Messages in this thread | | | Date | Wed, 8 Jan 2020 09:15:28 +0100 | From | Miquel Raynal <> | Subject | Re: [PATCH] mtd: sm_ftl: fix NULL pointer warning |
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Hi Arnd,
Arnd Bergmann <arnd@arndb.de> wrote on Tue, 7 Jan 2020 22:24:52 +0100:
> With gcc -O3, we get a new warning: > > In file included from arch/arm64/include/asm/processor.h:28, > from drivers/mtd/sm_ftl.c:8: > In function 'memset', > inlined from 'sm_read_sector.constprop' at drivers/mtd/sm_ftl.c:250:3: > include/linux/string.h:411:9: error: argument 1 null where non-null expected [-Werror=nonnull] > return __builtin_memset(p, c, size); > > From all I can tell, this cannot happen (the function is called > either with a NULL buffer or with a -1 block number but not both), > but adding a check makes it more robust and avoids the warning. > > Fixes: mmtom ("init/Kconfig: enable -O3 for all arches") > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > drivers/mtd/sm_ftl.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/mtd/sm_ftl.c b/drivers/mtd/sm_ftl.c > index 4744bf94ad9a..b9f272408c4d 100644 > --- a/drivers/mtd/sm_ftl.c > +++ b/drivers/mtd/sm_ftl.c > @@ -247,7 +247,8 @@ static int sm_read_sector(struct sm_ftl *ftl, > > /* FTL can contain -1 entries that are by default filled with bits */ > if (block == -1) { > - memset(buffer, 0xFF, SM_SECTOR_SIZE); > + if (buffer) > + memset(buffer, 0xFF, SM_SECTOR_SIZE); > return 0; > } >
What about a simpler form:
if (buffer && block == -1) { ...
Instead of an additional indentation level?
Thanks, Miquèl
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