KVM: PPC: Book3S HV: Fix register usage when loading/saving VRSAVE

Commit 595e4f7e69 ("KVM: PPC: Book3S HV: Use load/store_fp_state
functions in HV guest entry/exit") changed the register usage in
kvmppc_save_fp() and kvmppc_load_fp() but omitted changing the
instructions that load and save VRSAVE.  The result is that the
VRSAVE value was loaded from a constant address, and saved to a
location past the end of the vcpu struct, causing host kernel
memory corruption and various kinds of host kernel crashes.

This fixes the problem by using register r31, which contains the
vcpu pointer, instead of r3 and r4.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paul Mackerras 2014-03-13 20:02:48 +11:00 коммит произвёл Paolo Bonzini
Родитель a5b0ccb0b5
Коммит e724f080f5
1 изменённых файлов: 2 добавлений и 2 удалений

Просмотреть файл

@ -2136,7 +2136,7 @@ BEGIN_FTR_SECTION
END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
#endif #endif
mfspr r6,SPRN_VRSAVE mfspr r6,SPRN_VRSAVE
stw r6,VCPU_VRSAVE(r3) stw r6,VCPU_VRSAVE(r31)
mtlr r30 mtlr r30
mtmsrd r5 mtmsrd r5
isync isync
@ -2173,7 +2173,7 @@ BEGIN_FTR_SECTION
bl .load_vr_state bl .load_vr_state
END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
#endif #endif
lwz r7,VCPU_VRSAVE(r4) lwz r7,VCPU_VRSAVE(r31)
mtspr SPRN_VRSAVE,r7 mtspr SPRN_VRSAVE,r7
mtlr r30 mtlr r30
mr r4,r31 mr r4,r31