powerpc: switch to generic sys_execve()/kernel_execve()

the only non-obvious part is that current_pt_regs() is really needed
here - task_pt_regs() is NULL for kernel threads; it's OK for ptrace
uses (the thing task_pt_regs() is intended for), but not for us.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 6 insertions, 19 deletions

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 3b06898fa175..6fdf044f475c 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1064,26 +1064,13 @@ int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3,
 			regs, 0, NULL, NULL);
 }
 
-int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2,
-	       unsigned long a3, unsigned long a4, unsigned long a5,
-	       struct pt_regs *regs)
+void __ret_from_kernel_execve(struct pt_regs *normal)
+__noreturn;
+
+void ret_from_kernel_execve(struct pt_regs *normal)
 {
-	int error;
-	char *filename;
-
-	filename = getname((const char __user *) a0);
-	error = PTR_ERR(filename);
-	if (IS_ERR(filename))
-		goto out;
-	flush_fp_to_thread(current);
-	flush_altivec_to_thread(current);
-	flush_spe_to_thread(current);
-	error = do_execve(filename,
-			  (const char __user *const __user *) a1,
-			  (const char __user *const __user *) a2, regs);
-	putname(filename);
-out:
-	return error;
+	set_thread_flag(TIF_RESTOREALL);
+	__ret_from_kernel_execve(normal);
 }
 
 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,