From b655843444152c0a14b749308e4cb35d91cbcf0b Mon Sep 17 00:00:00 2001
From: Vasily Averin <vvs@virtuozzo.com>
Date: Thu, 2 Sep 2021 14:55:14 -0700
Subject: [PATCH] memcg: enable accounting for pollfd and select bits arrays
User can call select/poll system calls with a large number of assigned
file descriptors and force kernel to allocate up to several pages of
memory till end of these sleeping system calls. We have here long-living
unaccounted per-task allocations.
It makes sense to account for these allocations to restrict the host's
memory consumption from inside the memcg-limited container.
Link: https://lkml.kernel.org/r/56e31cb5-6e1e-bdba-d7ca-be64b9842363@virtuozzo.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Yutian Yang <nglaive@gmail.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
fs/select.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/select.c b/fs/select.c
index 945896d0ac9e7..e83e563a351db 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -655,7 +655,7 @@ int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
goto out_nofds;
alloc_size = 6 * size;
- bits = kvmalloc(alloc_size, GFP_KERNEL);
+ bits = kvmalloc(alloc_size, GFP_KERNEL_ACCOUNT);
if (!bits)
goto out_nofds;
}
@@ -1000,7 +1000,7 @@ static int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds,
len = min(todo, POLLFD_PER_PAGE);
walk = walk->next = kmalloc(struct_size(walk, entries, len),
- GFP_KERNEL);
+ GFP_KERNEL_ACCOUNT);
if (!walk) {
err = -ENOMEM;
goto out_fds;
--
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