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* [PATCH] UefiCpuPkg RegisterCpuFeaturesLib: NumberOfCpus may be uninitialized
@ 2021-01-21  9:39 Zeng, Star
  2021-01-21 13:47 ` [edk2-devel] " Laszlo Ersek
  2021-01-21 14:38 ` Laszlo Ersek
  0 siblings, 2 replies; 5+ messages in thread
From: Zeng, Star @ 2021-01-21  9:39 UTC (permalink / raw)
  To: devel; +Cc: Star Zeng, Eric Dong, Ray Ni, Laszlo Ersek

NumberOfCpus local variable in GetAcpiCpuData will be uninitialized
when CpuS3DataDxe runs before DxeRegisterCpuFeaturesLib (linked by
CpuFeaturesDxe) because there is no code to initialize it at
(AcpiCpuData != NULL) execution path.

The issue is exposed after cefad282fb31aff3e1a6dcbd368cbbffc3fce900
and 38ee7bafa72f58982f99ac6f61eef160f80bad69.
There was negligence in that code review.
One further topic may be "Could EDK2 CI be enhanced to catch this kind
of uninitialized local variable case?". :)

This patch fixes this regression issue.

Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Star Zeng <star.zeng@intel.com>
---
 .../Library/RegisterCpuFeaturesLib/RegisterCpuFeaturesLib.c      | 1 +
 1 file changed, 1 insertion(+)

diff --git a/UefiCpuPkg/Library/RegisterCpuFeaturesLib/RegisterCpuFeaturesLib.c b/UefiCpuPkg/Library/RegisterCpuFeaturesLib/RegisterCpuFeaturesLib.c
index 7bb92404027f..60daa5cc87f0 100644
--- a/UefiCpuPkg/Library/RegisterCpuFeaturesLib/RegisterCpuFeaturesLib.c
+++ b/UefiCpuPkg/Library/RegisterCpuFeaturesLib/RegisterCpuFeaturesLib.c
@@ -957,6 +957,7 @@ GetAcpiCpuData (
     //
     // Allocate buffer for empty RegisterTable and PreSmmInitRegisterTable for all CPUs
     //
+    NumberOfCpus = AcpiCpuData->NumberOfCpus;
     TableSize = 2 * NumberOfCpus * sizeof (CPU_REGISTER_TABLE);
     RegisterTable  = AllocatePages (EFI_SIZE_TO_PAGES (TableSize));
     ASSERT (RegisterTable != NULL);
-- 
2.27.0.windows.1


^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2021-01-21 14:44 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2021-01-21  9:39 [PATCH] UefiCpuPkg RegisterCpuFeaturesLib: NumberOfCpus may be uninitialized Zeng, Star
2021-01-21 13:47 ` [edk2-devel] " Laszlo Ersek
2021-01-21 14:32   ` Zeng, Star
2021-01-21 14:38 ` Laszlo Ersek
2021-01-21 14:44   ` Zeng, Star

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