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Lorenzo Bianconi b2c4d95cb4 mt76: mt76u: rely only on data buffer for usb control messagges
Starting from commit 'a6bfb6d13f33 ("mt76: usb: use max packet length
for m76u_copy")' reg_val does not share memory with usb data buffer.
On non-coherent devices this approach can corrupt data pointer since data
and reg_val share the same cache-line, resulting in the following crash:

[  371.544901] CPU 0 Unable to handle kernel paging request at virtual address 00000000, epc == 8042fbb0
[  371.558521] CPU: 0 PID: 11 Comm: kworker/u2:2 Not tainted 4.14.160 #0
[  371.565204] Workqueue: mt76u mt76u_deinit [mt76_usb]
[  371.570331] task: 83823ac0 task.stack: 8386c000
[  371.575004] $ 0   : 00000000 80590000 00000000 00000000
[  371.580407] $ 4   : 82edaad0 00000002 83823ac0 fffffff8
[  371.585810] $ 8   : fffffffd 0000fc00 8052da00 00000000
[  371.591212] $12   : 000b2285 ae53a1a9 00108845 89da44c4
[  371.596615] $16   : 82edaad0 82ed9d20 00001798 832edf00
[  371.602019] $20   : 00000000 8386dda8 80530000 fffffffe
[  371.607421] $24   : 8051d040 76274d1b
[  371.612824] $28   : 8386c000 8386dd88 82edaad4 830d4d50
[  371.618228] Hi    : 000000f7
[  371.621203] Lo    : 33333371
[  371.624196] epc   : 8042fbb0 __mutex_lock.isra.2+0x134/0x378
[  371.630043] ra    : 830d4d50 mt76u_deinit+0x418/0xa6c [mt76_usb]
[  371.636237] Status: 1000fc03KERNEL EXL IE
[  371.640557] Cause : 0080000c (ExcCode 03)
[  371.644696] BadVA : 00000000
[  371.647671] PrId  : 00019374 (MIPS 24Kc)
[  371.726123]  usbcore nls_base usb_common
[  371.730180] Process kworker/u2:2 (pid: 11, threadinfo=8386c000, task=83823ac0, tls=00000000)
[  371.738884] Stack : 833d009c 83210b4c 82ed8bc0 8386ddac 000001ff 8008ac50 8386ddac 83b74b00
[  371.747519]         82edaad4 00000000 83b74b48 83210c38 82edaad0 82ed9d20 00001798 832edf00
[  371.756157]         00000000 00000000 80530000 fffffffe 80530000 830d4d50 00000040 8389d850
[  371.764794]         8052d9d8 8389d850 8386de30 82ed9d20 8386de5f 831c27bc 833d48ec 8052d9d8
[  371.773431]         83823ac0 83823af0 82edab00 82ed9d20 8386de5f 831c5c30 00000000 8052d9a8
[  371.782069]         ...
[  371.784598] Call Trace:
[  371.787130] [<8042fbb0>] __mutex_lock.isra.2+0x134/0x378
[  371.792622] [<830d4d50>] mt76u_deinit+0x418/0xa6c [mt76_usb]
[  371.808546]
[  371.810920] ---[ end trace c62f0601f6730eb0 ]---
[  371.818101] Kernel panic - not syncing: Fatal exception
[  371.824420] Rebooting in 3 seconds..

Fix the issue relying only on data buffer to send/receive usb control messages

Fixes: a6bfb6d13f ("mt76: usb: use max packet length for m76u_copy")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
2020-03-17 17:13:58 +01:00
Documentation Merge ath-next from git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git 2020-03-16 07:29:55 +02:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
arch arm64: dts: sdm845: add IPA information 2020-03-08 22:07:10 -07:00
block block-5.6-2020-02-05 2020-02-06 06:15:23 +00:00
certs certs: Add wrapper function to check blacklisted binary hash 2019-11-12 12:25:50 +11:00
crypto Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity 2020-02-20 15:15:16 -08:00
drivers mt76: mt76u: rely only on data buffer for usb control messagges 2020-03-17 17:13:58 +01:00
fs Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-02-27 18:31:39 -08:00
include net: sched: make newly activated qdiscs visible 2020-03-11 23:17:28 -07:00
init Tracing updates: 2020-02-26 10:34:42 -08:00
ipc Revert "ipc,sem: remove uneeded sem_undo_list lock usage in exit_sem()" 2020-02-21 11:22:15 -08:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2020-02-29 15:53:35 -08:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2020-02-29 15:53:35 -08:00
mm Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-02-24 11:32:15 -08:00
net net: mptcp: don't hang before sending 'MP capable with data' 2020-03-11 23:59:11 -07:00
samples Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
scripts Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2020-02-29 15:53:35 -08:00
security Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity 2020-02-20 15:15:16 -08:00
sound sound: bt87x: use pci_status_get_and_clear_errors 2020-03-04 14:21:00 -08:00
tools mptcp: selftests: add rcvbuf set option 2020-03-09 19:30:08 -07:00
usr Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
virt KVM: Disable preemption in kvm_get_running_vcpu() 2020-02-12 12:19:35 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.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 selftest/lkdtm: Don't pollute 'git status' 2020-02-20 08:55:06 -07:00
.mailmap A handful of small documentation fixes that wandered in. 2020-02-07 13:03:10 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Hand MIPS over to Thomas 2020-02-24 22:43:18 -08:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS net: phy: Add Synopsys DesignWare XPCS MDIO module 2020-03-09 20:13:16 -07:00
Makefile kbuild: add dt_binding_check to PHONY in a correct place 2020-02-27 02:28:15 +09:00
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.