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
| ||
|
Date: Sun, 09 Jun 2019 13:08:54 +0300 From: Konstantin Khlebnikov <khlebnikov@...dex-team.ru> To: linux-mm@...ck.org, Andrew Morton <akpm@...ux-foundation.org>, linux-kernel@...r.kernel.org Cc: Oleg Nesterov <oleg@...hat.com>, Matthew Wilcox <willy@...radead.org>, Michal Hocko <mhocko@...nel.org>, Cyrill Gorcunov <gorcunov@...il.com>, Kirill Tkhai <ktkhai@...tuozzo.com>, Michal Koutný <mkoutny@...e.com>, Al Viro <viro@...iv.linux.org.uk>, Roman Gushchin <guro@...com> Subject: [PATCH v2 2/6] proc: use down_read_killable mmap_sem for /proc/pid/smaps_rollup Do not stuck forever if something wrong. Killable lock allows to cleanup stuck tasks and simplifies investigation. Signed-off-by: Konstantin Khlebnikov <khlebnikov@...dex-team.ru> Reviewed-by: Roman Gushchin <guro@...com> Reviewed-by: Cyrill Gorcunov <gorcunov@...il.com> Reviewed-by: Kirill Tkhai <ktkhai@...tuozzo.com> Acked-by: Michal Hocko <mhocko@...e.com> --- fs/proc/task_mmu.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 2bf210229daf..781879a91e3b 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -832,7 +832,10 @@ static int show_smaps_rollup(struct seq_file *m, void *v) memset(&mss, 0, sizeof(mss)); - down_read(&mm->mmap_sem); + ret = down_read_killable(&mm->mmap_sem); + if (ret) + goto out_put_mm; + hold_task_mempolicy(priv); for (vma = priv->mm->mmap; vma; vma = vma->vm_next) { @@ -849,8 +852,9 @@ static int show_smaps_rollup(struct seq_file *m, void *v) release_task_mempolicy(priv); up_read(&mm->mmap_sem); - mmput(mm); +out_put_mm: + mmput(mm); out_put_task: put_task_struct(priv->task); priv->task = NULL;
Powered by blists - more mailing lists