Commit Graph

91 Commits

Author SHA1 Message Date
Shuah Khan (Samsung OSG)
40ecdeb1a1 usbip: usbip_detach: fix to check for invalid ports
usbip detach doesn't check for invalid ports and ports that are already
detached. It attempts to remove state file(s) without validating the port
and sends detach request to the driver for ports that are already detached.

Add check for invalid ports (port > maxports) and ports that are already
detached (status == VDEV_ST_NULL). Don't remove state files and don't send
detach request for invalid ports and ports that are already detached.

Add error and information messages that make sense.

Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-31 12:44:39 +02:00
Shuah Khan (Samsung OSG)
d179f99a65 usbip: usbip_detach: Fix memory, udev context and udev leak
detach_port() fails to call usbip_vhci_driver_close() from its error
path after usbip_vhci_detach_device() returns failure, leaking memory
allocated in usbip_vhci_driver_open() and holding udev_context and udev
references. Fix it to call usbip_vhci_driver_close().

Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-31 12:44:39 +02:00
Michael Grzeschik
de19ca6fd7 usbip: dynamically allocate idev by nports found in sysfs
As the amount of available ports varies by the kernels build
configuration. To remove the limitation of the fixed 128 ports
we allocate the amount of idevs by using the number we get
from the kernel.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Acked-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-31 12:43:14 +02:00
Shuah Khan
2699126bcf usbip: tools: usbipd: exclude exported devices from exportable device list
usbipd includes exported devices in response to exportable device list.
Exclude exported devices from exportable device list to avoid:

- import requests for devices that are exported only to fail the request.
- revealing devices that are imported by a client to another client.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-22 13:08:20 +01:00
Shuah Khan
ad81b15d56 usbip: tools: change to use new error codes in server reply messages
Changed usbip_network, usbip_attach, usbip_list, and usbipd to use
and propagate the new error codes in server reply messages.

usbip_net_recv_op_common() is changed to take a pointer to status
return the status returned in the op_common.status to callers.

usbip_attach and usbip_list use the common interface to print error
messages to indicate why the request failed.

With this change the messages say why a request failed:

- when a client requests a device that is already exported:

usbip attach -r server_name -b 3-10.2
usbip: error: Attach Request for 3-10.2 failed - Device busy (exported)

- when a client requests a device that isn't exportable,

usbip attach -r server_name -b 3-10.4
usbip: error: Attach Request for 3-10.4 failed - Device not found

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09 09:17:09 -08:00
Shuah Khan
c207a10d2f usbip: usbip_host_common: Use new error codes to return request status
Currently ST_OK and ST_NA are the only values used to communicate
status of a request from a client. Use new error codes to clearly
indicate what failed. For example, when client sends request to
import a device that isn't export-able, send ST_DEV_BUSY to the client.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09 09:17:08 -08:00
Shuah Khan
f6bcbf2e24 usbip: tools: add more error codes for usbip request/reply messages
Currently ST_OK and ST_NA are the only values defined to communicate
status of a request from a client. Add more error codes to clearly
indicate what failed. For example, when client sends request to import
a device that isn't export-able, server can send a specific error code
to the client.

Existing defines are moved to a common header in libsrc to be included
in the libusbip_la-usbip_common.o to be used by all the usbip tools.
Supporting interface to print error strings is added to the common lib.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09 09:17:08 -08:00
Shuah Khan
8fe8f5821c usbip: tools usbip_network: Fix cryptic error messages
Kernel and tool version mismatch message is cryptic. Fix it to be
informative.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09 09:16:20 -08:00
Shuah Khan
0c60b14860 usbip: tools usbip_attach: Fix cryptic error messages
Attach device error message is cryptic and useless. Fix it to be
informative.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Reviewed-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09 09:16:19 -08:00
Martin Kelly
7ed1c1901f tools: fix cross-compile var clobbering
Currently a number of Makefiles break when used with toolchains that
pass extra flags in CC and other cross-compile related variables (such
as --sysroot).

Thus we get this error when we use a toolchain that puts --sysroot in
the CC var:

  ~/src/linux/tools$ make iio
  [snip]
  iio_event_monitor.c:18:10: fatal error: unistd.h: No such file or directory
    #include <unistd.h>
             ^~~~~~~~~~

This occurs because we clobber several env vars related to
cross-compiling with lines like this:

  CC = $(CROSS_COMPILE)gcc

Although this will point to a valid cross-compiler, we lose any extra
flags that might exist in the CC variable, which can break toolchains
that rely on them (for example, those that use --sysroot).

This easily shows up using a Yocto SDK:

  $ . [snip]/sdk/environment-setup-cortexa8hf-neon-poky-linux-gnueabi

  $ echo $CC
  arm-poky-linux-gnueabi-gcc -march=armv7-a -mfpu=neon -mfloat-abi=hard
  -mcpu=cortex-a8
  --sysroot=[snip]/sdk/sysroots/cortexa8hf-neon-poky-linux-gnueabi

  $ echo $CROSS_COMPILE
  arm-poky-linux-gnueabi-

  $ echo ${CROSS_COMPILE}gcc
  krm-poky-linux-gnueabi-gcc

Although arm-poky-linux-gnueabi-gcc is a cross-compiler, we've lost the
--sysroot and other flags that enable us to find the right libraries to
link against, so we can't find unistd.h and other libraries and headers.
Normally with the --sysroot flag we would find unistd.h in the sdk
directory in the sysroot:

  $ find [snip]/sdk/sysroots -path '*/usr/include/unistd.h'
  [snip]/sdk/sysroots/cortexa8hf-neon-poky-linux-gnueabi/usr/include/unistd.h

The perf Makefile adds CC = $(CROSS_COMPILE)gcc if and only if CC is not
already set, and it compiles correctly with the above toolchain.

So, generalize the logic that perf uses in the common Makefile and
remove the manual CC = $(CROSS_COMPILE)gcc lines from each Makefile.

Note that this patch does not fix cross-compile for all the tools (some
have other bugs), but it does fix it for all except usb and acpi, which
still have other unrelated issues.

I tested both with and without the patch on native and cross-build and
there appear to be no regressions.

Link: http://lkml.kernel.org/r/20180107214028.23771-1-martin@martingkelly.com
Signed-off-by: Martin Kelly <martin@martingkelly.com>
Acked-by: Mark Brown <broonie@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Pali Rohar <pali.rohar@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Robert Moore <robert.moore@intel.com>
Cc: Lv Zheng <lv.zheng@intel.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Valentina Manea <valentina.manea.m@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-21 15:35:42 -08:00
Shuah Khan
ef824501f5 usbip: list: don't list devices attached to vhci_hcd
usbip host lists devices attached to vhci_hcd on the same server
when user does attach over localhost or specifies the server as the
remote.

usbip attach -r localhost -b busid
or
usbip attach -r servername (or server IP)

Fix it to check and not list devices that are attached to vhci_hcd.

Cc: stable@vger.kernel.org
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-22 15:34:37 +01:00
Shuah Khan
ef54cf0c60 usbip: prevent bind loops on devices attached to vhci_hcd
usbip host binds to devices attached to vhci_hcd on the same server
when user does attach over localhost or specifies the server as the
remote.

usbip attach -r localhost -b busid
or
usbip attach -r servername (or server IP)

Unbind followed by bind works, however device is left in a bad state with
accesses via the attached busid result in errors and system hangs during
shutdown.

Fix it to check and bail out if the device is already attached to vhci_hcd.

Cc: stable@vger.kernel.org
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-22 15:34:37 +01:00
Elad Wexler
f7a5d7b3ab tools: usb: usbip: fix fd leak in case of 'fread' failure
Fix possible resource leak: fd

Signed-off-by: Elad Wexler <elad.wexler@gmail.com>
Acked-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-04 17:05:55 +01:00
Elad Wexler
5c65a2fdb3 tools: usb: usbip_device_driver: prefer 'unsigned int' to 'unsigned'
Fixup a coding style issue

Signed-off-by: Elad Wexler <elad.wexler@gmail.com>
Acked-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-04 17:05:55 +01:00
Greg Kroah-Hartman
01f1918833 Merge 4.15.0-rc6 into usb-next
We want the USB fixes in here, and this resolves a merge issue with the
vhci_rx.c file.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-02 15:13:41 +01:00
Juan Zea
544c4605ac usbip: fix usbip bind writing random string after command in match_busid
usbip bind writes commands followed by random string when writing to
match_busid attribute in sysfs, caused by using full variable size
instead of string length.

Signed-off-by: Juan Zea <juan.zea@qindel.com>
Acked-by: Shuah Khan <shuahkh@osg.samsung.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-19 11:40:55 +01:00
Greg Kroah-Hartman
d9e3d899bc Merge 4.15-rc4 into usb-next
We want the USB fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-18 09:08:05 +01:00
Shuah Khan
2f2d0088eb usbip: prevent vhci_hcd driver from leaking a socket pointer address
When a client has a USB device attached over IP, the vhci_hcd driver is
locally leaking a socket pointer address via the

/sys/devices/platform/vhci_hcd/status file (world-readable) and in debug
output when "usbip --debug port" is run.

Fix it to not leak. The socket pointer address is not used at the moment
and it was made visible as a convenient way to find IP address from socket
pointer address by looking up /proc/net/{tcp,tcp6}.

As this opens a security hole, the fix replaces socket pointer address with
sockfd.

Reported-by: Secunia Research <vuln@secunia.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-08 17:32:23 +01:00
Julien BOIBESSOT
82a2b827c9 tools/usbip: fixes potential (minor) "buffer overflow" (detected on recent gcc with -Werror)
Fixes following build error:
vhci_driver.c: In function 'refresh_imported_device_list':
vhci_driver.c:118:37: error: 'snprintf' output may be truncated before
	the last format character [-Werror=format-truncation=]
    snprintf(status, sizeof(status), "status.%d", i);
                                     ^~~~~~~~~~~
vhci_driver.c:118:4: note: 'snprintf' output between 9 and 18 bytes into
	a destination of size 17
    snprintf(status, sizeof(status), "status.%d", i);
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors

Signed-off-by: Julien BOIBESSOT <julien.boibessot@armadeus.com>
Acked-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-08 17:31:20 +01:00
Julien BOIBESSOT
77be4c878c tools/usbip: fixes build with musl libc toolchain
Indeed musl doesn't define old SIGCLD signal name but only new one SIGCHLD.
SIGCHLD is the new POSIX name for that signal so it doesn't change
anything on other libcs.

This fixes this kind of build error:

usbipd.c: In function ‘set_signal’:
usbipd.c:459:12: error: 'SIGCLD' undeclared (first use in this function)
  sigaction(SIGCLD, &act, NULL);
            ^~~~~~
usbipd.c:459:12: note: each undeclared identifier is reported only once
	for each function it appears in
Makefile:407: recipe for target 'usbipd.o' failed
make[3]: *** [usbipd.o] Error 1

Signed-off-by: Julien BOIBESSOT <julien.boibessot@armadeus.com>
Acked-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-07 16:03:15 +01:00
Shuah Khan
1ac7c8a78b usbip: fix usbip attach to find a port that matches the requested speed
usbip attach fails to find a free port when the device on the first port
is a USB_SPEED_SUPER device and non-super speed device is being attached.
It keeps checking the first port and returns without a match getting stuck
in a loop.

Fix it check to find the first port with matching speed.

Reported-by: Juan Zea <juan.zea@qindel.com>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-30 16:40:02 +00:00
Linus Torvalds
894025f24b Merge tag 'usb-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB/PHY updates from Greg KH:
 "Here is the big set of USB and PHY driver updates for 4.15-rc1.

  There is the usual amount of gadget and xhci driver updates, along
  with phy and chipidea enhancements. There's also a lot of SPDX tags
  and license boilerplate cleanups as well, which provide some churn in
  the diffstat.

  Other major thing is the typec code that moved out of staging and into
  the "real" part of the drivers/usb/ tree, which was nice to see
  happen.

  All of these have been in linux-next with no reported issues for a
  while"

* tag 'usb-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (263 commits)
  usb: gadget: f_fs: Fix use-after-free in ffs_free_inst
  USB: usbfs: compute urb->actual_length for isochronous
  usb: core: message: remember to reset 'ret' to 0 when necessary
  USB: typec: Remove remaining redundant license text
  USB: typec: add SPDX identifiers to some files
  USB: renesas_usbhs: rcar?.h: add SPDX tags
  USB: chipidea: ci_hdrc_tegra.c: add SPDX line
  USB: host: xhci-debugfs: add SPDX lines
  USB: add SPDX identifiers to all remaining Makefiles
  usb: host: isp1362-hcd: remove a couple of redundant assignments
  USB: adutux: remove redundant variable minor
  usb: core: add a new usb_get_ptm_status() helper
  usb: core: add a 'type' parameter to usb_get_status()
  usb: core: introduce a new usb_get_std_status() helper
  usb: core: rename usb_get_status() 'type' argument to 'recip'
  usb: core: add Status Type definitions
  USB: gadget: Remove redundant license text
  USB: gadget: function: Remove redundant license text
  USB: gadget: udc: Remove redundant license text
  USB: gadget: legacy: Remove redundant license text
  ...
2017-11-13 21:14:07 -08:00
Greg Kroah-Hartman
b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Ben Hutchings
c15562c0dc usbip: tools: Install all headers needed for libusbip development
usbip_host_driver.h now depends on several additional headers, which
need to be installed along with it.

Fixes: 021aed8453 ("staging: usbip: userspace: migrate usbip_host_driver ...")
Fixes: 3391ba0e27 ("usbip: tools: Extract generic code to be shared with ...")
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Acked-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-04 09:57:02 +02:00
Nobuo Iwata
a38711a88b usbip: auto retry for concurrent attach
This patch adds recovery from false busy state on concurrent attach
operation.

The procedure of attach operation is as below.
1) Find an unused port in /sys/devices/platform/vhci_hcd/status.
(userspace)
2) Request attach found port to driver through
/sys/devices/platform/vhci_hcd/attach. (userspace)
3) Lock table, reserve requested port and unlock table. (vhci driver)

Attaching more than one remote devices concurrently, same unused port
number will be found in step-1. Then one request will succeed and
others will fail even though there are some unused ports.

With this patch, driver returns EBUSY when requested port has already
been used. In this case, attach command retries from step-1: finding
another unused port. If there's no unused port, the attach operation
will fail in step-1. Otherwise it retries automatically using another
unused port.

vhci-hcd's interface (only errno) is changed as following.

Current	errno	New errno	Condition
EINVAL		same as left	specified port number is in invalid
				range
EAGAIN		same as left	platform_get_drvdata() failed
EINVAL		same as left	specified socket fd is not valid
EINVAL		EBUSY		specified port status is not free

The errno EBUSY was not used in userspace
src/usbip_attach.c:import_device(). It is needed to distinguish the
condition to be able to retry from other unrecoverable errors.

It is possible to avoid this failure by introducing userspace exclusive
control. But it's exaggerated for this special condition. The locking
itself has done in driver.
As an alternate solution, userspace doesn't specify port number, driver
searches unused port and it returns port number to the userspace. With
this solution, the interface is much different than this patch.

Signed-off-by: Nobuo Iwata <nobuo.iwata@fujixerox.co.jp>
Acked-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-31 18:08:45 +02:00