| Message ID | 20211118124553.599419-1-kai.heng.feng@canonical.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | cpufreq: intel_pstate: Avoid using CPPC when ACPI CPC is not valid | expand |
On Thu, Nov 18, 2021 at 1:46 PM Kai-Heng Feng <kai.heng.feng@canonical.com> wrote: > > If ACPI CPC is not valid, dereference cpc_desc in cppc_get_perf() causes > a NULL pointer dereference. So avoid using CPPC for that scenario. > > Fixes: 46573fd6369f ("cpufreq: intel_pstate: hybrid: Rework HWP calibration") > Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> The bug is real, but it is not in intel_pstate. cppc_get_perf() should return an error in that case. Let me fix this. > --- > drivers/cpufreq/intel_pstate.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c > index 815df3daae9df..24c7d705b99b6 100644 > --- a/drivers/cpufreq/intel_pstate.c > +++ b/drivers/cpufreq/intel_pstate.c > @@ -3369,7 +3369,7 @@ static int __init intel_pstate_init(void) > if (!default_driver) > default_driver = &intel_pstate; > > - if (boot_cpu_has(X86_FEATURE_HYBRID_CPU)) > + if (boot_cpu_has(X86_FEATURE_HYBRID_CPU) && acpi_cpc_valid()) > intel_pstate_cppc_set_cpu_scaling(); > > goto hwp_cpu_matched; > -- > 2.32.0 >
Hi Kai-Heng,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on rafael-pm/linux-next]
[also build test ERROR on v5.16-rc1 next-20211118]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Kai-Heng-Feng/cpufreq-intel_pstate-Avoid-using-CPPC-when-ACPI-CPC-is-not-valid/20211118-204820
base: https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
config: i386-buildonly-randconfig-r006-20211119 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
# https://github.com/0day-ci/linux/commit/a6f59fd494dbbef65364b58fad14c1368c728dea
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Kai-Heng-Feng/cpufreq-intel_pstate-Avoid-using-CPPC-when-ACPI-CPC-is-not-valid/20211118-204820
git checkout a6f59fd494dbbef65364b58fad14c1368c728dea
# save the attached .config to linux build tree
make W=1 ARCH=i386
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
drivers/cpufreq/intel_pstate.c: In function 'intel_pstate_init':
>> drivers/cpufreq/intel_pstate.c:3372:48: error: implicit declaration of function 'acpi_cpc_valid' [-Werror=implicit-function-declaration]
3372 | if (boot_cpu_has(X86_FEATURE_HYBRID_CPU) && acpi_cpc_valid())
| ^~~~~~~~~~~~~~
At top level:
drivers/cpufreq/intel_pstate.c:2352:32: warning: 'intel_pstate_cpu_oob_ids' defined but not used [-Wunused-const-variable=]
2352 | static const struct x86_cpu_id intel_pstate_cpu_oob_ids[] __initconst = {
| ^~~~~~~~~~~~~~~~~~~~~~~~
cc1: some warnings being treated as errors
vim +/acpi_cpc_valid +3372 drivers/cpufreq/intel_pstate.c
3334
3335 static int __init intel_pstate_init(void)
3336 {
3337 static struct cpudata **_all_cpu_data;
3338 const struct x86_cpu_id *id;
3339 int rc;
3340
3341 if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
3342 return -ENODEV;
3343
3344 id = x86_match_cpu(hwp_support_ids);
3345 if (id) {
3346 bool hwp_forced = intel_pstate_hwp_is_enabled();
3347
3348 if (hwp_forced)
3349 pr_info("HWP enabled by BIOS\n");
3350 else if (no_load)
3351 return -ENODEV;
3352
3353 copy_cpu_funcs(&core_funcs);
3354 /*
3355 * Avoid enabling HWP for processors without EPP support,
3356 * because that means incomplete HWP implementation which is a
3357 * corner case and supporting it is generally problematic.
3358 *
3359 * If HWP is enabled already, though, there is no choice but to
3360 * deal with it.
3361 */
3362 if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) || hwp_forced) {
3363 WRITE_ONCE(hwp_active, 1);
3364 hwp_mode_bdw = id->driver_data;
3365 intel_pstate.attr = hwp_cpufreq_attrs;
3366 intel_cpufreq.attr = hwp_cpufreq_attrs;
3367 intel_cpufreq.flags |= CPUFREQ_NEED_UPDATE_LIMITS;
3368 intel_cpufreq.adjust_perf = intel_cpufreq_adjust_perf;
3369 if (!default_driver)
3370 default_driver = &intel_pstate;
3371
> 3372 if (boot_cpu_has(X86_FEATURE_HYBRID_CPU) && acpi_cpc_valid())
3373 intel_pstate_cppc_set_cpu_scaling();
3374
3375 goto hwp_cpu_matched;
3376 }
3377 pr_info("HWP not enabled\n");
3378 } else {
3379 if (no_load)
3380 return -ENODEV;
3381
3382 id = x86_match_cpu(intel_pstate_cpu_ids);
3383 if (!id) {
3384 pr_info("CPU model not supported\n");
3385 return -ENODEV;
3386 }
3387
3388 copy_cpu_funcs((struct pstate_funcs *)id->driver_data);
3389 }
3390
3391 if (intel_pstate_msrs_not_valid()) {
3392 pr_info("Invalid MSRs\n");
3393 return -ENODEV;
3394 }
3395 /* Without HWP start in the passive mode. */
3396 if (!default_driver)
3397 default_driver = &intel_cpufreq;
3398
3399 hwp_cpu_matched:
3400 /*
3401 * The Intel pstate driver will be ignored if the platform
3402 * firmware has its own power management modes.
3403 */
3404 if (intel_pstate_platform_pwr_mgmt_exists()) {
3405 pr_info("P-states controlled by the platform\n");
3406 return -ENODEV;
3407 }
3408
3409 if (!hwp_active && hwp_only)
3410 return -ENOTSUPP;
3411
3412 pr_info("Intel P-state driver initializing\n");
3413
3414 _all_cpu_data = vzalloc(array_size(sizeof(void *), num_possible_cpus()));
3415 if (!_all_cpu_data)
3416 return -ENOMEM;
3417
3418 WRITE_ONCE(all_cpu_data, _all_cpu_data);
3419
3420 intel_pstate_request_control_from_smm();
3421
3422 intel_pstate_sysfs_expose_params();
3423
3424 mutex_lock(&intel_pstate_driver_lock);
3425 rc = intel_pstate_register_driver(default_driver);
3426 mutex_unlock(&intel_pstate_driver_lock);
3427 if (rc) {
3428 intel_pstate_sysfs_remove();
3429 return rc;
3430 }
3431
3432 if (hwp_active) {
3433 const struct x86_cpu_id *id;
3434
3435 id = x86_match_cpu(intel_pstate_cpu_ee_disable_ids);
3436 if (id) {
3437 set_power_ctl_ee_state(false);
3438 pr_info("Disabling energy efficiency optimization\n");
3439 }
3440
3441 pr_info("HWP enabled\n");
3442 } else if (boot_cpu_has(X86_FEATURE_HYBRID_CPU)) {
3443 pr_warn("Problematic setup: Hybrid processor with disabled HWP\n");
3444 }
3445
3446 return 0;
3447 }
3448 device_initcall(intel_pstate_init);
3449
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 815df3daae9df..24c7d705b99b6 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -3369,7 +3369,7 @@ static int __init intel_pstate_init(void) if (!default_driver) default_driver = &intel_pstate; - if (boot_cpu_has(X86_FEATURE_HYBRID_CPU)) + if (boot_cpu_has(X86_FEATURE_HYBRID_CPU) && acpi_cpc_valid()) intel_pstate_cppc_set_cpu_scaling(); goto hwp_cpu_matched;
If ACPI CPC is not valid, dereference cpc_desc in cppc_get_perf() causes a NULL pointer dereference. So avoid using CPPC for that scenario. Fixes: 46573fd6369f ("cpufreq: intel_pstate: hybrid: Rework HWP calibration") Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> --- drivers/cpufreq/intel_pstate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)