Attachment 181726 Details for Bug 218598 – Patch to not wait on our own pid.

[patch] Patch to not wait on our own pid.

0001-Do-not-wait-for-our-own-pid.patch (text/plain), 1.22 KB, created by Dan McGregor on 2017-04-12 16:23:33 UTC

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Creator: Dan McGregor

Created: 2017-04-12 16:23:33 UTC

Size: 1.22 KB

patch

obsolete

>From 8a6aae9071313f23790c0f429f8e4ece3ca130e1 Mon Sep 17 00:00:00 2001
>From: Dan McGregor <dan.mcgregor@usask.ca>
>Date: Wed, 14 Sep 2016 09:16:25 -0600
>Subject: [PATCH] Do not wait for our own pid
>
>Fix a race condition where pwait would hang if passed its own pid. This
>could happen if kern.randompid is set and a the intended waitee pid gets
>recycled before pwait got called.
>
>Instead of deadlocking just exit immediately.
>---
> bin/pwait/pwait.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
>diff --git a/bin/pwait/pwait.c b/bin/pwait/pwait.c
>index 76989c919371..85ecc7b7b2b0 100644
>--- a/bin/pwait/pwait.c
>+++ b/bin/pwait/pwait.c
>@@ -71,6 +71,7 @@ main(int argc, char *argv[])
> 	long pid;
> 	char *s, *end;
> 	double timeout;
>+	pid_t me;
> 
> 	tflag = verbose = 0;
> 	memset(&itv, 0, sizeof(itv));
>@@ -118,6 +119,8 @@ main(int argc, char *argv[])
> 	if (argc == 0)
> 		usage();
> 
>+	me = getpid();
>+
> 	kq = kqueue();
> 	if (kq == -1)
> 		err(1, "kqueue");
>@@ -136,6 +139,10 @@ main(int argc, char *argv[])
> 			warnx("%s: bad process id", s);
> 			continue;
> 		}
>+		if (pid == me) {
>+			warnx("%s: ignoring own process id", s);
>+			continue;
>+		}
> 		duplicate = 0;
> 		for (i = 0; i < nleft; i++)
> 			if (e[i].ident == (uintptr_t)pid)
>-- 
>2.12.2.89.g49800c940
>

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Attachments on bug 218598: 181726