mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
164 lines
3.7 KiB
164 lines
3.7 KiB
// SPDX-License-Identifier: GPL-2.0 |
|
/* |
|
* Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
|
*/ |
|
|
|
#include <stdlib.h> |
|
#include <unistd.h> |
|
#include <errno.h> |
|
#include <sched.h> |
|
#include <linux/limits.h> |
|
#include <sys/socket.h> |
|
#include <sys/wait.h> |
|
#include <kern_util.h> |
|
#include <os.h> |
|
#include <um_malloc.h> |
|
|
|
struct helper_data { |
|
void (*pre_exec)(void*); |
|
void *pre_data; |
|
char **argv; |
|
int fd; |
|
char *buf; |
|
}; |
|
|
|
static int helper_child(void *arg) |
|
{ |
|
struct helper_data *data = arg; |
|
char **argv = data->argv; |
|
int err, ret; |
|
|
|
if (data->pre_exec != NULL) |
|
(*data->pre_exec)(data->pre_data); |
|
err = execvp_noalloc(data->buf, argv[0], argv); |
|
|
|
/* If the exec succeeds, we don't get here */ |
|
CATCH_EINTR(ret = write(data->fd, &err, sizeof(err))); |
|
|
|
return 0; |
|
} |
|
|
|
/* Returns either the pid of the child process we run or -E* on failure. */ |
|
int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv) |
|
{ |
|
struct helper_data data; |
|
unsigned long stack, sp; |
|
int pid, fds[2], ret, n; |
|
|
|
stack = alloc_stack(0, __cant_sleep()); |
|
if (stack == 0) |
|
return -ENOMEM; |
|
|
|
ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fds); |
|
if (ret < 0) { |
|
ret = -errno; |
|
printk(UM_KERN_ERR "run_helper : pipe failed, errno = %d\n", |
|
errno); |
|
goto out_free; |
|
} |
|
|
|
ret = os_set_exec_close(fds[1]); |
|
if (ret < 0) { |
|
printk(UM_KERN_ERR "run_helper : setting FD_CLOEXEC failed, " |
|
"ret = %d\n", -ret); |
|
goto out_close; |
|
} |
|
|
|
sp = stack + UM_KERN_PAGE_SIZE - sizeof(void *); |
|
data.pre_exec = pre_exec; |
|
data.pre_data = pre_data; |
|
data.argv = argv; |
|
data.fd = fds[1]; |
|
data.buf = __cant_sleep() ? uml_kmalloc(PATH_MAX, UM_GFP_ATOMIC) : |
|
uml_kmalloc(PATH_MAX, UM_GFP_KERNEL); |
|
pid = clone(helper_child, (void *) sp, CLONE_VM, &data); |
|
if (pid < 0) { |
|
ret = -errno; |
|
printk(UM_KERN_ERR "run_helper : clone failed, errno = %d\n", |
|
errno); |
|
goto out_free2; |
|
} |
|
|
|
close(fds[1]); |
|
fds[1] = -1; |
|
|
|
/* |
|
* Read the errno value from the child, if the exec failed, or get 0 if |
|
* the exec succeeded because the pipe fd was set as close-on-exec. |
|
*/ |
|
n = read(fds[0], &ret, sizeof(ret)); |
|
if (n == 0) { |
|
ret = pid; |
|
} else { |
|
if (n < 0) { |
|
n = -errno; |
|
printk(UM_KERN_ERR "run_helper : read on pipe failed, " |
|
"ret = %d\n", -n); |
|
ret = n; |
|
} |
|
CATCH_EINTR(waitpid(pid, NULL, __WALL)); |
|
} |
|
|
|
out_free2: |
|
kfree(data.buf); |
|
out_close: |
|
if (fds[1] != -1) |
|
close(fds[1]); |
|
close(fds[0]); |
|
out_free: |
|
free_stack(stack, 0); |
|
return ret; |
|
} |
|
|
|
int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags, |
|
unsigned long *stack_out) |
|
{ |
|
unsigned long stack, sp; |
|
int pid, status, err; |
|
|
|
stack = alloc_stack(0, __cant_sleep()); |
|
if (stack == 0) |
|
return -ENOMEM; |
|
|
|
sp = stack + UM_KERN_PAGE_SIZE - sizeof(void *); |
|
pid = clone(proc, (void *) sp, flags, arg); |
|
if (pid < 0) { |
|
err = -errno; |
|
printk(UM_KERN_ERR "run_helper_thread : clone failed, " |
|
"errno = %d\n", errno); |
|
return err; |
|
} |
|
if (stack_out == NULL) { |
|
CATCH_EINTR(pid = waitpid(pid, &status, __WALL)); |
|
if (pid < 0) { |
|
err = -errno; |
|
printk(UM_KERN_ERR "run_helper_thread - wait failed, " |
|
"errno = %d\n", errno); |
|
pid = err; |
|
} |
|
if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) |
|
printk(UM_KERN_ERR "run_helper_thread - thread " |
|
"returned status 0x%x\n", status); |
|
free_stack(stack, 0); |
|
} else |
|
*stack_out = stack; |
|
return pid; |
|
} |
|
|
|
int helper_wait(int pid) |
|
{ |
|
int ret, status; |
|
int wflags = __WALL; |
|
|
|
CATCH_EINTR(ret = waitpid(pid, &status, wflags)); |
|
if (ret < 0) { |
|
printk(UM_KERN_ERR "helper_wait : waitpid process %d failed, " |
|
"errno = %d\n", pid, errno); |
|
return -errno; |
|
} else if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { |
|
printk(UM_KERN_ERR "helper_wait : process %d exited with " |
|
"status 0x%x\n", pid, status); |
|
return -ECHILD; |
|
} else |
|
return 0; |
|
}
|
|
|