From d451e73496fc389ecbe2662aa07e6b77c63bf1fd Mon Sep 17 00:00:00 2001 From: Jerin Jacob Date: Tue, 3 Sep 2013 17:31:54 +0530 Subject: [PATCH] MIPS: DMA: Fix BUG due to smp_processor_id() in preemptible code The use of current_cpu_type() in cpu_is_noncoherent_r10000() is not preemption-safe. Use boot_cpu_type() instead to make it preemption-safe. / # insmod mtd_readtest.ko dev=4 mtd_readtest: MTD device: 4 mtd_readtest: MTD device size 996671488, eraseblock size 524288, page size 4096, count of eraseblocks 1901, pages per eraseblock 128, OOB size 224 mtd_readtest: scanning for bad eraseblocks mtd_readtest: scanned 1901 eraseblocks, 0 are bad mtd_readtest: testing page read BUG: using smp_processor_id() in preemptible [00000000] code: insmod/99 caller is mips_dma_sync_single_for_cpu+0x2c/0x128 CPU: 2 PID: 99 Comm: insmod Not tainted 3.10.4 #67 Stack : 00000006 69735f63 00000000 00000000 00000000 00000000 808273d6 00000032 80820000 00000002 8d700000 8de48fa0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 8d6afb00 8d6afb24 80721f24 807b9927 8012c130 80820000 80721f24 00000002 00000063 8de48fa0 8082333c 807b98e6 8d6afaa0 ... Call Trace: [<80109984>] show_stack+0x64/0x7c [<80666230>] dump_stack+0x20/0x2c [<803a2210>] debug_smp_processor_id+0xe0/0xf0 [<801116f0>] mips_dma_sync_single_for_cpu+0x2c/0x128 [<8043456c>] nand_plat_read_page+0x16c/0x234 [<8042fad4>] nand_do_read_ops+0x194/0x480 [<804301dc>] nand_read+0x50/0x7c [<804261c8>] part_read+0x70/0xc0 [<804231dc>] mtd_read+0x80/0xe4 [] init_module+0x354/0x6f8 [mtd_readtest] [<8010057c>] do_one_initcall+0x140/0x1a4 [<80176d7c>] load_module+0x1b5c/0x2258 [<8017752c>] SyS_init_module+0xb4/0xec [<8010f3fc>] stack_done+0x20/0x44 BUG: using smp_processor_id() in preemptible [00000000] code: insmod/99 Signed-off-by: Jerin Jacob Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/5800/ Signed-off-by: Ralf Baechle --- arch/mips/mm/dma-default.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c index aaccf1c10699..2f26835803eb 100644 --- a/arch/mips/mm/dma-default.c +++ b/arch/mips/mm/dma-default.c @@ -58,8 +58,8 @@ static inline struct page *dma_addr_to_page(struct device *dev, static inline int cpu_is_noncoherent_r10000(struct device *dev) { return !plat_device_is_coherent(dev) && - (current_cpu_type() == CPU_R10000 || - current_cpu_type() == CPU_R12000); + (boot_cpu_type() == CPU_R10000 || + boot_cpu_type() == CPU_R12000); } static gfp_t massage_gfp_flags(const struct device *dev, gfp_t gfp)