Merge branch 'x86/asm' into x86/urgent

Merge reason: it's stable so lets push it upstream.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 70 insertions, 0 deletions

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 7a7bd4e3ec49..98c2cdeb599e 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -255,6 +255,76 @@ int sys_vfork(struct pt_regs *regs)
                        NULL, NULL);
 }
 
+long
+sys_clone(unsigned long clone_flags, unsigned long newsp,
+          void __user *parent_tid, void __user *child_tid, struct pt_regs *regs)
+{
+        if (!newsp)
+                newsp = regs->sp;
+        return do_fork(clone_flags, newsp, regs, 0, parent_tid, child_tid);
+}
+
+/*
+ * This gets run with %si containing the
+ * function to call, and %di containing
+ * the "args".
+ */
+extern void kernel_thread_helper(void);
+
+/*
+ * Create a kernel thread
+ */
+int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
+{
+        struct pt_regs regs;
+
+        memset(&regs, 0, sizeof(regs));
+
+        regs.si = (unsigned long) fn;
+        regs.di = (unsigned long) arg;
+
+#ifdef CONFIG_X86_32
+        regs.ds = __USER_DS;
+        regs.es = __USER_DS;
+        regs.fs = __KERNEL_PERCPU;
+        regs.gs = __KERNEL_STACK_CANARY;
+#endif
+
+        regs.orig_ax = -1;
+        regs.ip = (unsigned long) kernel_thread_helper;
+        regs.cs = __KERNEL_CS | get_kernel_rpl();
+        regs.flags = X86_EFLAGS_IF | 0x2;
+
+        /* Ok, create the new process.. */
+        return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
+}
+EXPORT_SYMBOL(kernel_thread);
+
+/*
+ * sys_execve() executes a new program.
+ */
+long sys_execve(char __user *name, char __user * __user *argv,
+                char __user * __user *envp, struct pt_regs *regs)
+{
+        long error;
+        char *filename;
+
+        filename = getname(name);
+        error = PTR_ERR(filename);
+        if (IS_ERR(filename))
+                return error;
+        error = do_execve(filename, argv, envp, regs);
+
+#ifdef CONFIG_X86_32
+        if (error == 0) {
+                /* Make sure we don't return using sysenter.. */
+                set_thread_flag(TIF_IRET);
+        }
+#endif
+
+        putname(filename);
+        return error;
+}
 
 /*
  * Idle related variables and functions