xnu-3248.20.55.tar.gz

[apple/xnu.git] / bsd / dev / i386 / fasttrap_isa.c

diff --git a/bsd/dev/i386/fasttrap_isa.c b/bsd/dev/i386/fasttrap_isa.c
index c96666b0b93db3dbfe6f12fdc93a5940f513f1d1..4eeb6d140f0b4060e13e28b1e52aefeb45111373 100644 (file)
--- a/bsd/dev/i386/fasttrap_isa.c
+++ b/bsd/dev/i386/fasttrap_isa.c
@@ -20,12 +20,12 @@
  */
 
 /*
  */
 
 /*

- * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
+ * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.

  * Use is subject to license terms.
  */
 
 /*
  * Use is subject to license terms.
  */
 
 /*

- * #pragma ident       "@(#)fasttrap_isa.c     1.23    06/09/19 SMI"
+ * #pragma ident       "@(#)fasttrap_isa.c     1.27    08/04/09 SMI"

  */
 
 #ifdef KERNEL
  */
 
 #ifdef KERNEL


@@ -45,7 +45,10 @@ extern dtrace_id_t dtrace_probeid_error;
 #include <sys/dtrace_ptss.h>
 #include <kern/debug.h>
 
 #include <sys/dtrace_ptss.h>
 #include <kern/debug.h>
 

-#define proc_t struct proc
+#include <machine/pal_routines.h>
+
+/* Solaris proc_t is the struct. Darwin's proc_t is a pointer to it. */
+#define proc_t struct proc /* Steer clear of the Darwin typedef for proc_t */

 
 /*
  * Lossless User-Land Tracing on x86
 
 /*
  * Lossless User-Land Tracing on x86


@@ -194,21 +197,19 @@ extern dtrace_id_t dtrace_probeid_error;
  *
  * REG_RAX -> EAX
  * REG_RCX -> ECX
  *
  * REG_RAX -> EAX
  * REG_RCX -> ECX

- * ...
+ * REG_RDX -> EDX
+ * REG_RBX -> EBX
+ * REG_RSP -> UESP
+ * REG_RBP -> EBP
+ * REG_RSI -> ESI

  * REG_RDI -> EDI
  *
  * The fasttrap_getreg function knows how to make the correct transformation.
  */
  * REG_RDI -> EDI
  *
  * The fasttrap_getreg function knows how to make the correct transformation.
  */

-#if __sol64 || defined(__APPLE__)

 static const uint8_t regmap[16] = {
        REG_RAX, REG_RCX, REG_RDX, REG_RBX, REG_RSP, REG_RBP, REG_RSI, REG_RDI,
        REG_R8, REG_R9, REG_R10, REG_R11, REG_R12, REG_R13, REG_R14, REG_R15,
 };
 static const uint8_t regmap[16] = {
        REG_RAX, REG_RCX, REG_RDX, REG_RBX, REG_RSP, REG_RBP, REG_RSI, REG_RDI,
        REG_R8, REG_R9, REG_R10, REG_R11, REG_R12, REG_R13, REG_R14, REG_R15,
 };

-#else
-static const uint8_t regmap[8] = {
-       EAX, ECX, EDX, EBX, UESP, EBP, ESI, EDI
-};
-#endif

 
 static user_addr_t fasttrap_getreg(x86_saved_state_t *, uint_t);
 
 
 static user_addr_t fasttrap_getreg(x86_saved_state_t *, uint_t);
 


@@ -247,7 +248,7 @@ fasttrap_anarg(x86_saved_state_t *regs, int function_entry, int argno)
                value = dtrace_fuword64(stack);
                DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT | CPU_DTRACE_BADADDR);
        } else {
                value = dtrace_fuword64(stack);
                DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT | CPU_DTRACE_BADADDR);
        } else {

-               uint32_t *stack = (uint32_t *)regs32->uesp;
+               uint32_t *stack = (uint32_t *)(uintptr_t)(regs32->uesp);

                DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
                value = dtrace_fuword32((user_addr_t)(unsigned long)&stack[argno + shift]);
                DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT | CPU_DTRACE_BADADDR);
                DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
                value = dtrace_fuword32((user_addr_t)(unsigned long)&stack[argno + shift]);
                DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT | CPU_DTRACE_BADADDR);


@@ -360,13 +361,11 @@ fasttrap_tracepoint_init(proc_t *p, fasttrap_tracepoint_t *tp, user_addr_t pc,
                break;
        }
 
                break;
        }
 

-#if __sol64 || defined(__APPLE__)

        /*
         * Identify the REX prefix on 64-bit processes.
         */
        if (p_model == DATAMODEL_LP64 && (instr[start] & 0xf0) == 0x40)
                rex = instr[start++];
        /*
         * Identify the REX prefix on 64-bit processes.
         */
        if (p_model == DATAMODEL_LP64 && (instr[start] & 0xf0) == 0x40)
                rex = instr[start++];

-#endif

 
        /*
         * Now that we're pretty sure that the instruction is okay, copy the
 
        /*
         * Now that we're pretty sure that the instruction is okay, copy the


@@ -396,6 +395,7 @@ fasttrap_tracepoint_init(proc_t *p, fasttrap_tracepoint_t *tp, user_addr_t pc,
                        tp->ftt_type = FASTTRAP_T_JCC;
                        tp->ftt_code = (instr[start + 1] & 0x0f) | FASTTRAP_JO;
                        tp->ftt_dest = pc + tp->ftt_size +
                        tp->ftt_type = FASTTRAP_T_JCC;
                        tp->ftt_code = (instr[start + 1] & 0x0f) | FASTTRAP_JO;
                        tp->ftt_dest = pc + tp->ftt_size +

+                           /* LINTED - alignment */

                            *(int32_t *)&instr[start + 2];
                        break;
                }
                            *(int32_t *)&instr[start + 2];
                        break;
                }


@@ -448,11 +448,9 @@ fasttrap_tracepoint_init(proc_t *p, fasttrap_tracepoint_t *tp, user_addr_t pc,
                                 * modes, there is a 32-bit operand.
                                 */
                                if (mod == 0 && rm == 5) {
                                 * modes, there is a 32-bit operand.
                                 */
                                if (mod == 0 && rm == 5) {

-#if __sol64 || defined(__APPLE__)

                                        if (p_model == DATAMODEL_LP64)
                                                tp->ftt_base = REG_RIP;
                                        else
                                        if (p_model == DATAMODEL_LP64)
                                                tp->ftt_base = REG_RIP;
                                        else

-#endif

                                                tp->ftt_base = FASTTRAP_NOREG;
                                        sz = 4;
                                } else  {
                                                tp->ftt_base = FASTTRAP_NOREG;
                                        sz = 4;
                                } else  {


@@ -466,12 +464,14 @@ fasttrap_tracepoint_init(proc_t *p, fasttrap_tracepoint_t *tp, user_addr_t pc,
                                i = 2;
                        }
 
                                i = 2;
                        }
 

-                       if (sz == 1)
+                       if (sz == 1) {

                                tp->ftt_dest = *(int8_t *)&instr[start + i];
                                tp->ftt_dest = *(int8_t *)&instr[start + i];

-                       else if (sz == 4)
+                       } else if (sz == 4) {
+                               /* LINTED - alignment */

                                tp->ftt_dest = *(int32_t *)&instr[start + i];
                                tp->ftt_dest = *(int32_t *)&instr[start + i];

-                       else
+                       } else {

                                tp->ftt_dest = 0;
                                tp->ftt_dest = 0;

+                       }

                }
        } else {
                switch (instr[start]) {
                }
        } else {
                switch (instr[start]) {


@@ -481,6 +481,7 @@ fasttrap_tracepoint_init(proc_t *p, fasttrap_tracepoint_t *tp, user_addr_t pc,
 
                case FASTTRAP_RET16:
                        tp->ftt_type = FASTTRAP_T_RET16;
 
                case FASTTRAP_RET16:
                        tp->ftt_type = FASTTRAP_T_RET16;

+                       /* LINTED - alignment */

                        tp->ftt_dest = *(uint16_t *)&instr[start + 1];
                        break;
 
                        tp->ftt_dest = *(uint16_t *)&instr[start + 1];
                        break;
 


@@ -524,6 +525,7 @@ fasttrap_tracepoint_init(proc_t *p, fasttrap_tracepoint_t *tp, user_addr_t pc,
                case FASTTRAP_CALL:
                        tp->ftt_type = FASTTRAP_T_CALL;
                        tp->ftt_dest = pc + tp->ftt_size +
                case FASTTRAP_CALL:
                        tp->ftt_type = FASTTRAP_T_CALL;
                        tp->ftt_dest = pc + tp->ftt_size +

+                           /* LINTED - alignment */

                            *(int32_t *)&instr[start + 1];
                        tp->ftt_code = 0;
                        break;
                            *(int32_t *)&instr[start + 1];
                        tp->ftt_code = 0;
                        break;


@@ -531,6 +533,7 @@ fasttrap_tracepoint_init(proc_t *p, fasttrap_tracepoint_t *tp, user_addr_t pc,
                case FASTTRAP_JMP32:
                        tp->ftt_type = FASTTRAP_T_JMP;
                        tp->ftt_dest = pc + tp->ftt_size +
                case FASTTRAP_JMP32:
                        tp->ftt_type = FASTTRAP_T_JMP;
                        tp->ftt_dest = pc + tp->ftt_size +

+                               /* LINTED - alignment */

                            *(int32_t *)&instr[start + 1];
                        break;
                case FASTTRAP_JMP8:
                            *(int32_t *)&instr[start + 1];
                        break;
                case FASTTRAP_JMP8:


@@ -545,7 +548,6 @@ fasttrap_tracepoint_init(proc_t *p, fasttrap_tracepoint_t *tp, user_addr_t pc,
                        break;
 
                case FASTTRAP_NOP:
                        break;
 
                case FASTTRAP_NOP:

-#if __sol64 || defined(__APPLE__)

                        ASSERT(p_model == DATAMODEL_LP64 || rex == 0);
 
                        /*
                        ASSERT(p_model == DATAMODEL_LP64 || rex == 0);
 
                        /*


@@ -555,7 +557,6 @@ fasttrap_tracepoint_init(proc_t *p, fasttrap_tracepoint_t *tp, user_addr_t pc,
                         * (e.g. xchgl %r8d, %eax or xcghq %r8, %rax).
                         */
                        if (FASTTRAP_REX_B(rex) == 0)
                         * (e.g. xchgl %r8d, %eax or xcghq %r8, %rax).
                         */
                        if (FASTTRAP_REX_B(rex) == 0)

-#endif

                                tp->ftt_type = FASTTRAP_T_NOP;
                        break;
 
                                tp->ftt_type = FASTTRAP_T_NOP;
                        break;
 


@@ -582,7 +583,6 @@ fasttrap_tracepoint_init(proc_t *p, fasttrap_tracepoint_t *tp, user_addr_t pc,
                }
        }
 
                }
        }
 

-#if __sol64 || defined(__APPLE__)

        if (p_model == DATAMODEL_LP64 && tp->ftt_type == FASTTRAP_T_COMMON) {
                /*
                 * If the process is 64-bit and the instruction type is still
        if (p_model == DATAMODEL_LP64 && tp->ftt_type == FASTTRAP_T_COMMON) {
                /*
                 * If the process is 64-bit and the instruction type is still


@@ -628,7 +628,6 @@ fasttrap_tracepoint_init(proc_t *p, fasttrap_tracepoint_t *tp, user_addr_t pc,
                        }
                }
        }
                        }
                }
        }

-#endif

 
        return (0);
 }
 
        return (0);
 }


@@ -671,6 +670,8 @@ fasttrap_return_common(x86_saved_state_t *regs, user_addr_t pc, pid_t pid,
        x86_saved_state32_t *regs32;
        unsigned int p_model;
 
        x86_saved_state32_t *regs32;
        unsigned int p_model;
 

+       dtrace_icookie_t cookie;
+

         if (is_saved_state64(regs)) {
                 regs64 = saved_state64(regs);
                regs32 = NULL;
         if (is_saved_state64(regs)) {
                 regs64 = saved_state64(regs);
                regs32 = NULL;


@@ -692,7 +693,7 @@ fasttrap_return_common(x86_saved_state_t *regs, user_addr_t pc, pid_t pid,
 
        for (tp = bucket->ftb_data; tp != NULL; tp = tp->ftt_next) {
                if (pid == tp->ftt_pid && pc == tp->ftt_pc &&
 
        for (tp = bucket->ftb_data; tp != NULL; tp = tp->ftt_next) {
                if (pid == tp->ftt_pid && pc == tp->ftt_pc &&

-                   !tp->ftt_proc->ftpc_defunct)
+                   tp->ftt_proc->ftpc_acount != 0)

                        break;
        }
 
                        break;
        }
 


@@ -718,6 +719,13 @@ fasttrap_return_common(x86_saved_state_t *regs, user_addr_t pc, pid_t pid,
                    id->fti_probe->ftp_fsize)
                        continue;
 
                    id->fti_probe->ftp_fsize)
                        continue;
 

+               /*
+                * Provide a hint to the stack trace functions to add the
+                * following pc to the top of the stack since it's missing
+                * on a return probe yet highly desirable for consistency.
+                */
+               cookie = dtrace_interrupt_disable();
+               cpu_core[CPU->cpu_id].cpuc_missing_tos = pc;

                if (ISSET(current_proc()->p_lflag, P_LNOATTACH)) {
                        dtrace_probe(dtrace_probeid_error, 0 /* state */, id->fti_probe->ftp_id, 
                                     1 /* ndx */, -1 /* offset */, DTRACEFLT_UPRIV);
                if (ISSET(current_proc()->p_lflag, P_LNOATTACH)) {
                        dtrace_probe(dtrace_probeid_error, 0 /* state */, id->fti_probe->ftp_id, 
                                     1 /* ndx */, -1 /* offset */, DTRACEFLT_UPRIV);


@@ -730,6 +738,9 @@ fasttrap_return_common(x86_saved_state_t *regs, user_addr_t pc, pid_t pid,
                                     pc - id->fti_probe->ftp_faddr,
                                     regs32->eax, regs32->edx, 0, 0);
                }
                                     pc - id->fti_probe->ftp_faddr,
                                     regs32->eax, regs32->edx, 0, 0);
                }

+               /* remove the hint */
+               cpu_core[CPU->cpu_id].cpuc_missing_tos = 0;
+               dtrace_interrupt_enable(cookie);

        }
 
        lck_mtx_unlock(pid_mtx);
        }
 
        lck_mtx_unlock(pid_mtx);


@@ -786,7 +797,7 @@ fasttrap_usdt_args32(fasttrap_probe_t *probe, x86_saved_state32_t *regs32, int a
     uint32_t *argv)
 {
        int i, x, cap = MIN(argc, probe->ftp_nargs);
     uint32_t *argv)
 {
        int i, x, cap = MIN(argc, probe->ftp_nargs);

-       uint32_t *stack = (uint32_t *)regs32->uesp;
+       uint32_t *stack = (uint32_t *)(uintptr_t)(regs32->uesp);

 
        for (i = 0; i < cap; i++) {
                x = probe->ftp_argmap[i];
 
        for (i = 0; i < cap; i++) {
                x = probe->ftp_argmap[i];


@@ -972,12 +983,12 @@ fasttrap_pid_probe32(x86_saved_state_t *regs)
         * parent. We know that there's only one thread of control in such a
         * process: this one.
         */
         * parent. We know that there's only one thread of control in such a
         * process: this one.
         */

-       /*
-        * APPLE NOTE: Terry says: "You need to hold the process locks (currently: kernel funnel) for this traversal"
-        * FIXME: How do we assert this?
-        */
-       while (p->p_lflag & P_LINVFORK)
-               p = p->p_pptr;
+       if (p->p_lflag & P_LINVFORK) {
+               proc_list_lock();
+               while (p->p_lflag & P_LINVFORK)
+                       p = p->p_pptr;
+               proc_list_unlock();
+       }

 
        pid = p->p_pid;
        pid_mtx = &cpu_core[CPU->cpu_id].cpuc_pid_lock;
 
        pid = p->p_pid;
        pid_mtx = &cpu_core[CPU->cpu_id].cpuc_pid_lock;


@@ -989,7 +1000,7 @@ fasttrap_pid_probe32(x86_saved_state_t *regs)
         */
        for (tp = bucket->ftb_data; tp != NULL; tp = tp->ftt_next) {
                if (pid == tp->ftt_pid && pc == tp->ftt_pc &&
         */
        for (tp = bucket->ftb_data; tp != NULL; tp = tp->ftt_next) {
                if (pid == tp->ftt_pid && pc == tp->ftt_pc &&

-                   !tp->ftt_proc->ftpc_defunct)
+                   tp->ftt_proc->ftpc_acount != 0)

                        break;
        }
 
                        break;
        }
 


@@ -1013,7 +1024,7 @@ fasttrap_pid_probe32(x86_saved_state_t *regs)
                fasttrap_id_t *id;
                
                uint32_t s0, s1, s2, s3, s4, s5;
                fasttrap_id_t *id;
                
                uint32_t s0, s1, s2, s3, s4, s5;

-               uint32_t *stack = (uint32_t *)regs32->uesp;
+               uint32_t *stack = (uint32_t *)(uintptr_t)(regs32->uesp);

                
                /*
                 * In 32-bit mode, all arguments are passed on the
                
                /*
                 * In 32-bit mode, all arguments are passed on the


@@ -1341,7 +1352,7 @@ fasttrap_pid_probe32(x86_saved_state_t *regs)
                case FASTTRAP_T_COMMON:
                {
                        user_addr_t addr;
                case FASTTRAP_T_COMMON:
                {
                        user_addr_t addr;

-                       uint8_t scratch[2 * FASTTRAP_MAX_INSTR_SIZE + 5 + 2];
+                       uint8_t scratch[2 * FASTTRAP_MAX_INSTR_SIZE + 7];

                        uint_t i = 0;
 
                        /*
                        uint_t i = 0;
 
                        /*


@@ -1402,6 +1413,7 @@ fasttrap_pid_probe32(x86_saved_state_t *regs)
                         * the size of the traced instruction cancels out.
                         */
                        scratch[i++] = FASTTRAP_JMP32;
                         * the size of the traced instruction cancels out.
                         */
                        scratch[i++] = FASTTRAP_JMP32;

+                       /* LINTED - alignment */

                        *(uint32_t *)&scratch[i] = pc - addr - 5;
                        i += sizeof (uint32_t);
 
                        *(uint32_t *)&scratch[i] = pc - addr - 5;
                        i += sizeof (uint32_t);
 


@@ -1411,6 +1423,8 @@ fasttrap_pid_probe32(x86_saved_state_t *regs)
                        scratch[i++] = FASTTRAP_INT;
                        scratch[i++] = T_DTRACE_RET;
                        
                        scratch[i++] = FASTTRAP_INT;
                        scratch[i++] = T_DTRACE_RET;
                        

+                       ASSERT(i <= sizeof (scratch));
+

                        if (fasttrap_copyout(scratch, addr, i)) {
                                fasttrap_sigtrap(p, uthread, pc);
                                new_pc = pc;
                        if (fasttrap_copyout(scratch, addr, i)) {
                                fasttrap_sigtrap(p, uthread, pc);
                                new_pc = pc;


@@ -1528,12 +1542,12 @@ fasttrap_pid_probe64(x86_saved_state_t *regs)
         * parent. We know that there's only one thread of control in such a
         * process: this one.
         */
         * parent. We know that there's only one thread of control in such a
         * process: this one.
         */

-       /*
-        * APPLE NOTE: Terry says: "You need to hold the process locks (currently: kernel funnel) for this traversal"
-        * FIXME: How do we assert this?
-        */
-       while (p->p_lflag & P_LINVFORK)
-               p = p->p_pptr;
+       if (p->p_lflag & P_LINVFORK) {
+               proc_list_lock();
+               while (p->p_lflag & P_LINVFORK)
+                       p = p->p_pptr;
+               proc_list_unlock();
+       }

 
        pid = p->p_pid;
        pid_mtx = &cpu_core[CPU->cpu_id].cpuc_pid_lock;
 
        pid = p->p_pid;
        pid_mtx = &cpu_core[CPU->cpu_id].cpuc_pid_lock;


@@ -1545,7 +1559,7 @@ fasttrap_pid_probe64(x86_saved_state_t *regs)
         */
        for (tp = bucket->ftb_data; tp != NULL; tp = tp->ftt_next) {
                if (pid == tp->ftt_pid && pc == tp->ftt_pc &&
         */
        for (tp = bucket->ftb_data; tp != NULL; tp = tp->ftt_next) {
                if (pid == tp->ftt_pid && pc == tp->ftt_pc &&

-                   !tp->ftt_proc->ftpc_defunct)
+                   tp->ftt_proc->ftpc_acount != 0)

                        break;
        }
 
                        break;
        }
 


@@ -1878,7 +1892,7 @@ fasttrap_pid_probe64(x86_saved_state_t *regs)
                case FASTTRAP_T_COMMON:
                {
                        user_addr_t addr;
                case FASTTRAP_T_COMMON:
                {
                        user_addr_t addr;

-                       uint8_t scratch[2 * FASTTRAP_MAX_INSTR_SIZE + 5 + 2];
+                       uint8_t scratch[2 * FASTTRAP_MAX_INSTR_SIZE + 22];

                        uint_t i = 0;
                        
                        /*
                        uint_t i = 0;
                        
                        /*


@@ -2025,6 +2039,7 @@ fasttrap_pid_probe64(x86_saved_state_t *regs)
                                                panic("unhandled ripmode in fasttrap_pid_probe64");
                                }
                                
                                                panic("unhandled ripmode in fasttrap_pid_probe64");
                                }
                                

+                               /* LINTED - alignment */

                                *(uint64_t *)&scratch[i] = *reg;
                                uthread->t_dtrace_regv = *reg;
                                *reg = pc + tp->ftt_size;
                                *(uint64_t *)&scratch[i] = *reg;
                                uthread->t_dtrace_regv = *reg;
                                *reg = pc + tp->ftt_size;


@@ -2040,8 +2055,10 @@ fasttrap_pid_probe64(x86_saved_state_t *regs)
                         */
                        scratch[i++] = FASTTRAP_GROUP5_OP;
                        scratch[i++] = FASTTRAP_MODRM(0, 4, 5);
                         */
                        scratch[i++] = FASTTRAP_GROUP5_OP;
                        scratch[i++] = FASTTRAP_MODRM(0, 4, 5);

+                       /* LINTED - alignment */

                        *(uint32_t *)&scratch[i] = 0;
                        i += sizeof (uint32_t);
                        *(uint32_t *)&scratch[i] = 0;
                        i += sizeof (uint32_t);

+                       /* LINTED - alignment */

                        *(uint64_t *)&scratch[i] = pc + tp->ftt_size;
                        i += sizeof (uint64_t);
 
                        *(uint64_t *)&scratch[i] = pc + tp->ftt_size;
                        i += sizeof (uint64_t);
 


@@ -2051,6 +2068,8 @@ fasttrap_pid_probe64(x86_saved_state_t *regs)
                        scratch[i++] = FASTTRAP_INT;
                        scratch[i++] = T_DTRACE_RET;
 
                        scratch[i++] = FASTTRAP_INT;
                        scratch[i++] = T_DTRACE_RET;
 

+                       ASSERT(i <= sizeof (scratch));
+

                        if (fasttrap_copyout(scratch, addr, i)) {
                                fasttrap_sigtrap(p, uthread, pc);
                                new_pc = pc;
                        if (fasttrap_copyout(scratch, addr, i)) {
                                fasttrap_sigtrap(p, uthread, pc);
                                new_pc = pc;


@@ -2155,13 +2174,10 @@ fasttrap_return_probe(x86_saved_state_t *regs)
         * parent. We know that there's only one thread of control in such a
         * process: this one.
         */
         * parent. We know that there's only one thread of control in such a
         * process: this one.
         */

-       /*
-        * APPLE NOTE: Terry says: "You need to hold the process locks (currently: kernel funnel) for this traversal"
-        * How do we assert this?
-        */
-       while (p->p_lflag & P_LINVFORK) {
+       proc_list_lock();
+       while (p->p_lflag & P_LINVFORK)

                p = p->p_pptr;
                p = p->p_pptr;

-       }
+       proc_list_unlock();

 
        /*
         * We set rp->r_pc to the address of the traced instruction so
 
        /*
         * We set rp->r_pc to the address of the traced instruction so


@@ -2184,6 +2200,7 @@ uint64_t
 fasttrap_pid_getarg(void *arg, dtrace_id_t id, void *parg, int argno,
     int aframes)
 {
 fasttrap_pid_getarg(void *arg, dtrace_id_t id, void *parg, int argno,
     int aframes)
 {

+       pal_register_cache_state(current_thread(), VALID);

 #pragma unused(arg, id, parg, aframes)
        return (fasttrap_anarg((x86_saved_state_t *)find_user_regs(current_thread()), 1, argno));
 }
 #pragma unused(arg, id, parg, aframes)
        return (fasttrap_anarg((x86_saved_state_t *)find_user_regs(current_thread()), 1, argno));
 }


@@ -2192,6 +2209,7 @@ uint64_t
 fasttrap_usdt_getarg(void *arg, dtrace_id_t id, void *parg, int argno,
     int aframes)
 {
 fasttrap_usdt_getarg(void *arg, dtrace_id_t id, void *parg, int argno,
     int aframes)
 {

+       pal_register_cache_state(current_thread(), VALID);

 #pragma unused(arg, id, parg, aframes)
        return (fasttrap_anarg((x86_saved_state_t *)find_user_regs(current_thread()), 0, argno));
 }
 #pragma unused(arg, id, parg, aframes)
        return (fasttrap_anarg((x86_saved_state_t *)find_user_regs(current_thread()), 0, argno));
 }


@@ -2223,6 +2241,20 @@ fasttrap_getreg(x86_saved_state_t *regs, uint_t reg)
                        case REG_R13:           return regs64->r13;
                        case REG_R14:           return regs64->r14;
                        case REG_R15:           return regs64->r15;
                        case REG_R13:           return regs64->r13;
                        case REG_R14:           return regs64->r14;
                        case REG_R15:           return regs64->r15;

+                       case REG_TRAPNO:        return regs64->isf.trapno;
+                       case REG_ERR:           return regs64->isf.err;
+                       case REG_RIP:           return regs64->isf.rip;
+                       case REG_CS:            return regs64->isf.cs;
+                       case REG_RFL:           return regs64->isf.rflags;
+                       case REG_SS:            return regs64->isf.ss;
+                       case REG_FS:            return regs64->fs;
+                       case REG_GS:            return regs64->gs;
+                       case REG_ES:
+                       case REG_DS:
+                       case REG_FSBASE:
+                       case REG_GSBASE:
+                               // Important to distinguish these requests (which should be legal) from other values.
+                               panic("dtrace: unimplemented x86_64 getreg()");

                }
 
                panic("dtrace: unhandled x86_64 getreg() constant");
                }
 
                panic("dtrace: unhandled x86_64 getreg() constant");