lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-ID: <CALOAHbDMrHkNHTxeBWP22iTjJd+HfqfFhAfmC_m0jsVkhu5vEA@mail.gmail.com> Date: Thu, 21 May 2020 10:39:25 +0800 From: Yafang Shao <laoar.shao@...il.com> To: Naresh Kamboju <naresh.kamboju@...aro.org> Cc: Chris Down <chris@...isdown.name>, Michal Hocko <mhocko@...nel.org>, Anders Roxell <anders.roxell@...aro.org>, "Linux F2FS DEV, Mailing List" <linux-f2fs-devel@...ts.sourceforge.net>, linux-ext4 <linux-ext4@...r.kernel.org>, linux-block <linux-block@...r.kernel.org>, Andrew Morton <akpm@...ux-foundation.org>, open list <linux-kernel@...r.kernel.org>, Linux-Next Mailing List <linux-next@...r.kernel.org>, linux-mm <linux-mm@...ck.org>, Arnd Bergmann <arnd@...db.de>, Andreas Dilger <adilger.kernel@...ger.ca>, Jaegeuk Kim <jaegeuk@...nel.org>, "Theodore Ts'o" <tytso@....edu>, Chao Yu <chao@...nel.org>, Hugh Dickins <hughd@...gle.com>, Andrea Arcangeli <aarcange@...hat.com>, Matthew Wilcox <willy@...radead.org>, Chao Yu <yuchao0@...wei.com>, lkft-triage@...ts.linaro.org, Johannes Weiner <hannes@...xchg.org>, Roman Gushchin <guro@...com>, Cgroups <cgroups@...r.kernel.org> Subject: Re: mm: mkfs.ext4 invoked oom-killer on i386 - pagecache_get_page On Thu, May 21, 2020 at 2:00 AM Naresh Kamboju <naresh.kamboju@...aro.org> wrote: > > On Wed, 20 May 2020 at 17:26, Naresh Kamboju <naresh.kamboju@...aro.org> wrote: > > > > > > This issue is specific on 32-bit architectures i386 and arm on linux-next tree. > > As per the test results history this problem started happening from > > Bad : next-20200430 > > Good : next-20200429 > > > > steps to reproduce: > > dd if=/dev/disk/by-id/ata-SanDisk_SSD_PLUS_120GB_190504A00573 > > of=/dev/null bs=1M count=2048 > > or > > mkfs -t ext4 /dev/disk/by-id/ata-SanDisk_SSD_PLUS_120GB_190804A00BE5 > > > > > > Problem: > > [ 38.802375] dd invoked oom-killer: gfp_mask=0x100cc0(GFP_USER), > > order=0, oom_score_adj=0 > > As a part of investigation on this issue LKFT teammate Anders Roxell > git bisected the problem and found bad commit(s) which caused this problem. > > The following two patches have been reverted on next-20200519 and retested the > reproducible steps and confirmed the test case mkfs -t ext4 got PASS. > ( invoked oom-killer is gone now) > > Revert "mm, memcg: avoid stale protection values when cgroup is above > protection" > This reverts commit 23a53e1c02006120f89383270d46cbd040a70bc6. > > Revert "mm, memcg: decouple e{low,min} state mutations from protection > checks" > This reverts commit 7b88906ab7399b58bb088c28befe50bcce076d82. > My guess is that we made the same mistake in commit "mm, memcg: decouple e{low,min} state mutations from protection checks" that it read a stale memcg protection in mem_cgroup_below_low() and mem_cgroup_below_min(). Bellow is a possble fix, diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 7a2c56fc..6591b71 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -391,20 +391,28 @@ static inline unsigned long mem_cgroup_protection(struct mem_cgroup *root, void mem_cgroup_calculate_protection(struct mem_cgroup *root, struct mem_cgroup *memcg); -static inline bool mem_cgroup_below_low(struct mem_cgroup *memcg) +static inline bool mem_cgroup_below_low(struct mem_cgroup *root, + struct mem_cgroup *memcg) { if (mem_cgroup_disabled()) return false; + if (root == memcg) + return false; + return READ_ONCE(memcg->memory.elow) >= page_counter_read(&memcg->memory); } -static inline bool mem_cgroup_below_min(struct mem_cgroup *memcg) +static inline bool mem_cgroup_below_min(struct mem_cgroup *root, + struct mem_cgroup *memcg) { if (mem_cgroup_disabled()) return false; + if (root == memcg) + return false; + return READ_ONCE(memcg->memory.emin) >= page_counter_read(&memcg->memory); } @@ -896,12 +904,14 @@ static inline void mem_cgroup_calculate_protection(struct mem_cgroup *root, { } -static inline bool mem_cgroup_below_low(struct mem_cgroup *memcg) +static inline bool mem_cgroup_below_low(struct mem_cgroup *root, + struct mem_cgroup *memcg) { return false; } -static inline bool mem_cgroup_below_min(struct mem_cgroup *memcg) +static inline bool mem_cgroup_below_min(struct mem_cgroup *root, + struct mem_cgroup *memcg) { return false; } diff --git a/mm/vmscan.c b/mm/vmscan.c index c71660e..fdcdd88 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2637,13 +2637,13 @@ static void shrink_node_memcgs(pg_data_t *pgdat, struct scan_control *sc) mem_cgroup_calculate_protection(target_memcg, memcg); - if (mem_cgroup_below_min(memcg)) { + if (mem_cgroup_below_min(target_memcg, memcg)) { /* * Hard protection. * If there is no reclaimable memory, OOM. */ continue; - } else if (mem_cgroup_below_low(memcg)) { + } else if (mem_cgroup_below_low(target_memcg, memcg)) { /* * Soft protection. * Respect the protection only as long as > i386 test log shows mkfs -t ext4 pass > https://lkft.validation.linaro.org/scheduler/job/1443405#L1200 > > ref: > https://lore.kernel.org/linux-mm/cover.1588092152.git.chris@chrisdown.name/ > https://lore.kernel.org/linux-mm/CA+G9fYvzLm7n1BE7AJXd8_49fOgPgWWTiQ7sXkVre_zoERjQKg@mail.gmail.com/T/#t > > -- > Linaro LKFT > https://lkft.linaro.org -- Thanks Yafang
Powered by blists - more mailing lists