sysctl: Introduce a generic compat sysctl sysctl

[mv-sheeva.git] / kernel / sysctl_binary.c

diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c
index 930a31cd708b220890a341d2edd21fdb434d6581..775cc49da62276d91dde0d85a106a78c5d69b984 100644 (file)
--- a/kernel/sysctl_binary.c
+++ b/kernel/sysctl_binary.c
@@ -176,3 +176,53 @@ SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
 
        return error;
 }
+
+#ifdef CONFIG_COMPAT
+#include <asm/compat.h>
+
+struct compat_sysctl_args {
+       compat_uptr_t   name;
+       int             nlen;
+       compat_uptr_t   oldval;
+       compat_uptr_t   oldlenp;
+       compat_uptr_t   newval;
+       compat_size_t   newlen;
+       compat_ulong_t  __unused[4];
+};
+
+asmlinkage long compat_sys_sysctl(struct compat_sysctl_args __user *args)
+{
+       struct compat_sysctl_args tmp;
+       compat_size_t __user *compat_oldlenp;
+       size_t __user *oldlenp = NULL;
+       size_t oldlen = 0;
+       ssize_t result;
+
+       if (copy_from_user(&tmp, args, sizeof(tmp)))
+               return -EFAULT;
+
+       compat_oldlenp = compat_ptr(tmp.oldlenp);
+       if (compat_oldlenp) {
+               oldlenp = compat_alloc_user_space(sizeof(*compat_oldlenp));
+
+               if (get_user(oldlen, compat_oldlenp) ||
+                   put_user(oldlen, oldlenp))
+                       return -EFAULT;
+       }
+
+       lock_kernel();
+       result = do_sysctl(compat_ptr(tmp.name), tmp.nlen,
+                          compat_ptr(tmp.oldval), oldlenp,
+                          compat_ptr(tmp.newval), tmp.newlen);
+       unlock_kernel();
+
+       if (oldlenp && !result) {
+               if (get_user(oldlen, oldlenp) ||
+                   put_user(oldlen, compat_oldlenp))
+                       return -EFAULT;
+       }
+
+       return result;
+}
+
+#endif /* CONFIG_COMPAT */