2 * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
3 * Licensed under the GPL
12 #include <sys/signal.h>
15 #include "kern_util.h"
16 #include "user_util.h"
18 #include "um_malloc.h"
21 void (*pre_exec)(void*);
28 static int helper_child(void *arg)
30 struct helper_data *data = arg;
31 char **argv = data->argv;
34 if (data->pre_exec != NULL)
35 (*data->pre_exec)(data->pre_data);
36 errval = execvp_noalloc(data->buf, argv[0], argv);
37 printk("helper_child - execvp of '%s' failed - errno = %d\n", argv[0], -errval);
38 os_write_file(data->fd, &errval, sizeof(errval));
39 kill(os_getpid(), SIGKILL);
43 /* Returns either the pid of the child process we run or -E* on failure.
44 * XXX The alloc_stack here breaks if this is called in the tracing thread, so
45 * we need to receive a preallocated stack (a local buffer is ok). */
46 int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv,
47 unsigned long *stack_out)
49 struct helper_data data;
50 unsigned long stack, sp;
51 int pid, fds[2], ret, n;
53 if ((stack_out != NULL) && (*stack_out != 0))
56 stack = alloc_stack(0, __cant_sleep());
60 ret = os_pipe(fds, 1, 0);
62 printk("run_helper : pipe failed, ret = %d\n", -ret);
66 ret = os_set_exec_close(fds[1], 1);
68 printk("run_helper : setting FD_CLOEXEC failed, ret = %d\n",
73 sp = stack + page_size() - sizeof(void *);
74 data.pre_exec = pre_exec;
75 data.pre_data = pre_data;
78 data.buf = __cant_sleep() ? um_kmalloc_atomic(PATH_MAX) :
80 pid = clone(helper_child, (void *) sp, CLONE_VM | SIGCHLD, &data);
83 printk("run_helper : clone failed, errno = %d\n", errno);
90 /* Read the errno value from the child, if the exec failed, or get 0 if
91 * the exec succeeded because the pipe fd was set as close-on-exec. */
92 n = os_read_file(fds[0], &ret, sizeof(ret));
97 printk("run_helper : read on pipe failed, ret = %d\n",
102 CATCH_EINTR(waitpid(pid, NULL, 0));
112 if ((stack_out == NULL) || (*stack_out == 0))
113 free_stack(stack, 0);
117 int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags,
118 unsigned long *stack_out, int stack_order)
120 unsigned long stack, sp;
121 int pid, status, err;
123 stack = alloc_stack(stack_order, __cant_sleep());
127 sp = stack + (page_size() << stack_order) - sizeof(void *);
128 pid = clone(proc, (void *) sp, flags | SIGCHLD, arg);
131 printk("run_helper_thread : clone failed, errno = %d\n",
135 if (stack_out == NULL) {
136 CATCH_EINTR(pid = waitpid(pid, &status, 0));
139 printk("run_helper_thread - wait failed, errno = %d\n",
143 if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0))
144 printk("run_helper_thread - thread returned status "
146 free_stack(stack, stack_order);
152 int helper_wait(int pid)
156 CATCH_EINTR(ret = waitpid(pid, NULL, WNOHANG));
159 printk("helper_wait : waitpid failed, errno = %d\n", errno);