linux

mirror of https://github.com/torvalds/linux.git synced 2026-06-08 06:25:52 +02:00

Linux kernel source tree

Go to file

Juergen Gross 975859bb69 xen/xenbus: fix self-deadlock after killing user process commit `a8fabb3852` upstream. In case a user process using xenbus has open transactions and is killed e.g. via ctrl-C the following cleanup of the allocated resources might result in a deadlock due to trying to end a transaction in the xenbus worker thread: [ 2551.474706] INFO: task xenbus:37 blocked for more than 120 seconds. [ 2551.492215] Tainted: P OE 5.0.0-29-generic #5 [ 2551.510263] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 2551.528585] xenbus D 0 37 2 0x80000080 [ 2551.528590] Call Trace: [ 2551.528603] __schedule+0x2c0/0x870 [ 2551.528606] ? _cond_resched+0x19/0x40 [ 2551.528632] schedule+0x2c/0x70 [ 2551.528637] xs_talkv+0x1ec/0x2b0 [ 2551.528642] ? wait_woken+0x80/0x80 [ 2551.528645] xs_single+0x53/0x80 [ 2551.528648] xenbus_transaction_end+0x3b/0x70 [ 2551.528651] xenbus_file_free+0x5a/0x160 [ 2551.528654] xenbus_dev_queue_reply+0xc4/0x220 [ 2551.528657] xenbus_thread+0x7de/0x880 [ 2551.528660] ? wait_woken+0x80/0x80 [ 2551.528665] kthread+0x121/0x140 [ 2551.528667] ? xb_read+0x1d0/0x1d0 [ 2551.528670] ? kthread_park+0x90/0x90 [ 2551.528673] ret_from_fork+0x35/0x40 Fix this by doing the cleanup via a workqueue instead. Reported-by: James Dingwall <james@dingwall.me.uk> Fixes: `fd8aa9095a` ("xen: optimize xenbus driver for multiple concurrent xenstore accesses") Cc: <stable@vger.kernel.org> # 4.11 Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2019-10-11 18:21:06 +02:00
arch	MIPS: Treat Loongson Extensions as ASEs	2019-10-11 18:20:55 +02:00
block	block: mq-deadline: Fix queue restart handling	2019-10-07 18:57:19 +02:00
certs	export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR()	2018-08-22 23:21:44 +09:00
crypto	crypto: skcipher - Unmap pages after an external error	2019-10-11 18:20:52 +02:00
Documentation	ovl: fix regression caused by overlapping layers detection	2019-09-21 07:17:14 +02:00
drivers	xen/xenbus: fix self-deadlock after killing user process	2019-10-11 18:21:06 +02:00
firmware	kbuild: remove all dummy assignments to obj-	2017-11-18 11:46:06 +09:00
fs	9p/cache.c: Fix memory leak in v9fs_cache_session_get_cookie	2019-10-07 18:57:29 +02:00
include	ASoC: Define a set of DAPM pre/post-up events	2019-10-11 18:20:47 +02:00
init	initramfs: don't free a non-existent initrd	2019-10-01 08:26:09 +02:00
ipc	ipc/mqueue.c: only perform resource calculation if user valid	2019-08-06 19:06:52 +02:00
kernel	Revert "locking/pvqspinlock: Don't wait if vCPU is preempted"	2019-10-11 18:21:06 +02:00
lib	kmemleak: increase DEBUG_KMEMLEAK_EARLY_LOG_SIZE default to 16K	2019-10-07 18:57:17 +02:00
LICENSES	LICENSES: Remove CC-BY-SA-4.0 license text	2018-10-18 11:28:50 +02:00
mm	usercopy: Avoid HIGHMEM pfn warning	2019-10-11 18:20:58 +02:00
net	NFC: fix attrs checks in netlink interface	2019-10-07 18:57:28 +02:00
samples	samples, bpf: suppress compiler warning	2019-07-14 08:11:04 +02:00
scripts	randstruct: Check member structs in is_pure_ops_struct()	2019-10-05 13:10:02 +02:00
security	smack: use GFP_NOFS while holding inode_smack::smk_lock	2019-10-07 18:57:27 +02:00
sound	ASoC: sgtl5000: Improve VAG power and mute control	2019-10-11 18:20:47 +02:00
tools	perf stat: Fix a segmentation fault when using repeat forever	2019-10-11 18:21:01 +02:00
usr	kbuild: clean compressed initramfs image	2019-10-07 18:57:16 +02:00
virt	KVM: coalesced_mmio: add bounds checking	2019-09-21 07:16:44 +02:00
.clang-format	clang-format: Set IndentWrappedFunctionNames false	2018-08-01 18:38:51 +02:00
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore	Kbuild updates for v4.17 (2nd)	2018-04-15 17:21:30 -07:00
.mailmap	libnvdimm-for-4.19_misc	2018-08-25 18:13:10 -07:00
COPYING	COPYING: use the new text with points to the license files	2018-03-23 12:41:45 -06:00
CREDITS	9p: remove Ron Minnich from MAINTAINERS	2018-08-17 16:20:26 -07:00
Kbuild	Kbuild updates for v4.15	2017-11-17 17:45:29 -08:00
Kconfig	kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt	2018-08-02 08:06:55 +09:00
MAINTAINERS	platform/x86: Add Intel AtomISP2 dummy / power-management driver	2019-04-20 09:16:02 +02:00
Makefile	Linux 4.19.78	2019-10-07 18:57:29 +02:00
README	Docs: Added a pointer to the formatted docs to README	2018-03-21 09:02:53 -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.
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.