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John Garry 331d880b35 drm/hisilicon: hibmc: Do not carry error code in HiBMC framebuffer pointer
In hibmc_drm_fb_create(), when the call to hibmc_framebuffer_init() fails
with error, do not store the error code in the HiBMC device frame-buffer
pointer, as this will be later checked for non-zero value in
hibmc_fbdev_destroy() when our intention is to check for a valid function
pointer.

This fixes the following crash:
[    9.699791] Unable to handle kernel NULL pointer dereference at virtual address 000000000000001a
[    9.708672] Mem abort info:
[    9.711489]   ESR = 0x96000004
[    9.714570]   Exception class = DABT (current EL), IL = 32 bits
[    9.720551]   SET = 0, FnV = 0
[    9.723631]   EA = 0, S1PTW = 0
[    9.726799] Data abort info:
[    9.729702]   ISV = 0, ISS = 0x00000004
[    9.733573]   CM = 0, WnR = 0
[    9.736566] [000000000000001a] user address but active_mm is swapper
[    9.742987] Internal error: Oops: 96000004 [#1] PREEMPT SMP
[    9.748614] Modules linked in:
[    9.751694] CPU: 16 PID: 293 Comm: kworker/16:1 Tainted: G        W         4.19.0-rc4-next-20180920-00001-g9b0012c #322
[    9.762681] Hardware name: Huawei Taishan 2280 /D05, BIOS Hisilicon D05 IT21 Nemo 2.0 RC0 04/18/2018
[    9.771915] Workqueue: events work_for_cpu_fn
[    9.776312] pstate: 60000005 (nZCv daif -PAN -UAO)
[    9.781150] pc : drm_mode_object_put+0x0/0x20
[    9.785547] lr : hibmc_fbdev_fini+0x40/0x58
[    9.789767] sp : ffff00000af1bcf0
[    9.793108] x29: ffff00000af1bcf0 x28: 0000000000000000
[    9.798473] x27: 0000000000000000 x26: ffff000008f66630
[    9.803838] x25: 0000000000000000 x24: ffff0000095abb98
[    9.809203] x23: ffff8017db92fe00 x22: ffff8017d2b13000
[    9.814568] x21: ffffffffffffffea x20: ffff8017d2f80018
[    9.819933] x19: ffff8017d28a0018 x18: ffffffffffffffff
[    9.825297] x17: 0000000000000000 x16: 0000000000000000
[    9.830662] x15: ffff0000092296c8 x14: ffff00008939970f
[    9.836026] x13: ffff00000939971d x12: ffff000009229940
[    9.841391] x11: ffff0000085f8fc0 x10: ffff00000af1b9a0
[    9.846756] x9 : 000000000000000d x8 : 6620657a696c6169
[    9.852121] x7 : ffff8017d3340580 x6 : ffff8017d4168000
[    9.857486] x5 : 0000000000000000 x4 : ffff8017db92fb20
[    9.862850] x3 : 0000000000002690 x2 : ffff8017d3340480
[    9.868214] x1 : 0000000000000028 x0 : 0000000000000002
[    9.873580] Process kworker/16:1 (pid: 293, stack limit = 0x(____ptrval____))
[    9.880788] Call trace:
[    9.883252]  drm_mode_object_put+0x0/0x20
[    9.887297]  hibmc_unload+0x1c/0x80
[    9.890815]  hibmc_pci_probe+0x170/0x3c8
[    9.894773]  local_pci_probe+0x3c/0xb0
[    9.898555]  work_for_cpu_fn+0x18/0x28
[    9.902337]  process_one_work+0x1e0/0x318
[    9.906382]  worker_thread+0x228/0x450
[    9.910164]  kthread+0x128/0x130
[    9.913418]  ret_from_fork+0x10/0x18
[    9.917024] Code: a94153f3 a8c27bfd d65f03c0 d503201f (f9400c01)
[    9.923180] ---[ end trace 2695ffa0af5be375 ]---

Fixes: d1667b8679 ("drm/hisilicon/hibmc: Add support for frame buffer")
Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Xinliang Liu <z.liuxinliang@hisilicon.com>
Signed-off-by: Xinliang Liu <z.liuxinliang@hisilicon.com>
2018-09-26 11:38:52 +08:00
Documentation Merge branch 'drm-next-4.20' of git://people.freedesktop.org/~agd5f/linux into drm-next 2018-09-21 09:52:53 +10:00
LICENSES LICENSES: Add Linux-OpenIB license text 2018-04-27 16:41:53 -06:00
arch ARM: SoC fixes 2018-09-02 10:44:28 -07:00
block block: bsg: move atomic_t ref_count variable to refcount API 2018-08-27 19:17:02 -06:00
certs export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() 2018-08-22 23:21:44 +09:00
crypto DMAengine updates for v4.19-rc1 2018-08-18 15:55:59 -07:00
drivers drm/hisilicon: hibmc: Do not carry error code in HiBMC framebuffer pointer 2018-09-26 11:38:52 +08:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-09-02 09:41:45 -07:00
include Merge branch 'drm-next-4.20' of git://people.freedesktop.org/~agd5f/linux into drm-next 2018-09-21 09:52:53 +10:00
init Kbuild updates for v4.19 (2nd) 2018-08-25 13:40:38 -07:00
ipc ipc/util.c: update return value of ipc_getref from int to bool 2018-08-22 10:52:52 -07:00
kernel Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-09-02 10:09:35 -07:00
lib Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-09-02 09:41:45 -07:00
mm notifier: Remove notifier header file wherever not used 2018-08-30 12:56:40 +02:00
net Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-09-02 09:41:45 -07:00
samples samples/bpf: all XDP samples should unload xdp/bpf prog on SIGTERM 2018-08-16 21:55:32 +02:00
scripts Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-09-02 10:11:30 -07:00
security + Cleanups 2018-08-24 13:00:33 -07:00
sound Merge branch 'akpm' (patches from Andrew) 2018-08-23 19:20:12 -07:00
tools drm-misc-next for 4.20: 2018-09-07 10:44:35 +10:00
usr initramfs: move gen_initramfs_list.sh from scripts/ to usr/ 2018-08-22 23:21:44 +09:00
virt ARM: Support for Group0 interrupts in guests, Cache management 2018-08-22 13:52:44 -07:00
.clang-format clang-format: Set IndentWrappedFunctionNames false 2018-08-01 18:38:51 +02:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.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 MAINTAINERS: rcar-du: Add co-maintainer 2018-09-14 13:54:00 +03:00
Makefile Linux 4.19-rc2 2018-09-02 14:37:30 -07:00
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.