21:32 ` [PATCH 03/17] exit: Fix the exit_code for wait_task_zombie Eric W. Biederman
2022-01-03 21:32 ` [PATCH 04/17] exit: Use the correct exit_code in /proc/<pid>/stat Eric W. Biederman
2022-01-03 21:33 ` [PATCH 05/17] taskstats: Cleanup the use of task->exit_code Eric W. Biederman
2022-01-03 21:33 ` [PATCH 06/17] ptrace: Remove second setting of PT_SEIZED in ptrace_attach Eric W. Biederman
2022-01-03 21:33 ` [PATCH 07/17] ptrace: Remove unused regs argument from ptrace_report_syscall Eric W. Biederman
2022-01-03 21:33 ` [PATCH 08/17] ptrace/m68k: Stop open coding ptrace_report_syscall Eric W. Biederman
2022-01-10 15:26 ` Geert Uytterhoeven
2022-01-10 16:20 ` Al Viro
2022-01-10 16:25 ` Al Viro
2022-01-10 17:54 ` Geert Uytterhoeven
2022-01-10 20:37 ` Al Viro
2022-01-10 21:18 ` Eric W. Biederman
2022-01-11 1:33 ` Michael Schmitz
2022-01-11 22:42 ` Finn Thain
2022-01-12 0:20 ` Michael Schmitz
2022-01-12 3:32 ` Finn Thain
2022-01-12 7:54 ` Michael Schmitz
2022-01-12 7:55 ` Geert Uytterhoeven
2022-01-12 8:05 ` Michael Schmitz
2022-01-03 21:33 ` [PATCH 09/17] ptrace: Move setting/clearing ptrace_message into ptrace_stop Eric W. Biederman
2022-01-03 21:33 ` [PATCH 10/17] ptrace: Return the signal to continue with from ptrace_stop Eric W. Biederman
2022-01-03 21:33 ` [PATCH 11/17] ptrace: Separate task->ptrace_code out from task->exit_code Eric W. Biederman
2022-01-03 21:33 ` [PATCH 12/17] signal: Compute the process exit_code in get_signal Eric W. Biederman
2022-01-03 21:33 ` [PATCH 13/17] signal: Make individual tasks exiting a first class concept Eric W. Biederman
2022-01-03 21:33 ` [PATCH 14/17] signal: Remove zap_other_threads Eric W. Biederman
2022-01-03 21:33 ` [PATCH 15/17] signal: Add JOBCTL_WILL_EXIT to mark exiting tasks Eric W. Biederman
2022-01-03 21:33 ` [PATCH 16/17] signal: Record the exit_code when an exit is scheduled Eric W. Biederman
2022-01-03 21:33 ` [PATCH 17/17] signal: Always set SIGNAL_GROUP_EXIT on process exit Eric W. Biederman
2022-03-09 0:15 ` [PATCH 00/13] Removing tracehook.h Eric W. Biederman
2022-03-09 20:58 ` Linus Torvalds
2021-12-13 22:53 ` [PATCH 1/8] signal: Make SIGKILL during coredumps an explicit special case Eric W. Biederman
2022-01-04 6:30 ` Dmitry Osipenko
2022-01-04 16:18 ` Eric W. Biederman
2022-01-05 19:58 ` Eric W. Biederman
2022-01-05 21:39 ` Dmitry Osipenko
2022-01-08 18:13 ` Eric W. Biederman
2022-01-08 18:15 ` [PATCH 1/2] signal: Have prepare_signal detect coredumps using signal->core_state Eric W. Biederman
2022-01-08 18:15 ` [PATCH 2/2] signal: Make coredump handling explicit in complete_signal Eric W. Biederman
2022-01-11 8:59 ` [PATCH 1/8] signal: Make SIGKILL during coredumps an explicit special case Dmitry Osipenko
2022-01-11 17:20 ` Eric W. Biederman
2022-01-18 17:30 ` Dmitry Osipenko
2022-01-18 17:52 ` Eric W. Biederman
2022-01-18 18:01 ` Dmitry Osipenko
2022-01-04 18:44 ` Linus Torvalds
2022-01-04 19:47 ` Eric W. Biederman
2022-01-08 19:13 ` Heiko Carstens
[not found] ` <87ilurwjju.fsf@email.froward.int.ebiederm.org>
[not found] ` <87o84juwhg.fsf@email.froward.int.ebiederm.org>
2022-01-10 23:00 ` Olivier Langlois
2022-01-11 17:28 ` Eric W. Biederman
2022-01-11 18:51 ` Eric W. Biederman
2022-01-11 19:19 ` Linus Torvalds
2022-01-15 0:12 ` Eric W. Biederman
2022-01-15 19:23 ` Olivier Langlois
2022-01-17 16:09 ` Eric W. Biederman
2022-01-17 18:46 ` io_uring truncating coredumps Eric W. Biederman
2022-01-18 4:23 ` Linus Torvalds
2022-01-26 15:06 ` [PATCH 1/8] signal: Make SIGKILL during coredumps an explicit special case Olivier Langlois
2021-12-13 22:53 ` [PATCH 2/8] signal: Drop signals received after a fatal signal has been processed Eric W. Biederman
2021-12-13 22:53 ` [PATCH 3/8] signal: Have the oom killer detect coredumps using signal->core_state Eric W. Biederman
2021-12-13 22:53 ` [PATCH 4/8] signal: During coredumps set SIGNAL_GROUP_EXIT in zap_process Eric W. Biederman
2021-12-13 22:53 ` [PATCH 5/8] signal: Remove SIGNAL_GROUP_COREDUMP Eric W. Biederman
2021-12-13 22:53 ` [PATCH 6/8] coredump: Stop setting signal->group_exit_task Eric W. Biederman
2021-12-13 22:53 ` [PATCH 7/8] signal: Rename group_exit_task group_exec_task Eric W. Biederman
2021-12-13 22:53 ` [PATCH 8/8] signal: Remove the helper signal_group_exit Eric W. Biederman
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