mainlining shenanigans
Go to file
Tony Camuso 383035211c ipmi: move message error checking to avoid deadlock
V1->V2: in handle_one_rcv_msg, if data_size > 2, set requeue to zero and
        goto out instead of calling ipmi_free_msg.
        Kosuke Tatsukawa <tatsu@ab.jp.nec.com>

In the source stack trace below, function set_need_watch tries to
take out the same si_lock that was taken earlier by ipmi_thread.

ipmi_thread() [drivers/char/ipmi/ipmi_si_intf.c:995]
 smi_event_handler() [drivers/char/ipmi/ipmi_si_intf.c:765]
  handle_transaction_done() [drivers/char/ipmi/ipmi_si_intf.c:555]
   deliver_recv_msg() [drivers/char/ipmi/ipmi_si_intf.c:283]
    ipmi_smi_msg_received() [drivers/char/ipmi/ipmi_msghandler.c:4503]
     intf_err_seq() [drivers/char/ipmi/ipmi_msghandler.c:1149]
      smi_remove_watch() [drivers/char/ipmi/ipmi_msghandler.c:999]
       set_need_watch() [drivers/char/ipmi/ipmi_si_intf.c:1066]

Upstream commit e1891cffd4 adds code to
ipmi_smi_msg_received() to call smi_remove_watch() via intf_err_seq()
and this seems to be causing the deadlock.

commit e1891cffd4
Author: Corey Minyard <cminyard@mvista.com>
Date:   Wed Oct 24 15:17:04 2018 -0500
    ipmi: Make the smi watcher be disabled immediately when not needed

The fix is to put all messages in the queue and move the message
checking code out of ipmi_smi_msg_received and into handle_one_recv_msg,
which processes the message checking after ipmi_thread releases its
locks.

Additionally,Kosuke Tatsukawa <tatsu@ab.jp.nec.com> reported that
handle_new_recv_msgs calls ipmi_free_msg when handle_one_rcv_msg returns
zero, so that the call to ipmi_free_msg in handle_one_rcv_msg introduced
another panic when "ipmitool sensor list" was run in a loop. He
submitted this part of the patch.

+free_msg:
+               requeue = 0;
+               goto out;

Reported by: Osamu Samukawa <osa-samukawa@tg.jp.nec.com>
Characterized by: Kosuke Tatsukawa <tatsu@ab.jp.nec.com>
Signed-off-by: Tony Camuso <tcamuso@redhat.com>
Fixes: e1891cffd4 ("ipmi: Make the smi watcher be disabled immediately when not needed")
Cc: stable@vger.kernel.org # 5.1
Signed-off-by: Corey Minyard <cminyard@mvista.com>
2019-08-22 11:08:13 -05:00
arch SPDX fixes for 5.3-rc2 2019-07-28 10:00:06 -07:00
block for-linus-20190726-2 2019-07-26 19:20:34 -07:00
certs Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
crypto USB / PHY patches for 5.3-rc1 2019-07-11 15:40:06 -07:00
Documentation HMM patches for 5.3-rc 2019-07-30 12:54:44 -07:00
drivers ipmi: move message error checking to avoid deadlock 2019-08-22 11:08:13 -05:00
fs Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-31 13:26:54 -07:00
include Two minor fixes: 2019-07-31 10:26:59 -07:00
init Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
ipc Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
kernel Two minor fixes: 2019-07-31 10:26:59 -07:00
lib test_firmware: fix a memory leak bug 2019-07-25 14:39:52 +02:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm mm: slub: Fix slab walking for init_on_free 2019-07-31 13:16:06 -07:00
net tcp: be more careful in tcp_fragment() 2019-07-21 20:41:24 -07:00
samples treewide: remove SPDX "WITH Linux-syscall-note" from kernel-space headers again 2019-07-25 11:05:10 +02:00
scripts Kbuild fixes for v5.3 2019-07-28 10:35:04 -07:00
security meminit fix 2019-07-28 12:33:15 -07:00
sound sound fixes for 5.3-rc2 2019-07-26 10:23:45 -07:00
tools for-linus-20190730 2019-07-30 13:25:14 -07:00
usr kbuild: enable arch/s390/include/uapi/asm/zcrypt.h for uapi header test 2019-07-23 10:45:46 +02:00
virt Documentation: move Documentation/virtual to Documentation/virt 2019-07-24 10:52:11 +02:00
.clang-format Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-04-17 11:26:25 -07:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes
.gitignore .gitignore: Add compilation database file 2019-07-27 12:18:19 +09:00
.mailmap MAINTAINERS: Update my email address 2019-07-22 14:57:50 +01:00
COPYING
CREDITS Remove references to dead website. 2019-07-19 12:22:04 -07:00
Kbuild Kbuild updates for v5.1 2019-03-10 17:48:21 -07:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS Char/Misc driver fixes for 5.3-rc2 2019-07-28 10:26:10 -07:00
Makefile Linux 5.3-rc2 2019-07-28 12:47:02 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.