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Linux kernel source tree
22f7609418
The cstate->num_mixers member is only set to a non-zero value once
dpu_encoder_virt_mode_set() is called, but the atomic check function can
be called by userspace before that. Let's avoid the div-by-zero here and
inside _dpu_crtc_setup_lm_bounds() by skipping this part of the atomic
check if dpu_encoder_virt_mode_set() hasn't been called yet. This fixes
an UBSAN warning:
UBSAN: Undefined behaviour in drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c:860:31
division by zero
CPU: 7 PID: 409 Comm: frecon Tainted: G S 5.4.31 #128
Hardware name: Google Trogdor (rev0) (DT)
Call trace:
dump_backtrace+0x0/0x14c
show_stack+0x20/0x2c
dump_stack+0xa0/0xd8
__ubsan_handle_divrem_overflow+0xec/0x110
dpu_crtc_atomic_check+0x97c/0x9d4
drm_atomic_helper_check_planes+0x160/0x1c8
drm_atomic_helper_check+0x54/0xbc
drm_atomic_check_only+0x6a8/0x880
drm_atomic_commit+0x20/0x5c
drm_atomic_helper_set_config+0x98/0xa0
drm_mode_setcrtc+0x308/0x5dc
drm_ioctl_kernel+0x9c/0x114
drm_ioctl+0x2ac/0x4b0
drm_compat_ioctl+0xe8/0x13c
__arm64_compat_sys_ioctl+0x184/0x324
el0_svc_common+0xa4/0x154
el0_svc_compat_handler+0x
Cc: Abhinav Kumar <abhinavk@codeaurora.org>
Cc: Jeykumar Sankaran <jsanka@codeaurora.org>
Cc: Jordan Crouse <jcrouse@codeaurora.org>
Cc: Sean Paul <seanpaul@chromium.org>
Fixes:
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| 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 | ||
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.