Luo Qiu 109aa654f8 firmware: arm_scpi: Check the DVFS OPP count returned by the firmware
Fix a kernel crash with the below call trace when the SCPI firmware
returns OPP count of zero.

dvfs_info.opp_count may be zero on some platforms during the reboot
test, and the kernel will crash after dereferencing the pointer to
kcalloc(info->count, sizeof(*opp), GFP_KERNEL).

  |  Unable to handle kernel NULL pointer dereference at virtual address 0000000000000028
  |  Mem abort info:
  |    ESR = 0x96000004
  |    Exception class = DABT (current EL), IL = 32 bits
  |    SET = 0, FnV = 0
  |    EA = 0, S1PTW = 0
  |  Data abort info:
  |    ISV = 0, ISS = 0x00000004
  |    CM = 0, WnR = 0
  |  user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000faefa08c
  |  [0000000000000028] pgd=0000000000000000
  |  Internal error: Oops: 96000004 [#1] SMP
  |  scpi-hwmon: probe of PHYT000D:00 failed with error -110
  |  Process systemd-udevd (pid: 1701, stack limit = 0x00000000aaede86c)
  |  CPU: 2 PID: 1701 Comm: systemd-udevd Not tainted 4.19.90+ #1
  |  Hardware name: PHYTIUM LTD Phytium FT2000/4/Phytium FT2000/4, BIOS
  |  pstate: 60000005 (nZCv daif -PAN -UAO)
  |  pc : scpi_dvfs_recalc_rate+0x40/0x58 [clk_scpi]
  |  lr : clk_register+0x438/0x720
  |  Call trace:
  |   scpi_dvfs_recalc_rate+0x40/0x58 [clk_scpi]
  |   devm_clk_hw_register+0x50/0xa0
  |   scpi_clk_ops_init.isra.2+0xa0/0x138 [clk_scpi]
  |   scpi_clocks_probe+0x528/0x70c [clk_scpi]
  |   platform_drv_probe+0x58/0xa8
  |   really_probe+0x260/0x3d0
  |   driver_probe_device+0x12c/0x148
  |   device_driver_attach+0x74/0x98
  |   __driver_attach+0xb4/0xe8
  |   bus_for_each_dev+0x88/0xe0
  |   driver_attach+0x30/0x40
  |   bus_add_driver+0x178/0x2b0
  |   driver_register+0x64/0x118
  |   __platform_driver_register+0x54/0x60
  |   scpi_clocks_driver_init+0x24/0x1000 [clk_scpi]
  |   do_one_initcall+0x54/0x220
  |   do_init_module+0x54/0x1c8
  |   load_module+0x14a4/0x1668
  |   __se_sys_finit_module+0xf8/0x110
  |   __arm64_sys_finit_module+0x24/0x30
  |   el0_svc_common+0x78/0x170
  |   el0_svc_handler+0x38/0x78
  |   el0_svc+0x8/0x340
  |  Code: 937d7c00 a94153f3 a8c27bfd f9400421 (b8606820)
  |  ---[ end trace 06feb22469d89fa8 ]---
  |  Kernel panic - not syncing: Fatal exception
  |  SMP: stopping secondary CPUs
  |  Kernel Offset: disabled
  |  CPU features: 0x10,a0002008
  |  Memory Limit: none

Fixes: 8cb7cf56c9 ("firmware: add support for ARM System Control and Power Interface(SCPI) protocol")
Signed-off-by: Luo Qiu <luoqiu@kylinsec.com.cn>
Message-Id: <55A2F7A784391686+20241101032115.275977-1-luoqiu@kylinsec.com.cn>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2024-11-06 10:48:13 +00:00
2024-09-29 14:47:33 -07:00
2024-09-01 20:43:24 -07:00
2022-09-28 09:02:20 +02:00
2024-09-29 15:06:19 -07:00
2024-03-18 03:36:32 -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 reStructuredText 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.
Description
No description provided
Readme 3.6 GiB
Languages
C 97%
Assembly 1%
Shell 0.6%
Rust 0.5%
Python 0.4%
Other 0.3%