[PATCH] uml: Remove mm_indirect reference in modify_ldt

Spotted by Al Viro, there was some bogosity in the UML/x86_64 modify_ltd.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/um/sys-x86_64/syscalls.c

@@ -36,15 +36,11 @@ long sys_modify_ldt_tt(int func, void *ptr, unsigned long bytecount)
 #endif
 
 #ifdef CONFIG_MODE_SKAS
-extern int userspace_pid;
-
-#ifndef __NR_mm_indirect
-#define __NR_mm_indirect 241
-#endif
+extern int userspace_pid[];
 
 long sys_modify_ldt_skas(int func, void *ptr, unsigned long bytecount)
 {
-	unsigned long args[6];
+	struct ptrace_ldt ldt;
         void *buf;
         int res, n;
 
@@ -66,12 +62,11 @@ long sys_modify_ldt_skas(int func, void *ptr, unsigned long bytecount)
                 goto out;
         }
 
-	args[0] = func;
-	args[1] = (unsigned long) buf;
-	args[2] = bytecount;
-	res = syscall(__NR_mm_indirect, &current->mm->context.u,
-		      __NR_modify_ldt, args);
-
+	ldt = ((struct ptrace_ldt) { .func	= func,
+				     .ptr	= buf,
+				     .bytecount = bytecount });
+#warning Need to look up userspace_pid by cpu
+	res = ptrace(PTRACE_LDT, userspace_pid[0], 0, (unsigned long) &ldt);
         if(res < 0)
                 goto out;