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| author |   Paolo Bonzini <pbonzini@redhat.com> | 2016-02-19 18:07:21 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-02-24 14:47:45 +0100 |
| commit | 0c1d77f4ba5cc9c05a29adca3d6466cdf4969b70 (patch) | |
| tree | b7cdb81b498534c3deb7c8685405824ab1fb5b86 | |
| parent | KVM: x86: fix missed hardware breakpoints (diff) | |
| download | linux-dev-0c1d77f4ba5cc9c05a29adca3d6466cdf4969b70.tar.xz linux-dev-0c1d77f4ba5cc9c05a29adca3d6466cdf4969b70.zip | |
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>
| -rw-r--r-- | arch/x86/kvm/emulate.c | 4 |
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)) |