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Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kvm/emulate.c60
1 files changed, 33 insertions, 27 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index e8a58409b5ac..47e716ef46b7 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1410,11 +1410,11 @@ static int write_segment_descriptor(struct x86_emulate_ctxt *ctxt,
}
/* Does not support long mode */
-static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
- u16 selector, int seg)
+static int __load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
+ u16 selector, int seg, u8 cpl)
{
struct desc_struct seg_desc, old_desc;
- u8 dpl, rpl, cpl;
+ u8 dpl, rpl;
unsigned err_vec = GP_VECTOR;
u32 err_code = 0;
bool null_selector = !(selector & ~0x3); /* 0000-0003 are null */
@@ -1442,7 +1442,6 @@ static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
}
rpl = selector & 3;
- cpl = ctxt->ops->cpl(ctxt);
/* NULL selector is not valid for TR, CS and SS (except for long mode) */
if ((seg == VCPU_SREG_CS
@@ -1544,6 +1543,13 @@ exception:
return X86EMUL_PROPAGATE_FAULT;
}
+static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
+ u16 selector, int seg)
+{
+ u8 cpl = ctxt->ops->cpl(ctxt);
+ return __load_segment_descriptor(ctxt, selector, seg, cpl);
+}
+
static void write_register_operand(struct operand *op)
{
/* The 4-byte case *is* correct: in 64-bit mode we zero-extend. */
@@ -2405,6 +2411,7 @@ static int load_state_from_tss16(struct x86_emulate_ctxt *ctxt,
struct tss_segment_16 *tss)
{
int ret;
+ u8 cpl;
ctxt->_eip = tss->ip;
ctxt->eflags = tss->flag | 2;
@@ -2427,23 +2434,25 @@ static int load_state_from_tss16(struct x86_emulate_ctxt *ctxt,
set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS);
set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS);
+ cpl = tss->cs & 3;
+
/*
* Now load segment descriptors. If fault happens at this stage
* it is handled in a context of new task
*/
- ret = load_segment_descriptor(ctxt, tss->ldt, VCPU_SREG_LDTR);
+ ret = __load_segment_descriptor(ctxt, tss->ldt, VCPU_SREG_LDTR, cpl);
if (ret != X86EMUL_CONTINUE)
return ret;
- ret = load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES);
+ ret = __load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES, cpl);
if (ret != X86EMUL_CONTINUE)
return ret;
- ret = load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS);
+ ret = __load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS, cpl);
if (ret != X86EMUL_CONTINUE)
return ret;
- ret = load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS);
+ ret = __load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS, cpl);
if (ret != X86EMUL_CONTINUE)
return ret;
- ret = load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS);
+ ret = __load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS, cpl);
if (ret != X86EMUL_CONTINUE)
return ret;
@@ -2521,6 +2530,7 @@ static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt,
struct tss_segment_32 *tss)
{
int ret;
+ u8 cpl;
if (ctxt->ops->set_cr(ctxt, 3, tss->cr3))
return emulate_gp(ctxt, 0);
@@ -2539,7 +2549,8 @@ static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt,
/*
* SDM says that segment selectors are loaded before segment
- * descriptors
+ * descriptors. This is important because CPL checks will
+ * use CS.RPL.
*/
set_segment_selector(ctxt, tss->ldt_selector, VCPU_SREG_LDTR);
set_segment_selector(ctxt, tss->es, VCPU_SREG_ES);
@@ -2553,43 +2564,38 @@ static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt,
* If we're switching between Protected Mode and VM86, we need to make
* sure to update the mode before loading the segment descriptors so
* that the selectors are interpreted correctly.
- *
- * Need to get rflags to the vcpu struct immediately because it
- * influences the CPL which is checked at least when loading the segment
- * descriptors and when pushing an error code to the new kernel stack.
- *
- * TODO Introduce a separate ctxt->ops->set_cpl callback
*/
- if (ctxt->eflags & X86_EFLAGS_VM)
+ if (ctxt->eflags & X86_EFLAGS_VM) {
ctxt->mode = X86EMUL_MODE_VM86;
- else
+ cpl = 3;
+ } else {
ctxt->mode = X86EMUL_MODE_PROT32;
-
- ctxt->ops->set_rflags(ctxt, ctxt->eflags);
+ cpl = tss->cs & 3;
+ }
/*
* Now load segment descriptors. If fault happenes at this stage
* it is handled in a context of new task
*/
- ret = load_segment_descriptor(ctxt, tss->ldt_selector, VCPU_SREG_LDTR);
+ ret = __load_segment_descriptor(ctxt, tss->ldt_selector, VCPU_SREG_LDTR, cpl);
if (ret != X86EMUL_CONTINUE)
return ret;
- ret = load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES);
+ ret = __load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES, cpl);
if (ret != X86EMUL_CONTINUE)
return ret;
- ret = load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS);
+ ret = __load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS, cpl);
if (ret != X86EMUL_CONTINUE)
return ret;
- ret = load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS);
+ ret = __load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS, cpl);
if (ret != X86EMUL_CONTINUE)
return ret;
- ret = load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS);
+ ret = __load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS, cpl);
if (ret != X86EMUL_CONTINUE)
return ret;
- ret = load_segment_descriptor(ctxt, tss->fs, VCPU_SREG_FS);
+ ret = __load_segment_descriptor(ctxt, tss->fs, VCPU_SREG_FS, cpl);
if (ret != X86EMUL_CONTINUE)
return ret;
- ret = load_segment_descriptor(ctxt, tss->gs, VCPU_SREG_GS);
+ ret = __load_segment_descriptor(ctxt, tss->gs, VCPU_SREG_GS, cpl);
if (ret != X86EMUL_CONTINUE)
return ret;
generated by cgit v1.2.3 (git 2.25.1) at 2024-10-03 04:34:13 +0000