[PATCH] acpi: cppc: Prevent cpc_desc_ptr points to the invalid data

From: Hoan Tran
Date: Wed May 25 2016 - 15:10:38 EST


When CPPC fails to request PCC channel, the CPC data is freed
and cpc_desc_ptr points to the invalid data. This change prevents
this issue by moving cpc_desc_ptr assignment after PCC channel
request.

Signed-off-by: Hoan Tran <hotran@xxxxxxx>
---
drivers/acpi/cppc_acpi.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 8adac69..85fd8f7 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -595,9 +595,6 @@ 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)
@@ -610,6 +607,9 @@ 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);

--
1.9.1