Commit 1aa351a3 authored by Jeff Dike's avatar Jeff Dike Committed by Linus Torvalds
Browse files

uml: tidy helper code



Style fixes to arch/um/os/helper.c and tidying up the breakpoint fix a
bit.

helper.c gets all the usual style fixes -
	 updated copyright
	 all printks get severities

Also -
	 errval changes to err in helper_child
	 fixed an obsolete comment
	 run_helper was killing a child process which is guaranteed to
be dead or dying anyway

Removed the nohang and pname arguments from helper_wait and fixed the
declaration and callers.  nohang was used only in the slirp driver and
I don't think it was needed.  I think pname was a bit of overkill in
putting out an error message when something goes wrong.
Signed-off-by: default avatarJeff Dike <jdike@linux.intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent fce8c41c
......@@ -201,7 +201,7 @@ static int change_tramp(char **argv, char *output, int output_len)
close(fds[1]);
if (pid > 0)
helper_wait(pid, 0, "change_tramp");
helper_wait(pid);
return pid;
}
......
......@@ -109,7 +109,7 @@ static int slip_tramp(char **argv, int fd)
read_output(fds[0], output, output_len);
printk("%s", output);
err = helper_wait(pid, 0, argv[0]);
err = helper_wait(pid);
close(fds[0]);
out_free:
......
......@@ -98,7 +98,7 @@ static void slirp_close(int fd, void *data)
"(%d)\n", pri->pid, errno);
}
#endif
err = helper_wait(pri->pid, 1, "slirp_close");
err = helper_wait(pri->pid);
if (err < 0)
return;
......
......@@ -207,7 +207,7 @@ extern int execvp_noalloc(char *buf, const char *file, char *const argv[]);
extern int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv);
extern int run_helper_thread(int (*proc)(void *), void *arg,
unsigned int flags, unsigned long *stack_out);
extern int helper_wait(int pid, int nohang, char *pname);
extern int helper_wait(int pid);
/* tls.c */
......
......@@ -131,7 +131,7 @@ static int etap_tramp(char *dev, char *gate, int control_me,
}
if (c != 1) {
printk(UM_KERN_ERR "etap_tramp : uml_net failed\n");
err = helper_wait(pid, 0, "uml_net");
err = helper_wait(pid);
}
return err;
}
......
......@@ -108,7 +108,7 @@ static int tuntap_open_tramp(char *gate, int *fd_out, int me, int remote,
"errno = %d\n", errno);
return err;
}
helper_wait(pid, 0, "tuntap_open_tramp");
helper_wait(pid);
cmsg = CMSG_FIRSTHDR(&msg);
if (cmsg == NULL) {
......
/*
* Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
* Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <sched.h>
#include <limits.h>
#include <sys/signal.h>
#include <sys/wait.h>
#include <sys/socket.h>
#include "user.h"
#include <sys/wait.h>
#include "kern_constants.h"
#include "kern_util.h"
#include "os.h"
#include "um_malloc.h"
#include "kern_constants.h"
#include "user.h"
struct helper_data {
void (*pre_exec)(void*);
......@@ -30,21 +27,19 @@ static int helper_child(void *arg)
{
struct helper_data *data = arg;
char **argv = data->argv;
int errval;
int err;
if (data->pre_exec != NULL)
(*data->pre_exec)(data->pre_data);
errval = execvp_noalloc(data->buf, argv[0], argv);
printk("helper_child - execvp of '%s' failed - errno = %d\n", argv[0],
-errval);
write(data->fd, &errval, sizeof(errval));
kill(os_getpid(), SIGKILL);
err = execvp_noalloc(data->buf, argv[0], argv);
/* If the exec succeeds, we don't get here */
write(data->fd, &err, sizeof(err));
return 0;
}
/* Returns either the pid of the child process we run or -E* on failure.
* XXX The alloc_stack here breaks if this is called in the tracing thread, so
* we need to receive a preallocated stack (a local buffer is ok). */
/* 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;
......@@ -58,14 +53,15 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv)
ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fds);
if (ret < 0) {
ret = -errno;
printk("run_helper : pipe failed, errno = %d\n", 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("run_helper : setting FD_CLOEXEC failed, ret = %d\n",
-ret);
printk(UM_KERN_ERR "run_helper : setting FD_CLOEXEC failed, "
"ret = %d\n", -ret);
goto out_close;
}
......@@ -79,7 +75,8 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv)
pid = clone(helper_child, (void *) sp, CLONE_VM, &data);
if (pid < 0) {
ret = -errno;
printk("run_helper : clone failed, errno = %d\n", errno);
printk(UM_KERN_ERR "run_helper : clone failed, errno = %d\n",
errno);
goto out_free2;
}
......@@ -96,10 +93,9 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv)
} else {
if (n < 0) {
n = -errno;
printk("run_helper : read on pipe failed, ret = %d\n",
-n);
printk(UM_KERN_ERR "run_helper : read on pipe failed, "
"ret = %d\n", -n);
ret = n;
kill(pid, SIGKILL);
}
CATCH_EINTR(waitpid(pid, NULL, __WCLONE));
}
......@@ -129,50 +125,40 @@ int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags,
pid = clone(proc, (void *) sp, flags, arg);
if (pid < 0) {
err = -errno;
printk("run_helper_thread : clone failed, errno = %d\n",
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, __WCLONE));
if (pid < 0) {
err = -errno;
printk("run_helper_thread - wait failed, errno = %d\n",
errno);
printk(UM_KERN_ERR "run_helper_thread - wait failed, "
"errno = %d\n", errno);
pid = err;
}
if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0))
printk("run_helper_thread - thread returned status "
"0x%x\n", status);
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 nohang, char *pname)
int helper_wait(int pid)
{
int ret, status;
int wflags = __WCLONE;
if (nohang)
wflags |= WNOHANG;
if (!pname)
pname = "helper_wait";
CATCH_EINTR(ret = waitpid(pid, &status, wflags));
if (ret < 0) {
printk(UM_KERN_ERR "%s : waitpid process %d failed, "
"errno = %d\n", pname, pid, errno);
printk(UM_KERN_ERR "helper_wait : waitpid process %d failed, "
"errno = %d\n", pid, errno);
return -errno;
} else if (nohang && ret == 0) {
printk(UM_KERN_ERR "%s : process %d has not exited\n",
pname, pid);
return -ECHILD;
} else if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
printk(UM_KERN_ERR "%s : process %d didn't exit with "
"status 0\n", pname, pid);
printk(UM_KERN_ERR "helper_wait : process %d exited with "
"status 0x%x\n", pid, status);
return -ECHILD;
} else
return 0;
......
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