ash: jobs: Only clear gotsigchld when waiting for everything
Upstream commit:
Date: Sat, 19 May 2018 02:39:41 +0800
jobs: Only clear gotsigchld when waiting for everything
The gotsigchld flag is always cleared in dowait but not all callers
of dowait will wait for everything. In particular, when jp is set
we only wait until the set job isn't running anymore.
This patch fixes this by only clearing gotsigchld if jp is unset.
It also changes the waitcmd to actually set jp which corresponds
to the behaviour of bash/ksh93/mksh.
The only other caller of dowait that doesn't wait for everything
is the jobless reaper. This is in fact redundant now that we wait
after every simple command. This patch removes it.
Finally as every caller of dowait needs to wait until either the
given job is not running, or until all terminated jobs have been
processed, this patch moves the loop into dowait itself.
Fixes: 03876c0743a5 ("eval: Reap zombies after built-in...")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/ash.c b/shell/ash.c
index 2b13786..ff59405 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -3810,8 +3810,6 @@
static unsigned njobs; //4
/* current job */
static struct job *curjob; //lots
-/* number of presumed living untracked jobs */
-static int jobless; //4
#if 0
/* Bash has a feature: it restores termios after a successful wait for
@@ -4331,7 +4329,7 @@
#endif
static int
-dowait(int block, struct job *job)
+waitone(int block, struct job *job)
{
int pid;
int status;
@@ -4432,10 +4430,6 @@
goto out;
}
/* The process wasn't found in job list */
-#if JOBS
- if (!WIFSTOPPED(status))
- jobless--;
-#endif
out:
INT_ON;
@@ -4460,6 +4454,20 @@
return pid;
}
+static int
+dowait(int block, struct job *jp)
+{
+ int pid = block == DOWAIT_NONBLOCK ? got_sigchld : 1;
+
+ while (jp ? jp->state == JOBRUNNING : pid > 0) {
+ if (!jp)
+ got_sigchld = 0;
+ pid = waitone(block, jp);
+ }
+
+ return pid;
+}
+
#if JOBS
static void
showjob(struct job *jp, int mode)
@@ -4548,8 +4556,7 @@
TRACE(("showjobs(0x%x) called\n", mode));
/* Handle all finished jobs */
- while (dowait(DOWAIT_NONBLOCK, NULL) > 0)
- continue;
+ dowait(DOWAIT_NONBLOCK, NULL);
for (jp = curjob; jp; jp = jp->prev_job) {
if (!(mode & SHOW_CHANGED) || jp->changed) {
@@ -4666,10 +4673,10 @@
#else
dowait(DOWAIT_BLOCK_OR_SIG, NULL);
#endif
- /* if child sends us a signal *and immediately exits*,
- * dowait() returns pid > 0. Check this case,
- * not "if (dowait() < 0)"!
- */
+ /* if child sends us a signal *and immediately exits*,
+ * dowait() returns pid > 0. Check this case,
+ * not "if (dowait() < 0)"!
+ */
if (pending_sig)
goto sigout;
#if BASH_WAIT_N
@@ -4705,11 +4712,9 @@
job = getjob(*argv, 0);
}
/* loop until process terminated or stopped */
- while (job->state == JOBRUNNING) {
- dowait(DOWAIT_BLOCK_OR_SIG, NULL);
- if (pending_sig)
- goto sigout;
- }
+ dowait(DOWAIT_BLOCK_OR_SIG, NULL);
+ if (pending_sig)
+ goto sigout;
job->waited = 1;
retval = getstatus(job);
repeat: ;
@@ -5261,7 +5266,6 @@
#endif
for (jp = curjob; jp; jp = jp->prev_job)
freejob(jp);
- jobless = 0;
}
/* Called after fork(), in parent */
@@ -5272,13 +5276,8 @@
forkparent(struct job *jp, union node *n, int mode, pid_t pid)
{
TRACE(("In parent shell: child = %d\n", pid));
- if (!jp) {
- /* jp is NULL when called by openhere() for heredoc support */
- while (jobless && dowait(DOWAIT_NONBLOCK, NULL) > 0)
- continue;
- jobless++;
+ if (!jp) /* jp is NULL when called by openhere() for heredoc support */
return;
- }
#if JOBS
if (mode != FORK_NOJOB && jp->jobctl) {
int pgrp;
@@ -5357,48 +5356,39 @@
TRACE(("waitforjob(%%%d) called\n", jp ? jobno(jp) : 0));
- if (!jp) {
- int pid = got_sigchld;
-
- while (pid > 0)
- pid = dowait(DOWAIT_NONBLOCK, NULL);
-
+ /* In non-interactive shells, we _can_ get
+ * a keyboard signal here and be EINTRed, but we just loop
+ * inside dowait(), waiting for command to complete.
+ *
+ * man bash:
+ * "If bash is waiting for a command to complete and receives
+ * a signal for which a trap has been set, the trap
+ * will not be executed until the command completes."
+ *
+ * Reality is that even if trap is not set, bash
+ * will not act on the signal until command completes.
+ * Try this. sleep5intoff.c:
+ * #include <signal.h>
+ * #include <unistd.h>
+ * int main() {
+ * sigset_t set;
+ * sigemptyset(&set);
+ * sigaddset(&set, SIGINT);
+ * sigaddset(&set, SIGQUIT);
+ * sigprocmask(SIG_BLOCK, &set, NULL);
+ * sleep(5);
+ * return 0;
+ * }
+ * $ bash -c './sleep5intoff; echo hi'
+ * ^C^C^C^C <--- pressing ^C once a second
+ * $ _
+ * $ bash -c './sleep5intoff; echo hi'
+ * ^\^\^\^\hi <--- pressing ^\ (SIGQUIT)
+ * $ _
+ */
+ dowait(jp ? DOWAIT_BLOCK : DOWAIT_NONBLOCK, jp);
+ if (!jp)
return exitstatus;
- }
-
- while (jp->state == JOBRUNNING) {
- /* In non-interactive shells, we _can_ get
- * a keyboard signal here and be EINTRed,
- * but we just loop back, waiting for command to complete.
- *
- * man bash:
- * "If bash is waiting for a command to complete and receives
- * a signal for which a trap has been set, the trap
- * will not be executed until the command completes."
- *
- * Reality is that even if trap is not set, bash
- * will not act on the signal until command completes.
- * Try this. sleep5intoff.c:
- * #include <signal.h>
- * #include <unistd.h>
- * int main() {
- * sigset_t set;
- * sigemptyset(&set);
- * sigaddset(&set, SIGINT);
- * sigaddset(&set, SIGQUIT);
- * sigprocmask(SIG_BLOCK, &set, NULL);
- * sleep(5);
- * return 0;
- * }
- * $ bash -c './sleep5intoff; echo hi'
- * ^C^C^C^C <--- pressing ^C once a second
- * $ _
- * $ bash -c './sleep5intoff; echo hi'
- * ^\^\^\^\hi <--- pressing ^\ (SIGQUIT)
- * $ _
- */
- dowait(DOWAIT_BLOCK, jp);
- }
st = getstatus(jp);
#if JOBS
