x86: minor cleanup in the espfix code

Impact: Cleanup

Checkin be44d2aabc eliminates the use of
a 16-bit stack for espfix.  However, at least one instruction remained
that only operated on the low 16 bits of %esp.

This is not a bug per se because the kernel stack is always an aligned
4K or 8K block.  Therefore it cannot cross 64K boundaries; this code,
in fact, relies strictly on that fact.

However, it's a lot cleaner (and, for that matter, smaller) to operate
on the entire 32-bit register.

Signed-off-by: Stas Sergeev <stsp@aknet.ru>
CC: Zachary Amsden <zach@vmware.com>
CC: Chuck Ebbert <cebbert@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This commit is contained in:
Stas Sergeev 2009-02-23 19:13:07 +03:00 committed by H. Peter Anvin
parent 2366c298b5
commit bda3a89745

View file

@ -1359,7 +1359,7 @@ nmi_espfix_stack:
CFI_ADJUST_CFA_OFFSET 4
pushl %esp
CFI_ADJUST_CFA_OFFSET 4
addw $4, (%esp)
addl $4, (%esp)
/* copy the iret frame of 12 bytes */
.rept 3
pushl 16(%esp)