From d9a7e9df731670acdc69e81748941ad338f47fab Mon Sep 17 00:00:00 2001 From: Doug Smythies Date: Sun, 12 Sep 2021 11:50:29 -0700 Subject: cpufreq: intel_pstate: Override parameters if HWP forced by BIOS If HWP has been already been enabled by BIOS, it may be necessary to override some kernel command line parameters. Once it has been enabled it requires a reset to be disabled. Suggested-by: Rafael J. Wysocki Signed-off-by: Doug Smythies Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) (limited to 'drivers/cpufreq') diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 1097f826ad70..8c176b7dae41 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -3205,11 +3205,15 @@ static int __init intel_pstate_init(void) if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) return -ENODEV; - if (no_load) - return -ENODEV; - id = x86_match_cpu(hwp_support_ids); if (id) { + bool hwp_forced = intel_pstate_hwp_is_enabled(); + + if (hwp_forced) + pr_info("HWP enabled by BIOS\n"); + else if (no_load) + return -ENODEV; + copy_cpu_funcs(&core_funcs); /* * Avoid enabling HWP for processors without EPP support, @@ -3219,8 +3223,7 @@ static int __init intel_pstate_init(void) * If HWP is enabled already, though, there is no choice but to * deal with it. */ - if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) || - intel_pstate_hwp_is_enabled()) { + if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) || hwp_forced) { hwp_active++; hwp_mode_bdw = id->driver_data; intel_pstate.attr = hwp_cpufreq_attrs; @@ -3235,7 +3238,11 @@ static int __init intel_pstate_init(void) goto hwp_cpu_matched; } + pr_info("HWP not enabled\n"); } else { + if (no_load) + return -ENODEV; + id = x86_match_cpu(intel_pstate_cpu_ids); if (!id) { pr_info("CPU model not supported\n"); @@ -3314,10 +3321,9 @@ static int __init intel_pstate_setup(char *str) else if (!strcmp(str, "passive")) default_driver = &intel_cpufreq; - if (!strcmp(str, "no_hwp")) { - pr_info("HWP disabled\n"); + if (!strcmp(str, "no_hwp")) no_hwp = 1; - } + if (!strcmp(str, "force")) force_load = 1; if (!strcmp(str, "hwp_only")) -- cgit v1.2.3 From cdef1196608892b9a46caa5f2b64095a7f0be60c Mon Sep 17 00:00:00 2001 From: James Morse Date: Tue, 14 Sep 2021 16:56:23 +0000 Subject: cpufreq: schedutil: Destroy mutex before kobject_put() frees the memory Since commit e5c6b312ce3c ("cpufreq: schedutil: Use kobject release() method to free sugov_tunables") kobject_put() has kfree()d the attr_set before gov_attr_set_put() returns. kobject_put() isn't the last user of attr_set in gov_attr_set_put(), the subsequent mutex_destroy() triggers a use-after-free: | BUG: KASAN: use-after-free in mutex_is_locked+0x20/0x60 | Read of size 8 at addr ffff000800ca4250 by task cpuhp/2/20 | | CPU: 2 PID: 20 Comm: cpuhp/2 Not tainted 5.15.0-rc1 #12369 | Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development | Platform, BIOS EDK II Jul 30 2018 | Call trace: | dump_backtrace+0x0/0x380 | show_stack+0x1c/0x30 | dump_stack_lvl+0x8c/0xb8 | print_address_description.constprop.0+0x74/0x2b8 | kasan_report+0x1f4/0x210 | kasan_check_range+0xfc/0x1a4 | __kasan_check_read+0x38/0x60 | mutex_is_locked+0x20/0x60 | mutex_destroy+0x80/0x100 | gov_attr_set_put+0xfc/0x150 | sugov_exit+0x78/0x190 | cpufreq_offline.isra.0+0x2c0/0x660 | cpuhp_cpufreq_offline+0x14/0x24 | cpuhp_invoke_callback+0x430/0x6d0 | cpuhp_thread_fun+0x1b0/0x624 | smpboot_thread_fn+0x5e0/0xa6c | kthread+0x3a0/0x450 | ret_from_fork+0x10/0x20 Swap the order of the calls. Fixes: e5c6b312ce3c ("cpufreq: schedutil: Use kobject release() method to free sugov_tunables") Cc: 4.7+ # 4.7+ Signed-off-by: James Morse Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/cpufreq_governor_attr_set.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/cpufreq') diff --git a/drivers/cpufreq/cpufreq_governor_attr_set.c b/drivers/cpufreq/cpufreq_governor_attr_set.c index 66b05a326910..a6f365b9cc1a 100644 --- a/drivers/cpufreq/cpufreq_governor_attr_set.c +++ b/drivers/cpufreq/cpufreq_governor_attr_set.c @@ -74,8 +74,8 @@ unsigned int gov_attr_set_put(struct gov_attr_set *attr_set, struct list_head *l if (count) return count; - kobject_put(&attr_set->kobj); mutex_destroy(&attr_set->update_lock); + kobject_put(&attr_set->kobj); return 0; } EXPORT_SYMBOL_GPL(gov_attr_set_put); -- cgit v1.2.3