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Yang Yingliang says:
====================
net: don't call dev_kfree_skb() under spin_lock_irqsave()
It is not allowed to call consume_skb() from hardware interrupt context
or with interrupts being disabled. This patchset replace dev_kfree_skb()
with dev_kfree_skb_irq/dev_consume_skb_irq() under spin_lock_irqsave()
in some drivers, or move dev_kfree_skb() after spin_unlock_irqrestore().
v2 -> v3:
Update commit message, and change to use dev_kfree_skb_irq() in patch #1, #3.
v1 -> v2:
patch #2 Move dev_kfree_skb() after spin_unlock_irqrestore()
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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It is not allowed to call kfree_skb() or consume_skb() from hardware
interrupt context or with hardware interrupts being disabled.
It should use dev_kfree_skb_irq() or dev_consume_skb_irq() instead.
The difference between them is free reason, dev_kfree_skb_irq() means
the SKB is dropped in error and dev_consume_skb_irq() means the SKB
is consumed in normal.
In these two cases, dev_kfree_skb() is called consume the xmited SKB,
so replace it with dev_consume_skb_irq().
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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It is not allowed to call kfree_skb() or consume_skb() from hardware
interrupt context or with hardware interrupts being disabled.
It should use dev_kfree_skb_irq() or dev_consume_skb_irq() instead.
The difference between them is free reason, dev_kfree_skb_irq() means
the SKB is dropped in error and dev_consume_skb_irq() means the SKB
is consumed in normal.
In scc_discard_buffers(), dev_kfree_skb() is called to discard the SKBs,
so replace it with dev_kfree_skb_irq().
In scc_net_tx(), dev_kfree_skb() is called to drop the SKB that exceed
queue length, so replace it with dev_kfree_skb_irq().
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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It is not allowed to call kfree_skb() or consume_skb() from hardware
interrupt context or with hardware interrupts being disabled.
In this case, the lock is used to protected 'bp', so we can move
dev_kfree_skb() after the spin_unlock_irqrestore().
Fixes: 4796417417a6 ("dnet: Dave DNET ethernet controller driver (updated)")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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It is not allowed to call kfree_skb() or consume_skb() from hardware
interrupt context or with hardware interrupts being disabled.
It should use dev_kfree_skb_irq() or dev_consume_skb_irq() instead.
The difference between them is free reason, dev_kfree_skb_irq() means
the SKB is dropped in error and dev_consume_skb_irq() means the SKB
is consumed in normal.
In this case, dev_kfree_skb() is called in xemaclite_tx_timeout() to
drop the SKB, when tx timeout, so replace it with dev_kfree_skb_irq().
Fixes: bb81b2ddfa19 ("net: add Xilinx emac lite device driver")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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It is not allowed to call kfree_skb() or consume_skb() from hardware
interrupt context or with hardware interrupts being disabled.
It should use dev_kfree_skb_irq() or dev_consume_skb_irq() instead.
The difference between them is free reason, dev_kfree_skb_irq() means
the SKB is dropped in error and dev_consume_skb_irq() means the SKB
is consumed in normal.
In this case, dev_kfree_skb() is called in bmac_tx_timeout() to drop
the SKB, when tx timeout, so replace it with dev_kfree_skb_irq().
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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It is not allowed to call kfree_skb() or consume_skb() from hardware
interrupt context or with hardware interrupts being disabled.
It should use dev_kfree_skb_irq() or dev_consume_skb_irq() instead.
The difference between them is free reason, dev_kfree_skb_irq() means
the SKB is dropped in error and dev_consume_skb_irq() means the SKB
is consumed in normal.
In this case, dev_kfree_skb() is called in mace_tx_timeout() to drop
the SKB, when tx timeout, so replace it with dev_kfree_skb_irq().
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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There is a race condition in vxlan that when deleting a vxlan device
during receiving packets, there is a possibility that the sock is
released after getting vxlan_sock vs from sk_user_data. Then in
later vxlan_ecn_decapsulate(), vxlan_get_sk_family() we will got
NULL pointer dereference. e.g.
#0 [ffffa25ec6978a38] machine_kexec at ffffffff8c669757
#1 [ffffa25ec6978a90] __crash_kexec at ffffffff8c7c0a4d
#2 [ffffa25ec6978b58] crash_kexec at ffffffff8c7c1c48
#3 [ffffa25ec6978b60] oops_end at ffffffff8c627f2b
#4 [ffffa25ec6978b80] page_fault_oops at ffffffff8c678fcb
#5 [ffffa25ec6978bd8] exc_page_fault at ffffffff8d109542
#6 [ffffa25ec6978c00] asm_exc_page_fault at ffffffff8d200b62
[exception RIP: vxlan_ecn_decapsulate+0x3b]
RIP: ffffffffc1014e7b RSP: ffffa25ec6978cb0 RFLAGS: 00010246
RAX: 0000000000000008 RBX: ffff8aa000888000 RCX: 0000000000000000
RDX: 000000000000000e RSI: ffff8a9fc7ab803e RDI: ffff8a9fd1168700
RBP: ffff8a9fc7ab803e R8: 0000000000700000 R9: 00000000000010ae
R10: ffff8a9fcb748980 R11: 0000000000000000 R12: ffff8a9fd1168700
R13: ffff8aa000888000 R14: 00000000002a0000 R15: 00000000000010ae
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
#7 [ffffa25ec6978ce8] vxlan_rcv at ffffffffc10189cd [vxlan]
#8 [ffffa25ec6978d90] udp_queue_rcv_one_skb at ffffffff8cfb6507
#9 [ffffa25ec6978dc0] udp_unicast_rcv_skb at ffffffff8cfb6e45
#10 [ffffa25ec6978dc8] __udp4_lib_rcv at ffffffff8cfb8807
#11 [ffffa25ec6978e20] ip_protocol_deliver_rcu at ffffffff8cf76951
#12 [ffffa25ec6978e48] ip_local_deliver at ffffffff8cf76bde
#13 [ffffa25ec6978ea0] __netif_receive_skb_one_core at ffffffff8cecde9b
#14 [ffffa25ec6978ec8] process_backlog at ffffffff8cece139
#15 [ffffa25ec6978f00] __napi_poll at ffffffff8ceced1a
#16 [ffffa25ec6978f28] net_rx_action at ffffffff8cecf1f3
#17 [ffffa25ec6978fa0] __softirqentry_text_start at ffffffff8d4000ca
#18 [ffffa25ec6978ff0] do_softirq at ffffffff8c6fbdc3
Reproducer: https://github.com/Mellanox/ovs-tests/blob/master/test-ovs-vxlan-remove-tunnel-during-traffic.sh
Fix this by waiting for all sk_user_data reader to finish before
releasing the sock.
Reported-by: Jianlin Shi <jishi@redhat.com>
Suggested-by: Jakub Sitnicki <jakub@cloudflare.com>
Fixes: 6a93cc905274 ("udp-tunnel: Add a few more UDP tunnel APIs")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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There are two memory leaks reported by kmemleak:
unreferenced object 0xffff888114b20200 (size 128):
comm "modprobe", pid 4846, jiffies 4295146524 (age 401.345s)
hex dump (first 32 bytes):
e0 62 57 09 81 88 ff ff e0 62 57 09 81 88 ff ff .bW......bW.....
01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff815bcd82>] kmalloc_trace+0x22/0x60
[<ffffffff83d35c78>] __hw_addr_add_ex+0x198/0x6c0
[<ffffffff83d3989d>] dev_addr_init+0x13d/0x230
[<ffffffff83d1063d>] alloc_netdev_mqs+0x10d/0xe50
[<ffffffff82b4a06e>] alloc_hdlcdev+0x2e/0x80
[<ffffffffa016a741>] fst_add_one+0x601/0x10e0 [farsync]
...
unreferenced object 0xffff88810b85b000 (size 1024):
comm "modprobe", pid 4846, jiffies 4295146523 (age 401.346s)
hex dump (first 32 bytes):
00 00 b0 02 00 c9 ff ff 00 70 0a 00 00 c9 ff ff .........p......
00 00 00 f2 00 00 00 f3 0a 00 00 00 02 00 00 00 ................
backtrace:
[<ffffffff815bcd82>] kmalloc_trace+0x22/0x60
[<ffffffffa016a294>] fst_add_one+0x154/0x10e0 [farsync]
[<ffffffff82060e83>] local_pci_probe+0xd3/0x170
...
The root cause is traced to the netdev and fst_card_info are not freed
when removes one fst in fst_remove_one(), which may trigger oom if
repeated insmod and rmmod module.
Fix it by adding free_netdev() and kfree() in fst_remove_one(), just as
the operations on the error handling path in fst_add_one().
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Li Zetao <lizetao1@huawei.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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It is not allowed to call kfree_skb() or consume_skb() from hardware
interrupt context or with hardware interrupts being disabled.
It should use dev_kfree_skb_irq() or dev_consume_skb_irq() instead.
The difference between them is free reason, dev_kfree_skb_irq() means
the SKB is dropped in error and dev_consume_skb_irq() means the SKB
is consumed in normal.
In this case, dev_kfree_skb() is called in free_tx_buffers() to drop
the SKBs in tx buffers, when the card is down, so replace it with
dev_kfree_skb_irq() here.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Adds a boundary check to prevent negative basetime input from user
while configuring taprio.
Signed-off-by: Michael Sit Wei Hong <michael.wei.hong.sit@intel.com>
Signed-off-by: Lai Peter Jun Ann <jun.ann.lai@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Had a duplicate event typo, so just fixed the 1 character typo.
Fixes: 1a218d312e65 ("platform/mellanox: mlxbf-pmc: Add Mellanox BlueField PMC driver")
Signed-off-by: James Hurley <jahurley@nvidia.com>
Reviewed-by: David Thompson <davthompson@nvidia.com>
Reviewed-by: Shravan Kumar Ramani <shravankr@nvidia.com>
Link: https://lore.kernel.org/r/aadacdbbd3186c55e74ea9456fe011b77938eb6c.1670535330.git.jahurley@nvidia.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
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Andrew Melnychenko says:
====================
TUN/VirtioNet USO features support.
Added new offloads for TUN devices TUN_F_USO4 and TUN_F_USO6.
Technically they enable NETIF_F_GSO_UDP_L4
(and only if USO4 & USO6 are set simultaneously).
It allows the transmission of large UDP packets.
UDP Segmentation Offload (USO/GSO_UDP_L4) - ability to split UDP packets
into several segments. It's similar to UFO, except it doesn't use IP
fragmentation. The drivers may push big packets and the NIC will split
them(or assemble them in case of receive), but in the case of VirtioNet
we just pass big UDP to the host. So we are freeing the driver from doing
the unnecessary job of splitting. The same thing for several guests
on one host, we can pass big packets between guests.
Different features USO4 and USO6 are required for qemu where Windows
guests can enable disable USO receives for IPv4 and IPv6 separately.
On the other side, Linux can't really differentiate USO4 and USO6, for now.
For now, to enable USO for TUN it requires enabling USO4 and USO6 together.
In the future, there would be a mechanism to control UDP_L4 GSO separately.
New types for virtio-net already in virtio-net specification:
https://github.com/oasis-tcs/virtio-spec/issues/120
Test it WIP Qemu https://github.com/daynix/qemu/tree/USOv3
Changes since v4 & RFC:
* Fixed typo and refactored.
* Tun USO offload refactored.
* Add support for guest-to-guest segmentation offload (thx Jason).
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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Now, it possible to enable GSO_UDP_L4("tx-udp-segmentation") for VirtioNet.
Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Now, it's possible to convert USO vnet packets from/to skb.
Added support for GSO_UDP_L4 offload.
Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Added new GSO type for USO: VIRTIO_NET_HDR_GSO_UDP_L4.
Feature VIRTIO_NET_F_HOST_USO allows to enable NETIF_F_GSO_UDP_L4.
Separated VIRTIO_NET_F_GUEST_USO4 & VIRTIO_NET_F_GUEST_USO6 features
required for Windows guests.
Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Added support for USO4 and USO6.
For now, to "enable" USO, it's required to set both USO4 and USO6 simultaneously.
USO enables NETIF_F_GSO_UDP_L4.
Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Added 2 additional offlloads for USO(IPv4 & IPv6).
Separate offloads are required for Windows VM guests,
g.e. Windows may set USO rx only for IPv4.
Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Allow UDP_L4 for robust packets.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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When setup_mq_sysctls() failed in init_mqueue_fs(), mqueue_inode_cachep is
not released. In order to fix this issue, the release path is reordered.
Link: https://lkml.kernel.org/r/20221209092929.1978875-1-shaozhengchao@huawei.com
Fixes: dc55e35f9e81 ("ipc: Store mqueue sysctls in the ipc namespace")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Cc: Alexey Gladkov <legion@kernel.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Jingyu Wang <jingyuwang_vip@163.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Waiman Long <longman@redhat.com>
Cc: Wei Yongjun <weiyongjun1@huawei.com>
Cc: YueHaibing <yuehaibing@huawei.com>
Cc: Yu Zhe <yuzhe@nfschina.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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mount
Despite specifying UID and GID in mount command, the specified UID and GID
were not being assigned. This patch fixes this issue.
Link: https://lkml.kernel.org/r/C0264BF5-059C-45CF-B8DA-3A3BD2C803A2@live.com
Signed-off-by: Aditya Garg <gargaditya08@live.com>
Reviewed-by: Viacheslav Dubeyko <slava@dubeyko.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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When kfifo_alloc fails, the refcount of chdev->dev is left incremental.
We should use put_device(&chdev->dev) to decrease the ref count of
chdev->dev to avoid refcount leak.
Link: https://lkml.kernel.org/r/20221203085721.13146-1-caixinchen1@huawei.com
Fixes: e8de370188d0 ("rapidio: add mport char device driver")
Signed-off-by: Cai Xinchen <caixinchen1@huawei.com>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Dan Carpenter <error27@gmail.com>
Cc: Jakob Koschel <jakobkoschel@gmail.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Wang Weiyang <wangweiyang2@huawei.com>
Cc: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Fix the typo of 'suport' in kcov.h
Link: https://lkml.kernel.org/r/tencent_922CA94B789587D79FD154445D035AA19E07@qq.com
Signed-off-by: Rong Tao <rongtao@cestc.cn>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Syzbot reported a OOB Write bug:
loop0: detected capacity change from 0 to 64
==================================================================
BUG: KASAN: slab-out-of-bounds in hfs_asc2mac+0x467/0x9a0
fs/hfs/trans.c:133
Write of size 1 at addr ffff88801848314e by task syz-executor391/3632
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106
print_address_description+0x74/0x340 mm/kasan/report.c:284
print_report+0x107/0x1f0 mm/kasan/report.c:395
kasan_report+0xcd/0x100 mm/kasan/report.c:495
hfs_asc2mac+0x467/0x9a0 fs/hfs/trans.c:133
hfs_cat_build_key+0x92/0x170 fs/hfs/catalog.c:28
hfs_lookup+0x1ab/0x2c0 fs/hfs/dir.c:31
lookup_open fs/namei.c:3391 [inline]
open_last_lookups fs/namei.c:3481 [inline]
path_openat+0x10e6/0x2df0 fs/namei.c:3710
do_filp_open+0x264/0x4f0 fs/namei.c:3740
If in->len is much larger than HFS_NAMELEN(31) which is the maximum
length of an HFS filename, a OOB write could occur in hfs_asc2mac(). In
that case, when the dst reaches the boundary, the srclen is still
greater than 0, which causes a OOB write.
Fix this by adding a check on dstlen in while() before writing to dst
address.
Link: https://lkml.kernel.org/r/20221202030038.1391945-1-zhangpeng362@huawei.com
Fixes: 328b92278650 ("[PATCH] hfs: NLS support")
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Reviewed-by: Viacheslav Dubeyko <slava@dubeyko.com>
Reported-by: <syzbot+dc3b1cf9111ab5fe98e7@syzkaller.appspotmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Syzbot reported a OOB read bug:
==================================================================
BUG: KASAN: slab-out-of-bounds in hfs_strcmp+0x117/0x190
fs/hfs/string.c:84
Read of size 1 at addr ffff88807eb62c4e by task kworker/u4:1/11
CPU: 1 PID: 11 Comm: kworker/u4:1 Not tainted
6.1.0-rc6-syzkaller-00308-g644e9524388a #0
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106
print_address_description+0x74/0x340 mm/kasan/report.c:284
print_report+0x107/0x1f0 mm/kasan/report.c:395
kasan_report+0xcd/0x100 mm/kasan/report.c:495
hfs_strcmp+0x117/0x190 fs/hfs/string.c:84
__hfs_brec_find+0x213/0x5c0 fs/hfs/bfind.c:75
hfs_brec_find+0x276/0x520 fs/hfs/bfind.c:138
hfs_write_inode+0x34c/0xb40 fs/hfs/inode.c:462
write_inode fs/fs-writeback.c:1440 [inline]
If the input inode of hfs_write_inode() is incorrect:
struct inode
struct hfs_inode_info
struct hfs_cat_key
struct hfs_name
u8 len # len is greater than HFS_NAMELEN(31) which is the
maximum length of an HFS filename
OOB read occurred:
hfs_write_inode()
hfs_brec_find()
__hfs_brec_find()
hfs_cat_keycmp()
hfs_strcmp() # OOB read occurred due to len is too large
Fix this by adding a Check on len in hfs_write_inode() before calling
hfs_brec_find().
Link: https://lkml.kernel.org/r/20221130065959.2168236-1-zhangpeng362@huawei.com
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Reported-by: <syzbot+e836ff7133ac02be825f@syzkaller.appspotmail.com>
Cc: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Viacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The 'padding' field of the 'rchan_buf' structure is an array of 'size_t'
elements, but the memory is allocated for an array of 'size_t *' elements.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Link: https://lkml.kernel.org/r/20221129092002.3538384-1-Ilia.Gavrilov@infotecs.ru
Fixes: b86ff981a825 ("[PATCH] relay: migrate from relayfs to a generic relay API")
Signed-off-by: Ilia.Gavrilov <Ilia.Gavrilov@infotecs.ru>
Cc: Colin Ian King <colin.i.king@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: wuchi <wuchi.zero@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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When filesystem is using indexed-dirs feature, maximum link count values
can spill over to i_links_count_hi, up to OCFS2_DX_LINK_MAX links.
ocfs2_read_links_count() checks for OCFS2_INDEXED_DIR_FL flag in dinode,
but this flag is only valid for directories so for files the check causes
high part of the link count not being read back from file dinodes
resulting in wrong link count value when file has >65535 links.
As ocfs2_set_links_count() always writes both high and low parts of link
count, the flag check on reading may be removed.
Link: https://lkml.kernel.org/r/cbfca02b-b39f-89de-e1a8-904a6c60407e@alex-at.net
Signed-off-by: Alexey Asemov <alex@alex-at.net>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
It is spurious to have some code out-side the include guard in a .h file.
Fix it.
Link: https://lkml.kernel.org/r/4dbaf427d4300edba6c6bbfaf4d57493b9bec6ee.1669565241.git.christophe.jaillet@wanadoo.fr
Fixes: 1fbaf8fc12a0 ("mm: add a io_mapping_map_user helper")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Building kcsan_test with structleak plugin enabled makes the stack frame
size to grow.
kernel/kcsan/kcsan_test.c:704:1: error: the frame size of 3296 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]
Turn off the structleak plugin checks for kcsan_test.
Link: https://lkml.kernel.org/r/20221128104358.2660634-1-anders.roxell@linaro.org
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Marco Elver <elver@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Gow <davidgow@google.com>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
I'm sunsetting my gmail account and moving to personal domain.
Link: https://lkml.kernel.org/r/20221124114356.2187901-1-me@iskren.info
Signed-off-by: Iskren Chernev <me@iskren.info>
Acked-by: Iskren Chernev <iskren.chernev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Commit ee62c6b2dc93 ("eventfd: change int to __u64 in eventfd_signal()")
forgot to change int to __u64 in the CONFIG_EVENTFD=n stub function.
Link: https://lkml.kernel.org/r/20221124140154.104680-1-zhangqilong3@huawei.com
Fixes: ee62c6b2dc93 ("eventfd: change int to __u64 in eventfd_signal()")
Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Cc: Dylan Yudaken <dylany@fb.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sha Zhengju <handai.szj@taobao.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
If kfifo_alloc() fails in mport_cdev_open(), goto err_fifo and just free
priv. But priv is still in the chdev->file_list, then list traversal
may cause UAF. This fixes the following smatch warning:
drivers/rapidio/devices/rio_mport_cdev.c:1930 mport_cdev_open() warn: '&priv->list' not removed from list
Link: https://lkml.kernel.org/r/20221123095147.52408-1-wangweiyang2@huawei.com
Fixes: e8de370188d0 ("rapidio: add mport char device driver")
Signed-off-by: Wang Weiyang <wangweiyang2@huawei.com>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Dan Carpenter <error27@gmail.com>
Cc: Jakob Koschel <jakobkoschel@gmail.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The implementation of strscpy() is more robust and safer. That's now the
recommended way to copy NUL terminated strings.
Link: https://lkml.kernel.org/r/202211220853259244666@zte.com.cn
Signed-off-by: Xu Panda <xu.panda@zte.com.cn>
Signed-off-by: Yang Yang <yang.yang29@zte.com>
Cc: Colin Ian King <colin.i.king@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: wuchi <wuchi.zero@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Commit 5df397dec7c4 ("mm: delay page_remove_rmap() until after the TLB has
been flushed") limited the page batching for the mmu gather operation when
a dirty shared page needed to delay rmap removal until after the TLB had
been flushed.
It did so because it needs to walk that array of pages while still holding
the page table lock, and our mmu_gather infrastructure allows for batching
quite a lot of pages. We may have thousands on pages queued up for
freeing, and we wanted to walk only the last batch if we then added a
dirty page to the queue.
However, when I limited it to one batch, I didn't think of the degenerate
case of the special first batch that is embedded on-stack in the
mmu_gather structure (called "local") and that only has eight entries.
So with the right pattern, that "limit delayed rmap to just one batch"
will trigger over and over in that first small batch, and we'll waste a
lot of time flushing TLB's every eight pages.
And those right patterns are trivially triggered by just having a shared
mappings with lots of adjacent dirty pages. Like the 'page_fault3'
subtest of the 'will-it-scale' benchmark, that just maps a shared area,
dirties all pages, and unmaps it. Rinse and repeat.
We still want to limit the batching, but to fix this (easily triggered)
degenerate case, just expand the "only one batch" logic to instead be
"only one batch that isn't the special first on-stack ('local') batch".
That way, when we need to flush the delayed rmaps, we can still limit our
walk to just the last batch - and that first small one.
Link: https://lkml.kernel.org/r/CAHk-=whkL5aM1fR7kYUmhHQHBcMUc-bDoFP7EwYjTxy64DGtvw@mail.gmail.com
Fixes: 5df397dec7c4 ("mm: delay page_remove_rmap() until after the TLB has been flushed")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: kernel test robot <yujie.liu@intel.com>
Link: https://lore.kernel.org/oe-lkp/202212051534.852804af-yujie.liu@intel.com
Tested-by: Huang, Ying <ying.huang@intel.com>
Tested-by: Hugh Dickins <hughd@google.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Cc: "Yin, Fengwei" <fengwei.yin@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
change "stat" to "start".
Link: https://lkml.kernel.org/r/20221207074011.GA151242@cloud
Fixes: c959924b0dc5 ("memory tiering: adjust hot threshold automatically")
Signed-off-by: Wang Yong <yongw.kernel@gmail.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Recent Clang changes may cause it to delete calls of memcpy(), if the
source is an uninitialized volatile local. This happens because passing a
pointer to a volatile local into memcpy() discards the volatile qualifier,
giving the compiler a free hand to optimize the memcpy() call away.
Use OPTIMIZER_HIDE_VAR() to hide the uninitialized var from the too-smart
compiler.
Link: https://lkml.kernel.org/r/20221205145740.694038-1-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Suggested-by: Marco Elver <elver@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When handling MADV_WILLNEED in madvise(), a soflockup may occurr in
swapin_walk_pmd_entry() if swapping in lots of memory on a slow device.
Add a cond_resched() to avoid the possible softlockup.
Link: https://lkml.kernel.org/r/20221205140327.72304-1-wangkefeng.wang@huawei.com
Fixes: 1998cc048901 ("mm: make madvise(MADV_WILLNEED) support swap file prefetch")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Shaohua Li <shli@fusionio.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When VM_LOCKONFAULT was added, /proc/PID/smaps wasn't hooked up to it, so
looking at /proc/PID/smaps, it shows '??' instead of something
intelligable. This can be reached by userspace by simply calling
`mlock2(..., MLOCK_ONFAULT);`.
Fix this by adding "lf" to denote VM_LOCKONFAULT.
Link: https://lkml.kernel.org/r/20221205173007.580210-1-Jason@zx2c4.com
Fixes: de60f5f10c58 ("mm: introduce VM_LOCKONFAULT")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Eric B Munson <emunson@akamai.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The test currently fails on 32bit. Fixing the "-1ull" vs. "-1ul" seems
to make the test pass and the compiler happy.
Note: This test is not in mm-stable yet. This fix should be squashed into
"selftests/vm: add KSM unmerge tests".
Link: https://lkml.kernel.org/r/20221205193716.276024-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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|
The compiler complains about the conversion of a pointer to an int of
different width.
Link: https://lkml.kernel.org/r/20221205193716.276024-4-david@redhat.com
Fixes: 6f1405efc61b ("selftests/vm: anon_cow: add R/O longterm tests via gup_test")
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The tests fail to compile in some environments (e.g., Debian 11.5 on x86).
Let's simply conditionally define MADV_POPULATE_(READ|WRITE) if not
already defined, similar to how the khugepaged.c test handles it.
Link: https://lkml.kernel.org/r/20221205193716.276024-3-david@redhat.com
Fixes: 39b2e5cae43d ("selftests/vm: make MADV_POPULATE_(READ|WRITE) use in-tree headers")
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "selftests/vm: fix some tests on 32bit".
I finally had the time to run some of the selftests written by me
(especially "cow") on x86 PAE. I found some unexpected "surprises" :)
With these changes, and with [1] on top of mm-unstable, the "cow" tests
and the "ksm_functional_tests" compile and pass as expected (expected
failures with hugetlb in the "cow" tests). "madv_populate" has one
expected test failure -- x86 does not support softdirty tracking.
#1-#3 fix commits with stable commit ids. #4 fixes a test that is not in
mm-stable yet.
A note that there are many other compile errors/warnings when compiling on
32bit and with older Linux headers ... something for another day.
[1] https://lkml.kernel.org/r/20221205150857.167583-1-david@redhat.com
This patch (of 4):
... we have to kmap()/kunmap(), otherwise this won't work as expected
with highmem.
Link: https://lkml.kernel.org/r/20221205193716.276024-1-david@redhat.com
Link: https://lkml.kernel.org/r/20221205193716.276024-2-david@redhat.com
Fixes: c77369b437f9 ("mm/gup_test: start/stop/read functionality for PIN LONGTERM test")
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>,
Cc: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Commit 4b51634cd16a, introducing the COMPOUND_MAPPED bit, paid attention
to the impossibility of subpages_mapcount ever appearing negative; but did
not attend to those races in which it can momentarily appear larger than
thought possible.
These arise from how page_remove_rmap() first decrements page->_mapcount
or compound_mapcount, then, if that transition goes negative (logical 0),
decrements subpages_mapcount. The initial decrement lets a racing
page_add_*_rmap() reincrement _mapcount or compound_mapcount immediately,
and then in rare cases its corresponding increment of subpages_mapcount
may be completed before page_remove_rmap()'s decrement. There could even
(with increasing unlikelihood) be a series of increments intermixed with
the decrements.
In practice, checking subpages_mapcount with a temporary WARN on range,
has caught values of 0x1000000 (2*COMPOUND_MAPPED, when move_pages() was
using remove_migration_pmd()) and 0x800201 (do_huge_pmd_wp_page() using
__split_huge_pmd()): page_add_anon_rmap() racing page_remove_rmap(), as
predicted.
I certainly found it harder to reason about than when bit_spin_locked, but
the easy case gives a clue to how to handle the harder case. The easy
case being the three !(nr & COMPOUND_MAPPED) checks, which should
obviously be replaced by (nr < COMPOUND_MAPPED) checks - to count a page
as compound mapped, even while the bit in that position is 0.
The harder case is when trying to decide how many subpages are newly
covered or uncovered, when compound map is first added or last removed:
not knowing all that racily happened between first and second atomic ops.
But the easy way to handle that, is again to count the page as compound
mapped all the while that its subpages_mapcount indicates so - ignoring
the _mapcount or compound_mapcount transition while it is on the way to
being reversed.
Link: https://lkml.kernel.org/r/4388158-3092-a960-ff2d-55f2b0fe4ef8@google.com
Fixes: 4b51634cd16a ("mm,thp,rmap: subpages_mapcount COMPOUND_MAPPED if PMD-mapped")
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
I'd been worried by high "swapcached" counts in memcg OOM reports, thought
we had a problem freeing swapcache, but it was just the accounting that
was wrong.
Two issues:
1. When __remove_mapping() removes swapcache,
__delete_from_swap_cache() relies on memcg_data for the right counts to
be updated; but that had already been reset by mem_cgroup_swapout().
Swap those calls around - mem_cgroup_swapout() does not require the
swapcached flag to be set.
6.1 commit ac35a4902374 ("mm: multi-gen LRU: minimal
implementation") already made a similar swap for workingset_eviction(),
but not for this.
2. memcg's "swapcached" count was added for memcg v2 stats, but
displayed on OOM even for memcg v1: so mem_cgroup_move_account() ought
to move it.
Link: https://lkml.kernel.org/r/b8b96ee0-1e1e-85f8-df97-c82a11d7cd14@google.com
Fixes: b6038942480e ("mm: memcg: add swapcache stat for memcg v2")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeelb@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The nodes= arg instructs the kernel to only scan the given nodes for
proactive reclaim. For example use cases, consider a 2 tier memory
system:
nodes 0,1 -> top tier
nodes 2,3 -> second tier
$ echo "1m nodes=0" > memory.reclaim
This instructs the kernel to attempt to reclaim 1m memory from node 0.
Since node 0 is a top tier node, demotion will be attempted first. This
is useful to direct proactive reclaim to specific nodes that are under
pressure.
$ echo "1m nodes=2,3" > memory.reclaim
This instructs the kernel to attempt to reclaim 1m memory in the second
tier, since this tier of memory has no demotion targets the memory will be
reclaimed.
$ echo "1m nodes=0,1" > memory.reclaim
Instructs the kernel to reclaim memory from the top tier nodes, which can
be desirable according to the userspace policy if there is pressure on the
top tiers. Since these nodes have demotion targets, the kernel will
attempt demotion first.
Since commit 3f1509c57b1b ("Revert "mm/vmscan: never demote for memcg
reclaim""), the proactive reclaim interface memory.reclaim does both
reclaim and demotion. Reclaim and demotion incur different latency costs
to the jobs in the cgroup. Demoted memory would still be addressable by
the userspace at a higher latency, but reclaimed memory would need to
incur a pagefault.
The 'nodes' arg is useful to allow the userspace to control demotion and
reclaim independently according to its policy: if the memory.reclaim is
called on a node with demotion targets, it will attempt demotion first; if
it is called on a node without demotion targets, it will only attempt
reclaim.
Link: https://lkml.kernel.org/r/20221202223533.1785418-1-almasrymina@google.com
Signed-off-by: Mina Almasry <almasrymina@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Tejun Heo <tj@kernel.org>
Cc: Wei Xu <weixugc@google.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: zefan li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Reclaiming directly from top tier nodes breaks the aging pipeline of
memory tiers. If we have a RAM -> CXL -> storage hierarchy, we should
demote from RAM to CXL and from CXL to storage. If we reclaim a page from
RAM, it means we 'demote' it directly from RAM to storage, bypassing
potentially a huge amount of pages colder than it in CXL.
However disabling reclaim from top tier nodes entirely would cause ooms in
edge scenarios where lower tier memory is unreclaimable for whatever
reason, e.g. memory being mlocked() or too hot to reclaim. In these
cases we would rather the job run with a performance regression rather
than it oom altogether.
However, we can disable reclaim from top tier nodes for proactive reclaim.
That reclaim is not real memory pressure, and we don't have any cause to
be breaking the aging pipeline.
[akpm@linux-foundation.org: restore comment layout, per Ying Huang]
Link: https://lkml.kernel.org/r/20221201233317.1394958-1-almasrymina@google.com
Signed-off-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Make sure that we ignore protection of a memcg that is the target of memcg
reclaim.
Link: https://lkml.kernel.org/r/20221202031512.1365483-4-yosryahmed@google.com
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Chris Down <chris@chrisdown.name>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vasily Averin <vasily.averin@linux.dev>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Refactor the code that drives writing to memory.reclaim (retrying, error
handling, etc) from test_memcg_reclaim() to a helper called
reclaim_until(), which proactively reclaims from a memcg until its usage
reaches a certain value.
While we are at it, refactor and simplify the reclaim loop.
This will be used in a following patch in another test.
Link: https://lkml.kernel.org/r/20221202031512.1365483-3-yosryahmed@google.com
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Suggested-by: Roman Gushchin <roman.gushchin@linux.dev>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Chris Down <chris@chrisdown.name>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vasily Averin <vasily.averin@linux.dev>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "mm: memcg: fix protection of reclaim target memcg", v3.
This series fixes a bug in calculating the protection of the reclaim
target memcg where we end up using stale effective protection values from
the last reclaim operation, instead of completely ignoring the protection
of the reclaim target as intended. More detailed explanation and examples
in patch 1, which includes the fix. Patches 2 & 3 introduce a selftest
case that catches the bug.
This patch (of 3):
When we are doing memcg reclaim, the intended behavior is that we
ignore any protection (memory.min, memory.low) of the target memcg (but
not its children). Ever since the patch pointed to by the "Fixes" tag,
we actually read a stale value for the target memcg protection when
deciding whether to skip the memcg or not because it is protected. If
the stale value happens to be high enough, we don't reclaim from the
target memcg.
Essentially, in some cases we may falsely skip reclaiming from the
target memcg of reclaim because we read a stale protection value from
last time we reclaimed from it.
During reclaim, mem_cgroup_calculate_protection() is used to determine the
effective protection (emin and elow) values of a memcg. The protection of
the reclaim target is ignored, but we cannot set their effective
protection to 0 due to a limitation of the current implementation (see
comment in mem_cgroup_protection()). Instead, we leave their effective
protection values unchaged, and later ignore it in
mem_cgroup_protection().
However, mem_cgroup_protection() is called later in
shrink_lruvec()->get_scan_count(), which is after the
mem_cgroup_below_{min/low}() checks in shrink_node_memcgs(). As a result,
the stale effective protection values of the target memcg may lead us to
skip reclaiming from the target memcg entirely, before calling
shrink_lruvec(). This can be even worse with recursive protection, where
the stale target memcg protection can be higher than its standalone
protection. See two examples below (a similar version of example (a) is
added to test_memcontrol in a later patch).
(a) A simple example with proactive reclaim is as follows. Consider the
following hierarchy:
ROOT
|
A
|
B (memory.min = 10M)
Consider the following scenario:
- B has memory.current = 10M.
- The system undergoes global reclaim (or memcg reclaim in A).
- In shrink_node_memcgs():
- mem_cgroup_calculate_protection() calculates the effective min (emin)
of B as 10M.
- mem_cgroup_below_min() returns true for B, we do not reclaim from B.
- Now if we want to reclaim 5M from B using proactive reclaim
(memory.reclaim), we should be able to, as the protection of the
target memcg should be ignored.
- In shrink_node_memcgs():
- mem_cgroup_calculate_protection() immediately returns for B without
doing anything, as B is the target memcg, relying on
mem_cgroup_protection() to ignore B's stale effective min (still 10M).
- mem_cgroup_below_min() reads the stale effective min for B and we
skip it instead of ignoring its protection as intended, as we never
reach mem_cgroup_protection().
(b) An more complex example with recursive protection is as follows.
Consider the following hierarchy with memory_recursiveprot:
ROOT
|
A (memory.min = 50M)
|
B (memory.min = 10M, memory.high = 40M)
Consider the following scenario:
- B has memory.current = 35M.
- The system undergoes global reclaim (target memcg is NULL).
- B will have an effective min of 50M (all of A's unclaimed protection).
- B will not be reclaimed from.
- Now allocate 10M more memory in B, pushing it above it's high limit.
- The system undergoes memcg reclaim from B (target memcg is B).
- Like example (a), we do nothing in mem_cgroup_calculate_protection(),
then call mem_cgroup_below_min(), which will read the stale effective
min for B (50M) and skip it. In this case, it's even worse because we
are not just considering B's standalone protection (10M), but we are
reading a much higher stale protection (50M) which will cause us to not
reclaim from B at all.
This is an artifact of commit 45c7f7e1ef17 ("mm, memcg: decouple
e{low,min} state mutations from protection checks") which made
mem_cgroup_calculate_protection() only change the state without returning
any value. Before that commit, we used to return MEMCG_PROT_NONE for the
target memcg, which would cause us to skip the
mem_cgroup_below_{min/low}() checks. After that commit we do not return
anything and we end up checking the min & low effective protections for
the target memcg, which are stale.
Update mem_cgroup_supports_protection() to also check if we are reclaiming
from the target, and rename it to mem_cgroup_unprotected() (now returns
true if we should not protect the memcg, much simpler logic).
Link: https://lkml.kernel.org/r/20221202031512.1365483-1-yosryahmed@google.com
Link: https://lkml.kernel.org/r/20221202031512.1365483-2-yosryahmed@google.com
Fixes: 45c7f7e1ef17 ("mm, memcg: decouple e{low,min} state mutations from protection checks")
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Chris Down <chris@chrisdown.name>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vasily Averin <vasily.averin@linux.dev>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
security_vm_enough_memory_mm() accounts memory via a call to
vm_acct_memory(). Therefore any subsequent failures should unaccount for
this memory prior to returning the error.
Link: https://lkml.kernel.org/r/20221202045339.2999017-1-apopple@nvidia.com
Fixes: 28c5609fb236 ("mm/mmap: preallocate maple nodes for brk vma expansion")
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
