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restore signal mask on early returns
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@tjknoth
tjknoth committed Apr 9, 2024
1 parent ee6f2a5 commit 42df55a
Showing 1 changed file with 33 additions and 50 deletions.
83 changes: 33 additions & 50 deletions runtime/driver.c
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Original file line number Diff line number Diff line change
Expand Up @@ -653,7 +653,6 @@ typedef struct ProcessStatus {
} ProcessStatus;

// Linked list of live processes
// TODO: volatility annotations
volatile ProcessNode * volatile proc_head = NULL;
struct sigaction oldact;

Expand All @@ -680,7 +679,7 @@ static int register_proc (
child->fout = fout;
child->ferr = ferr;
child->status = status;
*(child->status) = -1; // TODO: is this OK?
*(child->status) = -1;
child->auto_cleanup = auto_cleanup;
// Store child in ProcessNode
volatile ProcessNode * new_node = (ProcessNode*)malloc(sizeof(ProcessNode));
Expand All @@ -692,14 +691,6 @@ static int register_proc (
return 0;
}


// Retrieve process state
// TODO: just get rid of this
static int get_status (Process* process, int* status) {
*status = process->status;
return 0;
}

// Cleanup all resources for process pid
static void cleanup_child (pid_t pid) {

Expand Down Expand Up @@ -959,6 +950,10 @@ static void restore (sigset_t* old_mask) {
if(sigprocmask(SIG_SETMASK, old_mask, NULL)) exit_with_error();
}

static int restore_and_err (sigset_t* old_mask) {
restore(old_mask);
return -1;
}


#ifdef PLATFORM_LINUX
Expand Down Expand Up @@ -1111,7 +1106,7 @@ stz_int launch_process(stz_byte* file, stz_byte** argvs, stz_int input,
//Generate array of pipes per-input-source
int pipes[NUM_STREAM_SPECS][2];
for(int i=0; i<NUM_STREAM_SPECS; i++) {
if(pipe(pipes[i])) return -1;
if(pipe(pipes[i])) restore_and_err(&old_mask);
}

//Setup file actions
Expand All @@ -1122,35 +1117,35 @@ stz_int launch_process(stz_byte* file, stz_byte** argvs, stz_int input,
//Setup input pipe if used
if(pipe_sources[PROCESS_IN] >= 0) {
if((posix_ret = posix_spawn_file_actions_addclose(&actions, pipes[PROCESS_IN][1])))
return -1;
restore_and_err(&old_mask);
if((posix_ret = posix_spawn_file_actions_adddup2(&actions, pipes[PROCESS_IN][0], STDIN_FILENO)))
return -1;
restore_and_err(&old_mask);
if((posix_ret = posix_spawn_file_actions_addclose(&actions, pipes[PROCESS_IN][0])))
return -1;
restore_and_err(&old_mask);
}
//Setup output pipe if used
if(pipe_sources[PROCESS_OUT] >= 0) {
if((posix_ret = posix_spawn_file_actions_addclose(&actions, pipes[PROCESS_OUT][0])))
return -1;
restore_and_err(&old_mask);
if((posix_ret = posix_spawn_file_actions_adddup2(&actions, pipes[PROCESS_OUT][1], STDOUT_FILENO)))
return -1;
restore_and_err(&old_mask);
if((posix_ret = posix_spawn_file_actions_addclose(&actions, pipes[PROCESS_OUT][1])))
return -1;
restore_and_err(&old_mask);
}
//Setup error pipe if used
if(pipe_sources[PROCESS_ERR] >= 0) {
if((posix_ret = posix_spawn_file_actions_addclose(&actions, pipes[PROCESS_ERR][0])))
return -1;
restore_and_err(&old_mask);
if((posix_ret = posix_spawn_file_actions_adddup2(&actions, pipes[PROCESS_ERR][1], STDERR_FILENO)))
return -1;
restore_and_err(&old_mask);
if((posix_ret = posix_spawn_file_actions_addclose(&actions, pipes[PROCESS_ERR][1])))
return -1;
restore_and_err(&old_mask);
}

//Setup working directory
if(working_dir) {
if((posix_ret = posix_spawn_file_actions_addchdir_np(&actions, C_CSTR(working_dir))))
return -1;
restore_and_err(&old_mask);
}

// Spawn child process
Expand All @@ -1160,7 +1155,7 @@ stz_int launch_process(stz_byte* file, stz_byte** argvs, stz_int input,
// success
} else {
errno = spawn_ret; // might not want to do this manually?
return -1;
restore_and_err(&old_mask);
}
// Cleanup
posix_spawn_file_actions_destroy(&actions);
Expand All @@ -1172,18 +1167,19 @@ stz_int launch_process(stz_byte* file, stz_byte** argvs, stz_int input,
close(pipes[PROCESS_IN][0]);
fin = fdopen(pipes[PROCESS_IN][1], "w");
if(fin == NULL) return -1;
restore_and_err(&old_mask);
}
FILE* fout = NULL;
if(pipe_sources[PROCESS_OUT] >= 0) {
close(pipes[PROCESS_OUT][1]);
fout = fdopen(pipes[PROCESS_OUT][0], "r");
if(fout == NULL) return -1;
if(fout == NULL) restore_and_err(&old_mask);
}
FILE* ferr = NULL;
if(pipe_sources[PROCESS_ERR] >= 0) {
close(pipes[PROCESS_ERR][1]);
ferr = fdopen(pipes[PROCESS_ERR][0], "r");
if(ferr == NULL) return -1;
if(ferr == NULL) restore_and_err(&old_mask);
}

process->pid = pid;
Expand Down Expand Up @@ -1211,45 +1207,36 @@ int retrieve_process_state (Process* process, ProcessState* s, stz_int wait_for_
bool state_unknown = true;

while(state_unknown) {

if(get_status(process, &status) == 0) {
if(WIFEXITED(status))
*s = (ProcessState){PROCESS_DONE, WEXITSTATUS(status)};
else if(WIFSIGNALED(status))
*s = (ProcessState){PROCESS_TERMINATED, WTERMSIG(status)};
else if(WIFSTOPPED(status))
*s = (ProcessState){PROCESS_STOPPED, WSTOPSIG(status)};
else
*s = (ProcessState){PROCESS_RUNNING, 0};
state_unknown = false;
} else {
return -1; // process not found
}
status = process->status;
if(WIFEXITED(status))
*s = (ProcessState){PROCESS_DONE, WEXITSTATUS(status)};
else if(WIFSIGNALED(status))
*s = (ProcessState){PROCESS_TERMINATED, WTERMSIG(status)};
else if(WIFSTOPPED(status))
*s = (ProcessState){PROCESS_STOPPED, WSTOPSIG(status)};
else
*s = (ProcessState){PROCESS_RUNNING, 0};
state_unknown = false;
if(wait_for_termination && !dead_status(status)) {
// Allow SIGCHLD during sigsuspend
// We allow SICHLD during sigsuspend
sigset_t allow_sigchld;
// This is overkill, but ensures SIGCHLD is allowed
sigfillset(&allow_sigchld);
// SIGCHLD is unmasked
sigdelset(&allow_sigchld, SIGCHLD);

// no file descriptors or timeout; just wait indefinitely for an interrupt
if(sigsuspend(&allow_sigchld) < 0) {
if(errno == EINTR) {
state_unknown = true;
} else {
// non-interrupt error: impossible
exit_with_error();
exit_with_error(); // non-interrupt error: impossible
}
}

}
// do not loop if we don't need the process to terminate
else if(!wait_for_termination) {
// do not loop if we don't need the process to terminate
state_unknown = false;
}
}
// Reset to old_mask
restore(&old_mask);
return 0;
}
Expand Down Expand Up @@ -1381,10 +1368,6 @@ STANZA_API_FUNC int MAIN_FUNC (int argc, char* argv[]) {
//Call Stanza entry
stanza_entry(&init);

// TODO: cleanup?
//#if defined(PLATFORM_LINUX) || defined(PLATFORM_OS_X)
// free_processes();
//#endif
//Heap and freespace are disposed by OS at process termination
return 0;
}

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