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head/emulators/xen-kernel/files/xsa165-4.5.patch
| Property | Old Value | New Value |
|---|---|---|
| fbsd:nokeywords | null | yes \ No newline at end of property |
| x86: don't leak ST(n)/XMMn values to domains first using them | |||||
| FNINIT doesn't alter these registers, and hence using it is | |||||
| insufficient to initialize a guest's initial state. | |||||
| This is XSA-165. | |||||
| Signed-off-by: Jan Beulich <jbeulich@suse.com> | |||||
| Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> | |||||
| --- a/xen/arch/x86/domain.c | |||||
| +++ b/xen/arch/x86/domain.c | |||||
| @@ -798,6 +798,17 @@ int arch_set_info_guest( | |||||
| if ( v->arch.xsave_area ) | |||||
| v->arch.xsave_area->xsave_hdr.xstate_bv = XSTATE_FP_SSE; | |||||
| } | |||||
| + else if ( v->arch.xsave_area ) | |||||
| + memset(&v->arch.xsave_area->xsave_hdr, 0, | |||||
| + sizeof(v->arch.xsave_area->xsave_hdr)); | |||||
| + else | |||||
| + { | |||||
| + typeof(v->arch.xsave_area->fpu_sse) *fpu_sse = v->arch.fpu_ctxt; | |||||
| + | |||||
| + memset(fpu_sse, 0, sizeof(*fpu_sse)); | |||||
| + fpu_sse->fcw = FCW_DEFAULT; | |||||
| + fpu_sse->mxcsr = MXCSR_DEFAULT; | |||||
| + } | |||||
| if ( !compat ) | |||||
| { | |||||
| --- a/xen/arch/x86/i387.c | |||||
| +++ b/xen/arch/x86/i387.c | |||||
| @@ -17,19 +17,6 @@ | |||||
| #include <asm/xstate.h> | |||||
| #include <asm/asm_defns.h> | |||||
| -static void fpu_init(void) | |||||
| -{ | |||||
| - unsigned long val; | |||||
| - | |||||
| - asm volatile ( "fninit" ); | |||||
| - if ( cpu_has_xmm ) | |||||
| - { | |||||
| - /* load default value into MXCSR control/status register */ | |||||
| - val = MXCSR_DEFAULT; | |||||
| - asm volatile ( "ldmxcsr %0" : : "m" (val) ); | |||||
| - } | |||||
| -} | |||||
| - | |||||
| /*******************************/ | |||||
| /* FPU Restore Functions */ | |||||
| /*******************************/ | |||||
| @@ -248,15 +235,8 @@ void vcpu_restore_fpu_lazy(struct vcpu * | |||||
| if ( cpu_has_xsave ) | |||||
| fpu_xrstor(v, XSTATE_LAZY); | |||||
| - else if ( v->fpu_initialised ) | |||||
| - { | |||||
| - if ( cpu_has_fxsr ) | |||||
| - fpu_fxrstor(v); | |||||
| - else | |||||
| - fpu_frstor(v); | |||||
| - } | |||||
| else | |||||
| - fpu_init(); | |||||
| + fpu_fxrstor(v); | |||||
| v->fpu_initialised = 1; | |||||
| v->fpu_dirtied = 1; | |||||
| @@ -317,7 +297,14 @@ int vcpu_init_fpu(struct vcpu *v) | |||||
| else | |||||
| { | |||||
| v->arch.fpu_ctxt = _xzalloc(sizeof(v->arch.xsave_area->fpu_sse), 16); | |||||
| - if ( !v->arch.fpu_ctxt ) | |||||
| + if ( v->arch.fpu_ctxt ) | |||||
| + { | |||||
| + typeof(v->arch.xsave_area->fpu_sse) *fpu_sse = v->arch.fpu_ctxt; | |||||
| + | |||||
| + fpu_sse->fcw = FCW_DEFAULT; | |||||
| + fpu_sse->mxcsr = MXCSR_DEFAULT; | |||||
| + } | |||||
| + else | |||||
| { | |||||
| rc = -ENOMEM; | |||||
| goto done; | |||||