x86/mpx: Do not use SIB.base if its value is 101b and ModRM.mod = 0

Section 2.2.1.2 of the Intel 64 and IA-32 Architectures Software
Developer's Manual volume 2A states that if a SIB byte is used and
SIB.base is 101b and ModRM.mod is zero, then the base part of the base
part of the effective address computation is null. To signal this
situation, a -EDOM error is returned to indicate callers to ignore the
base value present in the register operand.

In this scenario, a 32-bit displacement follows the SIB byte. Displacement
is obtained when the instruction decoder parses the operands.

Signed-off-by: Ricardo Neri <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Borislav Petkov <[email protected]>
Cc: Adan Hawthorn <[email protected]>
Cc: "Michael S. Tsirkin" <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: [email protected]
Cc: Paul Gortmaker <[email protected]>
Cc: Huang Rui <[email protected]>
Cc: Qiaowei Ren <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Nathan Howard <[email protected]>
Cc: "Ravi V. Shankar" <[email protected]>
Cc: Chris Metcalf <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Colin Ian King <[email protected]>
Cc: Chen Yucong <[email protected]>
Cc: Adam Buchbinder <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Joe Perches <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Andrew Morton <[email protected]>
Link: https://lkml.kernel.org/r/1509135945-13762-9-git-send-email-ricardo.neri-calderon@linux.intel.com

0 files changed, 0 insertions, 0 deletions