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| author | Christian Brauner <christian@brauner.io> | 2019-04-17 22:50:25 +0200 |
|---|---|---|
| committer | Christian Brauner <christian@brauner.io> | 2019-05-07 14:31:03 +0200 |
| commit | 2151ad1b067275730de1b38c7257478cae47d29e (patch) | |
| tree | 45276131c61540bef60a8b9e6fde6b8b95401b54 /kernel | |
| parent | b3e5838252665ee4cfa76b82bdf1198dca81e5be (diff) | |
| download | lwn-2151ad1b067275730de1b38c7257478cae47d29e.tar.gz lwn-2151ad1b067275730de1b38c7257478cae47d29e.zip | |
signal: support CLONE_PIDFD with pidfd_send_signal
Let pidfd_send_signal() use pidfds retrieved via CLONE_PIDFD. With this
patch pidfd_send_signal() becomes independent of procfs. This fullfils
the request made when we merged the pidfd_send_signal() patchset. The
pidfd_send_signal() syscall is now always available allowing for it to
be used by users without procfs mounted or even users without procfs
support compiled into the kernel.
Signed-off-by: Christian Brauner <christian@brauner.io>
Co-developed-by: Jann Horn <jannh@google.com>
Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: David Howells <dhowells@redhat.com>
Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.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>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/signal.c | 12 | ||||
| -rw-r--r-- | kernel/sys_ni.c | 3 |
2 files changed, 9 insertions, 6 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index f98448cf2def..1581140f2d99 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -3513,7 +3513,6 @@ SYSCALL_DEFINE2(kill, pid_t, pid, int, sig) return kill_something_info(sig, &info, pid); } -#ifdef CONFIG_PROC_FS /* * Verify that the signaler and signalee either are in the same pid namespace * or that the signaler's pid namespace is an ancestor of the signalee's pid @@ -3550,6 +3549,14 @@ static int copy_siginfo_from_user_any(kernel_siginfo_t *kinfo, siginfo_t *info) return copy_siginfo_from_user(kinfo, info); } +static struct pid *pidfd_to_pid(const struct file *file) +{ + if (file->f_op == &pidfd_fops) + return file->private_data; + + return tgid_pidfd_to_pid(file); +} + /** * sys_pidfd_send_signal - send a signal to a process through a task file * descriptor @@ -3586,7 +3593,7 @@ SYSCALL_DEFINE4(pidfd_send_signal, int, pidfd, int, sig, return -EBADF; /* Is this a pidfd? */ - pid = tgid_pidfd_to_pid(f.file); + pid = pidfd_to_pid(f.file); if (IS_ERR(pid)) { ret = PTR_ERR(pid); goto err; @@ -3620,7 +3627,6 @@ err: fdput(f); return ret; } -#endif /* CONFIG_PROC_FS */ static int do_send_specific(pid_t tgid, pid_t pid, int sig, struct kernel_siginfo *info) diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index d21f4befaea4..4d9ae5ea6caf 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -167,9 +167,6 @@ COND_SYSCALL(syslog); /* kernel/sched/core.c */ -/* kernel/signal.c */ -COND_SYSCALL(pidfd_send_signal); - /* kernel/sys.c */ COND_SYSCALL(setregid); COND_SYSCALL(setgid); |