diff options
| author | Avi Kivity <avi@redhat.com> | 2012-08-01 16:48:03 +0300 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2012-08-01 20:23:57 -0300 |
| commit | aa67f6096c19bcdb1951ef88be3cf3d2118809dc (patch) | |
| tree | 61a806e065b9db4eabfd85753333e580d8b0a465 /arch/x86/crypto/sha1_ssse3_glue.c | |
| parent | 4b6486659a7defef82ea51b276024b3aa357fefc (diff) | |
KVM: VMX: Fix ds/es corruption on i386 with preemption
Commit b2da15ac26a0c ("KVM: VMX: Optimize %ds, %es reload") broke i386
in the following scenario:
vcpu_load
...
vmx_save_host_state
vmx_vcpu_run
(ds.rpl, es.rpl cleared by hardware)
interrupt
push ds, es # pushes bad ds, es
schedule
vmx_vcpu_put
vmx_load_host_state
reload ds, es (with __USER_DS)
pop ds, es # of other thread's stack
iret
# other thread runs
interrupt
push ds, es
schedule # back in vcpu thread
pop ds, es # now with rpl=0
iret
...
vcpu_put
resume_userspace
iret # clears ds, es due to mismatched rpl
(instead of resume_userspace, we might return with SYSEXIT and then
take an exception; when the exception IRETs we end up with cleared
ds, es)
Fix by avoiding the optimization on i386 and reloading ds, es on the
lightweight exit path.
Reported-by: Chris Clayron <chris2553@googlemail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/x86/crypto/sha1_ssse3_glue.c')
0 files changed, 0 insertions, 0 deletions