OS-6066 want writable uregs[] in dtrace

Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Alex Wilson <alex.wilson@joyent.com>
Reviewed by: Bryan Cantrill <bryan@joyent.com>
Approved by: Jerry Jelinek <jerry.jelinek@joyent.com>

5 files changed, 195 insertions, 28 deletions

diff --git a/usr/src/uts/common/dtrace/dtrace.c b/usr/src/uts/common/dtrace/dtrace.c
index 6ec6c5ae9d..f5ce5608aa 100644
--- a/usr/src/uts/common/dtrace/dtrace.c
+++ b/usr/src/uts/common/dtrace/dtrace.c
@@ -21,7 +21,7 @@
 
 /*
  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2016, Joyent, Inc. All rights reserved.
+ * Copyright (c) 2017, Joyent, Inc.
  * Copyright (c) 2012, 2014 by Delphix. All rights reserved.
  */
 
@@ -3545,6 +3545,34 @@ dtrace_dif_variable(dtrace_mstate_t *mstate, dtrace_state_t *state, uint64_t v,
 	}
 }
 
+static void
+dtrace_dif_variable_write(dtrace_mstate_t *mstate, dtrace_state_t *state,
+    uint64_t v, uint64_t ndx, uint64_t data)
+{
+	switch (v) {
+	case DIF_VAR_UREGS: {
+		klwp_t *lwp;
+
+		if (dtrace_destructive_disallow ||
+		    !dtrace_priv_proc_control(state, mstate)) {
+			return;
+		}
+
+		if ((lwp = curthread->t_lwp) == NULL) {
+			DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
+			cpu_core[CPU->cpu_id].cpuc_dtrace_illval = NULL;
+			return;
+		}
+
+		dtrace_setreg(lwp->lwp_regs, ndx, data);
+		return;
+	}
+
+	default:
+		DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
+		return;
+	}
+}
 
 typedef enum dtrace_json_state {
 	DTRACE_JSON_REST = 1,
@@ -6024,6 +6052,11 @@ dtrace_dif_emulate(dtrace_difo_t *difo, dtrace_mstate_t *mstate,
 			regs[rd] = dtrace_dif_variable(mstate, state, id, 0);
 			break;
 
+		case DIF_OP_STGA:
+			dtrace_dif_variable_write(mstate, state, r1, regs[r2],
+			    regs[rd]);
+			break;
+
 		case DIF_OP_STGS:
 			id = DIF_INSTR_VAR(instr);
 
@@ -9407,6 +9440,15 @@ dtrace_difo_validate(dtrace_difo_t *dp, dtrace_vstate_t *vstate, uint_t nregs,
 			if (rd == 0)
 				err += efunc(pc, "cannot write to %r0\n");
 			break;
+		case DIF_OP_STGA:
+			if (r1 > DIF_VAR_ARRAY_MAX)
+				err += efunc(pc, "invalid array %u\n", r1);
+			if (r2 >= nregs)
+				err += efunc(pc, "invalid register %u\n", r2);
+			if (rd >= nregs)
+				err += efunc(pc, "invalid register %u\n", rd);
+			dp->dtdo_destructive = 1;
+			break;
 		case DIF_OP_LDGS:
 		case DIF_OP_LDTS:
 		case DIF_OP_LDLS:
@@ -9752,12 +9794,23 @@ dtrace_difo_validate_helper(dtrace_difo_t *dp)
 			break;
 
 		case DIF_OP_LDTA:
+			if (v < DIF_VAR_OTHER_UBASE) {
+				err += efunc(pc, "illegal variable load\n");
+				break;
+			}
+			/* FALLTHROUGH */
 		case DIF_OP_LDTS:
 		case DIF_OP_LDGAA:
 		case DIF_OP_LDTAA:
 			err += efunc(pc, "illegal dynamic variable load\n");
 			break;
 
+		case DIF_OP_STGA:
+			if (v < DIF_VAR_OTHER_UBASE) {
+				err += efunc(pc, "illegal variable store\n");
+				break;
+			}
+			/* FALLTHROUGH */
 		case DIF_OP_STTS:
 		case DIF_OP_STGAA:
 		case DIF_OP_STTAA:
diff --git a/usr/src/uts/common/sys/dtrace.h b/usr/src/uts/common/sys/dtrace.h
index 4ee1a94510..44ca7d8ae7 100644
--- a/usr/src/uts/common/sys/dtrace.h
+++ b/usr/src/uts/common/sys/dtrace.h
@@ -25,7 +25,7 @@
  */
 
 /*
- * Copyright 2016 Joyent, Inc.
+ * Copyright 2017 Joyent, Inc.
  * Copyright (c) 2013 by Delphix. All rights reserved.
  */
 
@@ -189,6 +189,7 @@ typedef enum dtrace_probespec {
 #define	DIF_OP_RLDX	77		/* rldx  [r1], rd */
 #define	DIF_OP_XLATE	78		/* xlate xlrindex, rd */
 #define	DIF_OP_XLARG	79		/* xlarg xlrindex, rd */
+#define	DIF_OP_STGA	80		/* stga var, ri, rd */
 
 #define	DIF_INTOFF_MAX		0xffff	/* highest integer table offset */
 #define	DIF_STROFF_MAX		0xffff	/* highest string table offset */
diff --git a/usr/src/uts/common/sys/dtrace_impl.h b/usr/src/uts/common/sys/dtrace_impl.h
index de7d0d25fb..a55d0d7e1f 100644
--- a/usr/src/uts/common/sys/dtrace_impl.h
+++ b/usr/src/uts/common/sys/dtrace_impl.h
@@ -25,7 +25,7 @@
  */
 
 /*
- * Copyright 2016 Joyent, Inc.
+ * Copyright 2017 Joyent, Inc.
  * Copyright (c) 2012 by Delphix. All rights reserved.
  */
 
@@ -1262,6 +1262,7 @@ extern void dtrace_copyoutstr(uintptr_t, uintptr_t, size_t,
     volatile uint16_t *);
 extern void dtrace_getpcstack(pc_t *, int, int, uint32_t *);
 extern ulong_t dtrace_getreg(struct regs *, uint_t);
+extern void dtrace_setreg(struct regs *, uint_t, ulong_t);
 extern uint64_t dtrace_getvmreg(uint_t, volatile uint16_t *);
 extern int dtrace_getstackdepth(int);
 extern void dtrace_getupcstack(uint64_t *, int);
diff --git a/usr/src/uts/intel/dtrace/dtrace_isa.c b/usr/src/uts/intel/dtrace/dtrace_isa.c
index f649473dfb..f52180b0c0 100644
--- a/usr/src/uts/intel/dtrace/dtrace_isa.c
+++ b/usr/src/uts/intel/dtrace/dtrace_isa.c
@@ -26,6 +26,7 @@
 
 /*
  * Copyright (c) 2013, 2014 by Delphix. All rights reserved.
+ * Copyright (c) 2017 Joyent, Inc.
  */
 
 #include <sys/dtrace_impl.h>
@@ -546,39 +547,42 @@ dtrace_getstackdepth(int aframes)
 	return (depth - aframes);
 }
 
+#if defined(__amd64)
+static const int dtrace_regmap[] = {
+	REG_GS,		/* GS */
+	REG_FS,		/* FS */
+	REG_ES,		/* ES */
+	REG_DS,		/* DS */
+	REG_RDI,	/* EDI */
+	REG_RSI,	/* ESI */
+	REG_RBP,	/* EBP */
+	REG_RSP,	/* ESP */
+	REG_RBX,	/* EBX */
+	REG_RDX,	/* EDX */
+	REG_RCX,	/* ECX */
+	REG_RAX,	/* EAX */
+	REG_TRAPNO,	/* TRAPNO */
+	REG_ERR,	/* ERR */
+	REG_RIP,	/* EIP */
+	REG_CS,		/* CS */
+	REG_RFL,	/* EFL */
+	REG_RSP,	/* UESP */
+	REG_SS		/* SS */
+};
+#endif
+
+
 ulong_t
 dtrace_getreg(struct regs *rp, uint_t reg)
 {
 #if defined(__amd64)
-	int regmap[] = {
-		REG_GS,		/* GS */
-		REG_FS,		/* FS */
-		REG_ES,		/* ES */
-		REG_DS,		/* DS */
-		REG_RDI,	/* EDI */
-		REG_RSI,	/* ESI */
-		REG_RBP,	/* EBP */
-		REG_RSP,	/* ESP */
-		REG_RBX,	/* EBX */
-		REG_RDX,	/* EDX */
-		REG_RCX,	/* ECX */
-		REG_RAX,	/* EAX */
-		REG_TRAPNO,	/* TRAPNO */
-		REG_ERR,	/* ERR */
-		REG_RIP,	/* EIP */
-		REG_CS,		/* CS */
-		REG_RFL,	/* EFL */
-		REG_RSP,	/* UESP */
-		REG_SS		/* SS */
-	};
-
 	if (reg <= SS) {
-		if (reg >= sizeof (regmap) / sizeof (int)) {
+		if (reg >= sizeof (dtrace_regmap) / sizeof (int)) {
 			DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
 			return (0);
 		}
 
-		reg = regmap[reg];
+		reg = dtrace_regmap[reg];
 	} else {
 		reg -= SS + 1;
 	}
@@ -651,6 +655,105 @@ dtrace_getreg(struct regs *rp, uint_t reg)
 #endif
 }
 
+void
+dtrace_setreg(struct regs *rp, uint_t reg, ulong_t val)
+{
+#if defined(__amd64)
+	if (reg <= SS) {
+		ASSERT(reg < (sizeof (dtrace_regmap) / sizeof (int)));
+
+		reg = dtrace_regmap[reg];
+	} else {
+		reg -= SS + 1;
+	}
+
+	switch (reg) {
+	case REG_RDI:
+		rp->r_rdi = val;
+		break;
+	case REG_RSI:
+		rp->r_rsi = val;
+		break;
+	case REG_RDX:
+		rp->r_rdx = val;
+		break;
+	case REG_RCX:
+		rp->r_rcx = val;
+		break;
+	case REG_R8:
+		rp->r_r8 = val;
+		break;
+	case REG_R9:
+		rp->r_r9 = val;
+		break;
+	case REG_RAX:
+		rp->r_rax = val;
+		break;
+	case REG_RBX:
+		rp->r_rbx = val;
+		break;
+	case REG_RBP:
+		rp->r_rbp = val;
+		break;
+	case REG_R10:
+		rp->r_r10 = val;
+		break;
+	case REG_R11:
+		rp->r_r11 = val;
+		break;
+	case REG_R12:
+		rp->r_r12 = val;
+		break;
+	case REG_R13:
+		rp->r_r13 = val;
+		break;
+	case REG_R14:
+		rp->r_r14 = val;
+		break;
+	case REG_R15:
+		rp->r_r15 = val;
+		break;
+	case REG_RSP:
+		rp->r_rsp = val;
+		break;
+	default:
+		DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
+		return;
+	}
+
+#else /* defined(__amd64) */
+	switch (reg) {
+	case EAX:
+		rp->r_eax = val;
+		break;
+	case ECX:
+		rp->r_ecx = val;
+		break;
+	case EDX:
+		rp->r_edx = val;
+		break;
+	case EBX:
+		rp->r_ebx = val;
+		break;
+	case ESP:
+		rp->r_esp = val;
+		break;
+	case EBP:
+		rp->r_ebp = val;
+		break;
+	case ESI:
+		rp->r_esi = val;
+		break;
+	case EDI:
+		rp->r_edi = val;
+		break;
+	default:
+		DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
+		return;
+	}
+#endif /* defined(__amd64) */
+}
+
 static int
 dtrace_copycheck(uintptr_t uaddr, uintptr_t kaddr, size_t size)
 {
diff --git a/usr/src/uts/sparc/dtrace/dtrace_isa.c b/usr/src/uts/sparc/dtrace/dtrace_isa.c
index 20d9bc420b..541f733b06 100644
--- a/usr/src/uts/sparc/dtrace/dtrace_isa.c
+++ b/usr/src/uts/sparc/dtrace/dtrace_isa.c
@@ -24,7 +24,7 @@
  * Use is subject to license terms.
  */
 /*
- * Copyright 2011 Joyent, Inc.  All rights reserved.
+ * Copyright 2017 Joyent, Inc.
  */
 
 #include <sys/dtrace_impl.h>
@@ -940,6 +940,15 @@ got_fp:
 	return (value);
 }
 
+/* ARGSUSED */
+int
+dtrace_setreg(struct regs *rp, uint_t reg, ulong_t val)
+{
+	/* Not supported at this time */
+	DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
+	return (0);
+}
+
 /*ARGSUSED*/
 uint64_t
 dtrace_getvmreg(uint_t ndx, volatile uint16_t *flags)