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Taehee Yoo 79432d2237 net: sfc: fix memory leak due to ptp channel 
[ Upstream commit 49e6123c65 ]

It fixes memory leak in ring buffer change logic.

When ring buffer size is changed(ethtool -G eth0 rx 4096), sfc driver
works like below.
1. stop all channels and remove ring buffers.
2. allocates new buffer array.
3. allocates rx buffers.
4. start channels.

While the above steps are working, it skips some steps if the channel
doesn't have a ->copy callback function.
Due to ptp channel doesn't have ->copy callback, these above steps are
skipped for ptp channel.
It eventually makes some problems.
a. ptp channel's ring buffer size is not changed, it works only
   1024(default).
b. memory leak.

The reason for memory leak is to use the wrong ring buffer values.
There are some values, which is related to ring buffer size.
a. efx->rxq_entries
 - This is global value of rx queue size.
b. rx_queue->ptr_mask
 - used for access ring buffer as circular ring.
 - roundup_pow_of_two(efx->rxq_entries) - 1
c. rx_queue->max_fill
 - efx->rxq_entries - EFX_RXD_HEAD_ROOM

These all values should be based on ring buffer size consistently.
But ptp channel's values are not.
a. efx->rxq_entries
 - This is global(for sfc) value, always new ring buffer size.
b. rx_queue->ptr_mask
 - This is always 1023(default).
c. rx_queue->max_fill
 - This is new ring buffer size - EFX_RXD_HEAD_ROOM.

Let's assume we set 4096 for rx ring buffer,

                      normal channel     ptp channel
efx->rxq_entries      4096               4096
rx_queue->ptr_mask    4095               1023
rx_queue->max_fill    4086               4086

sfc driver allocates rx ring buffers based on these values.
When it allocates ptp channel's ring buffer, 4086 ring buffers are
allocated then, these buffers are attached to the allocated array.
But ptp channel's ring buffer array size is still 1024(default)
and ptr_mask is still 1023 too.
So, 3062 ring buffers will be overwritten to the array.
This is the reason for memory leak.

Test commands:
   ethtool -G <interface name> rx 4096
   while :
   do
       ip link set <interface name> up
       ip link set <interface name> down
   done

In order to avoid this problem, it adds ->copy callback to ptp channel
type.
So that rx_queue->ptr_mask value will be updated correctly.

Fixes: 7c236c43b8 ("sfc: Add support for IEEE-1588 PTP")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-18 10:23:43 +02:00
arch arm: remove CONFIG_ARCH_HAS_HOLES_MEMORYMODEL 2022-05-15 20:00:09 +02:00
block block-map: add __GFP_ZERO flag for alloc_page in function bio_copy_kern 2022-05-12 12:25:45 +02:00
certs certs: Trigger creation of RSA module signing key if it's not an RSA key 2021-09-15 09:50:29 +02:00
crypto crypto: authenc - Fix sleep in atomic context in decrypt_tail 2022-04-08 14:39:59 +02:00
Documentation arm: remove CONFIG_ARCH_HAS_HOLES_MEMORYMODEL 2022-05-15 20:00:09 +02:00
drivers net: sfc: fix memory leak due to ptp channel 2022-05-18 10:23:43 +02:00
fs arm: remove CONFIG_ARCH_HAS_HOLES_MEMORYMODEL 2022-05-15 20:00:09 +02:00
include net: Fix features skip in for_each_netdev_feature() 2022-05-18 10:23:42 +02:00
init init/main.c: return 1 from handled __setup() functions 2022-04-13 21:01:01 +02:00
ipc shm: extend forced shm destroy to support objects from several IPC nses 2021-12-01 09:19:10 +01:00
kernel rcu: Apply callbacks processing time limit only on softirq 2022-05-12 12:25:45 +02:00
lib hex2bin: fix access beyond string end 2022-05-09 09:04:59 +02:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm mm: userfaultfd: fix missing cache flush in mcopy_atomic_pte() and __mcopy_atomic() 2022-05-15 20:00:09 +02:00
net netlink: do not reset transport header in netlink_recvmsg() 2022-05-18 10:23:43 +02:00
samples samples/bpf, xdpsock: Fix race when running for fix duration of time 2022-04-08 14:40:21 +02:00
scripts gcc-plugins: latent_entropy: use /dev/urandom 2022-04-20 09:23:26 +02:00
security Fix incorrect type in assignment of ipv6 port for audit 2022-04-08 14:40:31 +02:00
sound ASoC: dmaengine: Restore NULL prepare_slave_config() callback 2022-05-12 12:25:37 +02:00
tools selftests: ocelot: tc_flower_chains: specify conform-exceed action for policer 2022-05-12 12:25:42 +02:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:25:48 +01:00
virt KVM: Prevent module exit until all VMs are freed 2022-04-08 14:40:38 +02:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: generate Module.symvers only when vmlinux exists 2021-05-19 10:12:59 +02:00
.mailmap mailmap: add two more addresses of Uwe Kleine-König 2020-12-06 10:19:07 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Jason Cooper to CREDITS 2020-11-30 10:20:34 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: adjust GCC PLUGINS after gcc-plugin.sh removal 2021-12-14 11:32:46 +01:00
Makefile Linux 5.10.116 2022-05-15 20:00:09 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README 

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.