From 597b7305dd8bafdb3aef4957d97128bc90af8e9f Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Fri, 31 Mar 2017 15:11:47 -0700 Subject: mm: move mm_percpu_wq initialization earlier Yang Li has reported that drain_all_pages triggers a WARN_ON which means that this function is called earlier than the mm_percpu_wq is initialized on arm64 with CMA configured: WARNING: CPU: 2 PID: 1 at mm/page_alloc.c:2423 drain_all_pages+0x244/0x25c Modules linked in: CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.11.0-rc1-next-20170310-00027-g64dfbc5 #127 Hardware name: Freescale Layerscape 2088A RDB Board (DT) task: ffffffc07c4a6d00 task.stack: ffffffc07c4a8000 PC is at drain_all_pages+0x244/0x25c LR is at start_isolate_page_range+0x14c/0x1f0 [...] drain_all_pages+0x244/0x25c start_isolate_page_range+0x14c/0x1f0 alloc_contig_range+0xec/0x354 cma_alloc+0x100/0x1fc dma_alloc_from_contiguous+0x3c/0x44 atomic_pool_init+0x7c/0x208 arm64_dma_init+0x44/0x4c do_one_initcall+0x38/0x128 kernel_init_freeable+0x1a0/0x240 kernel_init+0x10/0xfc ret_from_fork+0x10/0x20 Fix this by moving the whole setup_vmstat which is an initcall right now to init_mm_internals which will be called right after the WQ subsystem is initialized. Link: http://lkml.kernel.org/r/20170315164021.28532-1-mhocko@kernel.org Signed-off-by: Michal Hocko Reported-by: Yang Li Tested-by: Yang Li Tested-by: Xiaolong Ye Cc: Mel Gorman Cc: Vlastimil Babka Cc: Tetsuo Handa Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mm.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/mm.h b/include/linux/mm.h index 5f01c88f0800..00a8fa7e366a 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -32,6 +32,8 @@ struct user_struct; struct writeback_control; struct bdi_writeback; +void init_mm_internals(void); + #ifndef CONFIG_NEED_MULTIPLE_NODES /* Don't use mapnrs, do it properly */ extern unsigned long max_mapnr; -- cgit v1.2.3 From 553af430e7c981e6e8fa5007c5b7b5773acc63dd Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Fri, 31 Mar 2017 15:11:50 -0700 Subject: mm: rmap: fix huge file mmap accounting in the memcg stats Huge pages are accounted as single units in the memcg's "file_mapped" counter. Account the correct number of base pages, like we do in the corresponding node counter. Link: http://lkml.kernel.org/r/20170322005111.3156-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner Reviewed-by: Kirill A. Shutemov Acked-by: Michal Hocko Cc: Vladimir Davydov Cc: [4.8+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memcontrol.h | 6 ++++++ mm/rmap.c | 4 ++-- 2 files changed, 8 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 5af377303880..bb7250c45cb8 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -740,6 +740,12 @@ static inline bool mem_cgroup_oom_synchronize(bool wait) return false; } +static inline void mem_cgroup_update_page_stat(struct page *page, + enum mem_cgroup_stat_index idx, + int nr) +{ +} + static inline void mem_cgroup_inc_page_stat(struct page *page, enum mem_cgroup_stat_index idx) { diff --git a/mm/rmap.c b/mm/rmap.c index 49ed681ccc7b..f6838015810f 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1159,7 +1159,7 @@ void page_add_file_rmap(struct page *page, bool compound) goto out; } __mod_node_page_state(page_pgdat(page), NR_FILE_MAPPED, nr); - mem_cgroup_inc_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED); + mem_cgroup_update_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED, nr); out: unlock_page_memcg(page); } @@ -1199,7 +1199,7 @@ static void page_remove_file_rmap(struct page *page, bool compound) * pte lock(a spinlock) is held, which implies preemption disabled. */ __mod_node_page_state(page_pgdat(page), NR_FILE_MAPPED, -nr); - mem_cgroup_dec_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED); + mem_cgroup_update_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED, -nr); if (unlikely(PageMlocked(page))) clear_page_mlock(page); -- cgit v1.2.3 From b0845ce58379d11dcad4cdb6824a6410de260216 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Fri, 31 Mar 2017 15:12:04 -0700 Subject: kasan: report only the first error by default Disable kasan after the first report. There are several reasons for this: - Single bug quite often has multiple invalid memory accesses causing storm in the dmesg. - Write OOB access might corrupt metadata so the next report will print bogus alloc/free stacktraces. - Reports after the first easily could be not bugs by itself but just side effects of the first one. Given that multiple reports usually only do harm, it makes sense to disable kasan after the first one. If user wants to see all the reports, the boot-time parameter kasan_multi_shot must be used. [aryabinin@virtuozzo.com: wrote changelog and doc, added missing include] Link: http://lkml.kernel.org/r/20170323154416.30257-1-aryabinin@virtuozzo.com Signed-off-by: Mark Rutland Signed-off-by: Andrey Ryabinin Cc: Andrey Konovalov Cc: Alexander Potapenko Cc: Dmitry Vyukov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/admin-guide/kernel-parameters.txt | 6 +++++ include/linux/kasan.h | 3 +++ lib/test_kasan.c | 10 +++++++ mm/kasan/kasan.h | 5 ---- mm/kasan/report.c | 36 +++++++++++++++++++++++++ 5 files changed, 55 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 2ba45caabada..facc20a3f962 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1725,6 +1725,12 @@ kernel and module base offset ASLR (Address Space Layout Randomization). + kasan_multi_shot + [KNL] Enforce KASAN (Kernel Address Sanitizer) to print + report on every invalid memory access. Without this + parameter KASAN will print report only for the first + invalid access. + keepinitrd [HW,ARM] kernelcore= [KNL,X86,IA-64,PPC] diff --git a/include/linux/kasan.h b/include/linux/kasan.h index 5734480c9590..a5c7046f26b4 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -76,6 +76,9 @@ size_t ksize(const void *); static inline void kasan_unpoison_slab(const void *ptr) { ksize(ptr); } size_t kasan_metadata_size(struct kmem_cache *cache); +bool kasan_save_enable_multi_shot(void); +void kasan_restore_multi_shot(bool enabled); + #else /* CONFIG_KASAN */ static inline void kasan_unpoison_shadow(const void *address, size_t size) {} diff --git a/lib/test_kasan.c b/lib/test_kasan.c index 0b1d3140fbb8..a25c9763fce1 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -20,6 +20,7 @@ #include #include #include +#include /* * Note: test functions are marked noinline so that their names appear in @@ -474,6 +475,12 @@ static noinline void __init use_after_scope_test(void) static int __init kmalloc_tests_init(void) { + /* + * Temporarily enable multi-shot mode. Otherwise, we'd only get a + * report for the first case. + */ + bool multishot = kasan_save_enable_multi_shot(); + kmalloc_oob_right(); kmalloc_oob_left(); kmalloc_node_oob_right(); @@ -499,6 +506,9 @@ static int __init kmalloc_tests_init(void) ksize_unpoisons_memory(); copy_user_test(); use_after_scope_test(); + + kasan_restore_multi_shot(multishot); + return -EAGAIN; } diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index 1c260e6b3b3c..dd2dea8eb077 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -96,11 +96,6 @@ static inline const void *kasan_shadow_to_mem(const void *shadow_addr) << KASAN_SHADOW_SCALE_SHIFT); } -static inline bool kasan_report_enabled(void) -{ - return !current->kasan_depth; -} - void kasan_report(unsigned long addr, size_t size, bool is_write, unsigned long ip); void kasan_report_double_free(struct kmem_cache *cache, void *object, diff --git a/mm/kasan/report.c b/mm/kasan/report.c index f479365530b6..ab42a0803f16 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -13,7 +13,9 @@ * */ +#include #include +#include #include #include #include @@ -293,6 +295,40 @@ static void kasan_report_error(struct kasan_access_info *info) kasan_end_report(&flags); } +static unsigned long kasan_flags; + +#define KASAN_BIT_REPORTED 0 +#define KASAN_BIT_MULTI_SHOT 1 + +bool kasan_save_enable_multi_shot(void) +{ + return test_and_set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags); +} +EXPORT_SYMBOL_GPL(kasan_save_enable_multi_shot); + +void kasan_restore_multi_shot(bool enabled) +{ + if (!enabled) + clear_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags); +} +EXPORT_SYMBOL_GPL(kasan_restore_multi_shot); + +static int __init kasan_set_multi_shot(char *str) +{ + set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags); + return 1; +} +__setup("kasan_multi_shot", kasan_set_multi_shot); + +static inline bool kasan_report_enabled(void) +{ + if (current->kasan_depth) + return false; + if (test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags)) + return true; + return !test_and_set_bit(KASAN_BIT_REPORTED, &kasan_flags); +} + void kasan_report(unsigned long addr, size_t size, bool is_write, unsigned long ip) { -- cgit v1.2.3