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Diffstat (limited to 'kernel/kmod.c')
-rw-r--r--kernel/kmod.c71
1 files changed, 69 insertions, 2 deletions
diff --git a/kernel/kmod.c b/kernel/kmod.c
index 5c470c57fb57..f8121b95183f 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -35,6 +35,7 @@
#include <linux/mount.h>
#include <linux/kernel.h>
#include <linux/init.h>
+#include <linux/resource.h>
#include <asm/uaccess.h>
extern int max_threads;
@@ -122,6 +123,7 @@ struct subprocess_info {
struct key *ring;
int wait;
int retval;
+ struct file *stdin;
};
/*
@@ -145,12 +147,29 @@ static int ____call_usermodehelper(void *data)
key_put(old_session);
+ /* Install input pipe when needed */
+ if (sub_info->stdin) {
+ struct files_struct *f = current->files;
+ struct fdtable *fdt;
+ /* no races because files should be private here */
+ sys_close(0);
+ fd_install(0, sub_info->stdin);
+ spin_lock(&f->file_lock);
+ fdt = files_fdtable(f);
+ FD_SET(0, fdt->open_fds);
+ FD_CLR(0, fdt->close_on_exec);
+ spin_unlock(&f->file_lock);
+
+ /* and disallow core files too */
+ current->signal->rlim[RLIMIT_CORE] = (struct rlimit){0, 0};
+ }
+
/* We can run anywhere, unlike our parent keventd(). */
set_cpus_allowed(current, CPU_MASK_ALL);
retval = -EPERM;
if (current->fs->root)
- retval = execve(sub_info->path, sub_info->argv,sub_info->envp);
+ retval = execve(sub_info->path, sub_info->argv, sub_info->envp);
/* Exec failed? */
sub_info->retval = retval;
@@ -176,6 +195,8 @@ static int wait_for_helper(void *data)
if (pid < 0) {
sub_info->retval = pid;
} else {
+ int ret;
+
/*
* Normally it is bogus to call wait4() from in-kernel because
* wait4() wants to write the exit code to a userspace address.
@@ -185,7 +206,15 @@ static int wait_for_helper(void *data)
*
* Thus the __user pointer cast is valid here.
*/
- sys_wait4(pid, (int __user *) &sub_info->retval, 0, NULL);
+ sys_wait4(pid, (int __user *)&ret, 0, NULL);
+
+ /*
+ * If ret is 0, either ____call_usermodehelper failed and the
+ * real error code is already in sub_info->retval or
+ * sub_info->retval is 0 anyway, so don't mess with it then.
+ */
+ if (ret)
+ sub_info->retval = ret;
}
complete(sub_info->complete);
@@ -258,6 +287,44 @@ int call_usermodehelper_keys(char *path, char **argv, char **envp,
}
EXPORT_SYMBOL(call_usermodehelper_keys);
+int call_usermodehelper_pipe(char *path, char **argv, char **envp,
+ struct file **filp)
+{
+ DECLARE_COMPLETION(done);
+ struct subprocess_info sub_info = {
+ .complete = &done,
+ .path = path,
+ .argv = argv,
+ .envp = envp,
+ .retval = 0,
+ };
+ struct file *f;
+ DECLARE_WORK(work, __call_usermodehelper, &sub_info);
+
+ if (!khelper_wq)
+ return -EBUSY;
+
+ if (path[0] == '\0')
+ return 0;
+
+ f = create_write_pipe();
+ if (!f)
+ return -ENOMEM;
+ *filp = f;
+
+ f = create_read_pipe(f);
+ if (!f) {
+ free_write_pipe(*filp);
+ return -ENOMEM;
+ }
+ sub_info.stdin = f;
+
+ queue_work(khelper_wq, &work);
+ wait_for_completion(&done);
+ return sub_info.retval;
+}
+EXPORT_SYMBOL(call_usermodehelper_pipe);
+
void __init usermodehelper_init(void)
{
khelper_wq = create_singlethread_workqueue("khelper");