Re: [PATCH] sysfs: turn WARN() into pr_warn()
From: Dmitry Vyukov <dvyukov@google.com>
Date: 2018-01-22 15:04:12
Also in:
linux-wireless, lkml
On Mon, Jan 22, 2018 at 3:57 PM, Greg KH [off-list ref] wrote:
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> It's not good to crash the machine if panic_on_warn() is set just because someone made a stupid mistake of trying to create a sysfs file with the same name of an existing one. This makes the automated testing tools a lot harder to find the real bugs in the kernel. So just print a warning out and dump the stack to get the attention of the developer that they did something foolish. Then keep on trucking, as this should not be a fatal error at all. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- Dmitry, does this look good to you? If so, I'll queue it up for 4.16-rc1.
Perfect! Looks good. syzbot reacts on "WARNING:" string (+ if kernel panic due to panic_on_warn that's also obviously a problem).
quoted hunk ↗ jump to hunk
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 2b67bda2021b..3a36a48a4b3f 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c@@ -10,6 +10,7 @@ * Please see Documentation/filesystems/sysfs.txt for more information. */ +#define pr_fmt(fmt) "sysfs: " fmt #undef DEBUG #include <linux/fs.h>@@ -27,8 +28,8 @@ void sysfs_warn_dup(struct kernfs_node *parent, const char *name) if (buf) kernfs_path(parent, buf, PATH_MAX); - WARN(1, KERN_WARNING "sysfs: cannot create duplicate filename '%s/%s'\n", - buf, name); + pr_warn("cannot create duplicate filename '%s/%s'\n", buf, name); + dump_stack(); kfree(buf); }