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Tobin C. Harding 44f98a9332 rsi: Remove stack VLA usage
The use of stack Variable Length Arrays needs to be avoided, as they
can be a vector for stack exhaustion, which can be both a runtime bug
(kernel Oops) or a security flaw (overwriting memory beyond the
stack). Also, in general, as code evolves it is easy to lose track of
how big a VLA can get. Thus, we can end up having runtime failures
that are hard to debug. As part of the directive[1] to remove all VLAs
from the kernel, and build with -Wvla.

Currently rsi code uses a VLA based on a function argument to
`rsi_sdio_load_data_master_write()`.  The function call chain is

Both these functions

	rsi_sdio_reinit_device()
	rsi_probe()

start the call chain:

	rsi_hal_device_init()
	rsi_load_fw()
	auto_fw_upgrade()
	ping_pong_write()
	rsi_sdio_load_data_master_write()

[Without familiarity with the code] it appears that none of the 4 locks

	mutex
	rx_mutex
	tx_mutex
	tx_bus_mutex

are held when `rsi_sdio_load_data_master_write()` is called.  It is therefore
safe to use kmalloc with GFP_KERNEL.

We can avoid using the VLA by using `kmalloc()` and free'ing the memory on all
exit paths.

Change buffer from 'u8 array' to 'u8 *'.  Call `kmalloc()` to allocate memory for
the buffer.  Using goto statement to call `kfree()` on all return paths.

It can be expected that this patch will result in a small increase in overhead
due to the use of `kmalloc()` however this code is only called on initialization
(and re-initialization) so this overhead should not degrade performance.

[1] https://lkml.org/lkml/2018/3/7/621

Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
2018-03-27 11:04:32 +03:00
Documentation tls: Add receive path documentation 2018-03-23 12:25:54 -04:00
LICENSES LICENSES: Add MPL-1.1 license 2018-01-06 10:59:44 -07:00
arch Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-03-23 11:31:58 -04:00
block for-linus-20180302 2018-03-02 09:35:36 -08:00
certs certs/blacklist_nohashes.c: fix const confusion in certs blacklist 2018-02-21 15:35:43 -08:00
crypto X.509: fix NULL dereference when restricting key with unsupported_sig 2018-02-22 14:38:34 +00:00
drivers rsi: Remove stack VLA usage 2018-03-27 11:04:32 +03:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-03-23 11:31:58 -04:00
include wireless-drivers-next patches for 4.17 2018-03-25 21:27:38 -04:00
init jump_label: Explicitly disable jump labels in __init code 2018-02-21 16:54:05 +01:00
ipc vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-03-23 11:31:58 -04:00
lib net: bpf: add a test for skb_segment in test_bpf module 2018-03-25 16:46:05 -04:00
mm mm, thp: do not cause memcg oom for thp 2018-03-22 17:07:02 -07:00
net tipc: tipc_disc_addr_trial_msg() can be static 2018-03-25 21:21:43 -04:00
samples bpf: sockmap test script 2018-03-19 21:14:41 +01:00
scripts kbuild: Handle builtin dtb file names containing hyphens 2018-03-09 01:14:38 +09:00
security net: Convert smack_net_ops 2018-02-27 11:01:39 -05:00
sound ASoC: Fixes for v4.16 2018-03-12 17:30:38 +01:00
tools tc-testing: updated police, mirred, skbedit and skbmod with more tests 2018-03-25 20:41:46 -04:00
usr initramfs: fix initramfs rebuilds w/ compression after disabling 2017-11-03 07:39:19 -07:00
virt kvm/arm fixes for 4.16, take 2 2018-03-15 21:45:37 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore .gitignore: ignore ASN.1 auto generated files 2018-02-14 21:05:38 +01:00
.mailmap mailmap: update Mark Yao's email address 2018-01-04 16:45:09 -08:00
COPYING
CREDITS MAINTAINERS: update TPM driver infrastructure changes 2017-11-09 17:58:40 -08:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-03-23 11:31:58 -04:00
Makefile Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-03-22 14:10:29 -07:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

README

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

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

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.