Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal

Pull generic execve() changes from Al Viro:
 "This introduces the generic kernel_thread() and kernel_execve()
  functions, and switches x86, arm, alpha, um and s390 over to them."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (26 commits)
  s390: convert to generic kernel_execve()
  s390: switch to generic kernel_thread()
  s390: fold kernel_thread_helper() into ret_from_fork()
  s390: fold execve_tail() into start_thread(), convert to generic sys_execve()
  um: switch to generic kernel_thread()
  x86, um/x86: switch to generic sys_execve and kernel_execve
  x86: split ret_from_fork
  alpha: introduce ret_from_kernel_execve(), switch to generic kernel_execve()
  alpha: switch to generic kernel_thread()
  alpha: switch to generic sys_execve()
  arm: get rid of execve wrapper, switch to generic execve() implementation
  arm: optimized current_pt_regs()
  arm: introduce ret_from_kernel_execve(), switch to generic kernel_execve()
  arm: split ret_from_fork, simplify kernel_thread() [based on patch by rmk]
  generic sys_execve()
  generic kernel_execve()
  new helper: current_pt_regs()
  preparation for generic kernel_thread()
  um: kill thread->forking
  um: let signal_delivered() do SIGTRAP on singlestepping into handler
  ...

4 files changed, 5 insertions, 55 deletions

diff --git a/arch/um/kernel/exec.c b/arch/um/kernel/exec.c
index de66c421ae9d..ab019c7f0b57 100644
--- a/arch/um/kernel/exec.c
+++ b/arch/um/kernel/exec.c
@@ -16,7 +16,6 @@
 #include <mem_user.h>
 #include <skas.h>
 #include <os.h>
-#include "internal.h"
 
 void flush_thread(void)
 {
@@ -49,27 +48,7 @@ void start_thread(struct pt_regs *regs, unsigned long eip, unsigned long esp)
 }
 EXPORT_SYMBOL(start_thread);
 
-long um_execve(const char *file, const char __user *const __user *argv, const char __user *const __user *env)
+void __noreturn ret_from_kernel_execve(struct pt_regs *unused)
 {
-	long err;
-
-	err = do_execve(file, argv, env, &current->thread.regs);
-	if (!err)
-		UML_LONGJMP(current->thread.exec_buf, 1);
-	return err;
-}
-
-long sys_execve(const char __user *file, const char __user *const __user *argv,
-		const char __user *const __user *env)
-{
-	long error;
-	char *filename;
-
-	filename = getname(file);
-	error = PTR_ERR(filename);
-	if (IS_ERR(filename)) goto out;
-	error = do_execve(filename, argv, env, &current->thread.regs);
-	putname(filename);
- out:
-	return error;
+	UML_LONGJMP(current->thread.exec_buf, 1);
 }
diff --git a/arch/um/kernel/internal.h b/arch/um/kernel/internal.h
deleted file mode 100644
index 5bf97db24a04..000000000000
--- a/arch/um/kernel/internal.h
+++ /dev/null
@@ -1 +0,0 @@
-extern long um_execve(const char *file, const char __user *const __user *argv, const char __user *const __user *env);
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index 41f53240e794..30629783b3e0 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -69,18 +69,6 @@ unsigned long alloc_stack(int order, int atomic)
 	return page;
 }
 
-int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
-{
-	int pid;
-
-	current->thread.request.u.thread.proc = fn;
-	current->thread.request.u.thread.arg = arg;
-	pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0,
-		      &current->thread.regs, 0, NULL, NULL);
-	return pid;
-}
-EXPORT_SYMBOL(kernel_thread);
-
 static inline void set_current(struct task_struct *task)
 {
 	cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
@@ -177,7 +165,7 @@ void fork_handler(void)
 }
 
 int copy_thread(unsigned long clone_flags, unsigned long sp,
-		unsigned long stack_top, struct task_struct * p,
+		unsigned long arg, struct task_struct * p,
 		struct pt_regs *regs)
 {
 	void (*handler)(void);
@@ -198,7 +186,8 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
 		arch_copy_thread(&current->thread.arch, &p->thread.arch);
 	} else {
 		get_safe_registers(p->thread.regs.regs.gp, p->thread.regs.regs.fp);
-		p->thread.request.u.thread = current->thread.request.u.thread;
+		p->thread.request.u.thread.proc = (int (*)(void *))sp;
+		p->thread.request.u.thread.arg = (void *)arg;
 		handler = new_thread_handler;
 	}
 
diff --git a/arch/um/kernel/syscall.c b/arch/um/kernel/syscall.c
index 10808bda3671..a81f3705e90f 100644
--- a/arch/um/kernel/syscall.c
+++ b/arch/um/kernel/syscall.c
@@ -13,7 +13,6 @@
 #include <asm/mman.h>
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
-#include "internal.h"
 
 long sys_fork(void)
 {
@@ -50,19 +49,3 @@ long old_mmap(unsigned long addr, unsigned long len,
  out:
 	return err;
 }
-
-int kernel_execve(const char *filename,
-		  const char *const argv[],
-		  const char *const envp[])
-{
-	mm_segment_t fs;
-	int ret;
-
-	fs = get_fs();
-	set_fs(KERNEL_DS);
-	ret = um_execve(filename, (const char __user *const __user *)argv,
-			(const char __user *const __user *) envp);
-	set_fs(fs);
-
-	return ret;
-}