kmod calls a user mode helper program (modprobe) to do the work.
I find this concept generally useful, I have a device that requires
complex initialization, which is currently done in userspace with
a helper program. I'd like to keep it that way.
Exec'ing a user mode program however is not so straigtforward,
everytime I look into kmod.c the code gets more complex 8-)
Up to now I just copied the code from kmod.c into my driver,
but the code duplication starts to get annoying, furthermore
a couple of routines (free_uid and flush_signal_handlers)
are not even exported.
So I'd like to export the exec-facility of kmod.
The following is a patch to do this.
Comments?
Tom
--- /mnt/hd/s/linux/include/linux/kmod.h Thu Feb 10 06:32:56 2000
+++ include/linux/kmod.h Fri Feb 11 22:44:31 2000
@@ -6,7 +6,12 @@
#ifdef CONFIG_KMOD
extern int request_module(const char * name);
+extern int exec_usermodehelper(char *program_path, char *argv[], char *envp[]);
#else
#define request_module(x) do {} while(0)
+extern inline int exec_usermodehelper(char *program_path, char *argv[], char *envp[])
+{
+ return -EACCES;
+}
#endif
--- /mnt/hd/s/linux/kernel/kmod.c Fri Jan 7 01:17:18 2000
+++ kernel/kmod.c Fri Feb 11 22:41:53 2000
@@ -63,10 +63,8 @@
unlock_kernel();
}
-static int exec_modprobe(void * module_name)
+int exec_usermodehelper(char *program_path, char *argv[], char *envp[])
{
- static char * envp[] = { "HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
- char *argv[] = { modprobe_path, "-s", "-k", (char*)module_name, NULL };
int i;
current->session = 1;
@@ -101,13 +99,24 @@
set_fs(KERNEL_DS);
/* Go, go, go... */
- if (execve(modprobe_path, argv, envp) < 0) {
+ if (execve(program_path, argv, envp) < 0)
+ return -errno;
+ return 0;
+}
+
+static int exec_modprobe(void * module_name)
+{
+ static char * envp[] = { "HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
+ char *argv[] = { modprobe_path, "-s", "-k", (char*)module_name, NULL };
+ int ret;
+
+ ret = exec_usermodehelper(modprobe_path, argv, envp);
+ if (ret) {
printk(KERN_ERR
"kmod: failed to exec %s -s -k %s, errno = %d\n",
modprobe_path, (char*) module_name, errno);
- return -errno;
}
- return 0;
+ return ret;
}
/*
--- /mnt/hd/s/linux/kernel/ksyms.c Sat Feb 12 00:43:52 2000
+++ kernel/ksyms.c Fri Feb 11 22:36:42 2000
@@ -74,6 +74,7 @@
#ifdef CONFIG_KMOD
EXPORT_SYMBOL(request_module);
+EXPORT_SYMBOL(exec_usermodehelper);
#endif
#ifdef CONFIG_MODULES
-
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This archive was generated by hypermail 2b29 : Tue Feb 15 2000 - 21:00:21 EST