From 8343c40d3de32ebfe8f48b043964e4ba0e7701f7 Mon Sep 17 00:00:00 2001 From: Hoan Tran Date: Fri, 17 Jun 2016 15:16:31 -0700 Subject: ACPI: CPPC: Return error if _CPC is invalid on a CPU Based on 8.4.7.1 section of ACPI 6.1 specification, if the platform supports CPPC, the _CPC object must exist under all processor objects. If cpc_desc_ptr pointer is invalid on any CPUs, acpi_get_psd_map() should return error and CPPC cpufreq driver can not be registered. Signed-off-by: Hoan Tran Reviewed-by: Prashanth Prakash Signed-off-by: Rafael J. Wysocki --- drivers/acpi/cppc_acpi.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'drivers/acpi/cppc_acpi.c') diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index 8adac69dba3d..f9be3150017c 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -299,8 +299,10 @@ int acpi_get_psd_map(struct cpudata **all_cpu_data) continue; cpc_ptr = per_cpu(cpc_desc_ptr, i); - if (!cpc_ptr) - continue; + if (!cpc_ptr) { + retval = -EFAULT; + goto err_ret; + } pdomain = &(cpc_ptr->domain_info); cpumask_set_cpu(i, pr->shared_cpu_map); @@ -322,8 +324,10 @@ int acpi_get_psd_map(struct cpudata **all_cpu_data) continue; match_cpc_ptr = per_cpu(cpc_desc_ptr, j); - if (!match_cpc_ptr) - continue; + if (!match_cpc_ptr) { + retval = -EFAULT; + goto err_ret; + } match_pdomain = &(match_cpc_ptr->domain_info); if (match_pdomain->domain != pdomain->domain) @@ -353,8 +357,10 @@ int acpi_get_psd_map(struct cpudata **all_cpu_data) continue; match_cpc_ptr = per_cpu(cpc_desc_ptr, j); - if (!match_cpc_ptr) - continue; + if (!match_cpc_ptr) { + retval = -EFAULT; + goto err_ret; + } match_pdomain = &(match_cpc_ptr->domain_info); if (match_pdomain->domain != pdomain->domain) -- cgit v1.2.3 From 2324d15447a9db168b1f85e3feac635b1ff8edb8 Mon Sep 17 00:00:00 2001 From: Hoan Tran Date: Wed, 25 May 2016 12:09:23 -0700 Subject: ACPI / CPPC: Prevent cpc_desc_ptr points to the invalid data When CPPC fails to request a PCC channel, the CPC data is freed and cpc_desc_ptr points to the invalid data. Avoid this issue by moving the cpc_desc_ptr assignment after the PCC channel request. Signed-off-by: Hoan Tran Acked-by: Ashwin Chaugule Signed-off-by: Rafael J. Wysocki --- drivers/acpi/cppc_acpi.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/acpi/cppc_acpi.c') diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index f9be3150017c..2e981732805b 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -601,9 +601,6 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr) /* Store CPU Logical ID */ cpc_ptr->cpu_id = pr->id; - /* Plug it into this CPUs CPC descriptor. */ - per_cpu(cpc_desc_ptr, pr->id) = cpc_ptr; - /* Parse PSD data for this CPU */ ret = acpi_get_psd(cpc_ptr, handle); if (ret) @@ -616,6 +613,9 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr) goto out_free; } + /* Plug PSD data into this CPUs CPC descriptor. */ + per_cpu(cpc_desc_ptr, pr->id) = cpc_ptr; + /* Everything looks okay */ pr_debug("Parsed CPC struct for CPU: %d\n", pr->id); -- cgit v1.2.3