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2022-01-17Merge branch 'signal-for-v5.17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull signal/exit/ptrace updates from Eric Biederman: "This set of changes deletes some dead code, makes a lot of cleanups which hopefully make the code easier to follow, and fixes bugs found along the way. The end-game which I have not yet reached yet is for fatal signals that generate coredumps to be short-circuit deliverable from complete_signal, for force_siginfo_to_task not to require changing userspace configured signal delivery state, and for the ptrace stops to always happen in locations where we can guarantee on all architectures that the all of the registers are saved and available on the stack. Removal of profile_task_ext, profile_munmap, and profile_handoff_task are the big successes for dead code removal this round. A bunch of small bug fixes are included, as most of the issues reported were small enough that they would not affect bisection so I simply added the fixes and did not fold the fixes into the changes they were fixing. There was a bug that broke coredumps piped to systemd-coredump. I dropped the change that caused that bug and replaced it entirely with something much more restrained. Unfortunately that required some rebasing. Some successes after this set of changes: There are few enough calls to do_exit to audit in a reasonable amount of time. The lifetime of struct kthread now matches the lifetime of struct task, and the pointer to struct kthread is no longer stored in set_child_tid. The flag SIGNAL_GROUP_COREDUMP is removed. The field group_exit_task is removed. Issues where task->exit_code was examined with signal->group_exit_code should been examined were fixed. There are several loosely related changes included because I am cleaning up and if I don't include them they will probably get lost. The original postings of these changes can be found at: https://lkml.kernel.org/r/87a6ha4zsd.fsf@email.froward.int.ebiederm.org https://lkml.kernel.org/r/87bl1kunjj.fsf@email.froward.int.ebiederm.org https://lkml.kernel.org/r/87r19opkx1.fsf_-_@email.froward.int.ebiederm.org I trimmed back the last set of changes to only the obviously correct once. Simply because there was less time for review than I had hoped" * 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (44 commits) ptrace/m68k: Stop open coding ptrace_report_syscall ptrace: Remove unused regs argument from ptrace_report_syscall ptrace: Remove second setting of PT_SEIZED in ptrace_attach taskstats: Cleanup the use of task->exit_code exit: Use the correct exit_code in /proc/<pid>/stat exit: Fix the exit_code for wait_task_zombie exit: Coredumps reach do_group_exit exit: Remove profile_handoff_task exit: Remove profile_task_exit & profile_munmap signal: clean up kernel-doc comments signal: Remove the helper signal_group_exit signal: Rename group_exit_task group_exec_task coredump: Stop setting signal->group_exit_task signal: Remove SIGNAL_GROUP_COREDUMP signal: During coredumps set SIGNAL_GROUP_EXIT in zap_process signal: Make coredump handling explicit in complete_signal signal: Have prepare_signal detect coredumps using signal->core_state signal: Have the oom killer detect coredumps using signal->core_state exit: Move force_uaccess back into do_exit exit: Guarantee make_task_dead leaks the tsk when calling do_task_exit ...
2021-12-13exit: Move oops specific logic from do_exit into make_task_deadEric W. Biederman
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. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-11-25futex: Remove futex_cmpxchg detectionArnd Bergmann
Now that all architectures have a working futex implementation in any configuration, remove the runtime detection code. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Acked-by: Vineet Gupta <vgupta@kernel.org> Acked-by: Max Filippov <jcmvbkbc@gmail.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Link: https://lore.kernel.org/r/20211026100432.1730393-2-arnd@kernel.org
2021-10-19futex: Fix PREEMPT_RT buildPeter Zijlstra
Mike reported that rcuwait went walk-about and is causing failures on the PREEMPT_RT builds, restore it. Reported-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2021-10-07futex: Implement sys_futex_waitv()André Almeida
Add support to wait on multiple futexes. This is the interface implemented by this syscall: futex_waitv(struct futex_waitv *waiters, unsigned int nr_futexes, unsigned int flags, struct timespec *timeout, clockid_t clockid) struct futex_waitv { __u64 val; __u64 uaddr; __u32 flags; __u32 __reserved; }; Given an array of struct futex_waitv, wait on each uaddr. The thread wakes if a futex_wake() is performed at any uaddr. The syscall returns immediately if any waiter has *uaddr != val. *timeout is an optional absolute timeout value for the operation. This syscall supports only 64bit sized timeout structs. The flags argument of the syscall should be empty, but it can be used for future extensions. Flags for shared futexes, sizes, etc. should be used on the individual flags of each waiter. __reserved is used for explicit padding and should be 0, but it might be used for future extensions. If the userspace uses 32-bit pointers, it should make sure to explicitly cast it when assigning to waitv::uaddr. Returns the array index of one of the woken futexes. There’s no given information of how many were woken, or any particular attribute of it (if it’s the first woken, if it is of the smaller index...). Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20210923171111.300673-17-andrealmeid@collabora.com
2021-10-07futex: Simplify double_lock_hb()Peter Zijlstra
We need to make sure that all requeue operations take the hash bucket locks in the same order to avoid deadlock. Simplify the current double_lock_hb implementation by making sure hb1 is always the "smallest" bucket to avoid extra checks. [André: Add commit description] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: André Almeida <andrealmeid@collabora.com> Link: https://lore.kernel.org/r/20210923171111.300673-16-andrealmeid@collabora.com
2021-10-07futex: Split out wait/wakePeter Zijlstra
Move the wait/wake bits into their own file. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: André Almeida <andrealmeid@collabora.com> Link: https://lore.kernel.org/r/20210923171111.300673-15-andrealmeid@collabora.com
2021-10-07futex: Split out requeuePeter Zijlstra
Move all the requeue bits into their own file. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: André Almeida <andrealmeid@collabora.com> Link: https://lore.kernel.org/r/20210923171111.300673-14-andrealmeid@collabora.com
2021-10-07futex: Rename mark_wake_futex()Peter Zijlstra
In order to prepare introducing these symbols into the global namespace; rename: s/mark_wake_futex/futex_wake_mark/g Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: André Almeida <andrealmeid@collabora.com> Link: https://lore.kernel.org/r/20210923171111.300673-13-andrealmeid@collabora.com
2021-10-07futex: Rename: match_futex()Peter Zijlstra
In order to prepare introducing these symbols into the global namespace; rename: s/match_futex/futex_match/g Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: André Almeida <andrealmeid@collabora.com> Link: https://lore.kernel.org/r/20210923171111.300673-12-andrealmeid@collabora.com
2021-10-07futex: Rename: hb_waiter_{inc,dec,pending}()Peter Zijlstra
In order to prepare introducing these symbols into the global namespace; rename them: s/hb_waiters_/futex_&/g Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: André Almeida <andrealmeid@collabora.com> Link: https://lore.kernel.org/r/20210923171111.300673-11-andrealmeid@collabora.com
2021-10-07futex: Split out PI futexPeter Zijlstra
Move the PI futex implementation into it's own file. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: André Almeida <andrealmeid@collabora.com> Link: https://lore.kernel.org/r/20210923171111.300673-10-andrealmeid@collabora.com
2021-10-07futex: Rename: {get,cmpxchg}_futex_value_locked()Peter Zijlstra
In order to prepare introducing these symbols into the global namespace; rename them: s/\<\([^_ ]*\)_futex_value_locked/futex_\1_value_locked/g Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: André Almeida <andrealmeid@collabora.com> Link: https://lore.kernel.org/r/20210923171111.300673-9-andrealmeid@collabora.com
2021-10-07futex: Rename hash_futex()Peter Zijlstra
In order to prepare introducing these symbols into the global namespace; rename: s/hash_futex/futex_hash/g Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: André Almeida <andrealmeid@collabora.com> Link: https://lore.kernel.org/r/20210923171111.300673-8-andrealmeid@collabora.com
2021-10-07futex: Rename __unqueue_futex()Peter Zijlstra
In order to prepare introducing these symbols into the global namespace; rename: s/__unqueue_futex/__futex_unqueue/g Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: André Almeida <andrealmeid@collabora.com> Link: https://lore.kernel.org/r/20210923171111.300673-7-andrealmeid@collabora.com
2021-10-07futex: Rename: queue_{,un}lock()Peter Zijlstra
In order to prepare introducing these symbols into the global namespace; rename them: s/queue_\(un\)*lock/futex_q_\1lock/g Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: André Almeida <andrealmeid@collabora.com> Link: https://lore.kernel.org/r/20210923171111.300673-6-andrealmeid@collabora.com
2021-10-07futex: Rename futex_wait_queue_me()Peter Zijlstra
In order to prepare introducing these symbols into the global namespace; rename them: s/futex_wait_queue_me/futex_wait_queue/g Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: André Almeida <andrealmeid@collabora.com> Link: https://lore.kernel.org/r/20210923171111.300673-5-andrealmeid@collabora.com
2021-10-07futex: Rename {,__}{,un}queue_me()Peter Zijlstra
In order to prepare introducing these symbols into the global namespace; rename them: s/\<\(__\)*\(un\)*queue_me/\1futex_\2queue/g Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: André Almeida <andrealmeid@collabora.com> Link: https://lore.kernel.org/r/20210923171111.300673-4-andrealmeid@collabora.com
2021-10-07futex: Split out syscallsPeter Zijlstra
Put the syscalls in their own little file. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: André Almeida <andrealmeid@collabora.com> Link: https://lore.kernel.org/r/20210923171111.300673-3-andrealmeid@collabora.com
2021-10-07futex: Move to kernel/futex/Peter Zijlstra
In preparation for splitup.. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: André Almeida <andrealmeid@collabora.com> Link: https://lore.kernel.org/r/20210923171111.300673-2-andrealmeid@collabora.com