fix waitid(2) breakage
We lose the distinction between "found a PID" and "nothing, but that's not
an error" a bit too early in waitid(). Easily fixed, fortunately...
Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Fixes: 67d7ddded322 ("waitid(2): leave copyout of siginfo to syscall itself")
Tested-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/kernel/exit.c b/kernel/exit.c
index 2bbc232..608c977 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1590,9 +1590,6 @@
wo.wo_rusage = ru;
ret = do_wait(&wo);
- if (ret > 0)
- ret = 0;
-
put_pid(pid);
return ret;
}
@@ -1603,6 +1600,11 @@
struct rusage r;
struct waitid_info info = {.status = 0};
long err = kernel_waitid(which, upid, &info, options, ru ? &r : NULL);
+ int signo = 0;
+ if (err > 0) {
+ signo = SIGCHLD;
+ err = 0;
+ }
if (!err) {
if (ru && copy_to_user(ru, &r, sizeof(struct rusage)))
@@ -1612,7 +1614,7 @@
return err;
user_access_begin();
- unsafe_put_user(err ? 0 : SIGCHLD, &infop->si_signo, Efault);
+ unsafe_put_user(signo, &infop->si_signo, Efault);
unsafe_put_user(0, &infop->si_errno, Efault);
unsafe_put_user((short)info.cause, &infop->si_code, Efault);
unsafe_put_user(info.pid, &infop->si_pid, Efault);
@@ -1714,6 +1716,11 @@
struct rusage ru;
struct waitid_info info = {.status = 0};
long err = kernel_waitid(which, pid, &info, options, uru ? &ru : NULL);
+ int signo = 0;
+ if (err > 0) {
+ signo = SIGCHLD;
+ err = 0;
+ }
if (!err && uru) {
/* kernel_waitid() overwrites everything in ru */
@@ -1729,7 +1736,7 @@
return err;
user_access_begin();
- unsafe_put_user(err ? 0 : SIGCHLD, &infop->si_signo, Efault);
+ unsafe_put_user(signo, &infop->si_signo, Efault);
unsafe_put_user(0, &infop->si_errno, Efault);
unsafe_put_user((short)info.cause, &infop->si_code, Efault);
unsafe_put_user(info.pid, &infop->si_pid, Efault);