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Date: Wed, 28 Oct 2020 16:18:16 -0400
From: Rich Felker <dalias@libc.org>
To: musl@lists.openwall.com
Message-ID: <20201028201815.GI534@brightrain.aerifal.cx>
References: <20201028201104.GH534@brightrain.aerifal.cx>
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In-Reply-To: <20201028201104.GH534@brightrain.aerifal.cx>
User-Agent: Mutt/1.5.21 (2010-09-15)
Subject: Re: [musl] bug: sem_close always unmaps semaphore regardless of ref
 count

On Wed, Oct 28, 2020 at 04:11:05PM -0400, Rich Felker wrote:
> I found this while reading the code during review of lock usage for
> MT-fork. Test case attached (can be adapted for libc-test regression
> tests, I think, or improved to be a conformance test).
> 
> Rich

> #include <semaphore.h>
> 
> int main()
> {
> 	char buf[] = "mysemXXXXXX";
> 	if (!mktemp(buf)) return 1;
> 	sem_t *sem = sem_open(buf, O_CREAT|O_EXCL, 0600);
> 	sem_open(buf, 0);
> 	sem_unlink(buf);
> 	sem_close(sem);
> 	sem_post(sem);
> }

Fixed in f70375df85d26235a45e74559afd69be59e5ff99.