KVM: x86: Perform limit checks when assigning EIP

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If branch (e.g., jmp, ret) causes limit violations, since the target IP >
limit, the #GP exception occurs before the branch.  In other words, the RIP
pushed on the stack should be that of the branch and not that of the target.

To do so, we can call __linearize, with new EIP, which also saves us the code
which performs the canonical address checks. On the case of assigning an EIP >=
2^32 (when switching cs.l), we also safe, as __linearize will check the new EIP
does not exceed the limit and would trigger #GP(0) otherwise.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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Nadav Amit 2014-11-19 17:43:11 +02:00 • committed by Paolo Bonzini

parent a7315d2f3c

commit d50eaa1803

1 changed files with 54 additions and 41 deletions

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arch/x86/kvm/emulate.c

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