From: "Lad, Prabhakar" <prabhakar.csengg@xxxxxxxxx> Subject: 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 pgd = c0004000 [00000000] *pgd=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 pc : [<c01a73b8>] lr : [<c01a6ff8>] psr: 60000013 sp : c4833e38 ip : 00000000 fp : 00000000 r10: c0428928 r9 : c0430e1c r8 : c0444b70 r7 : c04436f0 r6 : c5840000 r5 : 00000000 r4 : c4802fe0 r3 : 80000000 r2 : c4833e18 r1 : c4832018 r0 : 80000000 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 0005317f Table: c0004000 DAC: 00000017 Process swapper (pid: 1, stack limit = 0xc48321c0) Stack: (0xc4833e38 to 0xc4834000) 3e20: c0443700 c0461668 3e40: c0017df4 c0413f00 c0208b14 c0443700 c0444b5c c0485910 00000000 c0208b30 3e60: c0208b14 c0443700 00000001 c02072e0 c0443700 c0444b70 c0443734 00000000 3e80: 0000004f c0207500 c0444b70 c0207474 c4833e98 c0205cc4 c4822258 c48c9150 3ea0: 00000000 c0444b70 c4b2d780 c0459270 c4822200 c020644c c03a30d4 c019547c 3ec0: c0444b70 c0444b70 00000000 c040f01c c040c5c0 c0207a90 00000000 c0444b5c 3ee0: 00000001 c0208a90 c4832000 00000000 c040f01c c041298c c4832000 c040f038 3f00: 00000000 c0008848 c485ca80 c0468954 c4833f44 c4833f78 00000000 c0102b00 3f20: 00000000 c485ca20 00000000 c052c52c c03f1160 c00346c8 00000003 60000013 3f40: c039e7e8 00000000 00000007 00000007 c0445ca0 c0428924 c0428924 00000008 3f60: c04612e0 c040c5c0 0000004f c0428928 00000000 c040c4f8 00000007 00000007 3f80: c040c5c0 c003f3b0 00000000 c03021f8 00000000 00000000 00000000 00000000 3fa0: 00000000 c0302200 00000000 c0009710 00000000 00000000 00000000 00000000 3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 3fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000001 00000000 [<c01a73b8>] (gen_pool_dma_alloc+0x30/0x3c) from [<c0413f00>] (davinci_pm_probe+0x40/0xa8) [<c0413f00>] (davinci_pm_probe+0x40/0xa8) from [<c0208b30>] (platform_drv_probe+0x1c/0x4c) [<c0208b30>] (platform_drv_probe+0x1c/0x4c) from [<c02072e0>] (driver_probe_device+0x98/0x22c) [<c02072e0>] (driver_probe_device+0x98/0x22c) from [<c0207500>] (__driver_attach+0x8c/0x90) [<c0207500>] (__driver_attach+0x8c/0x90) from [<c0205cc4>] (bus_for_each_dev+0x6c/0x8c) [<c0205cc4>] (bus_for_each_dev+0x6c/0x8c) from [<c020644c>] (bus_add_driver+0x124/0x1d4) [<c020644c>] (bus_add_driver+0x124/0x1d4) from [<c0207a90>] (driver_register+0x78/0xf8) [<c0207a90>] (driver_register+0x78/0xf8) from [<c0208a90>] (platform_driver_probe+0x20/0xa4) [<c0208a90>] (platform_driver_probe+0x20/0xa4) from [<c041298c>] (davinci_init_late+0xc/0x14) [<c041298c>] (davinci_init_late+0xc/0x14) from [<c040f038>] (init_machine_late+0x1c/0x28) [<c040f038>] (init_machine_late+0x1c/0x28) from [<c0008848>] (do_one_initcall+0x34/0x15c) [<c0008848>] (do_one_initcall+0x34/0x15c) from [<c040c4f8>] (kernel_init_freeable+0xe4/0x1ac) [<c040c4f8>] (kernel_init_freeable+0xe4/0x1ac) from [<c0302200>] (kernel_init+0x8/0xec) [<c0302200>] (kernel_init+0x8/0xec) from [<c0009710>] (ret_from_fork+0x14/0x24) Code: 0afffffa e1a00004 e1a01006 ebfffef2 (e5850000) ---[ end trace 24fd42a15d1cdd7d ]--- This patch fixes the above. [akpm@xxxxxxxxxxxxxxxxxxxx: update kerneldoc] Signed-off-by: Lad, Prabhakar <prabhakar.csengg@xxxxxxxxx> Cc: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> Cc: Nicolin Chen <b42378@xxxxxxxxxxxxx> Cc: Joe Perches <joe@xxxxxxxxxxx> Cc: Sachin Kamat <sachin.kamat@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> [3.13.x] Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- lib/genalloc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff -puN lib/genalloc.c~lib-genallocc-add-check-gen_pool_dma_alloc-if-dma-pointer-is-not-null lib/genalloc.c --- a/lib/genalloc.c~lib-genallocc-add-check-gen_pool_dma_alloc-if-dma-pointer-is-not-null +++ a/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 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; } _ -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html