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authorLinus Torvalds <torvalds@linux-foundation.org>2019-09-16 09:28:19 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-09-16 09:28:19 -0700
commitc17112a5c413f20188da276c138484e7127cdc84 (patch)
tree9fb0607a64e4dd49bbf405ed456221640fa972d8 /kernel/signal.c
parent4d856f72c10ecb060868ed10ff1b1453943fc6c8 (diff)
parent821cc7b0b205c0df64cce59aacc330af251fa8f7 (diff)
Merge tag 'core-process-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull pidfd/waitid updates from Christian Brauner: "This contains two features and various tests. First, it adds support for waiting on process through pidfds by adding the P_PIDFD type to the waitid() syscall. This completes the basic functionality of the pidfd api (cf. [1]). In the meantime we also have a new adition to the userspace projects that make use of the pidfd api. The qt project was nice enough to send a mail pointing out that they have a pr up to switch to the pidfd api (cf. [2]). Second, this tag contains an extension to the waitid() syscall to make it possible to wait on the current process group in a race free manner (even though the actual problem is very unlikely) by specifing 0 together with the P_PGID type. This extension traces back to a discussion on the glibc development mailing list. There are also a range of tests for the features above. Additionally, the test-suite which detected the pidfd-polling race we fixed in [3] is included in this tag" [1] https://lwn.net/Articles/794707/ [2] https://codereview.qt-project.org/c/qt/qtbase/+/108456 [3] commit b191d6491be6 ("pidfd: fix a poll race when setting exit_state") * tag 'core-process-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: waitid: Add support for waiting for the current process group tests: add pidfd poll tests tests: move common definitions and functions into pidfd.h pidfd: add pidfd_wait tests pidfd: add P_PIDFD to waitid()
Diffstat (limited to 'kernel/signal.c')
-rw-r--r--kernel/signal.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/kernel/signal.c b/kernel/signal.c
index 534fec266a33..c4da1ef56fdf 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -3678,8 +3678,11 @@ static int copy_siginfo_from_user_any(kernel_siginfo_t *kinfo, siginfo_t *info)
static struct pid *pidfd_to_pid(const struct file *file)
{
- if (file->f_op == &pidfd_fops)
- return file->private_data;
+ struct pid *pid;
+
+ pid = pidfd_pid(file);
+ if (!IS_ERR(pid))
+ return pid;
return tgid_pidfd_to_pid(file);
}