Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-09-28 19:03:08 +00:00
Code Issues Packages Projects Releases Wiki Activity

KVM: x86: 32-bit wraparound read/write not emulated correctly

Browse Source 
If we got a wraparound of 32-bit operand, and the limit is 0xffffffff, read and
writes should be successful. It just needs to be done in two segments.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Nadav Amit 2015-01-26 09:32:26 +02:00 committed by Paolo Bonzini
parent 2b42fce695
commit bac155310b
2 changed files with 9 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
arch/x86/kvm/emulate.c
View File

@ -684,9 +684,13 @@ static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt,
}
if (addr.ea > lim)
goto bad;
*max_size = min_t(u64, ~0u, (u64)lim + 1 - addr.ea);
if (size > *max_size)
goto bad;
if (lim == 0xffffffff)
*max_size = ~0u;
else {
*max_size = (u64)lim + 1 - addr.ea;
if (size > *max_size)
goto bad;
}
la &= (u32)-1;
break;
}

2
arch/x86/kvm/x86.c
View File

@ -4495,6 +4495,8 @@ int emulator_read_write(struct x86_emulate_ctxt *ctxt, unsigned long addr,
if (rc != X86EMUL_CONTINUE)
return rc;
addr += now;
if (ctxt->mode != X86EMUL_MODE_PROT64)
addr = (u32)addr;
val += now;
bytes -= now;
}