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

7 files changed, 36 insertions, 184 deletions

diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index b6f3ad5441c..ab9ff4075f4 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -45,6 +45,8 @@ config BLACKFIN
 	select ARCH_USES_GETTIMEOFFSET if !GENERIC_CLOCKEVENTS
 	select HAVE_MOD_ARCH_SPECIFIC
 	select MODULES_USE_ELF_RELA
+	select GENERIC_KERNEL_THREAD
+	select GENERIC_KERNEL_EXECVE
 
 config GENERIC_CSUM
 	def_bool y
diff --git a/arch/blackfin/include/asm/processor.h b/arch/blackfin/include/asm/processor.h
index 4ef7cfe43ce..d0e72e9475a 100644
--- a/arch/blackfin/include/asm/processor.h
+++ b/arch/blackfin/include/asm/processor.h
@@ -75,8 +75,6 @@ static inline void release_thread(struct task_struct *dead_task)
 {
 }
 
-extern int kernel_thread(int (*fn) (void *), void *arg, unsigned long flags);
-
 /*
  * Free current thread data structures etc..
  */
diff --git a/arch/blackfin/include/asm/unistd.h b/arch/blackfin/include/asm/unistd.h
index 5b2a0748d7d..460514a1a4e 100644
--- a/arch/blackfin/include/asm/unistd.h
+++ b/arch/blackfin/include/asm/unistd.h
@@ -446,6 +446,8 @@
 #define __ARCH_WANT_SYS_NICE
 #define __ARCH_WANT_SYS_RT_SIGACTION
 #define __ARCH_WANT_SYS_RT_SIGSUSPEND
+#define __ARCH_WANT_SYS_EXECVE
+#define __ARCH_WANT_SYS_VFORK
 
 /*
  * "Conditional" syscalls
diff --git a/arch/blackfin/kernel/entry.S b/arch/blackfin/kernel/entry.S
index f33792cc1a0..4071265fc4f 100644
--- a/arch/blackfin/kernel/entry.S
+++ b/arch/blackfin/kernel/entry.S
@@ -46,53 +46,14 @@ ENTRY(_ret_from_fork)
 	SP += -12;
 	pseudo_long_call _schedule_tail, p5;
 	SP += 12;
-	r0 = [sp + PT_IPEND];
-	cc = bittst(r0,1);
-	if cc jump .Lin_kernel;
+	p1 = [sp++];
+	r0 = [sp++];
+	cc = p1 == 0;
+	if cc jump .Lfork;
+	sp += -12;
+	call (p1);
+	sp += 12;
+.Lfork:
 	RESTORE_CONTEXT
 	rti;
-.Lin_kernel:
-	bitclr(r0,1);
-	[sp + PT_IPEND] = r0;
-	/* do a 'fake' RTI by jumping to [RETI]
-	 * to avoid clearing supervisor mode in child
-	 */
-	r0 = [sp + PT_PC];
-	[sp + PT_P0] = r0;
-
-	RESTORE_ALL_SYS
-	jump (p0);
 ENDPROC(_ret_from_fork)
-
-ENTRY(_sys_vfork)
-	r0 = sp;
-	r0 += 24;
-	[--sp] = rets;
-	SP += -12;
-	pseudo_long_call _bfin_vfork, p2;
-	SP += 12;
-	rets = [sp++];
-	rts;
-ENDPROC(_sys_vfork)
-
-ENTRY(_sys_clone)
-	r0 = sp;
-	r0 += 24;
-	[--sp] = rets;
-	SP += -12;
-	pseudo_long_call _bfin_clone, p2;
-	SP += 12;
-	rets = [sp++];
-	rts;
-ENDPROC(_sys_clone)
-
-ENTRY(_sys_rt_sigreturn)
-	r0 = sp;
-	r0 += 24;
-	[--sp] = rets;
-	SP += -12;
-	pseudo_long_call _do_rt_sigreturn, p2;
-	SP += 12;
-	rets = [sp++];
-	rts;
-ENDPROC(_sys_rt_sigreturn)
diff --git a/arch/blackfin/kernel/process.c b/arch/blackfin/kernel/process.c
index bb1cc721fcf..3e16ad9b0a9 100644
--- a/arch/blackfin/kernel/process.c
+++ b/arch/blackfin/kernel/process.c
@@ -102,40 +102,6 @@ void cpu_idle(void)
 }
 
 /*
- * This gets run with P1 containing the
- * function to call, and R1 containing
- * the "args".  Note P0 is clobbered on the way here.
- */
-void kernel_thread_helper(void);
-__asm__(".section .text\n"
-	".align 4\n"
-	"_kernel_thread_helper:\n\t"
-	"\tsp += -12;\n\t"
-	"\tr0 = r1;\n\t" "\tcall (p1);\n\t" "\tcall _do_exit;\n" ".previous");
-
-/*
- * Create a kernel thread.
- */
-pid_t kernel_thread(int (*fn) (void *), void *arg, unsigned long flags)
-{
-	struct pt_regs regs;
-
-	memset(&regs, 0, sizeof(regs));
-
-	regs.r1 = (unsigned long)arg;
-	regs.p1 = (unsigned long)fn;
-	regs.pc = (unsigned long)kernel_thread_helper;
-	regs.orig_p0 = -1;
-	/* Set bit 2 to tell ret_from_fork we should be returning to kernel
-	   mode.  */
-	regs.ipend = 0x8002;
-	__asm__ __volatile__("%0 = syscfg;":"=da"(regs.syscfg):);
-	return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL,
-		       NULL);
-}
-EXPORT_SYMBOL(kernel_thread);
-
-/*
  * Do necessary setup to start up a newly executed thread.
  *
  * pass the data segment into user programs if it exists,
@@ -161,70 +127,48 @@ void flush_thread(void)
 {
 }
 
-asmlinkage int bfin_vfork(struct pt_regs *regs)
-{
-	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL,
-		       NULL);
-}
-
-asmlinkage int bfin_clone(struct pt_regs *regs)
+asmlinkage int bfin_clone(unsigned long clone_flags, unsigned long newsp)
 {
-	unsigned long clone_flags;
-	unsigned long newsp;
-
 #ifdef __ARCH_SYNC_CORE_DCACHE
 	if (current->nr_cpus_allowed == num_possible_cpus())
 		set_cpus_allowed_ptr(current, cpumask_of(smp_processor_id()));
 #endif
-
-	/* syscall2 puts clone_flags in r0 and usp in r1 */
-	clone_flags = regs->r0;
-	newsp = regs->r1;
-	if (!newsp)
-		newsp = rdusp();
-	else
+	if (newsp)
 		newsp -= 12;
-	return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
+	return do_fork(clone_flags, newsp, 0, NULL, NULL);
 }
 
 int
 copy_thread(unsigned long clone_flags,
 	    unsigned long usp, unsigned long topstk,
-	    struct task_struct *p, struct pt_regs *regs)
+	    struct task_struct *p)
 {
 	struct pt_regs *childregs;
+	unsigned long *v;
 
 	childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
-	*childregs = *regs;
-	childregs->r0 = 0;
+	v = ((unsigned long *)childregs) - 2;
+	if (unlikely(p->flags & PF_KTHREAD)) {
+		memset(childregs, 0, sizeof(struct pt_regs));
+		v[0] = usp;
+		v[1] = topstk;
+		childregs->orig_p0 = -1;
+		childregs->ipend = 0x8000;
+		__asm__ __volatile__("%0 = syscfg;":"=da"(childregs->syscfg):);
+		p->thread.usp = 0;
+	} else {
+		*childregs = *current_pt_regs();
+		childregs->r0 = 0;
+		p->thread.usp = usp ? : rdusp();
+		v[0] = v[1] = 0;
+	}
 
-	p->thread.usp = usp;
-	p->thread.ksp = (unsigned long)childregs;
+	p->thread.ksp = (unsigned long)v;
 	p->thread.pc = (unsigned long)ret_from_fork;
 
 	return 0;
 }
 
-/*
- * sys_execve() executes a new program.
- */
-asmlinkage int sys_execve(const char __user *name,
-			  const char __user *const __user *argv,
-			  const char __user *const __user *envp)
-{
-	int error;
-	struct filename *filename;
-	struct pt_regs *regs = (struct pt_regs *)((&name) + 6);
-
-	filename = getname(name);
-	error = PTR_ERR(filename);
-	if (IS_ERR(filename))
-		return error;
-	error = do_execve(filename->name, argv, envp, regs);
-	putname(filename);
-	return error;
-}
-
 unsigned long get_wchan(struct task_struct *p)
 {
 	unsigned long fp, pc;
diff --git a/arch/blackfin/kernel/signal.c b/arch/blackfin/kernel/signal.c
index 6ed20a1a4af..84b4be05840 100644
--- a/arch/blackfin/kernel/signal.c
+++ b/arch/blackfin/kernel/signal.c
@@ -82,9 +82,9 @@ rt_restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *p
 	return err;
 }
 
-asmlinkage int do_rt_sigreturn(unsigned long __unused)
+asmlinkage int sys_rt_sigreturn(void)
 {
-	struct pt_regs *regs = (struct pt_regs *)__unused;
+	struct pt_regs *regs = current_pt_regs();
 	unsigned long usp = rdusp();
 	struct rt_sigframe *frame = (struct rt_sigframe *)(usp);
 	sigset_t set;
diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index 1c3d2c5bb0b..86b5a095c5a 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -530,61 +530,6 @@ ENTRY(_trap) /* Exception: 4th entry into system event table(supervisor mode)*/
 	jump .Lsyscall_really_exit;
 ENDPROC(_trap)
 
-ENTRY(_kernel_execve)
-	link SIZEOF_PTREGS;
-	p0 = sp;
-	r3 = SIZEOF_PTREGS / 4;
-	r4 = 0(x);
-.Lclear_regs:
-	[p0++] = r4;
-	r3 += -1;
-	cc = r3 == 0;
-	if !cc jump .Lclear_regs (bp);
-
-	p0 = sp;
-	sp += -16;
-	[sp + 12] = p0;
-	pseudo_long_call _do_execve, p5;
-	SP += 16;
-	cc = r0 == 0;
-	if ! cc jump .Lexecve_failed;
-	/* Success.  Copy our temporary pt_regs to the top of the kernel
-	 * stack and do a normal exception return.
-	 */
-	r1 = sp;
-	r0 = (-KERNEL_STACK_SIZE) (x);
-	r1 = r1 & r0;
-	p2 = r1;
-	p3 = [p2];
-	r0 = KERNEL_STACK_SIZE - 4 (z);
-	p1 = r0;
-	p1 = p1 + p2;
-
-	p0 = fp;
-	r4 = [p0--];
-	r3 = SIZEOF_PTREGS / 4;
-.Lcopy_regs:
-	r4 = [p0--];
-	[p1--] = r4;
-	r3 += -1;
-	cc = r3 == 0;
-	if ! cc jump .Lcopy_regs (bp);
-
-	r0 = (KERNEL_STACK_SIZE - SIZEOF_PTREGS) (z);
-	p1 = r0;
-	p1 = p1 + p2;
-	sp = p1;
-	r0 = syscfg;
-	[SP + PT_SYSCFG] = r0;
-	[p3 + (TASK_THREAD + THREAD_KSP)] = sp;
-
-	RESTORE_CONTEXT;
-	rti;
-.Lexecve_failed:
-	unlink;
-	rts;
-ENDPROC(_kernel_execve)
-
 ENTRY(_system_call)
 	/* Store IPEND */
 	p2.l = lo(IPEND);
@@ -1486,7 +1431,7 @@ ENTRY(_sys_call_table)
 	.long _sys_ni_syscall	/* old sys_ipc */
 	.long _sys_fsync
 	.long _sys_ni_syscall	/* old sys_sigreturn */
-	.long _sys_clone		/* 120 */
+	.long _bfin_clone		/* 120 */
 	.long _sys_setdomainname
 	.long _sys_newuname
 	.long _sys_ni_syscall	/* old sys_modify_ldt */