- Linux-stable-mirror - lists.linaro.org

[PATCH v2] tools lib: Fix builds when glibc contains strlcpy

by Vitaly Chikunov

Disable a couple of compilation warning (which are treated as errors) on strlcpy definition and declaration, allow users to compile perf and kernel (objtool). 1. When glibc have strlcpy (such as in ALT Linux since 2004) objtool and perf build fails with this (in gcc): In file included from exec-cmd.c:3: tools/include/linux/string.h:20:15: error: redundant redeclaration of ‘strlcpy’ [-Werror=redundant-decls] 20 | extern size_t strlcpy(char *dest, const char *src, size_t size); 2. Clang ignores `-Wredundant-decls', but produces another warning when building perf: CC util/string.o ../lib/string.c:99:8: error: attribute declaration must precede definition [-Werror,-Wignored-attributes] size_t __weak strlcpy(char *dest, const char *src, size_t size) ../../tools/include/linux/compiler.h:66:34: note: expanded from macro '__weak' # define __weak __attribute__((weak)) /usr/include/bits/string_fortified.h:151:8: note: previous definition is here __NTH (strlcpy (char *__restrict __dest, const char *__restrict __src, Fixes: ce99091 ("perf tools: Move strlcpy() from perf to tools/lib/string.c") Fixes: 0215d59 ("tools lib: Reinstate strlcpy() header guard with __UCLIBC__") Signed-off-by: Vitaly Chikunov <vt(a)altlinux.org> Cc: Dmitry V. Levin <ldv(a)altlinux.org> Cc: Josh Poimboeuf <jpoimboe(a)redhat.com> Cc: Vineet Gupta <Vineet.Gupta1(a)synopsys.com> Cc: stable(a)vger.kernel.org --- tools/include/linux/string.h | 3 +++ tools/lib/string.c | 3 +++ 2 files changed, 6 insertions(+) diff --git a/tools/include/linux/string.h b/tools/include/linux/string.h index 980cb9266718..99ede7f5dfb8 100644 --- a/tools/include/linux/string.h +++ b/tools/include/linux/string.h @@ -17,7 +17,10 @@ int strtobool(const char *s, bool *res); * However uClibc headers also define __GLIBC__ hence the hack below */ #if defined(__GLIBC__) && !defined(__UCLIBC__) +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wredundant-decls" extern size_t strlcpy(char *dest, const char *src, size_t size); +#pragma GCC diagnostic pop #endif char *str_error_r(int errnum, char *buf, size_t buflen); diff --git a/tools/lib/string.c b/tools/lib/string.c index f2ae1b87c719..65b569014446 100644 --- a/tools/lib/string.c +++ b/tools/lib/string.c @@ -96,6 +96,8 @@ int strtobool(const char *s, bool *res) * If libc has strlcpy() then that version will override this * implementation: */ +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wignored-attributes" size_t __weak strlcpy(char *dest, const char *src, size_t size) { size_t ret = strlen(src); @@ -107,6 +109,7 @@ size_t __weak strlcpy(char *dest, const char *src, size_t size) } return ret; } +#pragma GCC diagnostic pop /** * skip_spaces - Removes leading whitespace from @str. -- 2.11.0

5 years, 8 months

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+ mm-debug_pagealloc-dont-rely-on-static-keys-too-early.patch added to -mm tree

by akpm＠linux-foundation.org

The patch titled Subject: mm, debug_pagealloc: don't rely on static keys too early has been added to the -mm tree. Its filename is mm-debug_pagealloc-dont-rely-on-static-keys-too-early.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-debug_pagealloc-dont-rely-on-st… and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-debug_pagealloc-dont-rely-on-st… Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Vlastimil Babka <vbabka(a)suse.cz> Subject: mm, debug_pagealloc: don't rely on static keys too early Commit 96a2b03f281d ("mm, debug_pagelloc: use static keys to enable debugging") has introduced a static key to reduce overhead when debug_pagealloc is compiled in but not enabled. It relied on the assumption that jump_label_init() is called before parse_early_param() as in start_kernel(), so when the "debug_pagealloc=on" option is parsed, it is safe to enable the static key. However, it turns out multiple architectures call parse_early_param() earlier from their setup_arch(). x86 also calls jump_label_init() even earlier, so no issue was found while testing the commit, but same is not true for e.g. ppc64 and s390 where the kernel would not boot with debug_pagealloc=on as found by our QA. To fix this without tricky changes to init code of multiple architectures, this patch partially reverts the static key conversion from 96a2b03f281d. Init-time and non-fastpath calls (such as in arch code) of debug_pagealloc_enabled() will again test a simple bool variable. Fastpath mm code is converted to a new debug_pagealloc_enabled_static() variant that relies on the static key, which is enabled in a well-defined point in mm_init() where it's guaranteed that jump_label_init() has been called, regardless of architecture. Link: http://lkml.kernel.org/r/20191219130612.23171-1-vbabka@suse.cz Fixes: 96a2b03f281d ("mm, debug_pagelloc: use static keys to enable debugging") Signed-off-by: Vlastimil Babka <vbabka(a)suse.cz> Cc: Joonsoo Kim <iamjoonsoo.kim(a)lge.com> Cc: "Kirill A. Shutemov" <kirill.shutemov(a)linux.intel.com> Cc: Michal Hocko <mhocko(a)kernel.org> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: Matthew Wilcox <willy(a)infradead.org> Cc: Mel Gorman <mgorman(a)techsingularity.net> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Borislav Petkov <bp(a)alien8.de> Cc: Qian Cai <cai(a)lca.pw> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- include/linux/mm.h | 18 +++++++++++++++--- init/main.c | 1 + mm/page_alloc.c | 36 ++++++++++++------------------------ mm/slab.c | 4 ++-- mm/slub.c | 2 +- mm/vmalloc.c | 4 ++-- 6 files changed, 33 insertions(+), 32 deletions(-) --- a/include/linux/mm.h~mm-debug_pagealloc-dont-rely-on-static-keys-too-early +++ a/include/linux/mm.h @@ -2652,14 +2652,26 @@ static inline bool want_init_on_free(voi !page_poisoning_enabled(); } -#ifdef CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT -DECLARE_STATIC_KEY_TRUE(_debug_pagealloc_enabled); +#ifdef CONFIG_DEBUG_PAGEALLOC +extern void init_debug_pagealloc(void); #else -DECLARE_STATIC_KEY_FALSE(_debug_pagealloc_enabled); +static inline void init_debug_pagealloc(void) {} #endif +extern bool _debug_pagealloc_enabled_early; +DECLARE_STATIC_KEY_FALSE(_debug_pagealloc_enabled); static inline bool debug_pagealloc_enabled(void) { + return IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) && + _debug_pagealloc_enabled_early; +} + +/* + * For use in fast paths after init_debug_pagealloc() has run, or when a + * false negative result is not harmful when called too early. + */ +static inline bool debug_pagealloc_enabled_static(void) +{ if (!IS_ENABLED(CONFIG_DEBUG_PAGEALLOC)) return false; --- a/init/main.c~mm-debug_pagealloc-dont-rely-on-static-keys-too-early +++ a/init/main.c @@ -554,6 +554,7 @@ static void __init mm_init(void) * bigger than MAX_ORDER unless SPARSEMEM. */ page_ext_init_flatmem(); + init_debug_pagealloc(); report_meminit(); mem_init(); kmem_cache_init(); --- a/mm/page_alloc.c~mm-debug_pagealloc-dont-rely-on-static-keys-too-early +++ a/mm/page_alloc.c @@ -694,34 +694,26 @@ void prep_compound_page(struct page *pag #ifdef CONFIG_DEBUG_PAGEALLOC unsigned int _debug_guardpage_minorder; -#ifdef CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT -DEFINE_STATIC_KEY_TRUE(_debug_pagealloc_enabled); -#else +bool _debug_pagealloc_enabled_early __read_mostly + = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT); DEFINE_STATIC_KEY_FALSE(_debug_pagealloc_enabled); -#endif EXPORT_SYMBOL(_debug_pagealloc_enabled); DEFINE_STATIC_KEY_FALSE(_debug_guardpage_enabled); static int __init early_debug_pagealloc(char *buf) { - bool enable = false; - - if (kstrtobool(buf, &enable)) - return -EINVAL; - - if (enable) - static_branch_enable(&_debug_pagealloc_enabled); - - return 0; + return kstrtobool(buf, &_debug_pagealloc_enabled_early); } early_param("debug_pagealloc", early_debug_pagealloc); -static void init_debug_guardpage(void) +void init_debug_pagealloc(void) { if (!debug_pagealloc_enabled()) return; + static_branch_enable(&_debug_pagealloc_enabled); + if (!debug_guardpage_minorder()) return; @@ -1186,7 +1178,7 @@ static __always_inline bool free_pages_p */ arch_free_page(page, order); - if (debug_pagealloc_enabled()) + if (debug_pagealloc_enabled_static()) kernel_map_pages(page, 1 << order, 0); kasan_free_nondeferred_pages(page, order); @@ -1207,7 +1199,7 @@ static bool free_pcp_prepare(struct page static bool bulkfree_pcp_prepare(struct page *page) { - if (debug_pagealloc_enabled()) + if (debug_pagealloc_enabled_static()) return free_pages_check(page); else return false; @@ -1221,7 +1213,7 @@ static bool bulkfree_pcp_prepare(struct */ static bool free_pcp_prepare(struct page *page) { - if (debug_pagealloc_enabled()) + if (debug_pagealloc_enabled_static()) return free_pages_prepare(page, 0, true); else return free_pages_prepare(page, 0, false); @@ -1973,10 +1965,6 @@ void __init page_alloc_init_late(void) for_each_populated_zone(zone) set_zone_contiguous(zone); - -#ifdef CONFIG_DEBUG_PAGEALLOC - init_debug_guardpage(); -#endif } #ifdef CONFIG_CMA @@ -2106,7 +2094,7 @@ static inline bool free_pages_prezeroed( */ static inline bool check_pcp_refill(struct page *page) { - if (debug_pagealloc_enabled()) + if (debug_pagealloc_enabled_static()) return check_new_page(page); else return false; @@ -2128,7 +2116,7 @@ static inline bool check_pcp_refill(stru } static inline bool check_new_pcp(struct page *page) { - if (debug_pagealloc_enabled()) + if (debug_pagealloc_enabled_static()) return check_new_page(page); else return false; @@ -2155,7 +2143,7 @@ inline void post_alloc_hook(struct page set_page_refcounted(page); arch_alloc_page(page, order); - if (debug_pagealloc_enabled()) + if (debug_pagealloc_enabled_static()) kernel_map_pages(page, 1 << order, 1); kasan_alloc_pages(page, order); kernel_poison_pages(page, 1 << order, 1); --- a/mm/slab.c~mm-debug_pagealloc-dont-rely-on-static-keys-too-early +++ a/mm/slab.c @@ -1416,7 +1416,7 @@ static void kmem_rcu_free(struct rcu_hea #if DEBUG static bool is_debug_pagealloc_cache(struct kmem_cache *cachep) { - if (debug_pagealloc_enabled() && OFF_SLAB(cachep) && + if (debug_pagealloc_enabled_static() && OFF_SLAB(cachep) && (cachep->size % PAGE_SIZE) == 0) return true; @@ -2008,7 +2008,7 @@ int __kmem_cache_create(struct kmem_cach * to check size >= 256. It guarantees that all necessary small * sized slab is initialized in current slab initialization sequence. */ - if (debug_pagealloc_enabled() && (flags & SLAB_POISON) && + if (debug_pagealloc_enabled_static() && (flags & SLAB_POISON) && size >= 256 && cachep->object_size > cache_line_size()) { if (size < PAGE_SIZE || size % PAGE_SIZE == 0) { size_t tmp_size = ALIGN(size, PAGE_SIZE); --- a/mm/slub.c~mm-debug_pagealloc-dont-rely-on-static-keys-too-early +++ a/mm/slub.c @@ -288,7 +288,7 @@ static inline void *get_freepointer_safe unsigned long freepointer_addr; void *p; - if (!debug_pagealloc_enabled()) + if (!debug_pagealloc_enabled_static()) return get_freepointer(s, object); freepointer_addr = (unsigned long)object + s->offset; --- a/mm/vmalloc.c~mm-debug_pagealloc-dont-rely-on-static-keys-too-early +++ a/mm/vmalloc.c @@ -1383,7 +1383,7 @@ static void free_unmap_vmap_area(struct { flush_cache_vunmap(va->va_start, va->va_end); unmap_vmap_area(va); - if (debug_pagealloc_enabled()) + if (debug_pagealloc_enabled_static()) flush_tlb_kernel_range(va->va_start, va->va_end); free_vmap_area_noflush(va); @@ -1681,7 +1681,7 @@ static void vb_free(const void *addr, un vunmap_page_range((unsigned long)addr, (unsigned long)addr + size); - if (debug_pagealloc_enabled()) + if (debug_pagealloc_enabled_static()) flush_tlb_kernel_range((unsigned long)addr, (unsigned long)addr + size); _ Patches currently in -mm which might be from vbabka(a)suse.cz are mm-thp-tweak-reclaim-compaction-effort-of-local-only-and-all-node-allocations.patch mm-debug_pagealloc-dont-rely-on-static-keys-too-early.patch

5 years, 8 months

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[PATCH for 4.4, 4.9, 4.14, 4.19] uio: make symbol 'uio_class_registered' static

by Nobuhiro Iwamatsu

From: Wei Yongjun <weiyongjun1(a)huawei.com> commit 6011002c1584d29c317e0895b9667d57f254537a upstream. Fixes the following sparse warning: drivers/uio/uio.c:277:6: warning: symbol 'uio_class_registered' was not declared. Should it be static? Fixes: ae61cf5b9913 ("uio: ensure class is registered before devices") Signed-off-by: Wei Yongjun <weiyongjun1(a)huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu(a)toshiba.co.jp> --- drivers/uio/uio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c index 2762148c169d..6c8114f77cfa 100644 --- a/drivers/uio/uio.c +++ b/drivers/uio/uio.c @@ -274,7 +274,7 @@ static struct class uio_class = { .dev_groups = uio_groups, }; -bool uio_class_registered; +static bool uio_class_registered; /* * device functions -- 2.23.0

5 years, 8 months

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+ mm-memcg-slab-fix-percpu-slab-vmstats-flushing.patch added to -mm tree

by akpm＠linux-foundation.org

The patch titled Subject: mm: memcg/slab: fix percpu slab vmstats flushing has been added to the -mm tree. Its filename is mm-memcg-slab-fix-percpu-slab-vmstats-flushing.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-memcg-slab-fix-percpu-slab-vmst… and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-memcg-slab-fix-percpu-slab-vmst… Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Roman Gushchin <guro(a)fb.com> Subject: mm: memcg/slab: fix percpu slab vmstats flushing Currently slab percpu vmstats are flushed twice: during the memcg offlining and just before freeing the memcg structure. Each time percpu counters are summed, added to the atomic counterparts and propagated up by the cgroup tree. The second flushing is required due to how recursive vmstats are implemented: counters are batched in percpu variables on a local level, and once a percpu value is crossing some predefined threshold, it spills over to atomic values on the local and each ascendant levels. It means that without flushing some numbers cached in percpu variables will be dropped on floor each time a cgroup is destroyed. And with uptime the error on upper levels might become noticeable. The first flushing aims to make counters on ancestor levels more precise. Dying cgroups may resume in the dying state for a long time. After kmem_cache reparenting which is performed during the offlining slab counters of the dying cgroup don't have any chances to be updated, because any slab operations will be performed on the parent level. It means that the inaccuracy caused by percpu batching will not decrease up to the final destruction of the cgroup. By the original idea flushing slab counters during the offlining should minimize the visible inaccuracy of slab counters on the parent level. The problem is that percpu counters are not zeroed after the first flushing. So every cached percpu value is summed twice. It creates a small error (up to 32 pages per cpu, but usually less) which accumulates on parent cgroup level. After creating and destroying of thousands of child cgroups, slab counter on parent level can be way off the real value. For now, let's just stop flushing slab counters on memcg offlining. It can't be done correctly without scheduling a work on each cpu: reading and zeroing it during css offlining can race with an asynchronous update, which doesn't expect values to be changed underneath. With this change, slab counters on parent level will become eventually consistent. Once all dying children are gone, values are correct. And if not, the error is capped by 32 * NR_CPUS pages per dying cgroup. It's not perfect, as slab are reparented, so any updates after the reparenting will happen on the parent level. It means that if a slab page was allocated, a counter on child level was bumped, then the page was reparented and freed, the annihilation of positive and negative counter values will not happen until the child cgroup is released. It makes slab counters different from others, and it might want us to implement flushing in a correct form again. But it's also a question of performance: scheduling a work on each cpu isn't free, and it's an open question if the benefit of having more accurate counters is worth it. We might also consider flushing all counters on offlining, not only slab counters. So let's fix the main problem now: make the slab counters eventually consistent, so at least the error won't grow with uptime (or more precisely the number of created and destroyed cgroups). And think about the accuracy of counters separately. Link: http://lkml.kernel.org/r/20191220042728.1045881-1-guro@fb.com Fixes: bee07b33db78 ("mm: memcontrol: flush percpu slab vmstats on kmem offlining") Signed-off-by: Roman Gushchin <guro(a)fb.com> Acked-by: Johannes Weiner <hannes(a)cmpxchg.org> Acked-by: Michal Hocko <mhocko(a)suse.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- include/linux/mmzone.h | 5 ++--- mm/memcontrol.c | 37 +++++++++---------------------------- 2 files changed, 11 insertions(+), 31 deletions(-) --- a/include/linux/mmzone.h~mm-memcg-slab-fix-percpu-slab-vmstats-flushing +++ a/include/linux/mmzone.h @@ -215,9 +215,8 @@ enum node_stat_item { NR_INACTIVE_FILE, /* " " " " " */ NR_ACTIVE_FILE, /* " " " " " */ NR_UNEVICTABLE, /* " " " " " */ - NR_SLAB_RECLAIMABLE, /* Please do not reorder this item */ - NR_SLAB_UNRECLAIMABLE, /* and this one without looking at - * memcg_flush_percpu_vmstats() first. */ + NR_SLAB_RECLAIMABLE, + NR_SLAB_UNRECLAIMABLE, NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */ NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */ WORKINGSET_NODES, --- a/mm/memcontrol.c~mm-memcg-slab-fix-percpu-slab-vmstats-flushing +++ a/mm/memcontrol.c @@ -3287,49 +3287,34 @@ static u64 mem_cgroup_read_u64(struct cg } } -static void memcg_flush_percpu_vmstats(struct mem_cgroup *memcg, bool slab_only) +static void memcg_flush_percpu_vmstats(struct mem_cgroup *memcg) { - unsigned long stat[MEMCG_NR_STAT]; + unsigned long stat[MEMCG_NR_STAT] = {0}; struct mem_cgroup *mi; int node, cpu, i; - int min_idx, max_idx; - - if (slab_only) { - min_idx = NR_SLAB_RECLAIMABLE; - max_idx = NR_SLAB_UNRECLAIMABLE; - } else { - min_idx = 0; - max_idx = MEMCG_NR_STAT; - } - - for (i = min_idx; i < max_idx; i++) - stat[i] = 0; for_each_online_cpu(cpu) - for (i = min_idx; i < max_idx; i++) + for (i = 0; i < MEMCG_NR_STAT; i++) stat[i] += per_cpu(memcg->vmstats_percpu->stat[i], cpu); for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) - for (i = min_idx; i < max_idx; i++) + for (i = 0; i < MEMCG_NR_STAT; i++) atomic_long_add(stat[i], &mi->vmstats[i]); - if (!slab_only) - max_idx = NR_VM_NODE_STAT_ITEMS; - for_each_node(node) { struct mem_cgroup_per_node *pn = memcg->nodeinfo[node]; struct mem_cgroup_per_node *pi; - for (i = min_idx; i < max_idx; i++) + for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) stat[i] = 0; for_each_online_cpu(cpu) - for (i = min_idx; i < max_idx; i++) + for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) stat[i] += per_cpu( pn->lruvec_stat_cpu->count[i], cpu); for (pi = pn; pi; pi = parent_nodeinfo(pi, node)) - for (i = min_idx; i < max_idx; i++) + for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) atomic_long_add(stat[i], &pi->lruvec_stat[i]); } } @@ -3403,13 +3388,9 @@ static void memcg_offline_kmem(struct me parent = root_mem_cgroup; /* - * Deactivate and reparent kmem_caches. Then flush percpu - * slab statistics to have precise values at the parent and - * all ancestor levels. It's required to keep slab stats - * accurate after the reparenting of kmem_caches. + * Deactivate and reparent kmem_caches. */ memcg_deactivate_kmem_caches(memcg, parent); - memcg_flush_percpu_vmstats(memcg, true); kmemcg_id = memcg->kmemcg_id; BUG_ON(kmemcg_id < 0); @@ -4913,7 +4894,7 @@ static void mem_cgroup_free(struct mem_c * Flush percpu vmstats and vmevents to guarantee the value correctness * on parent's and all ancestor levels. */ - memcg_flush_percpu_vmstats(memcg, false); + memcg_flush_percpu_vmstats(memcg); memcg_flush_percpu_vmevents(memcg); __mem_cgroup_free(memcg); } _ Patches currently in -mm which might be from guro(a)fb.com are mm-memcg-slab-fix-percpu-slab-vmstats-flushing.patch

5 years, 8 months

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FAILED: patch "[PATCH] Btrfs: fix removal logic of the tree mod log that leads to" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 6609fee8897ac475378388238456c84298bff802 Mon Sep 17 00:00:00 2001 From: Filipe Manana <fdmanana(a)suse.com> Date: Fri, 6 Dec 2019 12:27:39 +0000 Subject: [PATCH] Btrfs: fix removal logic of the tree mod log that leads to use-after-free issues When a tree mod log user no longer needs to use the tree it calls btrfs_put_tree_mod_seq() to remove itself from the list of users and delete all no longer used elements of the tree's red black tree, which should be all elements with a sequence number less then our equals to the caller's sequence number. However the logic is broken because it can delete and free elements from the red black tree that have a sequence number greater then the caller's sequence number: 1) At a point in time we have sequence numbers 1, 2, 3 and 4 in the tree mod log; 2) The task which got assigned the sequence number 1 calls btrfs_put_tree_mod_seq(); 3) Sequence number 1 is deleted from the list of sequence numbers; 4) The current minimum sequence number is computed to be the sequence number 2; 5) A task using sequence number 2 is at tree_mod_log_rewind() and gets a pointer to one of its elements from the red black tree through a call to tree_mod_log_search(); 6) The task with sequence number 1 iterates the red black tree of tree modification elements and deletes (and frees) all elements with a sequence number less then or equals to 2 (the computed minimum sequence number) - it ends up only leaving elements with sequence numbers of 3 and 4; 7) The task with sequence number 2 now uses the pointer to its element, already freed by the other task, at __tree_mod_log_rewind(), resulting in a use-after-free issue. When CONFIG_DEBUG_PAGEALLOC=y it produces a trace like the following: [16804.546854] general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI [16804.547451] CPU: 0 PID: 28257 Comm: pool Tainted: G W 5.4.0-rc8-btrfs-next-51 #1 [16804.548059] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014 [16804.548666] RIP: 0010:rb_next+0x16/0x50 (...) [16804.550581] RSP: 0018:ffffb948418ef9b0 EFLAGS: 00010202 [16804.551227] RAX: 6b6b6b6b6b6b6b6b RBX: ffff90e0247f6600 RCX: 6b6b6b6b6b6b6b6b [16804.551873] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff90e0247f6600 [16804.552504] RBP: ffff90dffe0d4688 R08: 0000000000000001 R09: 0000000000000000 [16804.553136] R10: ffff90dffa4a0040 R11: 0000000000000000 R12: 000000000000002e [16804.553768] R13: ffff90e0247f6600 R14: 0000000000001663 R15: ffff90dff77862b8 [16804.554399] FS: 00007f4b197ae700(0000) GS:ffff90e036a00000(0000) knlGS:0000000000000000 [16804.555039] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [16804.555683] CR2: 00007f4b10022000 CR3: 00000002060e2004 CR4: 00000000003606f0 [16804.556336] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [16804.556968] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [16804.557583] Call Trace: [16804.558207] __tree_mod_log_rewind+0xbf/0x280 [btrfs] [16804.558835] btrfs_search_old_slot+0x105/0xd00 [btrfs] [16804.559468] resolve_indirect_refs+0x1eb/0xc70 [btrfs] [16804.560087] ? free_extent_buffer.part.19+0x5a/0xc0 [btrfs] [16804.560700] find_parent_nodes+0x388/0x1120 [btrfs] [16804.561310] btrfs_check_shared+0x115/0x1c0 [btrfs] [16804.561916] ? extent_fiemap+0x59d/0x6d0 [btrfs] [16804.562518] extent_fiemap+0x59d/0x6d0 [btrfs] [16804.563112] ? __might_fault+0x11/0x90 [16804.563706] do_vfs_ioctl+0x45a/0x700 [16804.564299] ksys_ioctl+0x70/0x80 [16804.564885] ? trace_hardirqs_off_thunk+0x1a/0x20 [16804.565461] __x64_sys_ioctl+0x16/0x20 [16804.566020] do_syscall_64+0x5c/0x250 [16804.566580] entry_SYSCALL_64_after_hwframe+0x49/0xbe [16804.567153] RIP: 0033:0x7f4b1ba2add7 (...) [16804.568907] RSP: 002b:00007f4b197adc88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [16804.569513] RAX: ffffffffffffffda RBX: 00007f4b100210d8 RCX: 00007f4b1ba2add7 [16804.570133] RDX: 00007f4b100210d8 RSI: 00000000c020660b RDI: 0000000000000003 [16804.570726] RBP: 000055de05a6cfe0 R08: 0000000000000000 R09: 00007f4b197add44 [16804.571314] R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4b197add48 [16804.571905] R13: 00007f4b197add40 R14: 00007f4b100210d0 R15: 00007f4b197add50 (...) [16804.575623] ---[ end trace 87317359aad4ba50 ]--- Fix this by making btrfs_put_tree_mod_seq() skip deletion of elements that have a sequence number equals to the computed minimum sequence number, and not just elements with a sequence number greater then that minimum. Fixes: bd989ba359f2ac ("Btrfs: add tree modification log functions") CC: stable(a)vger.kernel.org # 4.4+ Reviewed-by: Josef Bacik <josef(a)toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 5b6e86aaf2e1..24658b5a5787 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -379,7 +379,7 @@ void btrfs_put_tree_mod_seq(struct btrfs_fs_info *fs_info, for (node = rb_first(tm_root); node; node = next) { next = rb_next(node); tm = rb_entry(node, struct tree_mod_elem, node); - if (tm->seq > min_seq) + if (tm->seq >= min_seq) continue; rb_erase(node, tm_root); kfree(tm);

5 years, 8 months

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FAILED: patch "[PATCH] btrfs: abort transaction after failed inode updates in" failed to apply to 4.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From c7e54b5102bf3614cadb9ca32d7be73bad6cecf0 Mon Sep 17 00:00:00 2001 From: Josef Bacik <josef(a)toxicpanda.com> Date: Fri, 6 Dec 2019 09:37:15 -0500 Subject: [PATCH] btrfs: abort transaction after failed inode updates in create_subvol We can just abort the transaction here, and in fact do that for every other failure in this function except these two cases. CC: stable(a)vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn(a)suse.de> Signed-off-by: Josef Bacik <josef(a)toxicpanda.com> Reviewed-by: David Sterba <dsterba(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 3418decb9e61..18e328ce4b54 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -704,11 +704,17 @@ static noinline int create_subvol(struct inode *dir, btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2); ret = btrfs_update_inode(trans, root, dir); - BUG_ON(ret); + if (ret) { + btrfs_abort_transaction(trans, ret); + goto fail; + } ret = btrfs_add_root_ref(trans, objectid, root->root_key.objectid, btrfs_ino(BTRFS_I(dir)), index, name, namelen); - BUG_ON(ret); + if (ret) { + btrfs_abort_transaction(trans, ret); + goto fail; + } ret = btrfs_uuid_tree_add(trans, root_item->uuid, BTRFS_UUID_KEY_SUBVOL, objectid);

5 years, 8 months

2
1
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FAILED: patch "[PATCH] btrfs: return error pointer from alloc_test_extent_buffer" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From b6293c821ea8fa2a631a2112cd86cd435effeb8b Mon Sep 17 00:00:00 2001 From: Dan Carpenter <dan.carpenter(a)oracle.com> Date: Tue, 3 Dec 2019 14:24:58 +0300 Subject: [PATCH] btrfs: return error pointer from alloc_test_extent_buffer Callers of alloc_test_extent_buffer have not correctly interpreted the return value as error pointer, as alloc_test_extent_buffer should behave as alloc_extent_buffer. The self-tests were unaffected but btrfs_find_create_tree_block could call both functions and that would cause problems up in the call chain. Fixes: faa2dbf004e8 ("Btrfs: add sanity tests for new qgroup accounting code") CC: stable(a)vger.kernel.org # 4.4+ Signed-off-by: Dan Carpenter <dan.carpenter(a)oracle.com> Reviewed-by: David Sterba <dsterba(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index eb8bd0258360..2f4802f405a2 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -5074,12 +5074,14 @@ struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info, return eb; eb = alloc_dummy_extent_buffer(fs_info, start); if (!eb) - return NULL; + return ERR_PTR(-ENOMEM); eb->fs_info = fs_info; again: ret = radix_tree_preload(GFP_NOFS); - if (ret) + if (ret) { + exists = ERR_PTR(ret); goto free_eb; + } spin_lock(&fs_info->buffer_lock); ret = radix_tree_insert(&fs_info->buffer_radix, start >> PAGE_SHIFT, eb); diff --git a/fs/btrfs/tests/free-space-tree-tests.c b/fs/btrfs/tests/free-space-tree-tests.c index 1a846bf6e197..914eea5ba6a7 100644 --- a/fs/btrfs/tests/free-space-tree-tests.c +++ b/fs/btrfs/tests/free-space-tree-tests.c @@ -452,9 +452,9 @@ static int run_test(test_func_t test_func, int bitmaps, u32 sectorsize, root->fs_info->tree_root = root; root->node = alloc_test_extent_buffer(root->fs_info, nodesize); - if (!root->node) { + if (IS_ERR(root->node)) { test_std_err(TEST_ALLOC_EXTENT_BUFFER); - ret = -ENOMEM; + ret = PTR_ERR(root->node); goto out; } btrfs_set_header_level(root->node, 0); diff --git a/fs/btrfs/tests/qgroup-tests.c b/fs/btrfs/tests/qgroup-tests.c index 09aaca1efd62..ac035a6fa003 100644 --- a/fs/btrfs/tests/qgroup-tests.c +++ b/fs/btrfs/tests/qgroup-tests.c @@ -484,9 +484,9 @@ int btrfs_test_qgroups(u32 sectorsize, u32 nodesize) * *cough*backref walking code*cough* */ root->node = alloc_test_extent_buffer(root->fs_info, nodesize); - if (!root->node) { + if (IS_ERR(root->node)) { test_err("couldn't allocate dummy buffer"); - ret = -ENOMEM; + ret = PTR_ERR(root->node); goto out; } btrfs_set_header_level(root->node, 0);

5 years, 8 months

2
1
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FAILED: patch "[PATCH] btrfs: do not call synchronize_srcu() in inode_tree_del" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From f72ff01df9cf5db25c76674cac16605992d15467 Mon Sep 17 00:00:00 2001 From: Josef Bacik <josef(a)toxicpanda.com> Date: Tue, 19 Nov 2019 13:59:35 -0500 Subject: [PATCH] btrfs: do not call synchronize_srcu() in inode_tree_del Testing with the new fsstress uncovered a pretty nasty deadlock with lookup and snapshot deletion. Process A unlink -> final iput -> inode_tree_del -> synchronize_srcu(subvol_srcu) Process B btrfs_lookup <- srcu_read_lock() acquired here -> btrfs_iget -> find inode that has I_FREEING set -> __wait_on_freeing_inode() We're holding the srcu_read_lock() while doing the iget in order to make sure our fs root doesn't go away, and then we are waiting for the inode to finish freeing. However because the free'ing process is doing a synchronize_srcu() we deadlock. Fix this by dropping the synchronize_srcu() in inode_tree_del(). We don't need people to stop accessing the fs root at this point, we're only adding our empty root to the dead roots list. A larger much more invasive fix is forthcoming to address how we deal with fs roots, but this fixes the immediate problem. Fixes: 76dda93c6ae2 ("Btrfs: add snapshot/subvolume destroy ioctl") CC: stable(a)vger.kernel.org # 4.4+ Signed-off-by: Josef Bacik <josef(a)toxicpanda.com> Reviewed-by: David Sterba <dsterba(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 56032c518b26..5766c2d19896 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -5728,7 +5728,6 @@ static void inode_tree_add(struct inode *inode) static void inode_tree_del(struct inode *inode) { - struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); struct btrfs_root *root = BTRFS_I(inode)->root; int empty = 0; @@ -5741,7 +5740,6 @@ static void inode_tree_del(struct inode *inode) spin_unlock(&root->inode_lock); if (empty && btrfs_root_refs(&root->root_item) == 0) { - synchronize_srcu(&fs_info->subvol_srcu); spin_lock(&root->inode_lock); empty = RB_EMPTY_ROOT(&root->inode_tree); spin_unlock(&root->inode_lock);

5 years, 8 months

2
1
0 0

FAILED: patch "[PATCH] btrfs: don't double lock the subvol_sem for rename exchange" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 943eb3bf25f4a7b745dd799e031be276aa104d82 Mon Sep 17 00:00:00 2001 From: Josef Bacik <josef(a)toxicpanda.com> Date: Tue, 19 Nov 2019 13:59:20 -0500 Subject: [PATCH] btrfs: don't double lock the subvol_sem for rename exchange If we're rename exchanging two subvols we'll try to lock this lock twice, which is bad. Just lock once if either of the ino's are subvols. Fixes: cdd1fedf8261 ("btrfs: add support for RENAME_EXCHANGE and RENAME_WHITEOUT") CC: stable(a)vger.kernel.org # 4.4+ Signed-off-by: Josef Bacik <josef(a)toxicpanda.com> Reviewed-by: David Sterba <dsterba(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 5766c2d19896..e3c76645cad7 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -9554,9 +9554,8 @@ static int btrfs_rename_exchange(struct inode *old_dir, btrfs_init_log_ctx(&ctx_dest, new_inode); /* close the race window with snapshot create/destroy ioctl */ - if (old_ino == BTRFS_FIRST_FREE_OBJECTID) - down_read(&fs_info->subvol_sem); - if (new_ino == BTRFS_FIRST_FREE_OBJECTID) + if (old_ino == BTRFS_FIRST_FREE_OBJECTID || + new_ino == BTRFS_FIRST_FREE_OBJECTID) down_read(&fs_info->subvol_sem); /* @@ -9790,9 +9789,8 @@ static int btrfs_rename_exchange(struct inode *old_dir, ret = ret ? ret : ret2; } out_notrans: - if (new_ino == BTRFS_FIRST_FREE_OBJECTID) - up_read(&fs_info->subvol_sem); - if (old_ino == BTRFS_FIRST_FREE_OBJECTID) + if (new_ino == BTRFS_FIRST_FREE_OBJECTID || + old_ino == BTRFS_FIRST_FREE_OBJECTID) up_read(&fs_info->subvol_sem); ASSERT(list_empty(&ctx_root.list));

5 years, 8 months

2
1
0 0

[merged] mm-vmscan-protect-shrinker-idr-replace-with-config_memcg.patch removed from -mm tree

by akpm＠linux-foundation.org

The patch titled Subject: mm: vmscan: protect shrinker idr replace with CONFIG_MEMCG has been removed from the -mm tree. Its filename was mm-vmscan-protect-shrinker-idr-replace-with-config_memcg.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Yang Shi <yang.shi(a)linux.alibaba.com> Subject: mm: vmscan: protect shrinker idr replace with CONFIG_MEMCG Since commit 0a432dcbeb32edc ("mm: shrinker: make shrinker not depend on memcg kmem"), shrinkers' idr is protected by CONFIG_MEMCG instead of CONFIG_MEMCG_KMEM, so it makes no sense to protect shrinker idr replace with CONFIG_MEMCG_KMEM. And in the CONFIG_MEMCG && CONFIG_SLOB case, shrinker_idr contains only shrinker, and it is deferred_split_shrinker. But it is never actually called, since idr_replace() is never compiled due to the wrong #ifdef. The deferred_split_shrinker all the time is staying in half-registered state, and it's never called for subordinate mem cgroups. Link: http://lkml.kernel.org/r/1575486978-45249-1-git-send-email-yang.shi@linux.a… Fixes: 0a432dcbeb32 ("mm: shrinker: make shrinker not depend on memcg kmem") Signed-off-by: Yang Shi <yang.shi(a)linux.alibaba.com> Reviewed-by: Kirill Tkhai <ktkhai(a)virtuozzo.com> Acked-by: Michal Hocko <mhocko(a)suse.com> Cc: Johannes Weiner <hannes(a)cmpxchg.org> Cc: Shakeel Butt <shakeelb(a)google.com> Cc: Roman Gushchin <guro(a)fb.com> Cc: <stable(a)vger.kernel.org> [5.4+] Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/vmscan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/vmscan.c~mm-vmscan-protect-shrinker-idr-replace-with-config_memcg +++ a/mm/vmscan.c @@ -387,7 +387,7 @@ void register_shrinker_prepared(struct s { down_write(&shrinker_rwsem); list_add_tail(&shrinker->list, &shrinker_list); -#ifdef CONFIG_MEMCG_KMEM +#ifdef CONFIG_MEMCG if (shrinker->flags & SHRINKER_MEMCG_AWARE) idr_replace(&shrinker_idr, shrinker, shrinker->id); #endif _ Patches currently in -mm which might be from yang.shi(a)linux.alibaba.com are mm-move_pages-return-valid-node-id-in-status-if-the-page-is-already-on-the-target-node.patch

5 years, 8 months

1
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