shinys000114/linux
1
0
Fork 0
mirror of https://github.com/hardkernel/linux.git synced 2026-06-06 10:58:48 +09:00
Code Issues Packages Projects Releases Wiki Activity

ACPI: CPPC: Perform fast check switch only for online CPUs

Browse Source 
[ Upstream commit 8821c8e80a65bc4eb73daf63b34aac6b8ad69461 ]

per_cpu(cpc_desc_ptr, cpu) object is initialized for only the online
CPUs via acpi_soft_cpu_online() --> __acpi_processor_start() -->
acpi_cppc_processor_probe().

However the function cppc_allow_fast_switch() checks for the validity
of the _CPC object for all the present CPUs. This breaks when the
kernel is booted with "nosmt=force".

Check fast_switch capability only on online CPUs

Fixes: 15eece6c5b05 ("ACPI: CPPC: Fix NULL pointer dereference when nosmp is used")
Reviewed-by: "Mario Limonciello (AMD) (kernel.org)" <superm1@kernel.org>
Signed-off-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Link: https://patch.msgid.link/20251107074145.2340-4-gautham.shenoy@amd.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Gautham R. Shenoy
2025-11-07 13:11:43 +05:30
committed by Greg Kroah-Hartman
parent a851ebcdc2
commit 4470b8bb9a
1 changed files with 1 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/acpi/cppc_acpi.c
View File

@@ -461,7 +461,7 @@ bool cppc_allow_fast_switch(void)
struct cpc_desc *cpc_ptr;
int cpu;
for_each_present_cpu(cpu) {
for_each_online_cpu(cpu) {
cpc_ptr = per_cpu(cpc_desc_ptr, cpu);
desired_reg = &cpc_ptr->cpc_regs[DESIRED_PERF];
if (!CPC_IN_SYSTEM_MEMORY(desired_reg) &&