diff options
| author | Chuck Ebbert <76306.1226@compuserve.com> | 2006-06-23 02:04:29 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-06-23 07:42:58 -0700 |
| commit | 19964fecf25c17f865dec07ae242b1a40ea93f16 (patch) | |
| tree | e3eae33af9583dd6a7f88f54b2e9e0f5ecd0b74d | |
| parent | 110cb1d2e343443c4a4b5f7e081928aa4da90f93 (diff) | |
[PATCH] i386: fix get_segment_eip() with vm86 segments
We need to check for vm86 mode first before looking at selector privilege
bits.
Segment limit is always base + 64k and only the low 16 bits of EIP are
significant in vm86 mode.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Rohit Seth <rohitseth@google.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | arch/i386/mm/fault.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/arch/i386/mm/fault.c b/arch/i386/mm/fault.c index f38085ff3c3..bd6fe96cc16 100644 --- a/arch/i386/mm/fault.c +++ b/arch/i386/mm/fault.c @@ -77,12 +77,15 @@ static inline unsigned long get_segment_eip(struct pt_regs *regs, unsigned seg = regs->xcs & 0xffff; u32 seg_ar, seg_limit, base, *desc; + /* Unlikely, but must come before segment checks. */ + if (unlikely(regs->eflags & VM_MASK)) { + base = seg << 4; + *eip_limit = base + 0xffff; + return base + (eip & 0xffff); + } + /* The standard kernel/user address space limit. */ *eip_limit = (seg & 3) ? USER_DS.seg : KERNEL_DS.seg; - - /* Unlikely, but must come before segment checks. */ - if (unlikely((regs->eflags & VM_MASK) != 0)) - return eip + (seg << 4); /* By far the most common cases. */ if (likely(seg == __USER_CS || seg == __KERNEL_CS)) |