iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

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

Browse Source 
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 committed by Paolo Bonzini
parent a5b0ccb0b5
commit e724f080f5
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
arch/powerpc/kvm/book3s_hv_rmhandlers.S
View File

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