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// Copyright © 2009 The Go Authors. All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
#define __DARWIN_UNIX03 0
#include <u.h>
#include <sys/ptrace.h>
#include <sys/signal.h>
#include <mach/mach.h>
#include <mach/mach_traps.h>
#include <errno.h>
#include <libc.h>
#include <bio.h>
#include <mach.h>
#define Ureg Ureg32
#include <ureg_x86.h>
#undef Ureg
#define Ureg Ureg64
#include <ureg_amd64.h>
#undef Ureg
#undef waitpid /* want Unix waitpid, not Plan 9 */
typedef struct Ureg32 Ureg32;
typedef struct Ureg64 Ureg64;
extern mach_port_t mach_reply_port(void); // should be in system headers, is not
// Mach-error wrapper.
// Takes a mach return code and converts it into 0 / -1,
// setting errstr when it returns -1.
static struct {
int code;
char *name;
} macherr[] = {
KERN_INVALID_ADDRESS, "invalid address",
KERN_PROTECTION_FAILURE, "protection failure",
KERN_NO_SPACE, "no space",
KERN_INVALID_ARGUMENT, "invalid argument",
KERN_FAILURE, "failure",
KERN_RESOURCE_SHORTAGE, "resource shortage",
KERN_NOT_RECEIVER, "not receiver",
KERN_NO_ACCESS, "no access",
KERN_MEMORY_FAILURE, "memory failure",
KERN_MEMORY_ERROR, "memory error",
KERN_ALREADY_IN_SET, "already in set",
KERN_NOT_IN_SET, "not in set",
KERN_NAME_EXISTS, "name exists",
KERN_ABORTED, "aborted",
KERN_INVALID_NAME, "invalid name",
KERN_INVALID_TASK, "invalid task",
KERN_INVALID_RIGHT, "invalid right",
KERN_INVALID_VALUE, "invalid value",
KERN_UREFS_OVERFLOW, "urefs overflow",
KERN_INVALID_CAPABILITY, "invalid capability",
KERN_RIGHT_EXISTS, "right exists",
KERN_INVALID_HOST, "invalid host",
KERN_MEMORY_PRESENT, "memory present",
KERN_MEMORY_DATA_MOVED, "memory data moved",
KERN_MEMORY_RESTART_COPY, "memory restart copy",
KERN_INVALID_PROCESSOR_SET, "invalid processor set",
KERN_POLICY_LIMIT, "policy limit",
KERN_INVALID_POLICY, "invalid policy",
KERN_INVALID_OBJECT, "invalid object",
KERN_ALREADY_WAITING, "already waiting",
KERN_DEFAULT_SET, "default set",
KERN_EXCEPTION_PROTECTED, "exception protected",
KERN_INVALID_LEDGER, "invalid ledger",
KERN_INVALID_MEMORY_CONTROL, "invalid memory control",
KERN_INVALID_SECURITY, "invalid security",
KERN_NOT_DEPRESSED, "not depressed",
KERN_TERMINATED, "terminated",
KERN_LOCK_SET_DESTROYED, "lock set destroyed",
KERN_LOCK_UNSTABLE, "lock unstable",
KERN_LOCK_OWNED, "lock owned",
KERN_LOCK_OWNED_SELF, "lock owned self",
KERN_SEMAPHORE_DESTROYED, "semaphore destroyed",
KERN_RPC_SERVER_TERMINATED, "rpc server terminated",
KERN_RPC_TERMINATE_ORPHAN, "rpc terminate orphan",
KERN_RPC_CONTINUE_ORPHAN, "rpc continue orphan",
KERN_NOT_SUPPORTED, "not supported",
KERN_NODE_DOWN, "node down",
KERN_NOT_WAITING, "not waiting",
KERN_OPERATION_TIMED_OUT, "operation timed out",
KERN_RETURN_MAX, "return max",
MACH_SEND_IN_PROGRESS, "send in progress",
MACH_SEND_INVALID_DATA, "send invalid data",
MACH_SEND_INVALID_DEST, "send invalid dest",
MACH_SEND_TIMED_OUT, "send timed out",
MACH_SEND_INTERRUPTED, "send interrupted",
MACH_SEND_MSG_TOO_SMALL, "send msg too small",
MACH_SEND_INVALID_REPLY, "send invalid reply",
MACH_SEND_INVALID_RIGHT, "send invalid right",
MACH_SEND_INVALID_NOTIFY, "send invalid notify",
MACH_SEND_INVALID_MEMORY, "send invalid memory",
MACH_SEND_NO_BUFFER, "send no buffer",
MACH_SEND_TOO_LARGE, "send too large",
MACH_SEND_INVALID_TYPE, "send invalid type",
MACH_SEND_INVALID_HEADER, "send invalid header",
MACH_SEND_INVALID_TRAILER, "send invalid trailer",
MACH_SEND_INVALID_RT_OOL_SIZE, "send invalid rt ool size",
MACH_RCV_IN_PROGRESS, "rcv in progress",
MACH_RCV_INVALID_NAME, "rcv invalid name",
MACH_RCV_TIMED_OUT, "rcv timed out",
MACH_RCV_TOO_LARGE, "rcv too large",
MACH_RCV_INTERRUPTED, "rcv interrupted",
MACH_RCV_PORT_CHANGED, "rcv port changed",
MACH_RCV_INVALID_NOTIFY, "rcv invalid notify",
MACH_RCV_INVALID_DATA, "rcv invalid data",
MACH_RCV_PORT_DIED, "rcv port died",
MACH_RCV_IN_SET, "rcv in set",
MACH_RCV_HEADER_ERROR, "rcv header error",
MACH_RCV_BODY_ERROR, "rcv body error",
MACH_RCV_INVALID_TYPE, "rcv invalid type",
MACH_RCV_SCATTER_SMALL, "rcv scatter small",
MACH_RCV_INVALID_TRAILER, "rcv invalid trailer",
MACH_RCV_IN_PROGRESS_TIMED, "rcv in progress timed",
MIG_TYPE_ERROR, "mig type error",
MIG_REPLY_MISMATCH, "mig reply mismatch",
MIG_REMOTE_ERROR, "mig remote error",
MIG_BAD_ID, "mig bad id",
MIG_BAD_ARGUMENTS, "mig bad arguments",
MIG_NO_REPLY, "mig no reply",
MIG_EXCEPTION, "mig exception",
MIG_ARRAY_TOO_LARGE, "mig array too large",
MIG_SERVER_DIED, "server died",
MIG_TRAILER_ERROR, "trailer has an unknown format",
};
static int
me(kern_return_t r)
{
int i;
if(r == 0)
return 0;
for(i=0; i<nelem(macherr); i++){
if(r == macherr[i].code){
werrstr("mach: %s", macherr[i].name);
return -1;
}
}
werrstr("mach error %#x", r);
return -1;
}
// Plan 9 and Linux do not distinguish between
// process ids and thread ids, so the interface here doesn't either.
// Unfortunately, Mach has three kinds of identifiers: process ids,
// handles to tasks (processes), and handles to threads within a
// process. All of them are small integers.
//
// To accommodate Mach, we employ a clumsy hack: in this interface,
// if you pass in a positive number, that's a process id.
// If you pass in a negative number, that identifies a thread that
// has been previously returned by procthreadpids (it indexes
// into the Thread table below).
// Table of threads we have handles for.
typedef struct Thread Thread;
struct Thread
{
int pid;
mach_port_t task;
mach_port_t thread;
int stopped;
int exc;
int code[10];
Map *map;
};
static Thread thr[1000];
static int nthr;
static pthread_mutex_t mu;
static pthread_cond_t cond;
static void* excthread(void*);
static void* waitthread(void*);
static mach_port_t excport;
enum {
ExcMask = EXC_MASK_BAD_ACCESS |
EXC_MASK_BAD_INSTRUCTION |
EXC_MASK_ARITHMETIC |
EXC_MASK_BREAKPOINT |
EXC_MASK_SOFTWARE
};
// Add process pid to the thread table.
// If it's already there, don't re-add it (unless force != 0).
static Thread*
addpid(int pid, int force)
{
int i, j;
mach_port_t task;
mach_port_t *thread;
uint nthread;
Thread *ret;
static int first = 1;
if(first){
// Allocate a port for exception messages and
// send all thread exceptions to that port.
// The excthread reads that port and signals
// us if we are waiting on that thread.
pthread_t p;
int err;
excport = mach_reply_port();
pthread_mutex_init(&mu, nil);
pthread_cond_init(&cond, nil);
err = pthread_create(&p, nil, excthread, nil);
if (err != 0) {
fprint(2, "pthread_create failed: %s\n", strerror(err));
abort();
}
err = pthread_create(&p, nil, waitthread, (void*)(uintptr)pid);
if (err != 0) {
fprint(2, "pthread_create failed: %s\n", strerror(err));
abort();
}
first = 0;
}
if(!force){
for(i=0; i<nthr; i++)
if(thr[i].pid == pid)
return &thr[i];
}
if(me(task_for_pid(mach_task_self(), pid, &task)) < 0)
return nil;
if(me(task_threads(task, &thread, &nthread)) < 0)
return nil;
mach_port_insert_right(mach_task_self(), excport, excport, MACH_MSG_TYPE_MAKE_SEND);
if(me(task_set_exception_ports(task, ExcMask,
excport, EXCEPTION_DEFAULT, MACHINE_THREAD_STATE)) < 0){
fprint(2, "warning: cannot set excport: %r\n");
}
ret = nil;
for(j=0; j<nthread; j++){
if(force){
// If we're forcing a refresh, don't re-add existing threads.
for(i=0; i<nthr; i++)
if(thr[i].pid == pid && thr[i].thread == thread[j]){
if(ret == nil)
ret = &thr[i];
goto skip;
}
}
if(nthr >= nelem(thr))
return nil;
// TODO: We probably should save the old thread exception
// ports for each bit and then put them back when we exit.
// Probably the BSD signal handlers have put stuff there.
mach_port_insert_right(mach_task_self(), excport, excport, MACH_MSG_TYPE_MAKE_SEND);
if(me(thread_set_exception_ports(thread[j], ExcMask,
excport, EXCEPTION_DEFAULT, MACHINE_THREAD_STATE)) < 0){
fprint(2, "warning: cannot set excport: %r\n");
}
thr[nthr].pid = pid;
thr[nthr].task = task;
thr[nthr].thread = thread[j];
if(ret == nil)
ret = &thr[nthr];
nthr++;
skip:;
}
return ret;
}
static Thread*
idtotable(int id)
{
if(id >= 0)
return addpid(id, 1);
id = -(id+1);
if(id >= nthr)
return nil;
return &thr[id];
}
/*
static int
idtopid(int id)
{
Thread *t;
if((t = idtotable(id)) == nil)
return -1;
return t->pid;
}
*/
static mach_port_t
idtotask(int id)
{
Thread *t;
if((t = idtotable(id)) == nil)
return -1;
return t->task;
}
static mach_port_t
idtothread(int id)
{
Thread *t;
if((t = idtotable(id)) == nil)
return -1;
return t->thread;
}
static int machsegrw(Map *map, Seg *seg, uvlong addr, void *v, uint n, int isr);
static int machregrw(Map *map, Seg *seg, uvlong addr, void *v, uint n, int isr);
Map*
attachproc(int id, Fhdr *fp)
{
Thread *t;
Map *map;
if((t = idtotable(id)) == nil)
return nil;
if(t->map)
return t->map;
map = newmap(0, 4);
if(!map)
return nil;
map->pid = -((t-thr) + 1);
if(mach->regsize)
setmap(map, -1, 0, mach->regsize, 0, "regs", machregrw);
setmap(map, -1, fp->txtaddr, fp->txtaddr+fp->txtsz, fp->txtaddr, "*text", machsegrw);
setmap(map, -1, fp->dataddr, mach->utop, fp->dataddr, "*data", machsegrw);
t->map = map;
return map;
}
// Return list of ids for threads in id.
int
procthreadpids(int id, int *out, int nout)
{
Thread *t;
int i, n, pid;
t = idtotable(id);
if(t == nil)
return -1;
pid = t->pid;
addpid(pid, 1); // force refresh of thread list
n = 0;
for(i=0; i<nthr; i++) {
if(thr[i].pid == pid) {
if(n < nout)
out[n] = -(i+1);
n++;
}
}
return n;
}
// Detach from proc.
// TODO(rsc): Perhaps should unsuspend any threads and clean-up the table.
void
detachproc(Map *m)
{
free(m);
}
// Should return array of pending signals (notes)
// but don't know how to do that on OS X.
int
procnotes(int pid, char ***pnotes)
{
*pnotes = 0;
return 0;
}
// There must be a way to do this. Gdb can do it.
// But I don't see, in the Apple gdb sources, how.
char*
proctextfile(int pid)
{
return nil;
}
// Read/write from a Mach data segment.
static int
machsegrw(Map *map, Seg *seg, uvlong addr, void *v, uint n, int isr)
{
mach_port_t task;
int r;
task = idtotask(map->pid);
if(task == -1)
return -1;
if(isr){
vm_size_t nn;
nn = n;
if(me(vm_read_overwrite(task, addr, n, (uintptr)v, &nn)) < 0) {
fprint(2, "vm_read_overwrite %#llux %d to %p: %r\n", addr, n, v);
return -1;
}
return nn;
}else{
r = vm_write(task, addr, (uintptr)v, n);
if(r == KERN_INVALID_ADDRESS){
// Happens when writing to text segment.
// Change protections.
if(me(vm_protect(task, addr, n, 0, VM_PROT_WRITE|VM_PROT_READ|VM_PROT_EXECUTE)) < 0){
fprint(2, "vm_protect: %s\n", r);
return -1;
}
r = vm_write(task, addr, (uintptr)v, n);
}
if(r != 0){
me(r);
return -1;
}
return n;
}
}
// Convert Ureg offset to x86_thread_state32_t offset.
static int
go2darwin32(uvlong addr)
{
switch(addr){
case offsetof(Ureg32, ax):
return offsetof(x86_thread_state32_t, eax);
case offsetof(Ureg32, bx):
return offsetof(x86_thread_state32_t, ebx);
case offsetof(Ureg32, cx):
return offsetof(x86_thread_state32_t, ecx);
case offsetof(Ureg32, dx):
return offsetof(x86_thread_state32_t, edx);
case offsetof(Ureg32, si):
return offsetof(x86_thread_state32_t, esi);
case offsetof(Ureg32, di):
return offsetof(x86_thread_state32_t, edi);
case offsetof(Ureg32, bp):
return offsetof(x86_thread_state32_t, ebp);
case offsetof(Ureg32, fs):
return offsetof(x86_thread_state32_t, fs);
case offsetof(Ureg32, gs):
return offsetof(x86_thread_state32_t, gs);
case offsetof(Ureg32, pc):
return offsetof(x86_thread_state32_t, eip);
case offsetof(Ureg32, cs):
return offsetof(x86_thread_state32_t, cs);
case offsetof(Ureg32, flags):
return offsetof(x86_thread_state32_t, eflags);
case offsetof(Ureg32, sp):
return offsetof(x86_thread_state32_t, esp);
}
return -1;
}
// Convert Ureg offset to x86_thread_state64_t offset.
static int
go2darwin64(uvlong addr)
{
switch(addr){
case offsetof(Ureg64, ax):
return offsetof(x86_thread_state64_t, rax);
case offsetof(Ureg64, bx):
return offsetof(x86_thread_state64_t, rbx);
case offsetof(Ureg64, cx):
return offsetof(x86_thread_state64_t, rcx);
case offsetof(Ureg64, dx):
return offsetof(x86_thread_state64_t, rdx);
case offsetof(Ureg64, si):
return offsetof(x86_thread_state64_t, rsi);
case offsetof(Ureg64, di):
return offsetof(x86_thread_state64_t, rdi);
case offsetof(Ureg64, bp):
return offsetof(x86_thread_state64_t, rbp);
case offsetof(Ureg64, r8):
return offsetof(x86_thread_state64_t, r8);
case offsetof(Ureg64, r9):
return offsetof(x86_thread_state64_t, r9);
case offsetof(Ureg64, r10):
return offsetof(x86_thread_state64_t, r10);
case offsetof(Ureg64, r11):
return offsetof(x86_thread_state64_t, r11);
case offsetof(Ureg64, r12):
return offsetof(x86_thread_state64_t, r12);
case offsetof(Ureg64, r13):
return offsetof(x86_thread_state64_t, r13);
case offsetof(Ureg64, r14):
return offsetof(x86_thread_state64_t, r14);
case offsetof(Ureg64, r15):
return offsetof(x86_thread_state64_t, r15);
case offsetof(Ureg64, fs):
return offsetof(x86_thread_state64_t, fs);
case offsetof(Ureg64, gs):
return offsetof(x86_thread_state64_t, gs);
case offsetof(Ureg64, ip):
return offsetof(x86_thread_state64_t, rip);
case offsetof(Ureg64, cs):
return offsetof(x86_thread_state64_t, cs);
case offsetof(Ureg64, flags):
return offsetof(x86_thread_state64_t, rflags);
case offsetof(Ureg64, sp):
return offsetof(x86_thread_state64_t, rsp);
}
return -1;
}
extern Mach mi386;
// Read/write from fake register segment.
static int
machregrw(Map *map, Seg *seg, uvlong addr, void *v, uint n, int isr)
{
uint nn, count, state;
mach_port_t thread;
int reg;
char buf[100];
union {
x86_thread_state64_t reg64;
x86_thread_state32_t reg32;
uchar p[1];
} u;
uchar *p;
if(n > 8){
werrstr("asked for %d-byte register", n);
return -1;
}
thread = idtothread(map->pid);
if(thread == -1){
werrstr("no such id");
return -1;
}
if(mach == &mi386) {
count = x86_THREAD_STATE32_COUNT;
state = x86_THREAD_STATE32;
if((reg = go2darwin32(addr)) < 0 || reg+n > sizeof u){
if(isr){
memset(v, 0, n);
return 0;
}
werrstr("register %llud not available", addr);
return -1;
}
} else {
count = x86_THREAD_STATE64_COUNT;
state = x86_THREAD_STATE64;
if((reg = go2darwin64(addr)) < 0 || reg+n > sizeof u){
if(isr){
memset(v, 0, n);
return 0;
}
werrstr("register %llud not available", addr);
return -1;
}
}
if(!isr && me(thread_suspend(thread)) < 0){
werrstr("thread suspend %#x: %r", thread);
return -1;
}
nn = count;
if(me(thread_get_state(thread, state, (void*)u.p, &nn)) < 0){
if(!isr)
thread_resume(thread);
rerrstr(buf, sizeof buf);
if(strstr(buf, "send invalid dest") != nil)
werrstr("process exited");
else
werrstr("thread_get_state: %r");
return -1;
}
p = u.p+reg;
if(isr)
memmove(v, p, n);
else{
memmove(p, v, n);
nn = count;
if(me(thread_set_state(thread, state, (void*)u.p, nn)) < 0){
thread_resume(thread);
werrstr("thread_set_state: %r");
return -1;
}
if(me(thread_resume(thread)) < 0){
werrstr("thread_resume: %r");
return -1;
}
}
return 0;
}
enum
{
FLAGS_TF = 0x100 // x86 single-step processor flag
};
// Is thread t suspended?
static int
threadstopped(Thread *t)
{
struct thread_basic_info info;
uint size;
size = sizeof info;
if(me(thread_info(t->thread, THREAD_BASIC_INFO, (thread_info_t)&info, &size)) < 0){
fprint(2, "threadstopped thread_info %#x: %r\n");
return 1;
}
return info.suspend_count > 0;
}
// If thread t is suspended, start it up again.
// If singlestep is set, only let it execute one instruction.
static int
threadstart(Thread *t, int singlestep)
{
int i;
uint n;
struct thread_basic_info info;
if(!threadstopped(t))
return 0;
// Set or clear the processor single-step flag, as appropriate.
if(mach == &mi386) {
x86_thread_state32_t regs;
n = x86_THREAD_STATE32_COUNT;
if(me(thread_get_state(t->thread, x86_THREAD_STATE32,
(thread_state_t)&regs,
&n)) < 0)
return -1;
if(singlestep)
regs.eflags |= FLAGS_TF;
else
regs.eflags &= ~FLAGS_TF;
if(me(thread_set_state(t->thread, x86_THREAD_STATE32,
(thread_state_t)&regs,
x86_THREAD_STATE32_COUNT)) < 0)
return -1;
} else {
x86_thread_state64_t regs;
n = x86_THREAD_STATE64_COUNT;
if(me(thread_get_state(t->thread, x86_THREAD_STATE64,
(thread_state_t)&regs,
&n)) < 0)
return -1;
if(singlestep)
regs.rflags |= FLAGS_TF;
else
regs.rflags &= ~FLAGS_TF;
if(me(thread_set_state(t->thread, x86_THREAD_STATE64,
(thread_state_t)&regs,
x86_THREAD_STATE64_COUNT)) < 0)
return -1;
}
// Run.
n = sizeof info;
if(me(thread_info(t->thread, THREAD_BASIC_INFO, (thread_info_t)&info, &n)) < 0)
return -1;
for(i=0; i<info.suspend_count; i++)
if(me(thread_resume(t->thread)) < 0)
return -1;
return 0;
}
// Stop thread t.
static int
threadstop(Thread *t)
{
if(threadstopped(t))
return 0;
if(me(thread_suspend(t->thread)) < 0)
return -1;
return 0;
}
// Callback for exc_server below. Called when a thread we are
// watching has an exception like hitting a breakpoint.
kern_return_t
catch_exception_raise(mach_port_t eport, mach_port_t thread,
mach_port_t task, exception_type_t exception,
exception_data_t code, mach_msg_type_number_t ncode)
{
Thread *t;
int i;
t = nil;
for(i=0; i<nthr; i++){
if(thr[i].thread == thread){
t = &thr[i];
goto havet;
}
}
if(nthr > 0)
addpid(thr[0].pid, 1);
for(i=0; i<nthr; i++){
if(thr[i].thread == thread){
t = &thr[i];
goto havet;
}
}
fprint(2, "did not find thread in catch_exception_raise\n");
return KERN_SUCCESS; // let thread continue
havet:
t->exc = exception;
if(ncode > nelem(t->code))
ncode = nelem(t->code);
memmove(t->code, code, ncode*sizeof t->code[0]);
// Suspend thread, so that we can look at it & restart it later.
if(me(thread_suspend(thread)) < 0)
fprint(2, "catch_exception_raise thread_suspend: %r\n");
// Synchronize with waitstop below.
pthread_mutex_lock(&mu);
pthread_cond_broadcast(&cond);
pthread_mutex_unlock(&mu);
return KERN_SUCCESS;
}
// Exception watching thread, started in addpid above.
static void*
excthread(void *v)
{
extern boolean_t exc_server();
mach_msg_server(exc_server, 2048, excport, 0);
return 0;
}
// Wait for pid to exit.
static int exited;
static void*
waitthread(void *v)
{
int pid, status;
pid = (int)(uintptr)v;
waitpid(pid, &status, 0);
exited = 1;
// Synchronize with waitstop below.
pthread_mutex_lock(&mu);
pthread_cond_broadcast(&cond);
pthread_mutex_unlock(&mu);
return nil;
}
// Wait for thread t to stop.
static int
waitstop(Thread *t)
{
pthread_mutex_lock(&mu);
while(!exited && !threadstopped(t))
pthread_cond_wait(&cond, &mu);
pthread_mutex_unlock(&mu);
return 0;
}
int
ctlproc(int id, char *msg)
{
Thread *t;
int status;
// Hang/attached dance is for debugging newly exec'ed programs.
// After fork, the child does ctlproc("hang") before exec,
// and the parent does ctlproc("attached") and then waitstop.
// Using these requires the BSD ptrace interface, unlike everything
// else we do, which uses only the Mach interface. Our goal here
// is to do as little as possible using ptrace and then flip over to Mach.
if(strcmp(msg, "hang") == 0)
return ptrace(PT_TRACE_ME, 0, 0, 0);
if(strcmp(msg, "attached") == 0){
// The pid "id" has done a ctlproc "hang" and then
// exec, so we should find it stoppped just before exec
// of the new program.
#undef waitpid
if(waitpid(id, &status, WUNTRACED) < 0){
fprint(2, "ctlproc attached waitpid: %r\n");
return -1;
}
if(WIFEXITED(status) || !WIFSTOPPED(status)){
fprint(2, "ctlproc attached: bad process state\n");
return -1;
}
// Find Mach thread for pid and suspend it.
t = addpid(id, 1);
if(t == nil) {
fprint(2, "ctlproc attached: addpid: %r\n");
return -1;
}
if(me(thread_suspend(t->thread)) < 0){
fprint(2, "ctlproc attached: thread_suspend: %r\n");
return -1;
}
// Let ptrace tell the process to keep going:
// then ptrace is out of the way and we're back in Mach land.
if(ptrace(PT_CONTINUE, id, (caddr_t)1, 0) < 0) {
fprint(2, "ctlproc attached: ptrace continue: %r\n");
return -1;
}
return 0;
}
// All the other control messages require a Thread structure.
if((t = idtotable(id)) == nil){
werrstr("no such thread");
return -1;
}
if(strcmp(msg, "kill") == 0)
return ptrace(PT_KILL, t->pid, 0, 0);
if(strcmp(msg, "start") == 0)
return threadstart(t, 0);
if(strcmp(msg, "stop") == 0)
return threadstop(t);
if(strcmp(msg, "startstop") == 0){
if(threadstart(t, 0) < 0)
return -1;
return waitstop(t);
}
if(strcmp(msg, "step") == 0){
if(threadstart(t, 1) < 0)
return -1;
return waitstop(t);
}
if(strcmp(msg, "waitstop") == 0)
return waitstop(t);
// sysstop not available on OS X
werrstr("unknown control message");
return -1;
}
char*
procstatus(int id)
{
Thread *t;
if((t = idtotable(id)) == nil)
return "gone!";
if(threadstopped(t))
return "Stopped";
return "Running";
}