| Message ID | 1458293329-5519-1-git-send-email-acourbot@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Mar 18, 2016 at 06:28:49PM +0900, Alexandre Courbot wrote: > Commit 19e6e5e5392b ("ARM: 8547/1: dma-mapping: store buffer > information") allocates a structure meant for internal buffer management > with the GFP flags of the buffer itself. This can trigger the following > safeguard in the slab/slub allocator: > > if (unlikely(flags & GFP_SLAB_BUG_MASK)) { > pr_emerg("gfp: %u\n", flags & GFP_SLAB_BUG_MASK); > BUG(); > } > > Fix this by filtering the flags that make the slab allocator unhappy. > > Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> > Cc: Rabin Vincent <rabin@rab.in> > --- > Changes since v1: > - Filter flags that may cause problem instead of forcing GFP_KERNEL > (and risk sleeping in atomic context), as suggested by Rabin. Acked-by: Rabin Vincent <rabin@rab.in> Thanks.
On Fri, Mar 18, 2016 at 06:28:49PM +0900, Alexandre Courbot wrote: > Commit 19e6e5e5392b ("ARM: 8547/1: dma-mapping: store buffer > information") allocates a structure meant for internal buffer management > with the GFP flags of the buffer itself. This can trigger the following > safeguard in the slab/slub allocator: > > if (unlikely(flags & GFP_SLAB_BUG_MASK)) { > pr_emerg("gfp: %u\n", flags & GFP_SLAB_BUG_MASK); > BUG(); > } > > Fix this by filtering the flags that make the slab allocator unhappy. > > Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> > Cc: Rabin Vincent <rabin@rab.in> Looks much better than the original. Please send it to the patch system, thanks.
On Fri, Mar 18, 2016 at 7:58 PM, Russell King - ARM Linux <linux@arm.linux.org.uk> wrote: > On Fri, Mar 18, 2016 at 06:28:49PM +0900, Alexandre Courbot wrote: >> Commit 19e6e5e5392b ("ARM: 8547/1: dma-mapping: store buffer >> information") allocates a structure meant for internal buffer management >> with the GFP flags of the buffer itself. This can trigger the following >> safeguard in the slab/slub allocator: >> >> if (unlikely(flags & GFP_SLAB_BUG_MASK)) { >> pr_emerg("gfp: %u\n", flags & GFP_SLAB_BUG_MASK); >> BUG(); >> } >> >> Fix this by filtering the flags that make the slab allocator unhappy. >> >> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> >> Cc: Rabin Vincent <rabin@rab.in> > > Looks much better than the original. Please send it to the patch system, > thanks. Just did that, thanks!
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index deac58d5f1f7..c941e93048ad 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -762,7 +762,8 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, if (!mask) return NULL; - buf = kzalloc(sizeof(*buf), gfp); + buf = kzalloc(sizeof(*buf), + gfp & ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM)); if (!buf) return NULL;
Commit 19e6e5e5392b ("ARM: 8547/1: dma-mapping: store buffer information") allocates a structure meant for internal buffer management with the GFP flags of the buffer itself. This can trigger the following safeguard in the slab/slub allocator: if (unlikely(flags & GFP_SLAB_BUG_MASK)) { pr_emerg("gfp: %u\n", flags & GFP_SLAB_BUG_MASK); BUG(); } Fix this by filtering the flags that make the slab allocator unhappy. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Cc: Rabin Vincent <rabin@rab.in> --- Changes since v1: - Filter flags that may cause problem instead of forcing GFP_KERNEL (and risk sleeping in atomic context), as suggested by Rabin. arch/arm/mm/dma-mapping.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)