From 4fe5934db4a7187d358f1af1b3ef9b6dd59bce58 Mon Sep 17 00:00:00 2001 From: "Gautham R. Shenoy" Date: Fri, 7 Nov 2025 13:11:41 +0530 Subject: [PATCH 1/5] ACPI: CPPC: Detect preferred core availability on online CPUs Commit 279f838a61f9 ("x86/amd: Detect preferred cores in amd_get_boost_ratio_numerator()") introduced the ability to detect the preferred core on AMD platforms by checking if there at least two distinct highest_perf values. However, it uses for_each_present_cpu() to iterate through all the CPUs in the platform, which is problematic when the kernel is booted with "nosmt=force" commandline option. Hence limit the search to only the online CPUs. Fixes: 279f838a61f9 ("x86/amd: Detect preferred cores in amd_get_boost_ratio_numerator()") Reported-by: Christopher Harris Closes: https://lore.kernel.org/lkml/CAM+eXpdDT7KjLV0AxEwOLkSJ2QtrsvGvjA2cCHvt1d0k2_C4Cw@mail.gmail.com/ Reviewed-by: "Mario Limonciello (AMD) (kernel.org)" Tested-by: Chrisopher Harris Signed-off-by: Gautham R. Shenoy Link: https://patch.msgid.link/20251107074145.2340-2-gautham.shenoy@amd.com Signed-off-by: Rafael J. Wysocki --- arch/x86/kernel/acpi/cppc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/acpi/cppc.c b/arch/x86/kernel/acpi/cppc.c index 7047124490f6..d7c8ef1e354d 100644 --- a/arch/x86/kernel/acpi/cppc.c +++ b/arch/x86/kernel/acpi/cppc.c @@ -196,7 +196,7 @@ int amd_detect_prefcore(bool *detected) break; } - for_each_present_cpu(cpu) { + for_each_online_cpu(cpu) { u32 tmp; int ret; From 6dd3b8a709a130a4d55c866af9804c81b8486d28 Mon Sep 17 00:00:00 2001 From: "Gautham R. Shenoy" Date: Fri, 7 Nov 2025 13:11:42 +0530 Subject: [PATCH 2/5] ACPI: CPPC: Check _CPC validity for only the online CPUs 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 acpi_cpc_valid() checks for the validity of the _CPC object for all the present CPUs. This breaks when the kernel is booted with "nosmt=force". Hence check the validity of the _CPC objects of only the online CPUs. Fixes: 2aeca6bd0277 ("ACPI: CPPC: Check present CPUs for determining _CPC is valid") Reported-by: Christopher Harris Closes: https://lore.kernel.org/lkml/CAM+eXpdDT7KjLV0AxEwOLkSJ2QtrsvGvjA2cCHvt1d0k2_C4Cw@mail.gmail.com/ Suggested-by: Mario Limonciello Reviewed-by: "Mario Limonciello (AMD) (kernel.org)" Tested-by: Chrisopher Harris Signed-off-by: Gautham R. Shenoy Link: https://patch.msgid.link/20251107074145.2340-3-gautham.shenoy@amd.com Signed-off-by: Rafael J. Wysocki --- drivers/acpi/cppc_acpi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index 6c684e54fe01..da6b35ac8c87 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -460,7 +460,7 @@ bool acpi_cpc_valid(void) if (acpi_disabled) return false; - for_each_present_cpu(cpu) { + for_each_online_cpu(cpu) { cpc_ptr = per_cpu(cpc_desc_ptr, cpu); if (!cpc_ptr) return false; From 8821c8e80a65bc4eb73daf63b34aac6b8ad69461 Mon Sep 17 00:00:00 2001 From: "Gautham R. Shenoy" Date: Fri, 7 Nov 2025 13:11:43 +0530 Subject: [PATCH 3/5] ACPI: CPPC: Perform fast check switch only for online CPUs 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)" Signed-off-by: Gautham R. Shenoy Link: https://patch.msgid.link/20251107074145.2340-4-gautham.shenoy@amd.com Signed-off-by: Rafael J. Wysocki --- drivers/acpi/cppc_acpi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index da6b35ac8c87..7492c9922866 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -476,7 +476,7 @@ 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) && From 0fce75870666b46b700cfbd3216380b422f975da Mon Sep 17 00:00:00 2001 From: "Gautham R. Shenoy" Date: Fri, 7 Nov 2025 13:11:44 +0530 Subject: [PATCH 4/5] ACPI: CPPC: Limit perf ctrs in PCC check only to online CPUs per_cpu(cpc_desc_ptr, cpu) object is initialized for only the online CPU via acpi_soft_cpu_online() --> __acpi_processor_start() --> acpi_cppc_processor_probe(). However the function cppc_perf_ctrs_in_pcc() checks if the CPPC perf-ctrs are in a PCC region for all the present CPUs, which breaks when the kernel is booted with "nosmt=force". Hence, limit the check only to the online CPUs. Fixes: ae2df912d1a5 ("ACPI: CPPC: Disable FIE if registers in PCC regions") Reviewed-by: "Mario Limonciello (AMD) (kernel.org)" Signed-off-by: Gautham R. Shenoy Link: https://patch.msgid.link/20251107074145.2340-5-gautham.shenoy@amd.com Signed-off-by: Rafael J. Wysocki --- drivers/acpi/cppc_acpi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index 7492c9922866..3bdeeee3414e 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -1435,7 +1435,7 @@ bool cppc_perf_ctrs_in_pcc(void) { int cpu; - for_each_present_cpu(cpu) { + for_each_online_cpu(cpu) { struct cpc_register_resource *ref_perf_reg; struct cpc_desc *cpc_desc; From 4b93d211bbffd3dce76664d95f2306d23e7215ce Mon Sep 17 00:00:00 2001 From: Kaushlendra Kumar Date: Thu, 30 Oct 2025 08:02:28 +0530 Subject: [PATCH 5/5] ACPI: MRRM: Fix memory leaks and improve error handling Add proper error handling and resource cleanup to prevent memory leaks in add_boot_memory_ranges(). The function now checks for NULL return from kobject_create_and_add(), uses local buffer for range names to avoid dynamic allocation, and implements a cleanup path that removes previously created sysfs groups and kobjects on failure. This prevents resource leaks when kobject creation or sysfs group creation fails during boot memory range initialization. Signed-off-by: Kaushlendra Kumar Reviewed-by: Tony Luck Link: https://patch.msgid.link/20251030023228.3956296-1-kaushlendra.kumar@intel.com Signed-off-by: Rafael J. Wysocki --- drivers/acpi/acpi_mrrm.c | 51 +++++++++++++++++++++++++++++----------- 1 file changed, 37 insertions(+), 14 deletions(-) diff --git a/drivers/acpi/acpi_mrrm.c b/drivers/acpi/acpi_mrrm.c index a6dbf623e557..6d69554c940e 100644 --- a/drivers/acpi/acpi_mrrm.c +++ b/drivers/acpi/acpi_mrrm.c @@ -152,26 +152,49 @@ ATTRIBUTE_GROUPS(memory_range); static __init int add_boot_memory_ranges(void) { - struct kobject *pkobj, *kobj; + struct kobject *pkobj, *kobj, **kobjs; int ret = -EINVAL; - char *name; + char name[16]; + int i; pkobj = kobject_create_and_add("memory_ranges", acpi_kobj); + if (!pkobj) + return -ENOMEM; - for (int i = 0; i < mrrm_mem_entry_num; i++) { - name = kasprintf(GFP_KERNEL, "range%d", i); - if (!name) { - ret = -ENOMEM; - break; - } - - kobj = kobject_create_and_add(name, pkobj); - - ret = sysfs_create_groups(kobj, memory_range_groups); - if (ret) - return ret; + kobjs = kcalloc(mrrm_mem_entry_num, sizeof(*kobjs), GFP_KERNEL); + if (!kobjs) { + kobject_put(pkobj); + return -ENOMEM; } + for (i = 0; i < mrrm_mem_entry_num; i++) { + scnprintf(name, sizeof(name), "range%d", i); + kobj = kobject_create_and_add(name, pkobj); + if (!kobj) { + ret = -ENOMEM; + goto cleanup; + } + + ret = sysfs_create_groups(kobj, memory_range_groups); + if (ret) { + kobject_put(kobj); + goto cleanup; + } + kobjs[i] = kobj; + } + + kfree(kobjs); + return 0; + +cleanup: + for (int j = 0; j < i; j++) { + if (kobjs[j]) { + sysfs_remove_groups(kobjs[j], memory_range_groups); + kobject_put(kobjs[j]); + } + } + kfree(kobjs); + kobject_put(pkobj); return ret; }