From 74d46d6b2d23d44d72c37df4c6a5d2e782f7b088 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 21 Jul 2009 17:11:50 +0900 Subject: percpu, sparc64: fix sparse possible cpu map handling percpu code has been assuming num_possible_cpus() == nr_cpu_ids which is incorrect if cpu_possible_map contains holes. This causes percpu code to access beyond allocated memories and vmalloc areas. On a sparc64 machine with cpus 0 and 2 (u60), this triggers the following warning or fails boot. WARNING: at /devel/tj/os/work/mm/vmalloc.c:106 vmap_page_range_noflush+0x1f0/0x240() Modules linked in: Call Trace: [00000000004b17d0] vmap_page_range_noflush+0x1f0/0x240 [00000000004b1840] map_vm_area+0x20/0x60 [00000000004b1950] __vmalloc_area_node+0xd0/0x160 [0000000000593434] deflate_init+0x14/0xe0 [0000000000583b94] __crypto_alloc_tfm+0xd4/0x1e0 [00000000005844f0] crypto_alloc_base+0x50/0xa0 [000000000058b898] alg_test_comp+0x18/0x80 [000000000058dad4] alg_test+0x54/0x180 [000000000058af00] cryptomgr_test+0x40/0x60 [0000000000473098] kthread+0x58/0x80 [000000000042b590] kernel_thread+0x30/0x60 [0000000000472fd0] kthreadd+0xf0/0x160 ---[ end trace 429b268a213317ba ]--- This patch fixes generic percpu functions and sparc64 setup_per_cpu_areas() so that they handle sparse cpu_possible_map properly. Please note that on x86, cpu_possible_map() doesn't contain holes and thus num_possible_cpus() == nr_cpu_ids and this patch doesn't cause any behavior difference. Signed-off-by: Tejun Heo Acked-by: David S. Miller Cc: Ingo Molnar --- arch/sparc/kernel/smp_64.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/sparc/kernel/smp_64.c') diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c index fa44eaf8d897..3691907a43b4 100644 --- a/arch/sparc/kernel/smp_64.c +++ b/arch/sparc/kernel/smp_64.c @@ -1499,7 +1499,7 @@ void __init setup_per_cpu_areas(void) dyn_size = pcpur_size - static_size - PERCPU_MODULE_RESERVE; - ptrs_size = PFN_ALIGN(num_possible_cpus() * sizeof(pcpur_ptrs[0])); + ptrs_size = PFN_ALIGN(nr_cpu_ids * sizeof(pcpur_ptrs[0])); pcpur_ptrs = alloc_bootmem(ptrs_size); for_each_possible_cpu(cpu) { @@ -1514,7 +1514,7 @@ void __init setup_per_cpu_areas(void) /* allocate address and map */ vm.flags = VM_ALLOC; - vm.size = num_possible_cpus() * PCPU_CHUNK_SIZE; + vm.size = nr_cpu_ids * PCPU_CHUNK_SIZE; vm_area_register_early(&vm, PCPU_CHUNK_SIZE); for_each_possible_cpu(cpu) { -- cgit v1.2.3