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

Pull big execve/kernel_thread/fork unification series from Al Viro:
 "All architectures are converted to new model.  Quite a bit of that
  stuff is actually shared with architecture trees; in such cases it's
  literally shared branch pulled by both, not a cherry-pick.

  A lot of ugliness and black magic is gone (-3KLoC total in this one):

   - kernel_thread()/kernel_execve()/sys_execve() redesign.

     We don't do syscalls from kernel anymore for either kernel_thread()
     or kernel_execve():

     kernel_thread() is essentially clone(2) with callback run before we
     return to userland, the callbacks either never return or do
     successful do_execve() before returning.

     kernel_execve() is a wrapper for do_execve() - it doesn't need to
     do transition to user mode anymore.

     As a result kernel_thread() and kernel_execve() are
     arch-independent now - they live in kernel/fork.c and fs/exec.c
     resp.  sys_execve() is also in fs/exec.c and it's completely
     architecture-independent.

   - daemonize() is gone, along with its parts in fs/*.c

   - struct pt_regs * is no longer passed to do_fork/copy_process/
     copy_thread/do_execve/search_binary_handler/->load_binary/do_coredump.

   - sys_fork()/sys_vfork()/sys_clone() unified; some architectures
     still need wrappers (ones with callee-saved registers not saved in
     pt_regs on syscall entry), but the main part of those suckers is in
     kernel/fork.c now."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (113 commits)
  do_coredump(): get rid of pt_regs argument
  print_fatal_signal(): get rid of pt_regs argument
  ptrace_signal(): get rid of unused arguments
  get rid of ptrace_signal_deliver() arguments
  new helper: signal_pt_regs()
  unify default ptrace_signal_deliver
  flagday: kill pt_regs argument of do_fork()
  death to idle_regs()
  don't pass regs to copy_process()
  flagday: don't pass regs to copy_thread()
  bfin: switch to generic vfork, get rid of pointless wrappers
  xtensa: switch to generic clone()
  openrisc: switch to use of generic fork and clone
  unicore32: switch to generic clone(2)
  score: switch to generic fork/vfork/clone
  c6x: sanitize copy_thread(), get rid of clone(2) wrapper, switch to generic clone()
  take sys_fork/sys_vfork/sys_clone prototypes to linux/syscalls.h
  mn10300: switch to generic fork/vfork/clone
  h8300: switch to generic fork/vfork/clone
  tile: switch to generic clone()
  ...

Conflicts:
	arch/microblaze/include/asm/Kbuild

4 files changed, 76 insertions, 197 deletions

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index fc7376bf..e37e6a1 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -200,7 +200,6 @@ struct audit_context {
 	struct list_head    names_list;	/* anchor for struct audit_names->list */
 	char *		    filterkey;	/* key for rule that triggered record */
 	struct path	    pwd;
-	struct audit_context *previous; /* For nested syscalls */
 	struct audit_aux_data *aux;
 	struct audit_aux_data *aux_pids;
 	struct sockaddr_storage *sockaddr;
@@ -1091,29 +1090,13 @@ int audit_alloc(struct task_struct *tsk)
 
 static inline void audit_free_context(struct audit_context *context)
 {
-	struct audit_context *previous;
-	int		     count = 0;
-
-	do {
-		previous = context->previous;
-		if (previous || (count &&  count < 10)) {
-			++count;
-			printk(KERN_ERR "audit(:%d): major=%d name_count=%d:"
-			       " freeing multiple contexts (%d)\n",
-			       context->serial, context->major,
-			       context->name_count, count);
-		}
-		audit_free_names(context);
-		unroll_tree_refs(context, NULL, 0);
-		free_tree_refs(context);
-		audit_free_aux(context);
-		kfree(context->filterkey);
-		kfree(context->sockaddr);
-		kfree(context);
-		context  = previous;
-	} while (context);
-	if (count >= 10)
-		printk(KERN_ERR "audit: freed %d contexts\n", count);
+	audit_free_names(context);
+	unroll_tree_refs(context, NULL, 0);
+	free_tree_refs(context);
+	audit_free_aux(context);
+	kfree(context->filterkey);
+	kfree(context->sockaddr);
+	kfree(context);
 }
 
 void audit_log_task_context(struct audit_buffer *ab)
@@ -1783,42 +1766,6 @@ void __audit_syscall_entry(int arch, int major,
 	if (!context)
 		return;
 
-	/*
-	 * This happens only on certain architectures that make system
-	 * calls in kernel_thread via the entry.S interface, instead of
-	 * with direct calls.  (If you are porting to a new
-	 * architecture, hitting this condition can indicate that you
-	 * got the _exit/_leave calls backward in entry.S.)
-	 *
-	 * i386     no
-	 * x86_64   no
-	 * ppc64    yes (see arch/powerpc/platforms/iseries/misc.S)
-	 *
-	 * This also happens with vm86 emulation in a non-nested manner
-	 * (entries without exits), so this case must be caught.
-	 */
-	if (context->in_syscall) {
-		struct audit_context *newctx;
-
-#if AUDIT_DEBUG
-		printk(KERN_ERR
-		       "audit(:%d) pid=%d in syscall=%d;"
-		       " entering syscall=%d\n",
-		       context->serial, tsk->pid, context->major, major);
-#endif
-		newctx = audit_alloc_context(context->state);
-		if (newctx) {
-			newctx->previous   = context;
-			context		   = newctx;
-			tsk->audit_context = newctx;
-		} else	{
-			/* If we can't alloc a new context, the best we
-			 * can do is to leak memory (any pending putname
-			 * will be lost).  The only other alternative is
-			 * to abandon auditing. */
-			audit_zero_context(context, context->state);
-		}
-	}
 	BUG_ON(context->in_syscall || context->name_count);
 
 	if (!audit_enabled)
@@ -1881,28 +1828,21 @@ void __audit_syscall_exit(int success, long return_code)
 	if (!list_empty(&context->killed_trees))
 		audit_kill_trees(&context->killed_trees);
 
-	if (context->previous) {
-		struct audit_context *new_context = context->previous;
-		context->previous  = NULL;
-		audit_free_context(context);
-		tsk->audit_context = new_context;
-	} else {
-		audit_free_names(context);
-		unroll_tree_refs(context, NULL, 0);
-		audit_free_aux(context);
-		context->aux = NULL;
-		context->aux_pids = NULL;
-		context->target_pid = 0;
-		context->target_sid = 0;
-		context->sockaddr_len = 0;
-		context->type = 0;
-		context->fds[0] = -1;
-		if (context->state != AUDIT_RECORD_CONTEXT) {
-			kfree(context->filterkey);
-			context->filterkey = NULL;
-		}
-		tsk->audit_context = context;
+	audit_free_names(context);
+	unroll_tree_refs(context, NULL, 0);
+	audit_free_aux(context);
+	context->aux = NULL;
+	context->aux_pids = NULL;
+	context->target_pid = 0;
+	context->target_sid = 0;
+	context->sockaddr_len = 0;
+	context->type = 0;
+	context->fds[0] = -1;
+	if (context->state != AUDIT_RECORD_CONTEXT) {
+		kfree(context->filterkey);
+		context->filterkey = NULL;
 	}
+	tsk->audit_context = context;
 }
 
 static inline void handle_one(const struct inode *inode)
diff --git a/kernel/exit.c b/kernel/exit.c
index 618f7ee..50d2e93 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -322,43 +322,6 @@ kill_orphaned_pgrp(struct task_struct *tsk, struct task_struct *parent)
 	}
 }
 
-/**
- * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd
- *
- * If a kernel thread is launched as a result of a system call, or if
- * it ever exits, it should generally reparent itself to kthreadd so it
- * isn't in the way of other processes and is correctly cleaned up on exit.
- *
- * The various task state such as scheduling policy and priority may have
- * been inherited from a user process, so we reset them to sane values here.
- *
- * NOTE that reparent_to_kthreadd() gives the caller full capabilities.
- */
-static void reparent_to_kthreadd(void)
-{
-	write_lock_irq(&tasklist_lock);
-
-	ptrace_unlink(current);
-	/* Reparent to init */
-	current->real_parent = current->parent = kthreadd_task;
-	list_move_tail(&current->sibling, &current->real_parent->children);
-
-	/* Set the exit signal to SIGCHLD so we signal init on exit */
-	current->exit_signal = SIGCHLD;
-
-	if (task_nice(current) < 0)
-		set_user_nice(current, 0);
-	/* cpus_allowed? */
-	/* rt_priority? */
-	/* signals? */
-	memcpy(current->signal->rlim, init_task.signal->rlim,
-	       sizeof(current->signal->rlim));
-
-	atomic_inc(&init_cred.usage);
-	commit_creds(&init_cred);
-	write_unlock_irq(&tasklist_lock);
-}
-
 void __set_special_pids(struct pid *pid)
 {
 	struct task_struct *curr = current->group_leader;
@@ -370,13 +333,6 @@ void __set_special_pids(struct pid *pid)
 		change_pid(curr, PIDTYPE_PGID, pid);
 }
 
-static void set_special_pids(struct pid *pid)
-{
-	write_lock_irq(&tasklist_lock);
-	__set_special_pids(pid);
-	write_unlock_irq(&tasklist_lock);
-}
-
 /*
  * Let kernel threads use this to say that they allow a certain signal.
  * Must not be used if kthread was cloned with CLONE_SIGHAND.
@@ -416,54 +372,6 @@ int disallow_signal(int sig)
 
 EXPORT_SYMBOL(disallow_signal);
 
-/*
- *	Put all the gunge required to become a kernel thread without
- *	attached user resources in one place where it belongs.
- */
-
-void daemonize(const char *name, ...)
-{
-	va_list args;
-	sigset_t blocked;
-
-	va_start(args, name);
-	vsnprintf(current->comm, sizeof(current->comm), name, args);
-	va_end(args);
-
-	/*
-	 * If we were started as result of loading a module, close all of the
-	 * user space pages.  We don't need them, and if we didn't close them
-	 * they would be locked into memory.
-	 */
-	exit_mm(current);
-	/*
-	 * We don't want to get frozen, in case system-wide hibernation
-	 * or suspend transition begins right now.
-	 */
-	current->flags |= (PF_NOFREEZE | PF_KTHREAD);
-
-	if (current->nsproxy != &init_nsproxy) {
-		get_nsproxy(&init_nsproxy);
-		switch_task_namespaces(current, &init_nsproxy);
-	}
-	set_special_pids(&init_struct_pid);
-	proc_clear_tty(current);
-
-	/* Block and flush all signals */
-	sigfillset(&blocked);
-	sigprocmask(SIG_BLOCK, &blocked, NULL);
-	flush_signals(current);
-
-	/* Become as one with the init task */
-
-	daemonize_fs_struct();
-	daemonize_descriptors();
-
-	reparent_to_kthreadd();
-}
-
-EXPORT_SYMBOL(daemonize);
-
 #ifdef CONFIG_MM_OWNER
 /*
  * A task is exiting.   If it owned this mm, find a new owner for the mm.
diff --git a/kernel/fork.c b/kernel/fork.c
index 79de9f9..3c31e87 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1129,7 +1129,6 @@ static void posix_cpu_timers_init(struct task_struct *tsk)
  */
 static struct task_struct *copy_process(unsigned long clone_flags,
 					unsigned long stack_start,
-					struct pt_regs *regs,
 					unsigned long stack_size,
 					int __user *child_tidptr,
 					struct pid *pid,
@@ -1321,7 +1320,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	retval = copy_io(clone_flags, p);
 	if (retval)
 		goto bad_fork_cleanup_namespaces;
-	retval = copy_thread(clone_flags, stack_start, stack_size, p, regs);
+	retval = copy_thread(clone_flags, stack_start, stack_size, p);
 	if (retval)
 		goto bad_fork_cleanup_io;
 
@@ -1510,12 +1509,6 @@ fork_out:
 	return ERR_PTR(retval);
 }
 
-noinline struct pt_regs * __cpuinit __attribute__((weak)) idle_regs(struct pt_regs *regs)
-{
-	memset(regs, 0, sizeof(struct pt_regs));
-	return regs;
-}
-
 static inline void init_idle_pids(struct pid_link *links)
 {
 	enum pid_type type;
@@ -1529,10 +1522,7 @@ static inline void init_idle_pids(struct pid_link *links)
 struct task_struct * __cpuinit fork_idle(int cpu)
 {
 	struct task_struct *task;
-	struct pt_regs regs;
-
-	task = copy_process(CLONE_VM, 0, idle_regs(&regs), 0, NULL,
-			    &init_struct_pid, 0);
+	task = copy_process(CLONE_VM, 0, 0, NULL, &init_struct_pid, 0);
 	if (!IS_ERR(task)) {
 		init_idle_pids(task->pids);
 		init_idle(task, cpu);
@@ -1549,7 +1539,6 @@ struct task_struct * __cpuinit fork_idle(int cpu)
  */
 long do_fork(unsigned long clone_flags,
 	      unsigned long stack_start,
-	      struct pt_regs *regs,
 	      unsigned long stack_size,
 	      int __user *parent_tidptr,
 	      int __user *child_tidptr)
@@ -1579,7 +1568,7 @@ long do_fork(unsigned long clone_flags,
 	 * requested, no event is reported; otherwise, report if the event
 	 * for the type of forking is enabled.
 	 */
-	if (!(clone_flags & CLONE_UNTRACED) && likely(user_mode(regs))) {
+	if (!(clone_flags & CLONE_UNTRACED)) {
 		if (clone_flags & CLONE_VFORK)
 			trace = PTRACE_EVENT_VFORK;
 		else if ((clone_flags & CSIGNAL) != SIGCHLD)
@@ -1591,7 +1580,7 @@ long do_fork(unsigned long clone_flags,
 			trace = 0;
 	}
 
-	p = copy_process(clone_flags, stack_start, regs, stack_size,
+	p = copy_process(clone_flags, stack_start, stack_size,
 			 child_tidptr, NULL, trace);
 	/*
 	 * Do this prior waking up the new thread - the thread pointer
@@ -1635,11 +1624,54 @@ long do_fork(unsigned long clone_flags,
  */
 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
 {
-	return do_fork(flags|CLONE_VM|CLONE_UNTRACED, (unsigned long)fn, NULL,
+	return do_fork(flags|CLONE_VM|CLONE_UNTRACED, (unsigned long)fn,
 		(unsigned long)arg, NULL, NULL);
 }
 #endif
 
+#ifdef __ARCH_WANT_SYS_FORK
+SYSCALL_DEFINE0(fork)
+{
+#ifdef CONFIG_MMU
+	return do_fork(SIGCHLD, 0, 0, NULL, NULL);
+#else
+	/* can not support in nommu mode */
+	return(-EINVAL);
+#endif
+}
+#endif
+
+#ifdef __ARCH_WANT_SYS_VFORK
+SYSCALL_DEFINE0(vfork)
+{
+	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, 0, 
+			0, NULL, NULL);
+}
+#endif
+
+#ifdef __ARCH_WANT_SYS_CLONE
+#ifdef CONFIG_CLONE_BACKWARDS
+SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp,
+		 int __user *, parent_tidptr,
+		 int, tls_val,
+		 int __user *, child_tidptr)
+#elif defined(CONFIG_CLONE_BACKWARDS2)
+SYSCALL_DEFINE5(clone, unsigned long, newsp, unsigned long, clone_flags,
+		 int __user *, parent_tidptr,
+		 int __user *, child_tidptr,
+		 int, tls_val)
+#else
+SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp,
+		 int __user *, parent_tidptr,
+		 int __user *, child_tidptr,
+		 int, tls_val)
+#endif
+{
+	return do_fork(clone_flags, newsp, 0,
+		parent_tidptr, child_tidptr);
+}
+#endif
+
 #ifndef ARCH_MIN_MMSTRUCT_ALIGN
 #define ARCH_MIN_MMSTRUCT_ALIGN 0
 #endif
diff --git a/kernel/signal.c b/kernel/signal.c
index 5ffb5626..a49c7f3 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1159,8 +1159,9 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
 	return __send_signal(sig, info, t, group, from_ancestor_ns);
 }
 
-static void print_fatal_signal(struct pt_regs *regs, int signr)
+static void print_fatal_signal(int signr)
 {
+	struct pt_regs *regs = signal_pt_regs();
 	printk("%s/%d: potentially unexpected fatal signal %d.\n",
 		current->comm, task_pid_nr(current), signr);
 
@@ -2131,10 +2132,9 @@ static void do_jobctl_trap(void)
 	}
 }
 
-static int ptrace_signal(int signr, siginfo_t *info,
-			 struct pt_regs *regs, void *cookie)
+static int ptrace_signal(int signr, siginfo_t *info)
 {
-	ptrace_signal_deliver(regs, cookie);
+	ptrace_signal_deliver();
 	/*
 	 * We do not check sig_kernel_stop(signr) but set this marker
 	 * unconditionally because we do not know whether debugger will
@@ -2257,8 +2257,7 @@ relock:
 			break; /* will return 0 */
 
 		if (unlikely(current->ptrace) && signr != SIGKILL) {
-			signr = ptrace_signal(signr, info,
-					      regs, cookie);
+			signr = ptrace_signal(signr, info);
 			if (!signr)
 				continue;
 		}
@@ -2343,7 +2342,7 @@ relock:
 
 		if (sig_kernel_coredump(signr)) {
 			if (print_fatal_signals)
-				print_fatal_signal(regs, info->si_signo);
+				print_fatal_signal(info->si_signo);
 			/*
 			 * If it was able to dump core, this kills all
 			 * other threads in the group and synchronizes with
@@ -2352,7 +2351,7 @@ relock:
 			 * first and our do_group_exit call below will use
 			 * that value and ignore the one we pass it.
 			 */
-			do_coredump(info, regs);
+			do_coredump(info);
 		}
 
 		/*