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authorPaolo Bonzini <pbonzini@redhat.com>2016-02-19 20:07:21 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2016-02-24 16:47:45 +0300
commit0c1d77f4ba5cc9c05a29adca3d6466cdf4969b70 (patch)
treeb7cdb81b498534c3deb7c8685405824ab1fb5b86 /arch
parent172b2386ed16a9143d9a456aae5ec87275c61489 (diff)
downloadlinux-0c1d77f4ba5cc9c05a29adca3d6466cdf4969b70.tar.xz
KVM: x86: fix conversion of addresses to linear in 32-bit protected mode
Commit e8dd2d2d641c ("Silence compiler warning in arch/x86/kvm/emulate.c", 2015-09-06) broke boot of the Hurd. The bug is that the "default:" case actually could modify "la", but after the patch this change is not reflected in *linear. The bug is visible whenever a non-zero segment base causes the linear address to wrap around the 4GB mark. Fixes: e8dd2d2d641cb2724ee10e76c0ad02e04289c017 Cc: stable@vger.kernel.org Reported-by: Aurelien Jarno <aurelien@aurel32.net> Tested-by: Aurelien Jarno <aurelien@aurel32.net> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/emulate.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 1505587d06e9..b9b09fec173b 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -650,10 +650,10 @@ static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt,
u16 sel;
la = seg_base(ctxt, addr.seg) + addr.ea;
- *linear = la;
*max_size = 0;
switch (mode) {
case X86EMUL_MODE_PROT64:
+ *linear = la;
if (is_noncanonical_address(la))
goto bad;
@@ -662,6 +662,7 @@ static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt,
goto bad;
break;
default:
+ *linear = la = (u32)la;
usable = ctxt->ops->get_segment(ctxt, &sel, &desc, NULL,
addr.seg);
if (!usable)
@@ -689,7 +690,6 @@ static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt,
if (size > *max_size)
goto bad;
}
- la &= (u32)-1;
break;
}
if (insn_aligned(ctxt, size) && ((la & (size - 1)) != 0))