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| author | Arnd Bergmann <arnd@arndb.de> | 2018-02-22 16:56:16 +0100 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2018-03-07 02:23:57 +0100 |
| commit | 590347e4000356f55eb10b03ced2686bd74dab40 (patch) | |
| tree | 7c38592e2dfa00683559b9e5a473f2fd2a2fa0d8 /drivers/md | |
| parent | Linux 4.16-rc4 (diff) | |
| download | linux-590347e4000356f55eb10b03ced2686bd74dab40.tar.xz linux-590347e4000356f55eb10b03ced2686bd74dab40.zip | |
dm bufio: avoid false-positive Wmaybe-uninitialized warning
gcc-6.3 and earlier show a new warning after a seemingly unrelated
change to the arm64 PAGE_KERNEL definition:
In file included from drivers/md/dm-bufio.c:14:0:
drivers/md/dm-bufio.c: In function 'alloc_buffer':
include/linux/sched/mm.h:182:56: warning: 'noio_flag' may be used uninitialized in this function [-Wmaybe-uninitialized]
current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags;
^
The same warning happened earlier on linux-3.18 for MIPS and I did a
workaround for that, but now it's come back.
gcc-7 and newer are apparently smart enough to figure this out, and
other architectures don't show it, so the best I could come up with is
to rework the caller slightly in a way that makes it obvious enough to
all arm64 compilers what is happening here.
Fixes: 41acec624087 ("arm64: kpti: Make use of nG dependent on arm64_kernel_unmapped_at_el0()")
Link: https://patchwork.kernel.org/patch/9692829/
Cc: stable@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[snitzer: moved declarations inside conditional, altered vmalloc return]
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/dm-bufio.c | 16 |
1 files changed, 6 insertions, 10 deletions
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c index 414c9af54ded..aa2032fa80d4 100644 --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -386,9 +386,6 @@ static void __cache_size_refresh(void) static void *alloc_buffer_data(struct dm_bufio_client *c, gfp_t gfp_mask, enum data_mode *data_mode) { - unsigned noio_flag; - void *ptr; - if (c->block_size <= DM_BUFIO_BLOCK_SIZE_SLAB_LIMIT) { *data_mode = DATA_MODE_SLAB; return kmem_cache_alloc(DM_BUFIO_CACHE(c), gfp_mask); @@ -412,16 +409,15 @@ static void *alloc_buffer_data(struct dm_bufio_client *c, gfp_t gfp_mask, * all allocations done by this process (including pagetables) are done * as if GFP_NOIO was specified. */ + if (gfp_mask & __GFP_NORETRY) { + unsigned noio_flag = memalloc_noio_save(); + void *ptr = __vmalloc(c->block_size, gfp_mask, PAGE_KERNEL); - if (gfp_mask & __GFP_NORETRY) - noio_flag = memalloc_noio_save(); - - ptr = __vmalloc(c->block_size, gfp_mask, PAGE_KERNEL); - - if (gfp_mask & __GFP_NORETRY) memalloc_noio_restore(noio_flag); + return ptr; + } - return ptr; + return __vmalloc(c->block_size, gfp_mask, PAGE_KERNEL); } /* |