Christian Brauner
32fcb426ec
pid: add pidfd_open() ...
This adds the pidfd_open() syscall. It allows a caller to retrieve pollable
pidfds for a process which did not get created via CLONE_PIDFD, i.e. for a
process that is created via traditional fork()/clone() calls that is only
referenced by a PID:
int pidfd = pidfd_open(1234, 0);
ret = pidfd_send_signal(pidfd, SIGSTOP, NULL, 0);
With the introduction of pidfds through CLONE_PIDFD it is possible to
created pidfds at process creation time.
However, a lot of processes get created with traditional PID-based calls
such as fork() or clone() (without CLONE_PIDFD). For these processes a
caller can currently not create a pollable pidfd. This is a problem for
Android's low memory killer (LMK) and service managers such as systemd.
Both are examples of tools that want to make use of pidfds to get reliable
notification of process exit for non-parents (pidfd polling) and race-free
signal sending (pidfd_send_signal()). They intend to switch to this API for
process supervision/management as soon as possible. Having no way to get
pollable pidfds from PID-only processes is one of the biggest blockers for
them in adopting this api. With pidfd_open() making it possible to retrieve
pidfds for PID-based processes we enable them to adopt this api.
In line with Arnd's recent changes to consolidate syscall numbers across
architectures, I have added the pidfd_open() syscall to all architectures
at the same time.
Signed-off-by: Christian Brauner <christian@brauner.io>
Reviewed-by: David Howells <dhowells@redhat.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jann Horn <jannh@google.com>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-api@vger.kernel.org
2019-06-28 12:17:55 +02:00
bpf: fix undefined behavior in narrow load handling
2019-05-13 02:05:50 +02:00
kernel/sched/psi.c: expose pressure metrics on root cgroup
2019-05-14 19:52:48 -07:00
kdb: Fix bound check compiler warning
2019-05-14 13:44:24 +01:00
DMA mapping updates for 5.2
2019-05-09 08:40:55 -07:00
mm/mmu_notifier: use correct mmu_notifier events for each invalidation
2019-05-14 09:47:49 -07:00
gcov: clang support
2019-05-14 19:52:51 -07:00
Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2019-05-19 10:58:45 -07:00
The major changes in this tracing update includes:
2019-05-15 16:05:47 -07:00
locking/rwsem: Prevent decrement of reader count before increment
2019-05-07 08:46:46 +02:00
Power management updates for 5.2-rc1
2019-05-06 19:40:31 -07:00
panic: add an option to replay all the printk message in buffer
2019-05-18 15:52:26 -07:00
The major changes in this tracing update includes:
2019-05-15 16:05:47 -07:00
kernel/sched/psi.c: expose pressure metrics on root cgroup
2019-05-14 19:52:48 -07:00
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2019-05-16 11:00:20 -07:00
The major changes in this tracing update includes:
2019-05-15 16:05:47 -07:00
Provide in-kernel headers to make extending kernel easier
2019-04-29 16:48:03 +02:00
acct_on(): don't mess with freeze protection
2019-04-04 21:04:13 -04:00
treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively
2019-04-09 14:19:06 +02:00
audit_compare_dname_path(): switch to const struct qstr *
2019-04-28 20:33:43 -04:00
audit_compare_dname_path(): switch to const struct qstr *
2019-04-28 20:33:43 -04:00
fsnotify: switch send_to_group() and ->handle_event to const struct qstr *
2019-04-26 13:51:03 -04:00
audit_compare_dname_path(): switch to const struct qstr *
2019-04-28 20:33:43 -04:00
Merge branch 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2019-05-07 20:03:32 -07:00
Merge branch 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2019-05-07 20:03:32 -07:00
backtrace-test: Simplify stack trace handling
2019-04-29 12:37:47 +02:00
kernel/compat.c: mark expected switch fall-throughs
2019-05-15 08:16:14 -07:00
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2019-05-06 14:50:46 -07:00
mm: change mm_update_next_owner() to update mm->owner with WRITE_ONCE
2019-05-14 19:52:47 -07:00
treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively
2019-04-09 14:19:06 +02:00
pidfd: add polling support
2019-06-28 12:17:55 +02:00
mm/gup: change GUP fast to use flags rather than a write 'bool'
2019-05-14 09:47:46 -07:00
Provide in-kernel headers to make extending kernel easier
2019-04-29 16:48:03 +02:00
mm/resource: Use resource_overlaps() to simplify region_intersects()
2019-04-19 12:59:36 +02:00
irq_work: Do not raise an IPI when queueing work on the local CPU
2019-04-18 14:07:52 +02:00
locking/static_key: Don't take sleeping locks in __static_key_slow_dec_deferred()
2019-04-29 08:29:21 +02:00
Remove Mysterious Macro Intended to Obscure Weird Behaviours (mmiowb())
2019-05-06 16:57:52 -07:00
power/suspend: Add function to disable secondaries for suspend
2019-05-03 19:42:41 +02:00
mm: memblock: make keeping memblock memory opt-in rather than opt-out
2019-05-14 09:47:50 -07:00
Provide in-kernel headers to make extending kernel easier
2019-04-29 16:48:03 +02:00
kprobes: Fix error check when reusing optimized probes
2019-04-16 09:38:16 +02:00
include/: refactor headers to allow kthread.h inclusion in psi_types.h
2019-05-14 19:52:48 -07:00
kernel/latencytop.c: rename clear_all_latency_tracing to clear_tsk_latency_tracing
2019-05-14 19:52:49 -07:00
kernel/Makefile: don't assume that kernel/gen_ikh_data.sh is executable
2019-05-14 19:52:47 -07:00
kernel/memremap.c: remove the unused device_private_entry_fault() export
2019-05-14 09:47:51 -07:00
Modules updates for v5.2
2019-05-14 10:55:54 -07:00
kernel/notifier.c: double register detection
2019-05-14 19:52:49 -07:00
padata: Replace padata_attr_type default_attrs field with groups
2019-04-25 22:06:11 +02:00
panic: add an option to replay all the printk message in buffer
2019-05-18 15:52:26 -07:00
pid: add pidfd_open()
2019-06-28 12:17:55 +02:00
panic/reboot: allow specifying reboot_mode for panic only
2019-05-14 19:52:51 -07:00
mm/resource: Use resource_overlaps() to simplify region_intersects()
2019-04-19 12:59:36 +02:00
rseq: Remove superfluous rseq_len from task_struct
2019-04-19 12:39:32 +02:00
audit/stable-5.2 PR 20190507
2019-05-07 19:06:04 -07:00
pidfd: add polling support
2019-06-28 12:17:55 +02:00
stacktrace: Provide common infrastructure
2019-04-29 12:37:57 +02:00
treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively
2019-04-09 14:19:06 +02:00
kernel/sys.c: prctl: fix false positive in validate_prctl_map()
2019-05-14 09:47:44 -07:00
signal: support CLONE_PIDFD with pidfd_send_signal
2019-05-07 14:31:03 +02:00
kernel/sysctl.c: fix proc_do_large_bitmap for large input buffers
2019-05-14 19:52:51 -07:00
genetlink: optionally validate strictly/dumps
2019-04-27 17:07:22 -04:00
kernel/user.c: clean up some leftover code
2019-05-14 19:52:49 -07:00
watchdog: Fix typo in comment
2019-04-18 14:05:51 +02:00
kernel/watchdog_hld.c: hard lockup message should end with a newline
2019-04-19 09:46:05 -07:00
Merge branch 'for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
2019-05-09 13:48:52 -07:00
sched/core, workqueues: Distangle worker accounting from rq lock
2019-04-16 16:55:15 +02:00
32fcb426ec