2 * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
3 * Licensed under the GPL
11 #include <sys/signal.h>
14 #include "kern_util.h"
15 #include "user_util.h"
19 void (*pre_exec)(void*);
25 /* Debugging aid, changed only from gdb */
28 static void helper_hup(int sig)
32 static int helper_child(void *arg)
34 struct helper_data *data = arg;
35 char **argv = data->argv;
39 signal(SIGHUP, helper_hup);
42 if (data->pre_exec != NULL)
43 (*data->pre_exec)(data->pre_data);
44 execvp(argv[0], argv);
46 printk("helper_child - execve of '%s' failed - errno = %d\n", argv[0], errno);
47 os_write_file(data->fd, &errval, sizeof(errval));
48 kill(os_getpid(), SIGKILL);
52 /* Returns either the pid of the child process we run or -E* on failure.
53 * XXX The alloc_stack here breaks if this is called in the tracing thread */
54 int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv,
55 unsigned long *stack_out)
57 struct helper_data data;
58 unsigned long stack, sp;
59 int pid, fds[2], ret, n;
61 if ((stack_out != NULL) && (*stack_out != 0))
64 stack = alloc_stack(0, __cant_sleep());
68 ret = os_pipe(fds, 1, 0);
70 printk("run_helper : pipe failed, ret = %d\n", -ret);
74 ret = os_set_exec_close(fds[1], 1);
76 printk("run_helper : setting FD_CLOEXEC failed, ret = %d\n",
81 sp = stack + page_size() - sizeof(void *);
82 data.pre_exec = pre_exec;
83 data.pre_data = pre_data;
86 pid = clone(helper_child, (void *) sp, CLONE_VM | SIGCHLD, &data);
89 printk("run_helper : clone failed, errno = %d\n", errno);
96 /* Read the errno value from the child, if the exec failed, or get 0 if
97 * the exec succeeded because the pipe fd was set as close-on-exec. */
98 n = os_read_file(fds[0], &ret, sizeof(ret));
103 printk("run_helper : read on pipe failed, ret = %d\n",
108 CATCH_EINTR(waitpid(pid, NULL, 0));
116 if (stack_out == NULL)
117 free_stack(stack, 0);
123 int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags,
124 unsigned long *stack_out, int stack_order)
126 unsigned long stack, sp;
127 int pid, status, err;
129 stack = alloc_stack(stack_order, __cant_sleep());
133 sp = stack + (page_size() << stack_order) - sizeof(void *);
134 pid = clone(proc, (void *) sp, flags | SIGCHLD, arg);
137 printk("run_helper_thread : clone failed, errno = %d\n",
141 if (stack_out == NULL) {
142 CATCH_EINTR(pid = waitpid(pid, &status, 0));
145 printk("run_helper_thread - wait failed, errno = %d\n",
149 if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0))
150 printk("run_helper_thread - thread returned status "
152 free_stack(stack, stack_order);
158 int helper_wait(int pid)
162 CATCH_EINTR(ret = waitpid(pid, NULL, WNOHANG));
165 printk("helper_wait : waitpid failed, errno = %d\n", errno);