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Fix Musl spawn usage
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@dd86k
dd86k committed Apr 30, 2024
1 parent 7559f43 commit 669e5f0
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Showing 3 changed files with 45 additions and 125 deletions.
2 changes: 1 addition & 1 deletion debugger/main.d
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Original file line number Diff line number Diff line change
Expand Up @@ -120,5 +120,5 @@ int main(int argc, const(char)** argv) {
return EXIT_FAILURE;
}

return shellinit(cnt, getoptleftovers());
return shell_start(cnt, getoptleftovers());
}
14 changes: 3 additions & 11 deletions debugger/shell.d
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Original file line number Diff line number Diff line change
Expand Up @@ -92,7 +92,7 @@ const(char) *shell_error_string(int code) {
}

//TODO: Turn into character array (like gdb --args)
int shellinit(int argc, const(char)** argv) {
int shell_start(int argc, const(char)** argv) {
int ecode = void;

if (loginit(null))
Expand All @@ -118,6 +118,7 @@ int shellinit(int argc, const(char)** argv) {

Lcommand:
printf("(adbg) ");
fflush(stdout);

// .ptr is temporary because a slice with a length of 0
// also make its pointer null.
Expand Down Expand Up @@ -727,16 +728,7 @@ int command_crash(int, const(char) **) {
}

int command_status(int argc, const(char) **argv) {
AdbgProcStatus state = adbg_process_status(process);
const(char) *m = void;
switch (state) with (AdbgProcStatus) {
case unloaded: m = "unloaded"; break;
case standby: m = "standby"; break;
case running: m = "running"; break;
case paused: m = "paused"; break;
default: m = "(unknown)";
}
puts(m);
puts(adbg_process_status_string(process));
return 0;
}

Expand Down
154 changes: 41 additions & 113 deletions src/adbg/debugger/process.d
View file
Original file line number Diff line number Diff line change
Expand Up @@ -46,8 +46,8 @@ version (Windows) {
import core.sys.posix.libgen : basename;
}

// I can't remember why, but problably Musl moment
version = USE_CLONE;
//version (CRuntime_Glibc)
// version = USE_CLONE;

extern (C):

Expand All @@ -60,7 +60,8 @@ enum AdbgEvent {
enum AdbgProcStatus : ubyte {
unknown, /// Process status is not known.
unloaded = unknown, /// Process is unloaded.
standby, /// Process is loaded and waiting to run.
loaded, /// Process is loaded and waiting to run.
standby = loaded, /// Alias for loaded.
running, /// Process is running.
paused, /// Process is paused due to an exception or by the debugger.
}
Expand Down Expand Up @@ -108,6 +109,7 @@ struct adbg_process_t {

version (Posix)
private struct __adbg_child_t {
int pid;
const(char) **argv, envp;
}

Expand Down Expand Up @@ -225,21 +227,24 @@ version (Windows) {
while (argv[argc])
argslen += strlen(argv[argc++]);

// Allocate argument line space
size_t minlen = commlen + 2 + argslen + argc + 1; // + quotes and spaces
proc.args = cast(char*)malloc(minlen);
if (proc.args == null) {
free(proc);
adbg_oops(AdbgError.crt);
return null;
}

// Place path into argv[0] with quotes
size_t i;
proc.args[i++] = '"';
memcpy(proc.args + i, path, commlen); i += commlen;
proc.args[i++] = '"';
proc.args[i++] = ' ';

// Flatten
int cl = cast(int)(minlen - i); // Buffer space left
// Flatten arguments
int cl = cast(int)minlen - cast(int)i; // Buffer space left
if (cl <= 0) {
free(proc);
adbg_oops(AdbgError.crt);
Expand All @@ -262,11 +267,10 @@ version (Windows) {
memset(&si, 0, si.sizeof);
memset(&pi, 0, pi.sizeof);
si.cb = STARTUPINFOA.sizeof;

DWORD flags = options & OPT_DEBUG_ALL ? DEBUG_PROCESS : DEBUG_PROCESS | DEBUG_ONLY_THIS_PROCESS;

flags |= CREATE_DEFAULT_ERROR_MODE;

// Create process
if (CreateProcessA(
path, // lpApplicationName
proc.args, // lpCommandLine
Expand All @@ -281,7 +285,6 @@ version (Windows) {
adbg_oops(AdbgError.os);
return null;
}

proc.hpid = pi.hProcess;
proc.htid = pi.hThread;
proc.pid = pi.dwProcessId;
Expand Down Expand Up @@ -349,6 +352,7 @@ version (USE_CLONE) { // clone(2)
// Clone
//TODO: Get default stack size
__adbg_child_t chld = void;
chld.pid = proc.pid;
chld.argv = cast(const(char)**)proc.argv;
chld.envp = envp;
proc.pid = clone(&__adbg_exec_child, stacktop, CLONE_PTRACE | CLONE_VFORK, &chld);
Expand All @@ -357,51 +361,7 @@ version (USE_CLONE) { // clone(2)
adbg_oops(AdbgError.os);
return null;
}

} else { // fork(2)
/*proc.argv = cast(char**)mmap(null,
(argc + 2) * size_t.sizeof,
PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_POPULATE,
-1, 0);
if (proc.argv == MAP_FAILED) {
version(Trace) trace("mmap=%s", strerror(errno));
free(proc);
adbg_oops(AdbgError.os);
return null;
}*/

// Setup pipes so we can communicate with child process
int[2] pipefds = void;
if (pipe(pipefds)) {
free(proc);
adbg_oops(AdbgError.os);
return null;
}
if (fcntl(pipefds[1], F_SETFD, fcntl(pipefds[1], F_GETFD) | FD_CLOEXEC)) {
free(proc);
adbg_oops(AdbgError.os);
return null;
}

// NOTE: exec family
// | | PATH | argv | envp |
// POSIX | execl(3) | No | No | No |
// | execlp(3) | Yes | No | No |
// | execle(3) | No | No | Yes |
// | execv(3) | No | Yes | No |
// | execvp(3) | Yes | Yes | No |
// | execvpe(3) | Yes | Yes | Yes |
// Linux | execve(2) | No | Yes | Yes |
// FreeBSD | execvP(2) | Yes | Yes | No |
// | exect(3) | No | Yes | Yes |
// OpenBSD | execve(2) | No | Yes | Yes |
// NetBSD | exect(3) | No | Yes | Yes |

// NOTE: Execution flow
// 1. Child is created with anonymous pipes
// 2. While parent waits for a signal, child inits ptrace

switch (proc.pid = fork()) {
case -1: // Error
version(Trace) trace("fork=%s", strerror(errno));
Expand All @@ -410,57 +370,16 @@ version (USE_CLONE) { // clone(2)
adbg_oops(AdbgError.os);
return null;
case 0: // New child process
close(pipefds[0]); // Close read
version(Trace) for (int i; i < argc + 2; ++i)
trace("argv[%d]=%s", i, proc.argv[i]);

__adbg_child_t chld = void;
chld.pid = proc.pid;
chld.argv = cast(const(char)**)proc.argv;
chld.envp = envp;
int e = __adbg_exec_child(&chld) < 0 ? errno : 0;

write(pipefds[1], &e, int.sizeof); // Write result to parent
close(pipefds[1]); // Close write
_exit(e);
__adbg_exec_child(&chld);
return null; // Make compiler happy
default: // This parent process
close(pipefds[1]); // Close write

int chlderr = void;
ssize_t count = void;
version(Trace) trace("read...", chlderr);
while ((count = read(pipefds[0], &chlderr, int.sizeof)) < 0)
if (errno != EAGAIN && errno != EINTR) break;
//ssize_t count = read(pipefds[0], &chlderr, int.sizeof);
version(Trace) trace("close...", chlderr);
close(pipefds[0]); // Close read
if (count < int.sizeof) { // Error
version(Trace) trace("read=%s", strerror(errno));
adbg_oops(AdbgError.os);
return null;
}
if (chlderr) {
version(Trace) trace("childerr=%d (%s)", chlderr, strerror(chlderr));
errno = chlderr;
adbg_oops(AdbgError.os);
return null;
}
// Waiting for child
/*while (waitpid(proc.pid, &chlderr, 0) == -1)
if (errno != EINTR) {
version(Trace) trace("waitpid=%s", strerror(errno));
adbg_oops(AdbgError.os);
return null;
}
if (WIFEXITED(chlderr)) {
version(Trace) trace("child exited by %d", WEXITSTATUS(chlderr));
adbg_oops(AdbgError.os);
return null;
} else if (WIFSIGNALED(chlderr)) {
version(Trace) trace("child kill by %d", WTERMSIG(chlderr));
adbg_oops(AdbgError.os);
return null;
}*/
} // switch(fork(2))
} // fork(2)
} // version (linux)
Expand All @@ -475,32 +394,24 @@ private int __adbg_exec_child(void* arg) {
__adbg_child_t *chld = cast(__adbg_child_t*)arg;

// Baby, Please Trace Me
version (Trace) trace("ptrace...");
if (ptrace(PT_TRACEME, 0, 0, 0) < 0) {
version (Trace) trace("PT_TRACEME...");
if (ptrace(PT_TRACEME, 0, null, null) < 0) {
version (Trace) trace("ptrace=%s", strerror(errno));
return -1;
goto Lexit;
}
version (Trace) trace("done");

version (CRuntime_Musl) {
version (Trace) trace("raise...");
if (raise(SIGTRAP)) {
version (Trace) trace("raise=%s", strerror(errno));
return -1;
}
version (Trace) trace("done");
}

// NOTE: On Glibc, sends a SIGTRAP on success and doesn't return
// Start specified process
version (Trace) trace("execve...");
if (execve(*chld.argv, chld.argv, chld.envp) < 0) {
version (Trace) trace("execve=%s", strerror(errno));
return -1;
goto Lexit;
}
version (Trace) trace("done");

Lexit:
_exit(errno);
return 0;
}

/// Debugger process attachment options
Expand Down Expand Up @@ -661,12 +572,29 @@ version (Windows) {
//TODO: Check process debugged remotely
//bool adbg_process_debugged(int pid) {

/// Get the debugger's current state.
/// Returns: Debugger status.
/// Get the debuggee's current status.
/// Returns: Debuggee status.
AdbgProcStatus adbg_process_status(adbg_process_t *tracee) pure {
if (tracee == null) return AdbgProcStatus.unknown;
return tracee.status;
}
/// Get the debuggee current status as a string.
/// Returns: Debuggee status string.
const(char)* adbg_process_status_string(adbg_process_t *tracee) pure {
if (tracee == null) {
Ldefault:
return "unknown";
}
const(char) *m = void;
switch (tracee.status) with (AdbgProcStatus) {
case unloaded: m = "unloaded"; break;
case loaded: m = "loaded"; break;
case running: m = "running"; break;
case paused: m = "paused"; break;
default: goto Ldefault;
}
return m;
}

/// Wait for a debug event.
///
Expand Down Expand Up @@ -741,15 +669,15 @@ L_DEBUG_LOOP:
L_DEBUG_LOOP:
tracee.pid = waitpid(-1, &wstatus, 0);

version (Trace) trace("wstatus=%#x", wstatus);

// Something bad happened
if (tracee.pid < 0) {
tracee.status = AdbgProcStatus.unloaded;
tracee.creation = AdbgCreation.unloaded;
return adbg_oops(AdbgError.crt);
}

version (Trace) trace("wstatus=%08x", wstatus);

// If exited or killed by signal, it's gone.
if (WIFEXITED(wstatus) || WIFSIGNALED(wstatus))
goto L_UNLOADED;
Expand Down

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