x86/mce/AMD: Fix HWID_MCATYPE calculation by grouping arguments
authorYazen Ghannam <Yazen.Ghannam@amd.com>
Thu, 10 Nov 2016 20:32:35 +0000 (14:32 -0600)
committerIngo Molnar <mingo@kernel.org>
Fri, 11 Nov 2016 07:14:02 +0000 (08:14 +0100)
The calculation of the hwid_mcatype value in get_smca_bank_info()
became incorrect after applying the following commit:

  1ce9cd7f9f0b ("x86/RAS: Simplify SMCA HWID descriptor struct")

This causes the function to not match a bank to its type.

Disassembly of hwid_mcatype calculation after change:

      db:       8b 45 e0                mov    -0x20(%rbp),%eax
      de:       41 89 c4                mov    %eax,%r12d
      e1:       25 00 00 ff 0f          and    $0xfff0000,%eax
      e6:       41 c1 ec 10             shr    $0x10,%r12d
      ea:       41 09 c4                or     %eax,%r12d

Disassembly of hwid_mcatype calculation in original code:

     286:       8b 45 d0                mov    -0x30(%rbp),%eax
     289:       41 89 c5                mov    %eax,%r13d
     28c:       c1 e8 10                shr    $0x10,%eax
     28f:       41 81 e5 ff 0f 00 00    and    $0xfff,%r13d
     296:       41 c1 e5 10             shl    $0x10,%r13d
     29a:       41 09 c5                or     %eax,%r13d

Grouping the arguments to the HWID_MCATYPE() macro fixes the issue.

( Boris suggested adding parentheses in the macro. )

Signed-off-by: Yazen Ghannam <Yazen.Ghannam@amd.com>
Cc: Aravind Gopalakrishnan <aravindksg.lkml@gmail.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86/include/asm/mce.h

index 748b8da..ecda6a9 100644 (file)
@@ -356,7 +356,7 @@ enum smca_bank_types {
        N_SMCA_BANK_TYPES
 };
 
-#define HWID_MCATYPE(hwid, mcatype) ((hwid << 16) | mcatype)
+#define HWID_MCATYPE(hwid, mcatype) (((hwid) << 16) | (mcatype))
 
 struct smca_hwid {
        unsigned int bank_type; /* Use with smca_bank_types for easy indexing. */