Module Name: src
Committed By: riastradh
Date: Sat Dec 21 19:02:31 UTC 2024
Modified Files:
src/sys/kern: kern_descrip.c
Log Message:
closef(9): Assert no ERESTART from struct fileops::fo_close.
This cannot possibly work so make sure we flag it early.
Currently the sys_close wrapper will neuter ERESTART by mapping it to
EINTR, but let's catch this mistake earlier where we have better
diagnostic information available like what the fo_close function is.
(Haven't seen the printf fire in the >decade since I added it, so I
think this KASSERT is unlikely.)
To generate a diff of this commit:
cvs rdiff -u -r1.264 -r1.265 src/sys/kern/kern_descrip.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/kern_descrip.c
diff -u src/sys/kern/kern_descrip.c:1.264 src/sys/kern/kern_descrip.c:1.265
--- src/sys/kern/kern_descrip.c:1.264 Sun Nov 10 00:11:43 2024
+++ src/sys/kern/kern_descrip.c Sat Dec 21 19:02:31 2024
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_descrip.c,v 1.264 2024/11/10 00:11:43 kre Exp $ */
+/* $NetBSD: kern_descrip.c,v 1.265 2024/12/21 19:02:31 riastradh Exp $ */
/*-
* Copyright (c) 2008, 2009, 2023 The NetBSD Foundation, Inc.
@@ -70,7 +70,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_descrip.c,v 1.264 2024/11/10 00:11:43 kre Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_descrip.c,v 1.265 2024/12/21 19:02:31 riastradh Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -857,6 +857,16 @@ closef(file_t *fp)
}
if (fp->f_ops != NULL) {
error = (*fp->f_ops->fo_close)(fp);
+
+ /*
+ * .fo_close is final, so real errors are frowned on
+ * (but allowed and passed on to close(2)), and
+ * ERESTART is absolutely forbidden because the file
+ * descriptor is gone and there is no chance to retry.
+ */
+ KASSERTMSG(error != ERESTART,
+ "file %p f_ops %p fo_close %p returned ERESTART",
+ fp, fp->f_ops, fp->f_ops->fo_close);
} else {
error = 0;
}
