path: root/lib
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authorLad, Prabhakar <prabhakar.csengg@gmail.com>2014-01-29 14:05:37 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-01-29 16:22:39 -0800
commit0368dfd01ae3b7647ef9b2f0525fdefd5e0d28e1 (patch)
tree333d316aee4c50851b7a2c07defa930e97d17380 /lib
parent0e47c969c65e213421450c31043353ebe3c67e0c (diff)
lib/genalloc.c: add check gen_pool_dma_alloc() if dma pointer is not NULL
In the gen_pool_dma_alloc() the dma pointer can be NULL and while assigning gen_pool_virt_to_phys(pool, vaddr) to dma caused the following crash on da850 evm: Unable to handle kernel NULL pointer dereference at virtual address 00000000 Internal error: Oops: 805 [#1] PREEMPT ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper Tainted: G W 3.13.0-rc1-00001-g0609e45-dirty #5 task: c4830000 ti: c4832000 task.ti: c4832000 PC is at gen_pool_dma_alloc+0x30/0x3c LR is at gen_pool_virt_to_phys+0x74/0x80 Process swapper, call trace: gen_pool_dma_alloc+0x30/0x3c davinci_pm_probe+0x40/0xa8 platform_drv_probe+0x1c/0x4c driver_probe_device+0x98/0x22c __driver_attach+0x8c/0x90 bus_for_each_dev+0x6c/0x8c bus_add_driver+0x124/0x1d4 driver_register+0x78/0xf8 platform_driver_probe+0x20/0xa4 davinci_init_late+0xc/0x14 init_machine_late+0x1c/0x28 do_one_initcall+0x34/0x15c kernel_init_freeable+0xe4/0x1ac kernel_init+0x8/0xec This patch fixes the above. [akpm@linux-foundation.org: update kerneldoc] Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com> Cc: Philipp Zabel <p.zabel@pengutronix.de> Cc: Nicolin Chen <b42378@freescale.com> Cc: Joe Perches <joe@perches.com> Cc: Sachin Kamat <sachin.kamat@linaro.org> Cc: <stable@vger.kernel.org> [3.13.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
1 files changed, 3 insertions, 2 deletions
diff --git a/lib/genalloc.c b/lib/genalloc.c
index dda31168844f..bdb9a456bcbb 100644
--- a/lib/genalloc.c
+++ b/lib/genalloc.c
@@ -316,7 +316,7 @@ EXPORT_SYMBOL(gen_pool_alloc);
* gen_pool_dma_alloc - allocate special memory from the pool for DMA usage
* @pool: pool to allocate from
* @size: number of bytes to allocate from the pool
- * @dma: dma-view physical address
+ * @dma: dma-view physical address return value. Use NULL if unneeded.
* Allocate the requested number of bytes from the specified pool.
* Uses the pool allocation function (with first-fit algorithm by default).
@@ -334,7 +334,8 @@ void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size, dma_addr_t *dma)
if (!vaddr)
return NULL;
- *dma = gen_pool_virt_to_phys(pool, vaddr);
+ if (dma)
+ *dma = gen_pool_virt_to_phys(pool, vaddr);
return (void *)vaddr;