diff options
| author | Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> | 2026-02-24 16:17:52 -0800 |
|---|---|---|
| committer | Sasha Levin <sashal@kernel.org> | 2026-03-12 07:09:35 -0400 |
| commit | d20d48916ce8531b157c2edeba76d69af2974270 (patch) | |
| tree | d5dc81b53cad86b7434a434cbf91b266ebee8525 /drivers/cpufreq | |
| parent | f4588b85efd6007d46b80aa1b9fb746628ffb3dc (diff) | |
cpufreq: intel_pstate: Fix crash during turbo disable
commit 6b050482ec40569429d963ac52afa878691b04c9 upstream.
When the system is booted with kernel command line argument "nosmt" or
"maxcpus" to limit the number of CPUs, disabling turbo via:
echo 1 > /sys/devices/system/cpu/intel_pstate/no_turbo
results in a crash:
PF: supervisor read access in kernel mode
PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP PTI
...
RIP: 0010:store_no_turbo+0x100/0x1f0
...
This occurs because for_each_possible_cpu() returns CPUs even if they
are not online. For those CPUs, all_cpu_data[] will be NULL. Since
commit 973207ae3d7c ("cpufreq: intel_pstate: Rearrange max frequency
updates handling code"), all_cpu_data[] is dereferenced even for CPUs
which are not online, causing the NULL pointer dereference.
To fix that, pass CPU number to intel_pstate_update_max_freq() and use
all_cpu_data[] for those CPUs for which there is a valid cpufreq policy.
Fixes: 973207ae3d7c ("cpufreq: intel_pstate: Rearrange max frequency updates handling code")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221068
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: 6.16+ <stable@vger.kernel.org> # 6.16+
Link: https://patch.msgid.link/20260225001752.890164-1-srinivas.pandruvada@linux.intel.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/cpufreq')
| -rw-r--r-- | drivers/cpufreq/intel_pstate.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 1625ec2d0d06..ec8308629432 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -1476,13 +1476,13 @@ static void __intel_pstate_update_max_freq(struct cpufreq_policy *policy, refresh_frequency_limits(policy); } -static bool intel_pstate_update_max_freq(struct cpudata *cpudata) +static bool intel_pstate_update_max_freq(int cpu) { - struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpudata->cpu); + struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpu); if (!policy) return false; - __intel_pstate_update_max_freq(policy, cpudata); + __intel_pstate_update_max_freq(policy, all_cpu_data[cpu]); return true; } @@ -1501,7 +1501,7 @@ static void intel_pstate_update_limits_for_all(void) int cpu; for_each_possible_cpu(cpu) - intel_pstate_update_max_freq(all_cpu_data[cpu]); + intel_pstate_update_max_freq(cpu); mutex_lock(&hybrid_capacity_lock); @@ -1908,7 +1908,7 @@ static void intel_pstate_notify_work(struct work_struct *work) struct cpudata *cpudata = container_of(to_delayed_work(work), struct cpudata, hwp_notify_work); - if (intel_pstate_update_max_freq(cpudata)) { + if (intel_pstate_update_max_freq(cpudata->cpu)) { /* * The driver will not be unregistered while this function is * running, so update the capacity without acquiring the driver |