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 --- mm/percpu.c | 33 ++++++++++++++++++--------------- 1 file changed, 18 insertions(+), 15 deletions(-) (limited to 'mm') diff --git a/mm/percpu.c b/mm/percpu.c index b70f2acd885..e0be1146f61 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 */ -- cgit v1.2.3 From 142d44b0dd6741a64a7bdbe029110e7c1dcf1d23 Mon Sep 17 00:00:00 2001 From: Amerigo Wang Date: Thu, 13 Aug 2009 02:00:13 -0400 Subject: percpu: use the right flag for get_vm_area() get_vm_area() only accepts VM_* flags, not GFP_*. And according to the doc of get_vm_area(), here should be VM_ALLOC. Signed-off-by: WANG Cong Acked-by: Tejun Heo Cc: Ingo Molnar --- mm/percpu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm') diff --git a/mm/percpu.c b/mm/percpu.c index e0be1146f61..5fe37842e0e 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -749,7 +749,7 @@ static struct pcpu_chunk *alloc_pcpu_chunk(void) chunk->map[chunk->map_used++] = pcpu_unit_size; chunk->page = chunk->page_ar; - chunk->vm = get_vm_area(pcpu_chunk_size, GFP_KERNEL); + chunk->vm = get_vm_area(pcpu_chunk_size, VM_ALLOC); if (!chunk->vm) { free_pcpu_chunk(chunk); return NULL; -- cgit v1.2.3 From 788084aba2ab7348257597496befcbccabdc98a3 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Fri, 31 Jul 2009 12:54:11 -0400 Subject: Security/SELinux: seperate lsm specific mmap_min_addr Currently SELinux enforcement of controls on the ability to map low memory is determined by the mmap_min_addr tunable. This patch causes SELinux to ignore the tunable and instead use a seperate Kconfig option specific to how much space the LSM should protect. The tunable will now only control the need for CAP_SYS_RAWIO and SELinux permissions will always protect the amount of low memory designated by CONFIG_LSM_MMAP_MIN_ADDR. This allows users who need to disable the mmap_min_addr controls (usual reason being they run WINE as a non-root user) to do so and still have SELinux controls preventing confined domains (like a web server) from being able to map some area of low memory. Signed-off-by: Eric Paris Signed-off-by: James Morris --- mm/Kconfig | 6 +++--- mm/mmap.c | 3 --- mm/nommu.c | 3 --- 3 files changed, 3 insertions(+), 9 deletions(-) (limited to 'mm') diff --git a/mm/Kconfig b/mm/Kconfig index c948d4ca8bd..fe5f674d7a7 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -225,9 +225,9 @@ config DEFAULT_MMAP_MIN_ADDR For most ia64, ppc64 and x86 users with lots of address space a value of 65536 is reasonable and should cause no problems. On arm and other archs it should not be higher than 32768. - Programs which use vm86 functionality would either need additional - permissions from either the LSM or the capabilities module or have - this protection disabled. + Programs which use vm86 functionality or have some need to map + this low address space will need CAP_SYS_RAWIO or disable this + protection by setting the value to 0. This value can be changed after boot using the /proc/sys/vm/mmap_min_addr tunable. diff --git a/mm/mmap.c b/mm/mmap.c index 34579b23ebd..8101de490c7 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -88,9 +88,6 @@ int sysctl_overcommit_ratio = 50; /* default is 50% */ int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT; struct percpu_counter vm_committed_as; -/* amount of vm to protect from userspace access */ -unsigned long mmap_min_addr = CONFIG_DEFAULT_MMAP_MIN_ADDR; - /* * Check that a process has enough memory to allocate a new virtual * mapping. 0 means there is enough memory for the allocation to diff --git a/mm/nommu.c b/mm/nommu.c index 53cab10fece..28754c40be9 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -69,9 +69,6 @@ int sysctl_max_map_count = DEFAULT_MAX_MAP_COUNT; int sysctl_nr_trim_pages = CONFIG_NOMMU_INITIAL_TRIM_EXCESS; int heap_stack_gap = 0; -/* amount of vm to protect from userspace access */ -unsigned long mmap_min_addr = CONFIG_DEFAULT_MMAP_MIN_ADDR; - atomic_long_t mmap_pages_allocated; EXPORT_SYMBOL(mem_map); -- cgit v1.2.3 From 0753ba01e126020bf0f8150934903b48935b697d Mon Sep 17 00:00:00 2001 From: KOSAKI Motohiro Date: Tue, 18 Aug 2009 14:11:10 -0700 Subject: mm: revert "oom: move oom_adj value" The commit 2ff05b2b (oom: move oom_adj value) moveed the oom_adj value to the mm_struct. It was a very good first step for sanitize OOM. However Paul Menage reported the commit makes regression to his job scheduler. Current OOM logic can kill OOM_DISABLED process. Why? His program has the code of similar to the following. ... set_oom_adj(OOM_DISABLE); /* The job scheduler never killed by oom */ ... if (vfork() == 0) { set_oom_adj(0); /* Invoked child can be killed */ execve("foo-bar-cmd"); } .... vfork() parent and child are shared the same mm_struct. then above set_oom_adj(0) doesn't only change oom_adj for vfork() child, it's also change oom_adj for vfork() parent. Then, vfork() parent (job scheduler) lost OOM immune and it was killed. Actually, fork-setting-exec idiom is very frequently used in userland program. We must not break this assumption. Then, this patch revert commit 2ff05b2b and related commit. Reverted commit list --------------------- - commit 2ff05b2b4e (oom: move oom_adj value from task_struct to mm_struct) - commit 4d8b9135c3 (oom: avoid unnecessary mm locking and scanning for OOM_DISABLE) - commit 8123681022 (oom: only oom kill exiting tasks with attached memory) - commit 933b787b57 (mm: copy over oom_adj value at fork time) Signed-off-by: KOSAKI Motohiro Cc: Paul Menage Cc: David Rientjes Cc: KAMEZAWA Hiroyuki Cc: Rik van Riel Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Nick Piggin Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/oom_kill.c | 64 ++++++++++++++++++++++++++++++++++++----------------------- 1 file changed, 39 insertions(+), 25 deletions(-) (limited to 'mm') diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 175a67a78a9..a7b2460e922 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -58,7 +58,6 @@ unsigned long badness(struct task_struct *p, unsigned long uptime) unsigned long points, cpu_time, run_time; struct mm_struct *mm; struct task_struct *child; - int oom_adj; task_lock(p); mm = p->mm; @@ -66,11 +65,6 @@ unsigned long badness(struct task_struct *p, unsigned long uptime) task_unlock(p); return 0; } - oom_adj = mm->oom_adj; - if (oom_adj == OOM_DISABLE) { - task_unlock(p); - return 0; - } /* * The memory size of the process is the basis for the badness. @@ -154,15 +148,15 @@ unsigned long badness(struct task_struct *p, unsigned long uptime) points /= 8; /* - * Adjust the score by oom_adj. + * Adjust the score by oomkilladj. */ - if (oom_adj) { - if (oom_adj > 0) { + if (p->oomkilladj) { + if (p->oomkilladj > 0) { if (!points) points = 1; - points <<= oom_adj; + points <<= p->oomkilladj; } else - points >>= -(oom_adj); + points >>= -(p->oomkilladj); } #ifdef DEBUG @@ -257,8 +251,11 @@ static struct task_struct *select_bad_process(unsigned long *ppoints, *ppoints = ULONG_MAX; } + if (p->oomkilladj == OOM_DISABLE) + continue; + points = badness(p, uptime.tv_sec); - if (points > *ppoints) { + if (points > *ppoints || !chosen) { chosen = p; *ppoints = points; } @@ -307,7 +304,8 @@ static void dump_tasks(const struct mem_cgroup *mem) } printk(KERN_INFO "[%5d] %5d %5d %8lu %8lu %3d %3d %s\n", p->pid, __task_cred(p)->uid, p->tgid, mm->total_vm, - get_mm_rss(mm), (int)task_cpu(p), mm->oom_adj, p->comm); + get_mm_rss(mm), (int)task_cpu(p), p->oomkilladj, + p->comm); task_unlock(p); } while_each_thread(g, p); } @@ -325,8 +323,11 @@ static void __oom_kill_task(struct task_struct *p, int verbose) return; } - if (!p->mm) + if (!p->mm) { + WARN_ON(1); + printk(KERN_WARNING "tried to kill an mm-less task!\n"); return; + } if (verbose) printk(KERN_ERR "Killed process %d (%s)\n", @@ -348,13 +349,28 @@ static int oom_kill_task(struct task_struct *p) struct mm_struct *mm; struct task_struct *g, *q; - task_lock(p); mm = p->mm; - if (!mm || mm->oom_adj == OOM_DISABLE) { - task_unlock(p); + + /* WARNING: mm may not be dereferenced since we did not obtain its + * value from get_task_mm(p). This is OK since all we need to do is + * compare mm to q->mm below. + * + * Furthermore, even if mm contains a non-NULL value, p->mm may + * change to NULL at any time since we do not hold task_lock(p). + * However, this is of no concern to us. + */ + + if (mm == NULL) return 1; - } - task_unlock(p); + + /* + * Don't kill the process if any threads are set to OOM_DISABLE + */ + do_each_thread(g, q) { + if (q->mm == mm && q->oomkilladj == OOM_DISABLE) + return 1; + } while_each_thread(g, q); + __oom_kill_task(p, 1); /* @@ -377,11 +393,10 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, struct task_struct *c; if (printk_ratelimit()) { - task_lock(current); printk(KERN_WARNING "%s invoked oom-killer: " - "gfp_mask=0x%x, order=%d, oom_adj=%d\n", - current->comm, gfp_mask, order, - current->mm ? current->mm->oom_adj : OOM_DISABLE); + "gfp_mask=0x%x, order=%d, oomkilladj=%d\n", + current->comm, gfp_mask, order, current->oomkilladj); + task_lock(current); cpuset_print_task_mems_allowed(current); task_unlock(current); dump_stack(); @@ -394,9 +409,8 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, /* * If the task is already exiting, don't alarm the sysadmin or kill * its children or threads, just set TIF_MEMDIE so it can die quickly - * if its mm is still attached. */ - if (p->mm && (p->flags & PF_EXITING)) { + if (p->flags & PF_EXITING) { __oom_kill_task(p, 0); return 0; } -- cgit v1.2.3 From 28d7a6ae92c099d81cbea08c20be0d2cf7ccd7ca Mon Sep 17 00:00:00 2001 From: Graff Yang Date: Tue, 18 Aug 2009 14:11:17 -0700 Subject: nommu: check fd read permission in validate_mmap_request() According to the POSIX (1003.1-2008), the file descriptor shall have been opened with read permission, regardless of the protection options specified to mmap(). The ltp test cases mmap06/07 need this. Signed-off-by: Graff Yang Acked-by: Paul Mundt Signed-off-by: David Howells Acked-by: Greg Ungerer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/nommu.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'mm') diff --git a/mm/nommu.c b/mm/nommu.c index 28754c40be9..4bde489ec43 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -919,6 +919,10 @@ static int validate_mmap_request(struct file *file, if (!file->f_op->read) capabilities &= ~BDI_CAP_MAP_COPY; + /* The file shall have been opened with read permission. */ + if (!(file->f_mode & FMODE_READ)) + return -EACCES; + if (flags & MAP_SHARED) { /* do checks for writing, appending and locking */ if ((prot & PROT_WRITE) && -- cgit v1.2.3 From 7f9cfb31030737a7fc9a1cbca3fd01bec184c849 Mon Sep 17 00:00:00 2001 From: Bo Liu Date: Tue, 18 Aug 2009 14:11:19 -0700 Subject: mm: build_zonelists(): move clear node_load[] to __build_all_zonelists() If node_load[] is cleared everytime build_zonelists() is called,node_load[] will have no help to find the next node that should appear in the given node's fallback list. Because of the bug, zonelist's node_order is not calculated as expected. This bug affects on big machine, which has asynmetric node distance. [synmetric NUMA's node distance] 0 1 2 0 10 12 12 1 12 10 12 2 12 12 10 [asynmetric NUMA's node distance] 0 1 2 0 10 12 20 1 12 10 14 2 20 14 10 This (my bug) is very old but no one has reported this for a long time. Maybe because the number of asynmetric NUMA is very small and they use cpuset for customizing node memory allocation fallback. [akpm@linux-foundation.org: fix CONFIG_NUMA=n build] Signed-off-by: Bo Liu Reviewed-by: KAMEZAWA Hiroyuki Cc: Mel Gorman Cc: Christoph Lameter Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'mm') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index d052abbe306..5cc986eb9f6 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2544,7 +2544,6 @@ static void build_zonelists(pg_data_t *pgdat) prev_node = local_node; nodes_clear(used_mask); - memset(node_load, 0, sizeof(node_load)); memset(node_order, 0, sizeof(node_order)); j = 0; @@ -2653,6 +2652,9 @@ static int __build_all_zonelists(void *dummy) { int nid; +#ifdef CONFIG_NUMA + memset(node_load, 0, sizeof(node_load)); +#endif for_each_online_node(nid) { pg_data_t *pgdat = NODE_DATA(nid); -- cgit v1.2.3 From 03ef83af528899aa339e42d8024b37e2f434fba4 Mon Sep 17 00:00:00 2001 From: Minchan Kim Date: Wed, 26 Aug 2009 14:29:23 -0700 Subject: mm: fix for infinite churning of mlocked pages An mlocked page might lose the isolatation race. This causes the page to clear PG_mlocked while it remains in a VM_LOCKED vma. This means it can be put onto the [in]active list. We can rescue it by using try_to_unmap() in shrink_page_list(). But now, As Wu Fengguang pointed out, vmscan has a bug. If the page has PG_referenced, it can't reach try_to_unmap() in shrink_page_list() but is put into the active list. If the page is referenced repeatedly, it can remain on the [in]active list without being moving to the unevictable list. This patch fixes it. Reported-by: Wu Fengguang Signed-off-by: Minchan Kim Reviewed-by: KOSAKI Motohiro < Cc: Lee Schermerhorn Acked-by: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/rmap.c | 1 + mm/vmscan.c | 9 +++++++-- 2 files changed, 8 insertions(+), 2 deletions(-) (limited to 'mm') diff --git a/mm/rmap.c b/mm/rmap.c index 836c6c63e1f..0895b5c7cbf 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -358,6 +358,7 @@ static int page_referenced_one(struct page *page, */ if (vma->vm_flags & VM_LOCKED) { *mapcount = 1; /* break early from loop */ + *vm_flags |= VM_LOCKED; goto out_unmap; } diff --git a/mm/vmscan.c b/mm/vmscan.c index dea7abd3109..94e86dd6954 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -630,9 +630,14 @@ static unsigned long shrink_page_list(struct list_head *page_list, referenced = page_referenced(page, 1, sc->mem_cgroup, &vm_flags); - /* In active use or really unfreeable? Activate it. */ + /* + * In active use or really unfreeable? Activate it. + * If page which have PG_mlocked lost isoltation race, + * try_to_unmap moves it to unevictable list + */ if (sc->order <= PAGE_ALLOC_COSTLY_ORDER && - referenced && page_mapping_inuse(page)) + referenced && page_mapping_inuse(page) + && !(vm_flags & VM_LOCKED)) goto activate_locked; /* -- cgit v1.2.3 From 04a13c7c632e1fe04a5f6e6c83565d2559e37598 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2009 21:12:28 +0900 Subject: percpu: don't assume existence of cpu0 percpu incorrectly assumed that cpu0 was always there which led to the following warning and eventual oops on sparc machines w/o cpu0. WARNING: at mm/percpu.c:651 pcpu_map+0xdc/0x100() Modules linked in: Call Trace: [000000000045eb70] warn_slowpath_common+0x50/0xa0 [000000000045ebdc] warn_slowpath_null+0x1c/0x40 [00000000004d493c] pcpu_map+0xdc/0x100 [00000000004d59a4] pcpu_alloc+0x3e4/0x4e0 [00000000004d5af8] __alloc_percpu+0x18/0x40 [00000000005b112c] __percpu_counter_init+0x4c/0xc0 ... Unable to handle kernel NULL pointer dereference ... I7: Disabling lock debugging due to kernel taint Caller[000000000053c1b0]: sysfs_new_dirent+0x30/0x120 Caller[000000000053c7a4]: create_dir+0x24/0xc0 Caller[000000000053c870]: sysfs_create_dir+0x30/0x80 Caller[00000000005990e8]: kobject_add_internal+0xc8/0x200 ... Kernel panic - not syncing: Attempted to kill the idle task! This patch fixes the problem by backporting parts from devel branch to make percpu core not depend on the existence of cpu0. Signed-off-by: Tejun Heo Reported-by: Meelis Roos Cc: David Miller --- mm/percpu.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) (limited to 'mm') diff --git a/mm/percpu.c b/mm/percpu.c index 5fe37842e0e..3311c8919f3 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -197,7 +197,12 @@ static unsigned long pcpu_chunk_addr(struct pcpu_chunk *chunk, static bool pcpu_chunk_page_occupied(struct pcpu_chunk *chunk, int page_idx) { - return *pcpu_chunk_pagep(chunk, 0, page_idx) != NULL; + /* + * Any possible cpu id can be used here, so there's no need to + * worry about preemption or cpu hotplug. + */ + return *pcpu_chunk_pagep(chunk, raw_smp_processor_id(), + page_idx) != NULL; } /* set the pointer to a chunk in a page struct */ @@ -297,6 +302,14 @@ static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr) return pcpu_first_chunk; } + /* + * The address is relative to unit0 which might be unused and + * thus unmapped. Offset the address to the unit space of the + * current processor before looking it up in the vmalloc + * space. Note that any possible cpu id can be used here, so + * there's no need to worry about preemption or cpu hotplug. + */ + addr += raw_smp_processor_id() * pcpu_unit_size; return pcpu_get_page_chunk(vmalloc_to_page(addr)); } -- cgit v1.2.3 From d76b1590e06a63a3d8697168cd0aabf1c4b3cb3a Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 3 Sep 2009 22:38:59 +0300 Subject: slub: Fix kmem_cache_destroy() with SLAB_DESTROY_BY_RCU kmem_cache_destroy() should call rcu_barrier() *after* kmem_cache_close() and *before* sysfs_slab_remove() or risk rcu_free_slab() being called after kmem_cache is deleted (kfreed). rmmod nf_conntrack can crash the machine because it has to kmem_cache_destroy() a SLAB_DESTROY_BY_RCU enabled cache. Cc: Reported-by: Zdenek Kabelac Signed-off-by: Eric Dumazet Acked-by: Paul E. McKenney Signed-off-by: Pekka Enberg --- mm/slub.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'mm') diff --git a/mm/slub.c b/mm/slub.c index b9f1491a58a..b6276753626 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2594,8 +2594,6 @@ static inline int kmem_cache_close(struct kmem_cache *s) */ void kmem_cache_destroy(struct kmem_cache *s) { - if (s->flags & SLAB_DESTROY_BY_RCU) - rcu_barrier(); down_write(&slub_lock); s->refcount--; if (!s->refcount) { @@ -2606,6 +2604,8 @@ void kmem_cache_destroy(struct kmem_cache *s) "still has objects.\n", s->name, __func__); dump_stack(); } + if (s->flags & SLAB_DESTROY_BY_RCU) + rcu_barrier(); sysfs_slab_remove(s); } else up_write(&slub_lock); -- cgit v1.2.3 From a190887b58c32d19c2eee007c5eb8faa970a69ba Mon Sep 17 00:00:00 2001 From: David Howells Date: Sat, 5 Sep 2009 11:17:07 -0700 Subject: nommu: fix error handling in do_mmap_pgoff() Fix the error handling in do_mmap_pgoff(). If do_mmap_shared_file() or do_mmap_private() fail, we jump to the error_put_region label at which point we cann __put_nommu_region() on the region - but we haven't yet added the region to the tree, and so __put_nommu_region() may BUG because the region tree is empty or it may corrupt the region tree. To get around this, we can afford to add the region to the region tree before calling do_mmap_shared_file() or do_mmap_private() as we keep nommu_region_sem write-locked, so no-one can race with us by seeing a transient region. Signed-off-by: David Howells Acked-by: Pekka Enberg Acked-by: Paul Mundt Cc: Mel Gorman Acked-by: Greg Ungerer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/nommu.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'mm') diff --git a/mm/nommu.c b/mm/nommu.c index 4bde489ec43..66e81e7e9fe 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -1352,6 +1352,7 @@ unsigned long do_mmap_pgoff(struct file *file, } vma->vm_region = region; + add_nommu_region(region); /* set up the mapping */ if (file && vma->vm_flags & VM_SHARED) @@ -1361,8 +1362,6 @@ unsigned long do_mmap_pgoff(struct file *file, if (ret < 0) goto error_put_region; - add_nommu_region(region); - /* okay... we have a mapping; now we have to register it */ result = vma->vm_start; -- cgit v1.2.3 From dd5d241ea955006122d76af88af87de73fec25b4 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Sat, 5 Sep 2009 11:17:11 -0700 Subject: page-allocator: always change pageblock ownership when anti-fragmentation is disabled On low-memory systems, anti-fragmentation gets disabled as fragmentation cannot be avoided on a sufficiently large boundary to be worthwhile. Once disabled, there is a period of time when all the pageblocks are marked MOVABLE and the expectation is that they get marked UNMOVABLE at each call to __rmqueue_fallback(). However, when MAX_ORDER is large the pageblocks do not change ownership because the normal criteria are not met. This has the effect of prematurely breaking up too many large contiguous blocks. This is most serious on NOMMU systems which depend on high-order allocations to boot. This patch causes pageblocks to change ownership on every fallback when anti-fragmentation is disabled. This prevents the large blocks being prematurely broken up. This is a fix to commit 49255c619fbd482d704289b5eb2795f8e3b7ff2e [page allocator: move check for disabled anti-fragmentation out of fastpath] and the problem affects 2.6.31-rc8. Signed-off-by: Mel Gorman Tested-by: Paul Mundt Cc: David Howells Cc: Pekka Enberg Acked-by: Greg Ungerer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'mm') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 5cc986eb9f6..a0de15f4698 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -817,13 +817,15 @@ __rmqueue_fallback(struct zone *zone, int order, int start_migratetype) * agressive about taking ownership of free pages */ if (unlikely(current_order >= (pageblock_order >> 1)) || - start_migratetype == MIGRATE_RECLAIMABLE) { + start_migratetype == MIGRATE_RECLAIMABLE || + page_group_by_mobility_disabled) { unsigned long pages; pages = move_freepages_block(zone, page, start_migratetype); /* Claim the whole block if over half of it is free */ - if (pages >= (1 << (pageblock_order-1))) + if (pages >= (1 << (pageblock_order-1)) || + page_group_by_mobility_disabled) set_pageblock_migratetype(page, start_migratetype); -- cgit v1.2.3