]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/dev/i386/fbt_x86.c
xnu-2782.10.72.tar.gz
[apple/xnu.git] / bsd / dev / i386 / fbt_x86.c
index baec24f8353f6d2c5488638c93489a47e5157c79..93c19c56113d63e351521c3924a0c8619cf21d7e 100644 (file)
@@ -217,8 +217,6 @@ static const char * probe_ctx_closure[] =
        "prf",
        "proc_is64bit",
        "proc_selfname",
-       "proc_selfpid",
-       "proc_selfppid",
        "psignal_lock",
        "rtc_nanotime_load",
        "rtc_nanotime_read",
@@ -289,7 +287,8 @@ is_module_valid(struct modctl* ctl)
 
        /*
         * These drivers control low level functions that when traced
-        * cause problems, especially in the sleep/wake paths.
+        * cause problems often in the sleep/wake paths as well as 
+        * critical debug and panic paths.
         * If somebody really wants to drill in on one of these kexts, then
         * they can override blacklisting using the boot-arg above.
         */
@@ -313,9 +312,10 @@ is_module_valid(struct modctl* ctl)
                return FALSE;
 
        if (strstr(ctl->mod_modname, "AppleIntelProfile") != NULL)
-               return FALSE;   
-       
-       
+               return FALSE;
+
+       if (strstr(ctl->mod_modname, "AppleEFI") != NULL)
+               return FALSE;
 
        return TRUE;
 }
@@ -472,10 +472,13 @@ is_symbol_valid(const char* name)
            LIT_STRNSTART(name, "kdbg_") ||
            LIT_STRNSTART(name, "kdebug_") ||
            LIT_STRNSTART(name, "kernel_debug") ||
+           LIT_STRNSTART(name, "debug_") ||
            LIT_STRNEQL(name, "Debugger") ||
            LIT_STRNEQL(name, "Call_DebuggerC") ||
            LIT_STRNEQL(name, "lock_debugger") ||
            LIT_STRNEQL(name, "unlock_debugger") ||
+           LIT_STRNEQL(name, "packA")  ||
+           LIT_STRNEQL(name, "unpackA")  ||
            LIT_STRNEQL(name, "SysChoked"))  {
                return FALSE;
        }
@@ -493,547 +496,6 @@ is_symbol_valid(const char* name)
        return TRUE;
 }
 
-#if defined(__i386__)
-int
-fbt_invop(uintptr_t addr, uintptr_t *stack, uintptr_t rval)
-{
-       uintptr_t stack0 = 0, stack1 = 0, stack2 = 0, stack3 = 0, stack4 = 0;
-       fbt_probe_t *fbt = fbt_probetab[FBT_ADDR2NDX(addr)];
-
-       for (; fbt != NULL; fbt = fbt->fbtp_hashnext) {
-               if ((uintptr_t)fbt->fbtp_patchpoint == addr) {
-
-                       if (fbt->fbtp_roffset == 0) {
-                               uintptr_t *stacktop;
-                               if (CPU_ON_INTR(CPU))
-                                       stacktop = (uintptr_t *)dtrace_get_cpu_int_stack_top();
-                               else
-                                       stacktop = (uintptr_t *)(dtrace_get_kernel_stack(current_thread()) + kernel_stack_size);
-
-                               stack += 1; /* skip over the target's pushl'd %ebp */
-
-                               if (stack <= stacktop)
-                                       CPU->cpu_dtrace_caller = *stack++;
-                               if (stack <= stacktop)
-                                       stack0 = *stack++;
-                               if (stack <= stacktop)
-                                       stack1 = *stack++;
-                               if (stack <= stacktop)
-                                       stack2 = *stack++;
-                               if (stack <= stacktop)
-                                       stack3 = *stack++;
-                               if (stack <= stacktop)
-                                       stack4 = *stack++;
-
-                               /* 32-bit ABI, arguments passed on stack. */
-                               dtrace_probe(fbt->fbtp_id, stack0, stack1, stack2, stack3, stack4);
-                               CPU->cpu_dtrace_caller = 0;
-                       } else {
-                               dtrace_probe(fbt->fbtp_id, fbt->fbtp_roffset, rval, 0, 0, 0);
-                               CPU->cpu_dtrace_caller = 0;
-                       }
-
-                       return (fbt->fbtp_rval);
-               }
-       }
-
-       return (0);
-}
-
-#define IS_USER_TRAP(regs) (regs && (((regs)->cs & 3) != 0))
-#define T_INVALID_OPCODE 6
-#define FBT_EXCEPTION_CODE T_INVALID_OPCODE
-#define T_PREEMPT       255
-
-kern_return_t
-fbt_perfCallback(
-                int                    trapno,
-                x86_saved_state_t      *tagged_regs,
-                uintptr_t              *lo_spp,
-               __unused int unused )
-{
-       kern_return_t retval = KERN_FAILURE;
-       x86_saved_state32_t *saved_state = saved_state32(tagged_regs);
-       struct x86_saved_state32_from_kernel *regs = (struct x86_saved_state32_from_kernel *)saved_state;
-
-       if (FBT_EXCEPTION_CODE == trapno && !IS_USER_TRAP(saved_state)) {
-               boolean_t oldlevel, cpu_64bit;
-               uint32_t esp_probe, fp, *pDst, delta = 0;
-               uintptr_t old_sp;
-               int emul;
-
-               cpu_64bit = ml_is64bit();
-               oldlevel = ml_set_interrupts_enabled(FALSE);
-
-               /* Calculate where the stack pointer was when the probe instruction "fired." */
-               if (cpu_64bit) {
-                       esp_probe = saved_state->uesp; /* Easy, x86_64 establishes this value in idt64.s */
-               } else {
-                       esp_probe = (uint32_t)&(regs[1]); /* Nasty, infer the location above the save area */
-               }
-
-               __asm__ volatile(
-                       "Ldtrace_invop_callsite_pre_label:\n"
-                       ".data\n"
-                       ".private_extern _dtrace_invop_callsite_pre\n"
-                       "_dtrace_invop_callsite_pre:\n"
-                       "  .long Ldtrace_invop_callsite_pre_label\n"
-                       ".text\n"
-                                );
-               
-               emul = dtrace_invop( saved_state->eip, (uintptr_t *)esp_probe, saved_state->eax );
-
-               __asm__ volatile(
-                       "Ldtrace_invop_callsite_post_label:\n"
-                       ".data\n"
-                       ".private_extern _dtrace_invop_callsite_post\n"
-                       "_dtrace_invop_callsite_post:\n"
-                       "  .long Ldtrace_invop_callsite_post_label\n"
-                       ".text\n"
-                                );
-               
-               switch (emul) {
-               case DTRACE_INVOP_NOP:
-                       saved_state->eip += DTRACE_INVOP_NOP_SKIP;      /* Skip over the patched NOP (planted by sdt.) */
-                       retval = KERN_SUCCESS;
-                       break;
-
-               case DTRACE_INVOP_MOVL_ESP_EBP:
-                       saved_state->ebp = esp_probe;                                           /* Emulate patched movl %esp,%ebp */
-                       saved_state->eip += DTRACE_INVOP_MOVL_ESP_EBP_SKIP;     /* Skip over the bytes of the patched movl %esp,%ebp */
-                       retval = KERN_SUCCESS;
-                       break;
-
-               case DTRACE_INVOP_POPL_EBP:
-               case DTRACE_INVOP_LEAVE:
-/*
- * Emulate first micro-op of patched leave: movl %ebp,%esp
- * fp points just below the return address slot for target's ret 
- * and at the slot holding the frame pointer saved by the target's prologue.
- */
-                       fp = saved_state->ebp;
-/* Emulate second micro-op of patched leave: patched popl %ebp
- * savearea ebp is set for the frame of the caller to target
- * The *live* %esp will be adjusted below for pop increment(s)
- */
-                       saved_state->ebp = *(uint32_t *)fp;
-/* Skip over the patched leave */
-                       saved_state->eip += DTRACE_INVOP_LEAVE_SKIP;
-/*
- * Lift the stack to account for the emulated leave
- * Account for words local in this frame
- * (in "case DTRACE_INVOP_POPL_EBP:" this is zero.)
- */
-                       delta = ((uint32_t *)fp) - ((uint32_t *)esp_probe);
-/* Account for popping off the ebp (just accomplished by the emulation
- * above...)
- */
-                       delta += 1;
-                       
-                       if (cpu_64bit)
-                               saved_state->uesp += (delta << 2);
-/* Obtain the stack pointer recorded by the trampolines */
-                       old_sp = *lo_spp;
-/* Shift contents of stack */
-                       for (pDst = (uint32_t *)fp;
-                            pDst > (((uint32_t *)old_sp));
-                                pDst--)
-                               *pDst = pDst[-delta];
-
-/* Track the stack lift in "saved_state". */
-                       saved_state = (x86_saved_state32_t *) (((uintptr_t)saved_state) + (delta << 2));
-/* Adjust the stack pointer utilized by the trampolines */
-                       *lo_spp = old_sp + (delta << 2);
-
-                       retval = KERN_SUCCESS;
-                       break;
-                       
-               default:
-                       retval = KERN_FAILURE;
-                       break;
-               }
-               saved_state->trapno = T_PREEMPT; /* Avoid call to i386_astintr()! */
-
-               ml_set_interrupts_enabled(oldlevel);
-       }
-
-       return retval;
-}
-
-/*ARGSUSED*/
-static void
-__provide_probe_32(struct modctl *ctl, uintptr_t instrLow, uintptr_t instrHigh, char *modname, char* symbolName, machine_inst_t* symbolStart)
-{
-       unsigned int    j;
-       unsigned int    doenable = 0;
-       dtrace_id_t     thisid;
-
-       fbt_probe_t *newfbt, *retfbt, *entryfbt;
-       machine_inst_t *instr, *limit, theInstr, i1, i2;
-       int size;
-
-       for (j = 0, instr = symbolStart, theInstr = 0;
-            (j < 4) && ((uintptr_t)instr >= instrLow) && (instrHigh > (uintptr_t)(instr + 2)); 
-            j++) {
-               theInstr = instr[0];
-               if (theInstr == FBT_PUSHL_EBP || theInstr == FBT_RET || theInstr == FBT_RET_IMM16)
-                       break;
-               
-               if ((size = dtrace_instr_size(instr)) <= 0)
-                       break;
-               
-               instr += size;
-       }
-       
-       if (theInstr != FBT_PUSHL_EBP)
-               return;
-       
-       i1 = instr[1];
-       i2 = instr[2];
-       
-       limit = (machine_inst_t *)instrHigh;
-       
-       if ((i1 == FBT_MOVL_ESP_EBP0_V0 && i2 == FBT_MOVL_ESP_EBP1_V0) ||
-           (i1 == FBT_MOVL_ESP_EBP0_V1 && i2 == FBT_MOVL_ESP_EBP1_V1)) {
-               instr += 1; /* Advance to the movl %esp,%ebp */
-               theInstr = i1;
-       } else {
-               /*
-                * Sometimes, the compiler will schedule an intervening instruction
-                * in the function prologue. Example:
-                *
-                * _mach_vm_read:
-                * 000006d8        pushl   %ebp
-                * 000006d9        movl    $0x00000004,%edx
-                * 000006de        movl    %esp,%ebp
-                * 
-                * Try the next instruction, to see if it is a movl %esp,%ebp
-                */
-               
-               instr += 1; /* Advance past the pushl %ebp */
-               if ((size = dtrace_instr_size(instr)) <= 0)
-                       return;
-               
-               instr += size;
-               
-               if ((instr + 1) >= limit)
-                       return;
-               
-               i1 = instr[0];
-               i2 = instr[1];
-               
-               if (!(i1 == FBT_MOVL_ESP_EBP0_V0 && i2 == FBT_MOVL_ESP_EBP1_V0) &&
-                   !(i1 == FBT_MOVL_ESP_EBP0_V1 && i2 == FBT_MOVL_ESP_EBP1_V1))
-                       return;
-               
-               /* instr already points at the movl %esp,%ebp */
-               theInstr = i1;
-       }
-       
-       thisid = dtrace_probe_lookup(fbt_id, modname, symbolName, FBT_ENTRY);
-       newfbt = kmem_zalloc(sizeof (fbt_probe_t), KM_SLEEP);
-       strlcpy( (char *)&(newfbt->fbtp_name), symbolName, MAX_FBTP_NAME_CHARS );
-       
-       if (thisid != 0) {
-               /*
-                * The dtrace_probe previously existed, so we have to hook
-                * the newfbt entry onto the end of the existing fbt's chain.
-                * If we find an fbt entry that was previously patched to
-                * fire, (as indicated by the current patched value), then
-                * we want to enable this newfbt on the spot.
-                */
-               entryfbt = dtrace_probe_arg (fbt_id, thisid);
-               ASSERT (entryfbt != NULL);
-               for(; entryfbt != NULL; entryfbt = entryfbt->fbtp_next) {
-                       if (entryfbt->fbtp_currentval == entryfbt->fbtp_patchval)
-                               doenable++;
-                       
-                       if (entryfbt->fbtp_next == NULL) {
-                               entryfbt->fbtp_next = newfbt;
-                               newfbt->fbtp_id = entryfbt->fbtp_id;
-                               break;
-                       }
-               }                   
-       }
-       else {
-               /*
-                * The dtrace_probe did not previously exist, so we
-                * create it and hook in the newfbt.  Since the probe is
-                * new, we obviously do not need to enable it on the spot.
-                */
-               newfbt->fbtp_id = dtrace_probe_create(fbt_id, modname, symbolName, FBT_ENTRY, FBT_AFRAMES_ENTRY, newfbt);
-               doenable = 0;
-       }
-       
-       
-       newfbt->fbtp_patchpoint = instr;
-       newfbt->fbtp_ctl = ctl;
-       newfbt->fbtp_loadcnt = ctl->mod_loadcnt;
-       newfbt->fbtp_rval = DTRACE_INVOP_MOVL_ESP_EBP;
-       newfbt->fbtp_savedval = theInstr;
-       newfbt->fbtp_patchval = FBT_PATCHVAL;
-       newfbt->fbtp_currentval = 0;
-       newfbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)];
-       fbt_probetab[FBT_ADDR2NDX(instr)] = newfbt;
-       
-       if (doenable)
-               fbt_enable(NULL, newfbt->fbtp_id, newfbt);
-       
-       /*
-        * The fbt entry chain is in place, one entry point per symbol.
-        * The fbt return chain can have multiple return points per symbol.
-        * Here we find the end of the fbt return chain.
-        */
-       
-       doenable=0;
-       
-       thisid = dtrace_probe_lookup(fbt_id, modname, symbolName, FBT_RETURN);
-       if (thisid != 0) {
-               /* The dtrace_probe previously existed, so we have to
-                * find the end of the existing fbt chain.  If we find
-                * an fbt return that was previously patched to fire,
-                * (as indicated by the currrent patched value), then
-                * we want to enable any new fbts on the spot.
-                */
-               retfbt = dtrace_probe_arg (fbt_id, thisid);
-               ASSERT(retfbt != NULL);
-               for (;  retfbt != NULL; retfbt =  retfbt->fbtp_next) {
-                       if (retfbt->fbtp_currentval == retfbt->fbtp_patchval)
-                               doenable++;
-                       if(retfbt->fbtp_next == NULL)
-                               break;
-               }
-       }
-       else {
-               doenable = 0;
-               retfbt = NULL;
-       }
-       
-again:
-       if (instr >= limit)
-               return;
-       
-       /*
-        * If this disassembly fails, then we've likely walked off into
-        * a jump table or some other unsuitable area.  Bail out of the
-        * disassembly now.
-        */
-       if ((size = dtrace_instr_size(instr)) <= 0)
-               return;
-       
-       /*
-        * We (desperately) want to avoid erroneously instrumenting a
-        * jump table, especially given that our markers are pretty
-        * short:  two bytes on x86, and just one byte on amd64.  To
-        * determine if we're looking at a true instruction sequence
-        * or an inline jump table that happens to contain the same
-        * byte sequences, we resort to some heuristic sleeze:  we
-        * treat this instruction as being contained within a pointer,
-        * and see if that pointer points to within the body of the
-        * function.  If it does, we refuse to instrument it.
-        */
-       for (j = 0; j < sizeof (uintptr_t); j++) {
-               uintptr_t check = (uintptr_t)instr - j;
-               uint8_t *ptr;
-               
-               if (check < (uintptr_t)symbolStart)
-                       break;
-               
-               if (check + sizeof (uintptr_t) > (uintptr_t)limit)
-                       continue;
-               
-               ptr = *(uint8_t **)check;
-               
-               if (ptr >= (uint8_t *)symbolStart && ptr < limit) {
-                       instr += size;
-                       goto again;
-               }
-       }
-       
-       /*
-        * OK, it's an instruction.
-        */
-       theInstr = instr[0];
-       
-       /* Walked onto the start of the next routine? If so, bail out of this function. */
-       if (theInstr == FBT_PUSHL_EBP)
-               return;
-       
-       if (!(size == 1 && (theInstr == FBT_POPL_EBP || theInstr == FBT_LEAVE))) {
-               instr += size;
-               goto again;
-       }
-       
-       /*
-        * Found the popl %ebp; or leave.
-        */
-       machine_inst_t *patch_instr = instr;
-       
-       /*
-        * Scan forward for a "ret", or "jmp".
-        */
-       instr += size;
-       if (instr >= limit)
-               return;
-       
-       size = dtrace_instr_size(instr);
-       if (size <= 0) /* Failed instruction decode? */
-               return;
-       
-       theInstr = instr[0];
-       
-       if (!(size == FBT_RET_LEN && (theInstr == FBT_RET)) &&
-           !(size == FBT_RET_IMM16_LEN && (theInstr == FBT_RET_IMM16)) &&
-           !(size == FBT_JMP_SHORT_REL_LEN && (theInstr == FBT_JMP_SHORT_REL)) &&
-           !(size == FBT_JMP_NEAR_REL_LEN && (theInstr == FBT_JMP_NEAR_REL)) &&
-           !(size == FBT_JMP_FAR_ABS_LEN && (theInstr == FBT_JMP_FAR_ABS)))
-               return;
-       
-       /*
-        * popl %ebp; ret; or leave; ret; or leave; jmp tailCalledFun; -- We have a winner!
-        */
-       newfbt = kmem_zalloc(sizeof (fbt_probe_t), KM_SLEEP);
-       strlcpy( (char *)&(newfbt->fbtp_name), symbolName, MAX_FBTP_NAME_CHARS );
-       
-       if (retfbt == NULL) {
-               newfbt->fbtp_id = dtrace_probe_create(fbt_id, modname,
-                                                     symbolName, FBT_RETURN, FBT_AFRAMES_RETURN, newfbt);
-       } else {
-               retfbt->fbtp_next = newfbt;
-               newfbt->fbtp_id = retfbt->fbtp_id;
-       }
-       
-       retfbt = newfbt;
-       newfbt->fbtp_patchpoint = patch_instr;
-       newfbt->fbtp_ctl = ctl;
-       newfbt->fbtp_loadcnt = ctl->mod_loadcnt;
-       
-       if (*patch_instr == FBT_POPL_EBP) {
-               newfbt->fbtp_rval = DTRACE_INVOP_POPL_EBP;
-       } else {
-               ASSERT(*patch_instr == FBT_LEAVE);
-               newfbt->fbtp_rval = DTRACE_INVOP_LEAVE;
-       }
-       newfbt->fbtp_roffset =
-       (uintptr_t)(patch_instr - (uint8_t *)symbolStart);
-       
-       newfbt->fbtp_savedval = *patch_instr;
-       newfbt->fbtp_patchval = FBT_PATCHVAL;
-       newfbt->fbtp_currentval = 0;
-       newfbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(patch_instr)];
-       fbt_probetab[FBT_ADDR2NDX(patch_instr)] = newfbt;
-       
-       if (doenable)
-               fbt_enable(NULL, newfbt->fbtp_id, newfbt);
-       
-       instr += size;
-       goto again;
-}
-
-static void
-__kernel_syms_provide_module(void *arg, struct modctl *ctl)
-{
-#pragma unused(arg)
-       kernel_mach_header_t            *mh;
-       struct load_command             *cmd;
-       kernel_segment_command_t        *orig_ts = NULL, *orig_le = NULL;
-       struct symtab_command           *orig_st = NULL;
-       struct nlist                    *sym = NULL;
-       char                            *strings;
-       uintptr_t                       instrLow, instrHigh;
-       char                            *modname;
-       unsigned int                    i;
-       
-       mh = (kernel_mach_header_t *)(ctl->mod_address);
-       modname = ctl->mod_modname;
-       
-       if (mh->magic != MH_MAGIC)
-               return;
-       
-       cmd = (struct load_command *) &mh[1];
-       for (i = 0; i < mh->ncmds; i++) {
-               if (cmd->cmd == LC_SEGMENT_KERNEL) {
-                       kernel_segment_command_t *orig_sg = (kernel_segment_command_t *) cmd;
-                       
-                       if (LIT_STRNEQL(orig_sg->segname, SEG_TEXT))
-                               orig_ts = orig_sg;
-                       else if (LIT_STRNEQL(orig_sg->segname, SEG_LINKEDIT))
-                               orig_le = orig_sg;
-                       else if (LIT_STRNEQL(orig_sg->segname, ""))
-                               orig_ts = orig_sg; /* kexts have a single unnamed segment */
-               }
-               else if (cmd->cmd == LC_SYMTAB)
-                       orig_st = (struct symtab_command *) cmd;
-               
-               cmd = (struct load_command *) ((caddr_t) cmd + cmd->cmdsize);
-       }
-       
-       if ((orig_ts == NULL) || (orig_st == NULL) || (orig_le == NULL))
-               return;
-       
-       sym = (struct nlist *)(orig_le->vmaddr + orig_st->symoff - orig_le->fileoff);
-       strings = (char *)(orig_le->vmaddr + orig_st->stroff - orig_le->fileoff);
-       
-       /* Find extent of the TEXT section */
-       instrLow = (uintptr_t)orig_ts->vmaddr;
-       instrHigh = (uintptr_t)(orig_ts->vmaddr + orig_ts->vmsize);
-               
-       for (i = 0; i < orig_st->nsyms; i++) {
-               uint8_t n_type = sym[i].n_type & (N_TYPE | N_EXT);
-               char *name = strings + sym[i].n_un.n_strx;
-               
-               /* Check that the symbol is a global and that it has a name. */
-               if (((N_SECT | N_EXT) != n_type && (N_ABS | N_EXT) != n_type))
-                       continue;
-               
-               if (0 == sym[i].n_un.n_strx) /* iff a null, "", name. */
-                       continue;
-               
-               /* Lop off omnipresent leading underscore. */                   
-               if (*name == '_')
-                       name += 1;
-               
-               /*
-                * We're only blacklisting functions in the kernel for now.
-                */
-               if (MOD_IS_MACH_KERNEL(ctl) && !is_symbol_valid(name))
-                       continue;
-               
-               __provide_probe_32(ctl, instrLow, instrHigh, modname, name, (machine_inst_t*)sym[i].n_value);
-       }
-}
-
-static void
-__user_syms_provide_module(void *arg, struct modctl *ctl)
-{
-#pragma unused(arg)
-       char                            *modname;
-       unsigned int                    i;
-       
-       modname = ctl->mod_modname;
-       
-       dtrace_module_symbols_t* module_symbols = ctl->mod_user_symbols;
-       if (module_symbols) {
-               for (i=0; i<module_symbols->dtmodsyms_count; i++) {
-                       dtrace_symbol_t* symbol = &module_symbols->dtmodsyms_symbols[i];
-                       char* name = symbol->dtsym_name;
-                       
-                       /* Lop off omnipresent leading underscore. */                   
-                       if (*name == '_')
-                               name += 1;
-
-                       /*
-                        * We're only blacklisting functions in the kernel for now.
-                        */
-                       if (MOD_IS_MACH_KERNEL(ctl) && !is_symbol_valid(name))
-                               continue;
-
-                       __provide_probe_32(ctl, (uintptr_t)symbol->dtsym_addr, (uintptr_t)(symbol->dtsym_addr + symbol->dtsym_size), modname, name, (machine_inst_t*)(uintptr_t)symbol->dtsym_addr);
-               }
-       }
-}
-
-#elif defined(__x86_64__)
 int
 fbt_invop(uintptr_t addr, uintptr_t *state, uintptr_t rval)
 {
@@ -1456,7 +918,7 @@ __kernel_syms_provide_module(void *arg, struct modctl *ctl)
        struct load_command             *cmd;
        kernel_segment_command_t        *orig_ts = NULL, *orig_le = NULL;
        struct symtab_command           *orig_st = NULL;
-       struct nlist_64                 *sym = NULL;
+       kernel_nlist_t                  *sym = NULL;
        char                            *strings;
        uintptr_t                       instrLow, instrHigh;
        char                            *modname;
@@ -1465,7 +927,7 @@ __kernel_syms_provide_module(void *arg, struct modctl *ctl)
        mh = (kernel_mach_header_t *)(ctl->mod_address);
        modname = ctl->mod_modname;
        
-       if (mh->magic != MH_MAGIC_64)
+       if (mh->magic != MH_MAGIC_KERNEL)
                return;
        
        cmd = (struct load_command *) &mh[1];
@@ -1489,7 +951,7 @@ __kernel_syms_provide_module(void *arg, struct modctl *ctl)
        if ((orig_ts == NULL) || (orig_st == NULL) || (orig_le == NULL))
                return;
        
-       sym = (struct nlist_64 *)(orig_le->vmaddr + orig_st->symoff - orig_le->fileoff);
+       sym = (kernel_nlist_t *)(orig_le->vmaddr + orig_st->symoff - orig_le->fileoff);
        strings = (char *)(orig_le->vmaddr + orig_st->stroff - orig_le->fileoff);
        
        /* Find extent of the TEXT section */
@@ -1533,7 +995,13 @@ __user_syms_provide_module(void *arg, struct modctl *ctl)
        dtrace_module_symbols_t* module_symbols = ctl->mod_user_symbols;
        if (module_symbols) {
                for (i=0; i<module_symbols->dtmodsyms_count; i++) {
+
+                       /* 
+                        * symbol->dtsym_addr (the symbol address) passed in from
+                        * user space, is already slid for both kexts and kernel.
+                        */
                        dtrace_symbol_t* symbol = &module_symbols->dtmodsyms_symbols[i];
+
                        char* name = symbol->dtsym_name;
                        
                        /* Lop off omnipresent leading underscore. */                   
@@ -1543,16 +1011,13 @@ __user_syms_provide_module(void *arg, struct modctl *ctl)
                        /*
                         * We're only blacklisting functions in the kernel for now.
                         */
-                       if (MOD_IS_MACH_KERNEL(ctl) && !is_symbol_valid(name))
-                               continue;
+                        if (MOD_IS_MACH_KERNEL(ctl) && !is_symbol_valid(name))
+                               continue;
                        
                        __provide_probe_64(ctl, (uintptr_t)symbol->dtsym_addr, (uintptr_t)(symbol->dtsym_addr + symbol->dtsym_size), modname, name, (machine_inst_t*)(uintptr_t)symbol->dtsym_addr);
                }
        }
 }
-#else
-#error Unknown arch
-#endif
 
 extern int dtrace_kernel_symbol_mode;
 
@@ -1581,6 +1046,8 @@ fbt_provide_module(void *arg, struct modctl *ctl)
        if (MOD_HAS_USERSPACE_SYMBOLS(ctl)) {
                __user_syms_provide_module(arg, ctl);
                ctl->mod_flags |= MODCTL_FBT_PROBES_PROVIDED;
+               if (MOD_FBT_PROVIDE_PRIVATE_PROBES(ctl))
+                       ctl->mod_flags |= MODCTL_FBT_PRIVATE_PROBES_PROVIDED;
                return;
        }       
 }