firmware: arm_scpi: Check the DVFS OPP count returned by the firmware
[ Upstream commit 109aa654f85c5141e813b2cd1bd36d90be678407 ]
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: 8cb7cf56c9fe ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
26f3aa22d6