On Fri, Jul 27, 2018 at 01:37:57PM -0400, Noah Massey wrote: > On Thu, Jul 26, 2018, 10:23 AM Coly Li <colyli@xxxxxxx> wrote: > > > Global variable bcache_debug is firstly initialized in bch_debug_init(), > > and destroyed in bch_debug_exit(). bch_debug_init() is called in > > bcache_init() with many other functions, if one of the previous calling > > onces failed, bcache_exit() will be called in the failure path. > > > > The problem is, if bcache_init() fails before bch_debug_init() is called, > > then in bcache_exit() when bch_debug_exit() is called to destroy global > > variable bcache_debug, at this moment bcache_debug is unndefined, then the > > test of "if (!IS_ERR_OR_NULL(bcache_debug))" might be buggy. > > > > This patch initializes global varabile bcache_debug to be NULL, to make > > the failure code path to be predictable. > > > > Signed-off-by: Coly Li <colyli@xxxxxxx> > > --- > > > > Makes sense > > Reviewed-by: Noah Massey <noah.massey@xxxxxxxxx> Aren't global variables zeroed by default anyway? > drivers/md/bcache/debug.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/md/bcache/debug.c b/drivers/md/bcache/debug.c > > index 57f8f5aeee55..24b0eb65ddec 100644 > > --- a/drivers/md/bcache/debug.c > > +++ b/drivers/md/bcache/debug.c > > @@ -17,7 +17,7 @@ > > #include <linux/random.h> > > #include <linux/seq_file.h> > > > > -struct dentry *bcache_debug; > > +struct dentry *bcache_debug = NULL; > > > > #ifdef CONFIG_BCACHE_DEBUG > > > > -- > > 2.17.1 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-bcache" in > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- Vojtech Pavlik Director SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
