Merge branch 'perf/core' into perf/uprobes

Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 97 insertions, 15 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 0982507b962..83756223f8a 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -57,6 +57,7 @@
 #define OpDS              23ull  /* DS */
 #define OpFS              24ull  /* FS */
 #define OpGS              25ull  /* GS */
+#define OpMem8            26ull  /* 8-bit zero extended memory operand */
 
 #define OpBits             5  /* Width of operand field */
 #define OpMask             ((1ull << OpBits) - 1)
@@ -101,6 +102,7 @@
 #define SrcAcc      (OpAcc << SrcShift)
 #define SrcImmU16   (OpImmU16 << SrcShift)
 #define SrcDX       (OpDX << SrcShift)
+#define SrcMem8     (OpMem8 << SrcShift)
 #define SrcMask     (OpMask << SrcShift)
 #define BitOp       (1<<11)
 #define MemAbs      (1<<12)      /* Memory operand is absolute displacement */
@@ -858,8 +860,7 @@ static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data,
 }
 
 static void decode_register_operand(struct x86_emulate_ctxt *ctxt,
-				    struct operand *op,
-				    int inhibit_bytereg)
+				    struct operand *op)
 {
 	unsigned reg = ctxt->modrm_reg;
 	int highbyte_regs = ctxt->rex_prefix == 0;
@@ -876,7 +877,7 @@ static void decode_register_operand(struct x86_emulate_ctxt *ctxt,
 	}
 
 	op->type = OP_REG;
-	if ((ctxt->d & ByteOp) && !inhibit_bytereg) {
+	if (ctxt->d & ByteOp) {
 		op->addr.reg = decode_register(reg, ctxt->regs, highbyte_regs);
 		op->bytes = 1;
 	} else {
@@ -1151,6 +1152,22 @@ static int pio_in_emulated(struct x86_emulate_ctxt *ctxt,
 	return 1;
 }
 
+static int read_interrupt_descriptor(struct x86_emulate_ctxt *ctxt,
+				     u16 index, struct desc_struct *desc)
+{
+	struct desc_ptr dt;
+	ulong addr;
+
+	ctxt->ops->get_idt(ctxt, &dt);
+
+	if (dt.size < index * 8 + 7)
+		return emulate_gp(ctxt, index << 3 | 0x2);
+
+	addr = dt.address + index * 8;
+	return ctxt->ops->read_std(ctxt, addr, desc, sizeof *desc,
+				   &ctxt->exception);
+}
+
 static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt,
 				     u16 selector, struct desc_ptr *dt)
 {
@@ -1227,6 +1244,8 @@ static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
 		seg_desc.type = 3;
 		seg_desc.p = 1;
 		seg_desc.s = 1;
+		if (ctxt->mode == X86EMUL_MODE_VM86)
+			seg_desc.dpl = 3;
 		goto load;
 	}
 
@@ -1891,6 +1910,17 @@ setup_syscalls_segments(struct x86_emulate_ctxt *ctxt,
 	ss->p = 1;
 }
 
+static bool vendor_intel(struct x86_emulate_ctxt *ctxt)
+{
+	u32 eax, ebx, ecx, edx;
+
+	eax = ecx = 0;
+	return ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx)
+		&& ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx
+		&& ecx == X86EMUL_CPUID_VENDOR_GenuineIntel_ecx
+		&& edx == X86EMUL_CPUID_VENDOR_GenuineIntel_edx;
+}
+
 static bool em_syscall_is_enabled(struct x86_emulate_ctxt *ctxt)
 {
 	struct x86_emulate_ops *ops = ctxt->ops;
@@ -2007,6 +2037,14 @@ static int em_sysenter(struct x86_emulate_ctxt *ctxt)
 	if (ctxt->mode == X86EMUL_MODE_REAL)
 		return emulate_gp(ctxt, 0);
 
+	/*
+	 * Not recognized on AMD in compat mode (but is recognized in legacy
+	 * mode).
+	 */
+	if ((ctxt->mode == X86EMUL_MODE_PROT32) && (efer & EFER_LMA)
+	    && !vendor_intel(ctxt))
+		return emulate_ud(ctxt);
+
 	/* XXX sysenter/sysexit have not been tested in 64bit mode.
 	* Therefore, we inject an #UD.
 	*/
@@ -2306,6 +2344,8 @@ static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt,
 		return emulate_gp(ctxt, 0);
 	ctxt->_eip = tss->eip;
 	ctxt->eflags = tss->eflags | 2;
+
+	/* General purpose registers */
 	ctxt->regs[VCPU_REGS_RAX] = tss->eax;
 	ctxt->regs[VCPU_REGS_RCX] = tss->ecx;
 	ctxt->regs[VCPU_REGS_RDX] = tss->edx;
@@ -2328,6 +2368,24 @@ static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt,
 	set_segment_selector(ctxt, tss->gs, VCPU_SREG_GS);
 
 	/*
+	 * 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)
+		ctxt->mode = X86EMUL_MODE_VM86;
+	else
+		ctxt->mode = X86EMUL_MODE_PROT32;
+
+	ctxt->ops->set_rflags(ctxt, ctxt->eflags);
+
+	/*
 	 * Now load segment descriptors. If fault happenes at this stage
 	 * it is handled in a context of new task
 	 */
@@ -2401,7 +2459,7 @@ static int task_switch_32(struct x86_emulate_ctxt *ctxt,
 }
 
 static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt,
-				   u16 tss_selector, int reason,
+				   u16 tss_selector, int idt_index, int reason,
 				   bool has_error_code, u32 error_code)
 {
 	struct x86_emulate_ops *ops = ctxt->ops;
@@ -2423,12 +2481,35 @@ static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt,
 
 	/* FIXME: check that next_tss_desc is tss */
 
-	if (reason != TASK_SWITCH_IRET) {
-		if ((tss_selector & 3) > next_tss_desc.dpl ||
-		    ops->cpl(ctxt) > next_tss_desc.dpl)
-			return emulate_gp(ctxt, 0);
+	/*
+	 * Check privileges. The three cases are task switch caused by...
+	 *
+	 * 1. jmp/call/int to task gate: Check against DPL of the task gate
+	 * 2. Exception/IRQ/iret: No check is performed
+	 * 3. jmp/call to TSS: Check agains DPL of the TSS
+	 */
+	if (reason == TASK_SWITCH_GATE) {
+		if (idt_index != -1) {
+			/* Software interrupts */
+			struct desc_struct task_gate_desc;
+			int dpl;
+
+			ret = read_interrupt_descriptor(ctxt, idt_index,
+							&task_gate_desc);
+			if (ret != X86EMUL_CONTINUE)
+				return ret;
+
+			dpl = task_gate_desc.dpl;
+			if ((tss_selector & 3) > dpl || ops->cpl(ctxt) > dpl)
+				return emulate_gp(ctxt, (idt_index << 3) | 0x2);
+		}
+	} else if (reason != TASK_SWITCH_IRET) {
+		int dpl = next_tss_desc.dpl;
+		if ((tss_selector & 3) > dpl || ops->cpl(ctxt) > dpl)
+			return emulate_gp(ctxt, tss_selector);
 	}
 
+
 	desc_limit = desc_limit_scaled(&next_tss_desc);
 	if (!next_tss_desc.p ||
 	    ((desc_limit < 0x67 && (next_tss_desc.type & 8)) ||
@@ -2481,7 +2562,7 @@ static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt,
 }
 
 int emulator_task_switch(struct x86_emulate_ctxt *ctxt,
-			 u16 tss_selector, int reason,
+			 u16 tss_selector, int idt_index, int reason,
 			 bool has_error_code, u32 error_code)
 {
 	int rc;
@@ -2489,7 +2570,7 @@ int emulator_task_switch(struct x86_emulate_ctxt *ctxt,
 	ctxt->_eip = ctxt->eip;
 	ctxt->dst.type = OP_NONE;
 
-	rc = emulator_do_task_switch(ctxt, tss_selector, reason,
+	rc = emulator_do_task_switch(ctxt, tss_selector, idt_index, reason,
 				     has_error_code, error_code);
 
 	if (rc == X86EMUL_CONTINUE)
@@ -3514,13 +3595,13 @@ static struct opcode twobyte_table[256] = {
 	I(DstMem | SrcReg | ModRM | BitOp | Lock, em_btr),
 	I(DstReg | SrcMemFAddr | ModRM | Src2FS, em_lseg),
 	I(DstReg | SrcMemFAddr | ModRM | Src2GS, em_lseg),
-	D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
+	D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
 	/* 0xB8 - 0xBF */
 	N, N,
 	G(BitOp, group8),
 	I(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_btc),
 	I(DstReg | SrcMem | ModRM, em_bsf), I(DstReg | SrcMem | ModRM, em_bsr),
-	D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
+	D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
 	/* 0xC0 - 0xCF */
 	D2bv(DstMem | SrcReg | ModRM | Lock),
 	N, D(DstMem | SrcReg | ModRM | Mov),
@@ -3602,9 +3683,7 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op,
 
 	switch (d) {
 	case OpReg:
-		decode_register_operand(ctxt, op,
-			 op == &ctxt->dst &&
-			 ctxt->twobyte && (ctxt->b == 0xb6 || ctxt->b == 0xb7));
+		decode_register_operand(ctxt, op);
 		break;
 	case OpImmUByte:
 		rc = decode_imm(ctxt, op, 1, false);
@@ -3656,6 +3735,9 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op,
 	case OpImm:
 		rc = decode_imm(ctxt, op, imm_size(ctxt), true);
 		break;
+	case OpMem8:
+		ctxt->memop.bytes = 1;
+		goto mem_common;
 	case OpMem16:
 		ctxt->memop.bytes = 2;
 		goto mem_common;