3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ralf Baechle <ralf@xxxxxxxxxxxxxx> commit ff522058bd717506b2fa066fa564657f2b86477e upstream. This fixes the following issue BUG: using smp_processor_id() in preemptible [00000000] code: kjournald/1761 caller is blast_dcache32+0x30/0x254 Call Trace: [<8047f02c>] dump_stack+0x8/0x34 [<802e7e40>] debug_smp_processor_id+0xe0/0xf0 [<80114d94>] blast_dcache32+0x30/0x254 [<80118484>] r4k_dma_cache_wback_inv+0x200/0x288 [<80110ff0>] mips_dma_map_sg+0x108/0x180 [<80355098>] ide_dma_prepare+0xf0/0x1b8 [<8034eaa4>] do_rw_taskfile+0x1e8/0x33c [<8035951c>] ide_do_rw_disk+0x298/0x3e4 [<8034a3c4>] do_ide_request+0x2e0/0x704 [<802bb0dc>] __blk_run_queue+0x44/0x64 [<802be000>] queue_unplugged.isra.36+0x1c/0x54 [<802beb94>] blk_flush_plug_list+0x18c/0x24c [<802bec6c>] blk_finish_plug+0x18/0x48 [<8026554c>] journal_commit_transaction+0x3b8/0x151c [<80269648>] kjournald+0xec/0x238 [<8014ac00>] kthread+0xb8/0xc0 [<8010268c>] ret_from_kernel_thread+0x14/0x1c Caches in most systems are identical - but not always, so we can't avoid the use of smp_call_function() by just looking at the boot CPU's data, have to fiddle with preemption instead. Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Cc: Markos Chandras <markos.chandras@xxxxxxxxxx> Cc: linux-mips@xxxxxxxxxxxxxx Patchwork: https://patchwork.linux-mips.org/patch/5835 Cc: Guenter Roeck <linux@xxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/mips/mm/c-r4k.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/arch/mips/mm/c-r4k.c +++ b/arch/mips/mm/c-r4k.c @@ -12,6 +12,7 @@ #include <linux/highmem.h> #include <linux/kernel.h> #include <linux/linkage.h> +#include <linux/preempt.h> #include <linux/sched.h> #include <linux/smp.h> #include <linux/mm.h> @@ -601,6 +602,7 @@ static void r4k_dma_cache_wback_inv(unsi /* Catch bad driver code */ BUG_ON(size == 0); + preempt_disable(); if (cpu_has_inclusive_pcaches) { if (size >= scache_size) r4k_blast_scache(); @@ -621,6 +623,7 @@ static void r4k_dma_cache_wback_inv(unsi R4600_HIT_CACHEOP_WAR_IMPL; blast_dcache_range(addr, addr + size); } + preempt_enable(); bc_wback_inv(addr, size); __sync(); @@ -631,6 +634,7 @@ static void r4k_dma_cache_inv(unsigned l /* Catch bad driver code */ BUG_ON(size == 0); + preempt_disable(); if (cpu_has_inclusive_pcaches) { if (size >= scache_size) r4k_blast_scache(); @@ -655,6 +659,7 @@ static void r4k_dma_cache_inv(unsigned l R4600_HIT_CACHEOP_WAR_IMPL; blast_inv_dcache_range(addr, addr + size); } + preempt_enable(); bc_inv(addr, size); __sync();
