Module Name: src
Committed By: martin
Date: Fri Oct 8 14:58:08 UTC 2021
Modified Files:
src/sys/kern [netbsd-9]: sys_pipe.c
Log Message:
Pull up following revision(s) (requested by hannken in ticket #1357):
sys/kern/sys_pipe.c: revision 1.157
Fix a deadlock where one thread writes to a pipe, has more data
and no space in the pipe and waits on "pipe_wcv" while the reader
is closing the pipe and waits on "pipe_draincv".
Swap the test for "PIPE_EOF" and the "cv_wait_sig()" in "pipe_write()".
PR bin/56422 "zgrep -l sometimes hangs"
To generate a diff of this commit:
cvs rdiff -u -r1.148 -r1.148.2.1 src/sys/kern/sys_pipe.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/sys_pipe.c
diff -u src/sys/kern/sys_pipe.c:1.148 src/sys/kern/sys_pipe.c:1.148.2.1
--- src/sys/kern/sys_pipe.c:1.148 Fri Apr 26 17:24:23 2019
+++ src/sys/kern/sys_pipe.c Fri Oct 8 14:58:08 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: sys_pipe.c,v 1.148 2019/04/26 17:24:23 mlelstv Exp $ */
+/* $NetBSD: sys_pipe.c,v 1.148.2.1 2021/10/08 14:58:08 martin Exp $ */
/*-
* Copyright (c) 2003, 2007, 2008, 2009 The NetBSD Foundation, Inc.
@@ -68,7 +68,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sys_pipe.c,v 1.148 2019/04/26 17:24:23 mlelstv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sys_pipe.c,v 1.148.2.1 2021/10/08 14:58:08 martin Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -1006,11 +1006,6 @@ pipe_write(file_t *fp, off_t *offset, st
break;
}
- pipeunlock(wpipe);
- error = cv_wait_sig(&wpipe->pipe_wcv, lock);
- (void)pipelock(wpipe, false);
- if (error != 0)
- break;
/*
* If read side wants to go away, we just issue a signal
* to ourselves.
@@ -1019,6 +1014,12 @@ pipe_write(file_t *fp, off_t *offset, st
error = EPIPE;
break;
}
+
+ pipeunlock(wpipe);
+ error = cv_wait_sig(&wpipe->pipe_wcv, lock);
+ (void)pipelock(wpipe, false);
+ if (error != 0)
+ break;
wakeup_state = wpipe->pipe_state;
}
}
