korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-12-15 23:14:31 +08:00
Code Issues Packages Projects Releases Wiki Activity
ef5e2fa9f6
linux/drivers
History
Raz Manor ef5e2fa9f6 usb: gadget: udc: net2280: Fix tmp reusage in net2280 driver 
In the function scan_dma_completions() there is a reusage of tmp
variable. That coused a wrong value being used in some case when
reading a short packet terminated transaction from an endpoint,
in 2 concecutive reads.

This was my logic for the patch:

The req->td->dmadesc equals to 0 iff:
-- There was a transaction ending with a short packet, and
-- The read() to read it was shorter than the transaction length, and
-- The read() to complete it is longer than the residue.
I believe this is true from the printouts of various cases,
but I can't be positive it is correct.

Entering this if, there should be no more data in the endpoint
(a short packet terminated the transaction).
If there is, the transaction wasn't really done and we should exit and
wait for it to finish entirely. That is the inner if.
That inner if should never happen, but it is there to be on the safe
side. That is why it is marked with the comment /* paranoia */.
The size of the data available in the endpoint is ep->dma->dmacount
and it is read to tmp.
This entire clause is based on my own educated guesses.

If we passed that inner if without breaking in the original code,
than tmp & DMA_BYTE_MASK_COUNT== 0.
That means we will always pass dma bytes count of 0 to dma_done(),
meaning all the requested bytes were read.

dma_done() reports back to the upper layer that the request (read())
was done and how many bytes were read.
In the original code that would always be the request size,
regardless of the actual size of the data.
That did not make sense to me at all.

However, the original value of tmp is req->td->dmacount,
which is the dmacount value when the request's dma transaction was
finished. And that is a much more reasonable value to report back to
the caller.

To recreate the problem:
Read from a bulk out endpoint in a loop, 1024 * n bytes in each
iteration.
Connect the PLX to a host you can control.
Send to that endpoint 1024 * n + x bytes,
such that 0 < x < 1024 * n and (x % 1024) != 0
You would expect the first read() to return 1024 * n
and the second read() to return x.
But you will get the first read to return 1024 * n
and the second one to return 1024 * n.
That is true for every positive integer n.

Cc: Felipe Balbi <balbi@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Raz Manor <Raz.Manor@valens.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2017-03-06 17:14:26 +02:00
..
accessibility
acpi Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm 2017-03-03 16:48:48 -08:00
amba
android sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h> 2017-03-02 08:42:29 +01:00
ata SCSI misc on 20170303 2017-03-03 21:36:56 -08:00
atm sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
auxdisplay
base Merge branch 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-03-03 11:38:56 -08:00
bcma
block SCSI misc on 20170303 2017-03-03 21:36:56 -08:00
bluetooth btmrvl: fix spelling mistake: "actived" -> "activated" 2017-02-19 00:26:37 +01:00
bus ARM: SoC driver updates 2017-02-23 15:57:04 -08:00
cdrom Merge branch 'for-4.11/next' into for-4.11/linus-merge 2017-02-17 14:08:19 -07:00
char Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
clk ARM: SoC: late DT updates for v4.11 2017-03-03 16:15:48 -08:00
clocksource sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h> 2017-03-02 08:42:27 +01:00
connector
cpufreq Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
cpuidle Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-03-04 10:42:53 -08:00
dax sched/headers: Prepare to remove the <linux/magic.h> include from <linux/sched/task_stack.h> 2017-03-02 08:42:40 +01:00
dca
devfreq scripts/spelling.txt: add "followings" pattern and fix typo instances 2017-02-27 18:43:47 -08:00
dio
dma sched/headers: Prepare to move the get_task_struct()/put_task_struct() and related APIs from <linux/sched.h> to <linux/sched/task.h> 2017-03-02 08:42:40 +01:00
dma-buf sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
edac Merge branch 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-02-20 12:47:44 -08:00
eisa
extcon scripts/spelling.txt: add "swithc" pattern and fix typo instances 2017-02-27 18:43:46 -08:00
firewire Merge branch 'idr-4.11' of git://git.infradead.org/users/willy/linux-dax 2017-02-28 20:29:41 -08:00
firmware sched/headers: Prepare for new header dependencies before moving code to <uapi/linux/sched/types.h> 2017-03-02 08:42:27 +01:00
fmc
fpga
fsi
gpio This is the bulk of GPIO changes for the v4.11 cycle 2017-02-23 08:46:04 -08:00
gpu Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
hid sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
hsi sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
hv sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
hwmon scripts/spelling.txt: add "followings" pattern and fix typo instances 2017-02-27 18:43:47 -08:00
hwspinlock
hwtracing mm, fs: reduce fault, page_mkwrite, and pfn_mkwrite to take only vmf 2017-02-24 17:46:54 -08:00
i2c sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
ide sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
idle Power management turbostat utility updates for v4.11-rc1 2017-03-02 17:41:27 -08:00
iio Staging/IIO driver fixes for 4.11-rc1 2017-03-04 11:26:18 -08:00
infiniband sched/headers: Prepare to move the get_task_struct()/put_task_struct() and related APIs from <linux/sched.h> to <linux/sched/task.h> 2017-03-02 08:42:40 +01:00
input Input: rmi4 - f30: detect INPUT_PROP_BUTTONPAD from the button count 2017-03-01 10:01:56 -08:00
iommu sched/headers: Prepare for new header dependencies before moving code to <linux/sched/mm.h> 2017-03-02 08:42:28 +01:00
ipack
irqchip IOMMU Updates for Linux v4.11 2017-02-20 16:42:43 -08:00
isdn sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h> 2017-03-02 08:42:39 +01:00
leds sched/headers: Prepare for new header dependencies before moving code to <linux/sched/loadavg.h> 2017-03-02 08:42:27 +01:00
lguest sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
lightnvm
macintosh sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
mailbox sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
mcb
md Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
media sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h> 2017-03-02 08:42:37 +01:00
memory ARM: SoC driver updates 2017-02-23 15:57:04 -08:00
memstick Merge branch 'for-4.11/next' into for-4.11/linus-merge 2017-02-17 14:08:19 -07:00
message SCSI misc on 20170220 2017-02-21 11:51:42 -08:00
mfd staging/iio driver patches for 4.11-rc1 2017-02-22 12:14:01 -08:00
misc Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
mmc sched/headers: Prepare for new header dependencies before moving code to <uapi/linux/sched/types.h> 2017-03-02 08:42:27 +01:00
mtd Merge branch 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-03-03 11:38:56 -08:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-03-04 17:31:39 -08:00
nfc scripts/spelling.txt: add "omited" pattern and fix typo instances 2017-02-27 18:43:47 -08:00
ntb ntb: ntb_hw_intel: link_poll isn't clearing the pending status properly 2017-02-16 23:11:26 -05:00
nubus
nvdimm nfit, libnvdimm: fix interleave set cookie calculation 2017-03-01 00:49:42 -08:00
nvme Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2017-03-03 10:53:35 -08:00
nvmem
of DeviceTree updates for 4.11: 2017-02-22 19:23:14 -08:00
oprofile sched/headers: Prepare to move the get_task_struct()/put_task_struct() and related APIs from <linux/sched.h> to <linux/sched/task.h> 2017-03-02 08:42:40 +01:00
parisc Merge branch 'parisc-4.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2017-03-03 16:20:06 -08:00
parport sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
pci pci-v4.11-fixes-1 2017-03-03 16:44:21 -08:00
pcmcia
perf sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h> 2017-03-02 08:42:27 +01:00
phy pci-v4.11-changes 2017-02-23 11:53:22 -08:00
pinctrl scripts/spelling.txt: add "overrided" pattern and fix typo instances 2017-02-27 18:43:47 -08:00
platform sched/headers: Prepare for new header dependencies before moving code to <linux/sched/loadavg.h> 2017-03-02 08:42:27 +01:00
pnp
power scripts/spelling.txt: add "intialization" pattern and fix typo instances 2017-02-27 18:43:47 -08:00
powercap
pps
ps3 sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h> 2017-03-02 08:42:29 +01:00
ptp 4.11 is going to be a relatively large release for KVM, with a little over 2017-02-22 18:22:53 -08:00
pwm pwm: Changes for v4.11-rc1 2017-03-01 09:46:02 -08:00
rapidio rapidio: use get_user_pages_unlocked() 2017-02-27 18:43:45 -08:00
ras
regulator regulator: Updates for v4.11 2017-02-20 17:23:57 -08:00
remoteproc virtio, vhost: optimizations, fixes 2017-03-02 13:53:13 -08:00
reset ARM: SoC driver updates 2017-02-23 15:57:04 -08:00
rpmsg virtio, vhost: optimizations, fixes 2017-03-02 13:53:13 -08:00
rtc sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
s390 Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
sbus
scsi SCSI misc on 20170303 2017-03-03 21:36:56 -08:00
sfi
sh
sn
soc sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
spi sched/headers: Prepare for new header dependencies before moving code to <uapi/linux/sched/types.h> 2017-03-02 08:42:27 +01:00
spmi
ssb
staging Staging/IIO driver fixes for 4.11-rc1 2017-03-04 11:26:18 -08:00
target Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
tc
thermal sched/headers: Prepare for new header dependencies before moving code to <uapi/linux/sched/types.h> 2017-03-02 08:42:27 +01:00
thunderbolt
tty sched/headers: Prepare to move the get_task_struct()/put_task_struct() and related APIs from <linux/sched.h> to <linux/sched/task.h> 2017-03-02 08:42:40 +01:00
uio sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
usb usb: gadget: udc: net2280: Fix tmp reusage in net2280 driver 2017-03-06 17:14:26 +02:00
uwb
vfio sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h> 2017-03-02 08:42:29 +01:00
vhost Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
video sched/headers: Remove the <linux/mm_types.h> dependency from <linux/sched.h> 2017-03-03 01:45:16 +01:00
virt
virtio Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
vlynq
vme
w1 sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h> 2017-03-02 08:42:29 +01:00
watchdog watchdog: retu: restore MFD dependency 2017-03-01 06:15:10 -08:00
xen sched/headers: Prepare to remove <linux/cred.h> inclusion from <linux/sched.h> 2017-03-02 08:42:31 +01:00
zorro
Kconfig
Makefile pci-v4.11-changes 2017-02-23 11:53:22 -08:00