cca342d98b
A different wait queue was used when removing ctrl_wait than when adding it. This effectively made the remove operation without locking compared to other operations on the wait queue ctrl_wait was part of. This caused issues like below where dead000000000100 is LIST_POISON1 and dead000000000200 is LIST_POISON2. list_add corruption. next->prev should be prev (ffffffc1b0a33a08), \ but was dead000000000200. (next=ffffffc03ac77de0). ------------[ cut here ]------------ CPU: 3 PID: 2138 Comm: bluetoothd Tainted: G O 4.4.238+ #9 ... ---[ end trace 0adc2158f0646eac ]--- Call trace: [<ffffffc000443f78>] __list_add+0x38/0xb0 [<ffffffc0000f0d04>] add_wait_queue+0x4c/0x68 [<ffffffc00020eecc>] __pollwait+0xec/0x100 [<ffffffc000d1556c>] bt_sock_poll+0x74/0x200 [<ffffffc000bdb8a8>] sock_poll+0x110/0x128 [<ffffffc000210378>] do_sys_poll+0x220/0x480 [<ffffffc0002106f0>] SyS_poll+0x80/0x138 [<ffffffc00008510c>] __sys_trace_return+0x0/0x4 Unable to handle kernel paging request at virtual address dead000000000100 ... CPU: 4 PID: 5387 Comm: kworker/u15:3 Tainted: G W O 4.4.238+ #9 ... Call trace: [<ffffffc0000f079c>] __wake_up_common+0x7c/0xa8 [<ffffffc0000f0818>] __wake_up+0x50/0x70 [<ffffffc000be11b0>] sock_def_wakeup+0x58/0x60 [<ffffffc000de5e10>] l2cap_sock_teardown_cb+0x200/0x224 [<ffffffc000d3f2ac>] l2cap_chan_del+0xa4/0x298 [<ffffffc000d45ea0>] l2cap_conn_del+0x118/0x198 [<ffffffc000d45f8c>] l2cap_disconn_cfm+0x6c/0x78 [<ffffffc000d29934>] hci_event_packet+0x564/0x2e30 [<ffffffc000d19b0c>] hci_rx_work+0x10c/0x360 [<ffffffc0000c2218>] process_one_work+0x268/0x460 [<ffffffc0000c2678>] worker_thread+0x268/0x480 [<ffffffc0000c94e0>] kthread+0x118/0x128 [<ffffffc000085070>] ret_from_fork+0x10/0x20 ---[ end trace 0adc2158f0646ead ]--- Signed-off-by: Ole Bjørn Midtbø <omidtbo@cisco.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org> |
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|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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.