From 74d46d6b2d23d44d72c37df4c6a5d2e782f7b088 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 21 Jul 2009 17:11:50 +0900 Subject: [PATCH] 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 ++-- arch/x86/kernel/setup_percpu.c | 14 +++++++------- mm/percpu.c | 33 ++++++++++++++++++--------------- 3 files changed, 27 insertions(+), 24 deletions(-) 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) { 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); 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 @@ * * This is percpu allocator which can handle both static and dynamic * areas. Percpu areas are allocated in chunks in vmalloc area. Each - * chunk is consisted of num_possible_cpus() units and the first chunk - * is used for static percpu variables in the kernel image (special - * boot time alloc/init handling necessary as these areas need to be - * brought up before allocation services are running). Unit grows as - * necessary and all units grow or shrink in unison. When a chunk is - * filled up, another chunk is allocated. ie. in vmalloc area + * chunk is consisted of nr_cpu_ids units and the first chunk is used + * for static percpu variables in the kernel image (special boot time + * alloc/init handling necessary as these areas need to be brought up + * before allocation services are running). Unit grows as necessary + * and all units grow or shrink in unison. When a chunk is filled up, + * another chunk is allocated. ie. in vmalloc area * * c0 c1 c2 * ------------------- ------------------- ------------ @@ -558,7 +558,7 @@ static void pcpu_free_area(struct pcpu_chunk *chunk, int freeme) static void pcpu_unmap(struct pcpu_chunk *chunk, int page_start, int page_end, bool flush_tlb) { - unsigned int last = num_possible_cpus() - 1; + unsigned int last = nr_cpu_ids - 1; unsigned int cpu; /* 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, */ static int pcpu_map(struct pcpu_chunk *chunk, int page_start, int page_end) { - unsigned int last = num_possible_cpus() - 1; + unsigned int last = nr_cpu_ids - 1; unsigned int cpu; int err; @@ -1067,9 +1067,9 @@ size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn, PFN_UP(size_sum)); pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT; - pcpu_chunk_size = num_possible_cpus() * pcpu_unit_size; + pcpu_chunk_size = nr_cpu_ids * pcpu_unit_size; pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) - + num_possible_cpus() * pcpu_unit_pages * sizeof(struct page *); + + nr_cpu_ids * pcpu_unit_pages * sizeof(struct page *); if (dyn_size < 0) 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, } else pcpue_unit_size = max_t(size_t, pcpue_size, PCPU_MIN_UNIT_SIZE); - chunk_size = pcpue_unit_size * num_possible_cpus(); + chunk_size = pcpue_unit_size * nr_cpu_ids; pcpue_ptr = __alloc_bootmem_nopanic(chunk_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS)); @@ -1259,12 +1259,15 @@ ssize_t __init pcpu_embed_first_chunk(size_t static_size, size_t reserved_size, } /* return the leftover and copy */ - for_each_possible_cpu(cpu) { + for (cpu = 0; cpu < nr_cpu_ids; cpu++) { void *ptr = pcpue_ptr + cpu * pcpue_unit_size; - free_bootmem(__pa(ptr + pcpue_size), - pcpue_unit_size - pcpue_size); - memcpy(ptr, __per_cpu_load, static_size); + if (cpu_possible(cpu)) { + free_bootmem(__pa(ptr + pcpue_size), + pcpue_unit_size - pcpue_size); + memcpy(ptr, __per_cpu_load, static_size); + } else + free_bootmem(__pa(ptr), pcpue_unit_size); } /* we're ready, commit */ -- 2.39.2