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/x86/kernel/setup_percpu.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c index 29a3eef7cf4a..07d81916f212 100644 --- a/arch/x86/kernel/setup_percpu.c +++ b/arch/x86/kernel/setup_percpu.c @@ -165,7 +165,7 @@ static ssize_t __init setup_pcpu_lpage(size_t static_size, bool chosen) if (!chosen) { size_t vm_size = VMALLOC_END - VMALLOC_START; - size_t tot_size = num_possible_cpus() * PMD_SIZE; + size_t tot_size = nr_cpu_ids * PMD_SIZE; /* on non-NUMA, embedding is better */ if (!pcpu_need_numa()) @@ -199,7 +199,7 @@ static ssize_t __init setup_pcpu_lpage(size_t static_size, bool chosen) dyn_size = pcpul_size - static_size - PERCPU_FIRST_CHUNK_RESERVE; /* allocate pointer array and alloc large pages */ - map_size = PFN_ALIGN(num_possible_cpus() * sizeof(pcpul_map[0])); + map_size = PFN_ALIGN(nr_cpu_ids * sizeof(pcpul_map[0])); pcpul_map = alloc_bootmem(map_size); for_each_possible_cpu(cpu) { @@ -228,7 +228,7 @@ static ssize_t __init setup_pcpu_lpage(size_t static_size, bool chosen) /* allocate address and map */ pcpul_vm.flags = VM_ALLOC; - pcpul_vm.size = num_possible_cpus() * PMD_SIZE; + pcpul_vm.size = nr_cpu_ids * PMD_SIZE; vm_area_register_early(&pcpul_vm, PMD_SIZE); for_each_possible_cpu(cpu) { @@ -250,8 +250,8 @@ static ssize_t __init setup_pcpu_lpage(size_t static_size, bool chosen) PMD_SIZE, pcpul_vm.addr, NULL); /* sort pcpul_map array for pcpu_lpage_remapped() */ - for (i = 0; i < num_possible_cpus() - 1; i++) - for (j = i + 1; j < num_possible_cpus(); j++) + for (i = 0; i < nr_cpu_ids - 1; i++) + for (j = i + 1; j < nr_cpu_ids; j++) if (pcpul_map[i].ptr > pcpul_map[j].ptr) { struct pcpul_ent tmp = pcpul_map[i]; pcpul_map[i] = pcpul_map[j]; @@ -288,7 +288,7 @@ void *pcpu_lpage_remapped(void *kaddr) { void *pmd_addr = (void *)((unsigned long)kaddr & PMD_MASK); unsigned long offset = (unsigned long)kaddr & ~PMD_MASK; - int left = 0, right = num_possible_cpus() - 1; + int left = 0, right = nr_cpu_ids - 1; int pos; /* pcpul in use at all? */ @@ -377,7 +377,7 @@ static ssize_t __init setup_pcpu_4k(size_t static_size) pcpu4k_nr_static_pages = PFN_UP(static_size); /* unaligned allocations can't be freed, round up to page size */ - pages_size = PFN_ALIGN(pcpu4k_nr_static_pages * num_possible_cpus() + pages_size = PFN_ALIGN(pcpu4k_nr_static_pages * nr_cpu_ids * sizeof(pcpu4k_pages[0])); pcpu4k_pages = alloc_bootmem(pages_size); -- cgit v1.2.3