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author | Konstantin Belousov <kib@FreeBSD.org> | 2021-06-07 14:59:41 +0000 |
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committer | Konstantin Belousov <kib@FreeBSD.org> | 2021-06-15 23:00:19 +0000 |
commit | acced8b043c5df0ebd51934bca6dcae3322cf890 (patch) | |
tree | 37ae540304bf00419d63635e2aaa578cac0320cd | |
parent | afb36e289c1d96053b6063b0e548fc7d31dbd239 (diff) | |
download | src-acced8b043c5df0ebd51934bca6dcae3322cf890.tar.gz src-acced8b043c5df0ebd51934bca6dcae3322cf890.zip |
sigwait: add comment explaining EINTR/ERESTART details
Reviewed by: dchagin, markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D30675
-rw-r--r-- | sys/kern/kern_sig.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c index a2709f38c5cb..1cab25aa5a40 100644 --- a/sys/kern/kern_sig.c +++ b/sys/kern/kern_sig.c @@ -1167,6 +1167,13 @@ sys_sigwait(struct thread *td, struct sigwait_args *uap) error = kern_sigtimedwait(td, set, &ksi, NULL); if (error) { + /* + * sigwait() function shall not return EINTR, but + * the syscall does. Non-ancient libc provides the + * wrapper which hides EINTR. Otherwise, EINTR return + * is used by libthr to handle required cancellation + * point in the sigwait(). + */ if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) return (ERESTART); td->td_retval[0] = error; |