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Diffstat (limited to 'arch/um/os-Linux/helper.c')
-rw-r--r--arch/um/os-Linux/helper.c133
1 files changed, 62 insertions, 71 deletions
diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c
index c7ad6306e22..e3ee4a51ef6 100644
--- a/arch/um/os-Linux/helper.c
+++ b/arch/um/os-Linux/helper.c
@@ -1,21 +1,18 @@
/*
- * 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 <linux/limits.h>
+#include <sys/socket.h>
#include <sys/wait.h>
-#include "user.h"
-#include "kern_util.h"
-#include "user_util.h"
-#include "os.h"
-#include "um_malloc.h"
+#include <kern_util.h>
+#include <os.h>
+#include <um_malloc.h>
struct helper_data {
void (*pre_exec)(void*);
@@ -25,92 +22,81 @@ struct helper_data {
char *buf;
};
-/* Debugging aid, changed only from gdb */
-int helper_pause = 0;
-
-static void helper_hup(int sig)
-{
-}
-
static int helper_child(void *arg)
{
struct helper_data *data = arg;
char **argv = data->argv;
- int errval;
+ int err, ret;
- if (helper_pause){
- signal(SIGHUP, helper_hup);
- pause();
- }
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);
- os_write_file(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 */
+ 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.
- * 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). */
-int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv,
- unsigned long *stack_out)
+/* 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;
- if ((stack_out != NULL) && (*stack_out != 0))
- stack = *stack_out;
- else
- stack = alloc_stack(0, __cant_sleep());
+ stack = alloc_stack(0, __cant_sleep());
if (stack == 0)
return -ENOMEM;
- ret = os_pipe(fds, 1, 0);
+ ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fds);
if (ret < 0) {
- printk("run_helper : pipe failed, ret = %d\n", -ret);
+ ret = -errno;
+ printk(UM_KERN_ERR "run_helper : pipe failed, errno = %d\n",
+ errno);
goto out_free;
}
- ret = os_set_exec_close(fds[1], 1);
+ 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;
}
- sp = stack + page_size() - sizeof(void *);
+ 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() ? um_kmalloc_atomic(PATH_MAX) :
- um_kmalloc(PATH_MAX);
- pid = clone(helper_child, (void *) sp, CLONE_VM | SIGCHLD, &data);
+ 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("run_helper : clone failed, errno = %d\n", 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 = os_read_file(fds[0], &ret, sizeof(ret));
+ /*
+ * 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) {
- printk("run_helper : read on pipe failed, ret = %d\n",
- -n);
+ n = -errno;
+ printk(UM_KERN_ERR "run_helper : read on pipe failed, "
+ "ret = %d\n", -n);
ret = n;
- kill(pid, SIGKILL);
}
- CATCH_EINTR(waitpid(pid, NULL, 0));
+ CATCH_EINTR(waitpid(pid, NULL, __WCLONE));
}
out_free2:
@@ -120,41 +106,40 @@ out_close:
close(fds[1]);
close(fds[0]);
out_free:
- if ((stack_out == NULL) || (*stack_out == 0))
- free_stack(stack, 0);
+ free_stack(stack, 0);
return ret;
}
int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags,
- unsigned long *stack_out, int stack_order)
+ unsigned long *stack_out)
{
unsigned long stack, sp;
int pid, status, err;
- stack = alloc_stack(stack_order, __cant_sleep());
+ stack = alloc_stack(0, __cant_sleep());
if (stack == 0)
return -ENOMEM;
- sp = stack + (page_size() << stack_order) - sizeof(void *);
- pid = clone(proc, (void *) sp, flags | SIGCHLD, arg);
+ sp = stack + UM_KERN_PAGE_SIZE - sizeof(void *);
+ 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, 0));
+ 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);
- free_stack(stack, stack_order);
+ printk(UM_KERN_ERR "run_helper_thread - thread "
+ "returned status 0x%x\n", status);
+ free_stack(stack, 0);
} else
*stack_out = stack;
return pid;
@@ -162,12 +147,18 @@ int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags,
int helper_wait(int pid)
{
- int ret;
+ int ret, status;
+ int wflags = __WCLONE;
- CATCH_EINTR(ret = waitpid(pid, NULL, WNOHANG));
+ CATCH_EINTR(ret = waitpid(pid, &status, wflags));
if (ret < 0) {
- ret = -errno;
- printk("helper_wait : waitpid failed, errno = %d\n", errno);
- }
- return ret;
+ 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;
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-12-06 11:33:20 +0000