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: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/um/drivers/net_user.c b/arch/um/drivers/net_user.c
index 29185cad9fff97328b8b3be7a4cf6dfba6130f47..abf2653f5517cbf6f65b851dd10455e7bc8e27e2 100644 (file)
--- a/arch/um/drivers/net_user.c
+++ b/arch/um/drivers/net_user.c
@@ -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;
 }
 

diff --git a/arch/um/drivers/slip_user.c b/arch/um/drivers/slip_user.c
index b8711e50da801582081409b2c1d43ce398c83b67..8b80505a3fb0117ed35676de600cce0b11b2f721 100644 (file)
--- a/arch/um/drivers/slip_user.c
+++ b/arch/um/drivers/slip_user.c
@@ -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:

diff --git a/arch/um/drivers/slirp_user.c b/arch/um/drivers/slirp_user.c
index 89c1be225fda5f23525f0799673ba37fe11b6483..a0ada8fec72ab5cde45462e3a2ed0311a0561e50 100644 (file)
--- a/arch/um/drivers/slirp_user.c
+++ b/arch/um/drivers/slirp_user.c
@@ -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;
 

diff --git a/arch/um/include/os.h b/arch/um/include/os.h
index c8684b678eebf52a8a65f77f7d9afe0abf41dbe3..bce2881aebd728a3229f875d90263725bac9dd27 100644 (file)
--- a/arch/um/include/os.h
+++ b/arch/um/include/os.h
@@ -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 */

diff --git a/arch/um/os-Linux/drivers/ethertap_user.c b/arch/um/os-Linux/drivers/ethertap_user.c
index 07ca0cb472acf40b1ed8976070e5f4e2ac2cba25..6fb0b174f538df06711bf0f5b779f62ea4eb1f63 100644 (file)
--- a/arch/um/os-Linux/drivers/ethertap_user.c
+++ b/arch/um/os-Linux/drivers/ethertap_user.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;
 }

diff --git a/arch/um/os-Linux/drivers/tuntap_user.c b/arch/um/os-Linux/drivers/tuntap_user.c
index 7739e29cf341b44d09e7df3c0d09de4421bde6cc..2448be03fd7a5018691d3656d963d934b604c810 100644 (file)
--- a/arch/um/os-Linux/drivers/tuntap_user.c
+++ b/arch/um/os-Linux/drivers/tuntap_user.c
@@ -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) {

diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c
index fba3f0fefeef7ca78d3edd685f24e8d5d4c254bc..f4bd349d441222fb7c400ac63d8e7b8c390784a2 100644 (file)
--- a/arch/um/os-Linux/helper.c
+++ b/arch/um/os-Linux/helper.c
@@ -1,22 +1,19 @@
 /*
- * 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;