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authorLinus Torvalds <torvalds@linux-foundation.org>2019-07-10 22:17:21 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-10 22:17:21 -0700
commit5450e8a316a64cddcbc15f90733ebc78aa736545 (patch)
tree176eefe81164b86efb8ab2d0dbdea5723d4c06d3 /include/uapi/asm-generic
parent29cd581b59496c26334c910a8b848baa81a6becd (diff)
parent172bb24a4f480c180bee646f6616f714ac4bcab2 (diff)
Merge tag 'pidfd-updates-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull pidfd updates from Christian Brauner: "This adds two main features. - First, it adds polling support for pidfds. This allows process managers to know when a (non-parent) process dies in a race-free way. The notification mechanism used follows the same logic that is currently used when the parent of a task is notified of a child's death. With this patchset it is possible to put pidfds in an {e}poll loop and get reliable notifications for process (i.e. thread-group) exit. - The second feature compliments the first one by making it possible to retrieve pollable pidfds for processes that were not created using CLONE_PIDFD. 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 patchsets are accompanied by selftests. It's perhaps worth noting that the work done so far and the work done in this branch for pidfd_open() and polling support do already see some adoption: - Android is in the process of backporting this work to all their LTS kernels [1] - Service managers make use of pidfd_send_signal but will need to wait until we enable waiting on pidfds for full adoption. - And projects I maintain make use of both pidfd_send_signal and CLONE_PIDFD [2] and will use polling support and pidfd_open() too" [1] https://android-review.googlesource.com/q/topic:%22pidfd+polling+support+4.9+backport%22 https://android-review.googlesource.com/q/topic:%22pidfd+polling+support+4.14+backport%22 https://android-review.googlesource.com/q/topic:%22pidfd+polling+support+4.19+backport%22 [2] https://github.com/lxc/lxc/blob/aab6e3eb73c343231cdde775db938994fc6f2803/src/lxc/start.c#L1753 * tag 'pidfd-updates-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: tests: add pidfd_open() tests arch: wire-up pidfd_open() pid: add pidfd_open() pidfd: add polling selftests pidfd: add polling support
Diffstat (limited to 'include/uapi/asm-generic')
-rw-r--r--include/uapi/asm-generic/unistd.h4
1 files changed, 3 insertions, 1 deletions
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index a87904daf103..e5684a4512c0 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -844,9 +844,11 @@ __SYSCALL(__NR_fsconfig, sys_fsconfig)
__SYSCALL(__NR_fsmount, sys_fsmount)
#define __NR_fspick 433
__SYSCALL(__NR_fspick, sys_fspick)
+#define __NR_pidfd_open 434
+__SYSCALL(__NR_pidfd_open, sys_pidfd_open)
#undef __NR_syscalls
-#define __NR_syscalls 434
+#define __NR_syscalls 435
/*
* 32 bit systems traditionally used different