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authorTejun Heo <tj@kernel.org>2009-07-21 04:11:50 -0400
committerTejun Heo <tj@kernel.org>2009-08-14 00:20:53 -0400
commit74d46d6b2d23d44d72c37df4c6a5d2e782f7b088 (patch)
treebcc468968e738394b9c4a44b8936a0e6037be163 /mm/percpu.c
parentd6647bdf98a0de19963de8d5d9698d469ed72097 (diff)
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 <tj@kernel.org> Acked-by: David S. Miller <davem@davemloft.net> Cc: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'mm/percpu.c')
-rw-r--r--mm/percpu.c33
1 files changed, 18 insertions, 15 deletions
diff --git a/mm/percpu.c b/mm/percpu.c
index b70f2acd8853..e0be1146f617 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -8,12 +8,12 @@
8 * 8 *
9 * This is percpu allocator which can handle both static and dynamic 9 * This is percpu allocator which can handle both static and dynamic
10 * areas. Percpu areas are allocated in chunks in vmalloc area. Each 10 * areas. Percpu areas are allocated in chunks in vmalloc area. Each
11 * chunk is consisted of num_possible_cpus() units and the first chunk 11 * chunk is consisted of nr_cpu_ids units and the first chunk is used
12 * is used for static percpu variables in the kernel image (special 12 * for static percpu variables in the kernel image (special boot time
13 * boot time alloc/init handling necessary as these areas need to be 13 * alloc/init handling necessary as these areas need to be brought up
14 * brought up before allocation services are running). Unit grows as 14 * before allocation services are running). Unit grows as necessary
15 * necessary and all units grow or shrink in unison. When a chunk is 15 * and all units grow or shrink in unison. When a chunk is filled up,
16 * filled up, another chunk is allocated. ie. in vmalloc area 16 * another chunk is allocated. ie. in vmalloc area
17 * 17 *
18 * c0 c1 c2 18 * c0 c1 c2
19 * ------------------- ------------------- ------------ 19 * ------------------- ------------------- ------------
@@ -558,7 +558,7 @@ static void pcpu_free_area(struct pcpu_chunk *chunk, int freeme)
558static void pcpu_unmap(struct pcpu_chunk *chunk, int page_start, int page_end, 558static void pcpu_unmap(struct pcpu_chunk *chunk, int page_start, int page_end,
559 bool flush_tlb) 559 bool flush_tlb)
560{ 560{
561 unsigned int last = num_possible_cpus() - 1; 561 unsigned int last = nr_cpu_ids - 1;
562 unsigned int cpu; 562 unsigned int cpu;
563 563
564 /* unmap must not be done on immutable chunk */ 564 /* unmap must not be done on immutable chunk */
@@ -643,7 +643,7 @@ static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size,
643 */ 643 */
644static int pcpu_map(struct pcpu_chunk *chunk, int page_start, int page_end) 644static int pcpu_map(struct pcpu_chunk *chunk, int page_start, int page_end)
645{ 645{
646 unsigned int last = num_possible_cpus() - 1; 646 unsigned int last = nr_cpu_ids - 1;
647 unsigned int cpu; 647 unsigned int cpu;
648 int err; 648 int err;
649 649
@@ -1067,9 +1067,9 @@ size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn,
1067 PFN_UP(size_sum)); 1067 PFN_UP(size_sum));
1068 1068
1069 pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT; 1069 pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT;
1070 pcpu_chunk_size = num_possible_cpus() * pcpu_unit_size; 1070 pcpu_chunk_size = nr_cpu_ids * pcpu_unit_size;
1071 pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) 1071 pcpu_chunk_struct_size = sizeof(struct pcpu_chunk)
1072 + num_possible_cpus() * pcpu_unit_pages * sizeof(struct page *); 1072 + nr_cpu_ids * pcpu_unit_pages * sizeof(struct page *);
1073 1073
1074 if (dyn_size < 0) 1074 if (dyn_size < 0)
1075 dyn_size = pcpu_unit_size - static_size - reserved_size; 1075 dyn_size = pcpu_unit_size - static_size - reserved_size;
@@ -1248,7 +1248,7 @@ ssize_t __init pcpu_embed_first_chunk(size_t static_size, size_t reserved_size,
1248 } else 1248 } else
1249 pcpue_unit_size = max_t(size_t, pcpue_size, PCPU_MIN_UNIT_SIZE); 1249 pcpue_unit_size = max_t(size_t, pcpue_size, PCPU_MIN_UNIT_SIZE);
1250 1250
1251 chunk_size = pcpue_unit_size * num_possible_cpus(); 1251 chunk_size = pcpue_unit_size * nr_cpu_ids;
1252 1252
1253 pcpue_ptr = __alloc_bootmem_nopanic(chunk_size, PAGE_SIZE, 1253 pcpue_ptr = __alloc_bootmem_nopanic(chunk_size, PAGE_SIZE,
1254 __pa(MAX_DMA_ADDRESS)); 1254 __pa(MAX_DMA_ADDRESS));
@@ -1259,12 +1259,15 @@ ssize_t __init pcpu_embed_first_chunk(size_t static_size, size_t reserved_size,
1259 } 1259 }
1260 1260
1261 /* return the leftover and copy */ 1261 /* return the leftover and copy */
1262 for_each_possible_cpu(cpu) { 1262 for (cpu = 0; cpu < nr_cpu_ids; cpu++) {
1263 void *ptr = pcpue_ptr + cpu * pcpue_unit_size; 1263 void *ptr = pcpue_ptr + cpu * pcpue_unit_size;
1264 1264
1265 free_bootmem(__pa(ptr + pcpue_size), 1265 if (cpu_possible(cpu)) {
1266 pcpue_unit_size - pcpue_size); 1266 free_bootmem(__pa(ptr + pcpue_size),
1267 memcpy(ptr, __per_cpu_load, static_size); 1267 pcpue_unit_size - pcpue_size);
1268 memcpy(ptr, __per_cpu_load, static_size);
1269 } else
1270 free_bootmem(__pa(ptr), pcpue_unit_size);
1268 } 1271 }
1269 1272
1270 /* we're ready, commit */ 1273 /* we're ready, commit */