2 * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
3 * Licensed under the GPL
12 #include <sys/signal.h>
15 #include "kern_util.h"
17 #include "um_malloc.h"
18 #include "kern_constants.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],
39 write(data
->fd
, &errval
, sizeof(errval
));
40 kill(os_getpid(), SIGKILL
);
44 /* Returns either the pid of the child process we run or -E* on failure.
45 * XXX The alloc_stack here breaks if this is called in the tracing thread, so
46 * we need to receive a preallocated stack (a local buffer is ok). */
47 int run_helper(void (*pre_exec
)(void *), void *pre_data
, char **argv
)
49 struct helper_data data
;
50 unsigned long stack
, sp
;
51 int pid
, fds
[2], ret
, n
;
53 stack
= alloc_stack(0, __cant_sleep());
57 ret
= os_pipe(fds
, 1, 0);
59 printk("run_helper : pipe failed, ret = %d\n", -ret
);
63 ret
= os_set_exec_close(fds
[1], 1);
65 printk("run_helper : setting FD_CLOEXEC failed, ret = %d\n",
70 sp
= stack
+ UM_KERN_PAGE_SIZE
- sizeof(void *);
71 data
.pre_exec
= pre_exec
;
72 data
.pre_data
= pre_data
;
75 data
.buf
= __cant_sleep() ? um_kmalloc_atomic(PATH_MAX
) :
77 pid
= clone(helper_child
, (void *) sp
, CLONE_VM
| SIGCHLD
, &data
);
80 printk("run_helper : clone failed, errno = %d\n", errno
);
88 * Read the errno value from the child, if the exec failed, or get 0 if
89 * the exec succeeded because the pipe fd was set as close-on-exec.
91 n
= read(fds
[0], &ret
, sizeof(ret
));
97 printk("run_helper : read on pipe failed, ret = %d\n",
102 CATCH_EINTR(waitpid(pid
, NULL
, 0));
112 free_stack(stack
, 0);
116 int run_helper_thread(int (*proc
)(void *), void *arg
, unsigned int flags
,
117 unsigned long *stack_out
)
119 unsigned long stack
, sp
;
120 int pid
, status
, err
;
122 stack
= alloc_stack(0, __cant_sleep());
126 sp
= stack
+ UM_KERN_PAGE_SIZE
- sizeof(void *);
127 pid
= clone(proc
, (void *) sp
, flags
| SIGCHLD
, arg
);
130 printk("run_helper_thread : clone failed, errno = %d\n",
134 if (stack_out
== NULL
) {
135 CATCH_EINTR(pid
= waitpid(pid
, &status
, 0));
138 printk("run_helper_thread - wait failed, errno = %d\n",
142 if (!WIFEXITED(status
) || (WEXITSTATUS(status
) != 0))
143 printk("run_helper_thread - thread returned status "
145 free_stack(stack
, 0);
151 int helper_wait(int pid
)
155 CATCH_EINTR(ret
= waitpid(pid
, NULL
, WNOHANG
));
158 printk("helper_wait : waitpid failed, errno = %d\n", errno
);
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