From: Linus Torvalds Date: Sat, 16 Mar 2019 20:47:14 +0000 (-0700) Subject: Merge tag 'pidfd-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner... X-Git-Tag: v5.1-rc1~6 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=a9dce6679d736cb3d612af39bab9f31f8db66f9b;p=linux-2.6-block.git Merge tag 'pidfd-v5.1-rc1' of git://git./linux/kernel/git/brauner/linux Pull pidfd system call from Christian Brauner: "This introduces the ability to use file descriptors from /proc// as stable handles on struct pid. Even if a pid is recycled the handle will not change. For a start these fds can be used to send signals to the processes they refer to. With the ability to use /proc/ fds as stable handles on struct pid we can fix a long-standing issue where after a process has exited its pid can be reused by another process. If a caller sends a signal to a reused pid it will end up signaling the wrong process. With this patchset we enable a variety of use cases. One obvious example is that we can now safely delegate an important part of process management - sending signals - to processes other than the parent of a given process by sending file descriptors around via scm rights and not fearing that the given process will have been recycled in the meantime. It also allows for easy testing whether a given process is still alive or not by sending signal 0 to a pidfd which is quite handy. There has been some interest in this feature e.g. from systems management (systemd, glibc) and container managers. I have requested and gotten comments from glibc to make sure that this syscall is suitable for their needs as well. In the future I expect it to take on most other pid-based signal syscalls. But such features are left for the future once they are needed. This has been sitting in linux-next for quite a while and has not caused any issues. It comes with selftests which verify basic functionality and also test that a recycled pid cannot be signaled via a pidfd. Jon has written about a prior version of this patchset. It should cover the basic functionality since not a lot has changed since then: https://lwn.net/Articles/773459/ The commit message for the syscall itself is extensively documenting the syscall, including it's functionality and extensibility" * tag 'pidfd-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: selftests: add tests for pidfd_send_signal() signal: add pidfd_send_signal() syscall --- a9dce6679d736cb3d612af39bab9f31f8db66f9b diff --cc arch/x86/entry/syscalls/syscall_32.tbl index 8da78595d69d,234d91df8ca6..1f9607ed087c --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@@ -396,39 -396,6 +396,40 @@@ 382 i386 pkey_free sys_pkey_free __ia32_sys_pkey_free 383 i386 statx sys_statx __ia32_sys_statx 384 i386 arch_prctl sys_arch_prctl __ia32_compat_sys_arch_prctl -385 i386 io_pgetevents sys_io_pgetevents __ia32_compat_sys_io_pgetevents +385 i386 io_pgetevents sys_io_pgetevents_time32 __ia32_compat_sys_io_pgetevents 386 i386 rseq sys_rseq __ia32_sys_rseq +# don't use numbers 387 through 392, add new calls at the end +393 i386 semget sys_semget __ia32_sys_semget +394 i386 semctl sys_semctl __ia32_compat_sys_semctl +395 i386 shmget sys_shmget __ia32_sys_shmget +396 i386 shmctl sys_shmctl __ia32_compat_sys_shmctl +397 i386 shmat sys_shmat __ia32_compat_sys_shmat +398 i386 shmdt sys_shmdt __ia32_sys_shmdt +399 i386 msgget sys_msgget __ia32_sys_msgget +400 i386 msgsnd sys_msgsnd __ia32_compat_sys_msgsnd +401 i386 msgrcv sys_msgrcv __ia32_compat_sys_msgrcv +402 i386 msgctl sys_msgctl __ia32_compat_sys_msgctl +403 i386 clock_gettime64 sys_clock_gettime __ia32_sys_clock_gettime +404 i386 clock_settime64 sys_clock_settime __ia32_sys_clock_settime +405 i386 clock_adjtime64 sys_clock_adjtime __ia32_sys_clock_adjtime +406 i386 clock_getres_time64 sys_clock_getres __ia32_sys_clock_getres +407 i386 clock_nanosleep_time64 sys_clock_nanosleep __ia32_sys_clock_nanosleep +408 i386 timer_gettime64 sys_timer_gettime __ia32_sys_timer_gettime +409 i386 timer_settime64 sys_timer_settime __ia32_sys_timer_settime +410 i386 timerfd_gettime64 sys_timerfd_gettime __ia32_sys_timerfd_gettime +411 i386 timerfd_settime64 sys_timerfd_settime __ia32_sys_timerfd_settime +412 i386 utimensat_time64 sys_utimensat __ia32_sys_utimensat +413 i386 pselect6_time64 sys_pselect6 __ia32_compat_sys_pselect6_time64 +414 i386 ppoll_time64 sys_ppoll __ia32_compat_sys_ppoll_time64 +416 i386 io_pgetevents_time64 sys_io_pgetevents __ia32_sys_io_pgetevents +417 i386 recvmmsg_time64 sys_recvmmsg __ia32_compat_sys_recvmmsg_time64 +418 i386 mq_timedsend_time64 sys_mq_timedsend __ia32_sys_mq_timedsend +419 i386 mq_timedreceive_time64 sys_mq_timedreceive __ia32_sys_mq_timedreceive +420 i386 semtimedop_time64 sys_semtimedop __ia32_sys_semtimedop +421 i386 rt_sigtimedwait_time64 sys_rt_sigtimedwait __ia32_compat_sys_rt_sigtimedwait_time64 +422 i386 futex_time64 sys_futex __ia32_sys_futex +423 i386 sched_rr_get_interval_time64 sys_sched_rr_get_interval __ia32_sys_sched_rr_get_interval + 424 i386 pidfd_send_signal sys_pidfd_send_signal __ia32_sys_pidfd_send_signal +425 i386 io_uring_setup sys_io_uring_setup __ia32_sys_io_uring_setup +426 i386 io_uring_enter sys_io_uring_enter __ia32_sys_io_uring_enter +427 i386 io_uring_register sys_io_uring_register __ia32_sys_io_uring_register diff --cc arch/x86/entry/syscalls/syscall_64.tbl index c768447f97ec,58f4b3ad4fe0..92ee0b4378d4 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@@ -343,11 -343,7 +343,12 @@@ 332 common statx __x64_sys_statx 333 common io_pgetevents __x64_sys_io_pgetevents 334 common rseq __x64_sys_rseq +# don't use numbers 387 through 423, add new calls after the last +# 'common' entry + 424 common pidfd_send_signal __x64_sys_pidfd_send_signal +425 common io_uring_setup __x64_sys_io_uring_setup +426 common io_uring_enter __x64_sys_io_uring_enter +427 common io_uring_register __x64_sys_io_uring_register # # x32-specific system call numbers start at 512 to avoid cache impact diff --cc include/uapi/asm-generic/unistd.h index bf4624efe5e6,c861e7d1053b..dee7292e1df6 --- a/include/uapi/asm-generic/unistd.h +++ b/include/uapi/asm-generic/unistd.h @@@ -780,59 -740,11 +780,61 @@@ __SC_COMP_3264(__NR_io_pgetevents, sys_ __SYSCALL(__NR_rseq, sys_rseq) #define __NR_kexec_file_load 294 __SYSCALL(__NR_kexec_file_load, sys_kexec_file_load) +/* 295 through 402 are unassigned to sync up with generic numbers, don't use */ +#if __BITS_PER_LONG == 32 +#define __NR_clock_gettime64 403 +__SYSCALL(__NR_clock_gettime64, sys_clock_gettime) +#define __NR_clock_settime64 404 +__SYSCALL(__NR_clock_settime64, sys_clock_settime) +#define __NR_clock_adjtime64 405 +__SYSCALL(__NR_clock_adjtime64, sys_clock_adjtime) +#define __NR_clock_getres_time64 406 +__SYSCALL(__NR_clock_getres_time64, sys_clock_getres) +#define __NR_clock_nanosleep_time64 407 +__SYSCALL(__NR_clock_nanosleep_time64, sys_clock_nanosleep) +#define __NR_timer_gettime64 408 +__SYSCALL(__NR_timer_gettime64, sys_timer_gettime) +#define __NR_timer_settime64 409 +__SYSCALL(__NR_timer_settime64, sys_timer_settime) +#define __NR_timerfd_gettime64 410 +__SYSCALL(__NR_timerfd_gettime64, sys_timerfd_gettime) +#define __NR_timerfd_settime64 411 +__SYSCALL(__NR_timerfd_settime64, sys_timerfd_settime) +#define __NR_utimensat_time64 412 +__SYSCALL(__NR_utimensat_time64, sys_utimensat) +#define __NR_pselect6_time64 413 +__SC_COMP(__NR_pselect6_time64, sys_pselect6, compat_sys_pselect6_time64) +#define __NR_ppoll_time64 414 +__SC_COMP(__NR_ppoll_time64, sys_ppoll, compat_sys_ppoll_time64) +#define __NR_io_pgetevents_time64 416 +__SYSCALL(__NR_io_pgetevents_time64, sys_io_pgetevents) +#define __NR_recvmmsg_time64 417 +__SC_COMP(__NR_recvmmsg_time64, sys_recvmmsg, compat_sys_recvmmsg_time64) +#define __NR_mq_timedsend_time64 418 +__SYSCALL(__NR_mq_timedsend_time64, sys_mq_timedsend) +#define __NR_mq_timedreceive_time64 419 +__SYSCALL(__NR_mq_timedreceive_time64, sys_mq_timedreceive) +#define __NR_semtimedop_time64 420 +__SYSCALL(__NR_semtimedop_time64, sys_semtimedop) +#define __NR_rt_sigtimedwait_time64 421 +__SC_COMP(__NR_rt_sigtimedwait_time64, sys_rt_sigtimedwait, compat_sys_rt_sigtimedwait_time64) +#define __NR_futex_time64 422 +__SYSCALL(__NR_futex_time64, sys_futex) +#define __NR_sched_rr_get_interval_time64 423 +__SYSCALL(__NR_sched_rr_get_interval_time64, sys_sched_rr_get_interval) +#endif + + #define __NR_pidfd_send_signal 424 + __SYSCALL(__NR_pidfd_send_signal, sys_pidfd_send_signal) +#define __NR_io_uring_setup 425 +__SYSCALL(__NR_io_uring_setup, sys_io_uring_setup) +#define __NR_io_uring_enter 426 +__SYSCALL(__NR_io_uring_enter, sys_io_uring_enter) +#define __NR_io_uring_register 427 +__SYSCALL(__NR_io_uring_register, sys_io_uring_register) #undef __NR_syscalls -#define __NR_syscalls 425 +#define __NR_syscalls 428 /* * 32 bit systems traditionally used different