On Fri, Jul 27, 2018 at 1:37 PM Noah Massey <noah.massey@xxxxxxxxx> 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> > Wait... aren't static variables already initialized to 0? So this makes it explicit, but no code change to generated binary, right? >> 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
