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| author | Denys Vlasenko | 2020-02-18 14:37:56 +0100 |
|---|---|---|
| committer | Denys Vlasenko | 2020-02-18 15:37:22 +0100 |
| commit | 97edfc42f112a15828aaec886ef7012d24f34d5e (patch) | |
| tree | 49297967a0a7a1e1288e2113edc18d1fcbf813d8 | |
| parent | d81af7216b3305a1aac211dc847dd1c191f3b307 (diff) | |
| download | busybox-97edfc42f112a15828aaec886ef7012d24f34d5e.zip busybox-97edfc42f112a15828aaec886ef7012d24f34d5e.tar.gz | |
ash: jobs - Do not block when waiting on SIGCHLD
Upstream comment:
Date: Mon, 7 May 2018 00:40:34 +0800
jobs - Do not block when waiting on SIGCHLD
Because of the nature of SIGCHLD, the process may have already been
waited on and therefore we must be prepared for the case that wait
may block. So ensure that it doesn't by using WNOHANG.
Furthermore, multiple jobs may have exited when gotsigchld is set.
Therefore we need to wait until there are no zombies left.
Lastly, waitforjob needs to be called with interrupts off and
the original patch broke that.
Fixes: 03876c0743a5 ("eval: Reap zombies after built-in...")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
While at it, removed INT_ON/OFF in waitforjob() - it must be called
from INT_OFF region anyway.
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
| -rw-r--r-- | shell/ash.c | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/shell/ash.c b/shell/ash.c index 8047cf9..2b13786 100644 --- a/shell/ash.c +++ b/shell/ash.c @@ -5357,8 +5357,16 @@ waitforjob(struct job *jp) TRACE(("waitforjob(%%%d) called\n", jp ? jobno(jp) : 0)); - INT_OFF; - while ((jp && jp->state == JOBRUNNING) || got_sigchld) { + if (!jp) { + int pid = got_sigchld; + + while (pid > 0) + pid = dowait(DOWAIT_NONBLOCK, NULL); + + 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. @@ -5391,10 +5399,7 @@ waitforjob(struct job *jp) */ dowait(DOWAIT_BLOCK, jp); } - INT_ON; - if (!jp) - return exitstatus; st = getstatus(jp); #if JOBS if (jp->jobctl) { @@ -10369,7 +10374,6 @@ evalcommand(union node *cmd, int flags) jp = makejob(/*cmd,*/ 1); if (forkshell(jp, cmd, FORK_FG) != 0) { /* parent */ - INT_ON; TRACE(("forked child exited with %d\n", status)); break; } @@ -10387,11 +10391,9 @@ evalcommand(union node *cmd, int flags) if (cmd_is_exec && argc > 1) listsetvar(varlist.list, VEXPORT); } - if (evalbltin(cmdentry.u.cmd, argc, argv, flags)) { - if (exception_type == EXERROR && spclbltin <= 0) { - FORCE_INT_ON; - break; - } + if (evalbltin(cmdentry.u.cmd, argc, argv, flags) + && !(exception_type == EXERROR && spclbltin <= 0) + ) { raise: longjmp(exception_handler->loc, 1); } @@ -10404,6 +10406,7 @@ evalcommand(union node *cmd, int flags) } /* switch */ status = waitforjob(jp); + FORCE_INT_ON; out: if (cmd->ncmd.redirect) |