-#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__)
projects / apple / xnu.git / blobdiff