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, 45 insertions, 362 deletions

diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S
index 18670a078849..bfb44247d7a7 100644
--- a/arch/parisc/kernel/entry.S
+++ b/arch/parisc/kernel/entry.S
@@ -708,59 +708,9 @@ ENTRY(end_fault_vector)
 	.import		do_cpu_irq_mask,code
 
 	/*
-	 * r26 = function to be called
-	 * r25 = argument to pass in
-	 * r24 = flags for do_fork()
-	 *
-	 * Kernel threads don't ever return, so they don't need
-	 * a true register context. We just save away the arguments
-	 * for copy_thread/ret_ to properly set up the child.
-	 */
-
-#define CLONE_VM 0x100	/* Must agree with <linux/sched.h> */
-#define CLONE_UNTRACED 0x00800000
-
-	.import do_fork
-ENTRY(__kernel_thread)
-	STREG	%r2, -RP_OFFSET(%r30)
-
-	copy	%r30, %r1
-	ldo	PT_SZ_ALGN(%r30),%r30
-#ifdef CONFIG_64BIT
-	/* Yo, function pointers in wide mode are little structs... -PB */
-	ldd	24(%r26), %r2
-	STREG	%r2, PT_GR27(%r1)	/* Store childs %dp */
-	ldd	16(%r26), %r26
-
-	STREG	%r22, PT_GR22(%r1)	/* save r22 (arg5) */
-	copy	%r0, %r22		/* user_tid */
-#endif
-	STREG	%r26, PT_GR26(%r1)  /* Store function & argument for child */
-	STREG	%r25, PT_GR25(%r1)
-	ldil	L%CLONE_UNTRACED, %r26
-	ldo	CLONE_VM(%r26), %r26   /* Force CLONE_VM since only init_mm */
-	or	%r26, %r24, %r26      /* will have kernel mappings.	 */
-	ldi	1, %r25			/* stack_start, signals kernel thread */
-	stw	%r0, -52(%r30)	     	/* user_tid */
-#ifdef CONFIG_64BIT
-	ldo	-16(%r30),%r29		/* Reference param save area */
-#endif
-	BL	do_fork, %r2
-	copy	%r1, %r24		/* pt_regs */
-
-	/* Parent Returns here */
-
-	LDREG	-PT_SZ_ALGN-RP_OFFSET(%r30), %r2
-	ldo	-PT_SZ_ALGN(%r30), %r30
-	bv	%r0(%r2)
-	nop
-ENDPROC(__kernel_thread)
-
-	/*
 	 * Child Returns here
 	 *
-	 * copy_thread moved args from temp save area set up above
-	 * into task save area.
+	 * copy_thread moved args into task save area.
 	 */
 
 ENTRY(ret_from_kernel_thread)
@@ -769,51 +719,17 @@ ENTRY(ret_from_kernel_thread)
 	BL	schedule_tail, %r2
 	nop
 
-	LDREG	TI_TASK-THREAD_SZ_ALGN(%r30), %r1
+	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30), %r1
 	LDREG	TASK_PT_GR25(%r1), %r26
 #ifdef CONFIG_64BIT
 	LDREG	TASK_PT_GR27(%r1), %r27
-	LDREG	TASK_PT_GR22(%r1), %r22
 #endif
 	LDREG	TASK_PT_GR26(%r1), %r1
 	ble	0(%sr7, %r1)
 	copy	%r31, %r2
-
-#ifdef CONFIG_64BIT
-	ldo	-16(%r30),%r29		/* Reference param save area */
-	loadgp				/* Thread could have been in a module */
-#endif
-#ifndef CONFIG_64BIT
-	b	sys_exit
-#else
-	load32	sys_exit, %r1
-	bv	%r0(%r1)
-#endif
-	ldi	0, %r26
-ENDPROC(ret_from_kernel_thread)
-
-	.import	sys_execve, code
-ENTRY(__execve)
-	copy	%r2, %r15
-	copy	%r30, %r16
-	ldo	PT_SZ_ALGN(%r30), %r30
-	STREG	%r26, PT_GR26(%r16)
-	STREG	%r25, PT_GR25(%r16)
-	STREG	%r24, PT_GR24(%r16)
-#ifdef CONFIG_64BIT
-	ldo	-16(%r30),%r29		/* Reference param save area */
-#endif
-	BL	sys_execve, %r2
-	copy	%r16, %r26
-
-	cmpib,=,n 0,%r28,intr_return    /* forward */
-
-	/* yes, this will trap and die. */
-	copy	%r15, %r2
-	copy	%r16, %r30
-	bv	%r0(%r2)
+	b	finish_child_return
 	nop
-ENDPROC(__execve)
+ENDPROC(ret_from_kernel_thread)
 
 
 	/*
@@ -1772,151 +1688,36 @@ dtlb_fault:
 	LDREG   PT_GR18(\regs),%r18
 	.endm
 
-ENTRY(sys_fork_wrapper)
+	.macro	fork_like name
+ENTRY(sys_\name\()_wrapper)
 	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30), %r1
 	ldo	TASK_REGS(%r1),%r1
 	reg_save %r1
-	mfctl	%cr27, %r3
-	STREG	%r3, PT_CR27(%r1)
-
-	STREG	%r2,-RP_OFFSET(%r30)
-	ldo	FRAME_SIZE(%r30),%r30
-#ifdef CONFIG_64BIT
-	ldo	-16(%r30),%r29		/* Reference param save area */
-#endif
-
-	/* These are call-clobbered registers and therefore
-	   also syscall-clobbered (we hope). */
-	STREG	%r2,PT_GR19(%r1)	/* save for child */
-	STREG	%r30,PT_GR21(%r1)
-
-	LDREG	PT_GR30(%r1),%r25
-	copy	%r1,%r24
-	BL	sys_clone,%r2
-	ldi	SIGCHLD,%r26
-
-	LDREG	-RP_OFFSET-FRAME_SIZE(%r30),%r2
-wrapper_exit:
-	ldo	-FRAME_SIZE(%r30),%r30		/* get the stackframe */
-	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
-	ldo	TASK_REGS(%r1),%r1	 /* get pt regs */
-
-	LDREG	PT_CR27(%r1), %r3
-	mtctl	%r3, %cr27
-	reg_restore %r1
+	mfctl	%cr27, %r28
+	b	sys_\name
+	STREG	%r28, PT_CR27(%r1)
+ENDPROC(sys_\name\()_wrapper)
+	.endm
 
-	/* strace expects syscall # to be preserved in r20 */
-	ldi	__NR_fork,%r20
-	bv %r0(%r2)
-	STREG	%r20,PT_GR20(%r1)
-ENDPROC(sys_fork_wrapper)
+fork_like clone
+fork_like fork
+fork_like vfork
 
 	/* Set the return value for the child */
 ENTRY(child_return)
 	BL	schedule_tail, %r2
 	nop
+finish_child_return:
+	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30), %r1
+	ldo	TASK_REGS(%r1),%r1	 /* get pt regs */
 
-	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE-FRAME_SIZE(%r30), %r1
-	LDREG	TASK_PT_GR19(%r1),%r2
-	b	wrapper_exit
+	LDREG	PT_CR27(%r1), %r3
+	mtctl	%r3, %cr27
+	reg_restore %r1
+	b	syscall_exit
 	copy	%r0,%r28
 ENDPROC(child_return)
 
-
-ENTRY(sys_clone_wrapper)
-	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
-	ldo	TASK_REGS(%r1),%r1	/* get pt regs */
-	reg_save %r1
-	mfctl	%cr27, %r3
-	STREG	%r3, PT_CR27(%r1)
-
-	STREG	%r2,-RP_OFFSET(%r30)
-	ldo	FRAME_SIZE(%r30),%r30
-#ifdef CONFIG_64BIT
-	ldo	-16(%r30),%r29		/* Reference param save area */
-#endif
-
-	/* WARNING - Clobbers r19 and r21, userspace must save these! */
-	STREG	%r2,PT_GR19(%r1)	/* save for child */
-	STREG	%r30,PT_GR21(%r1)
-	BL	sys_clone,%r2
-	copy	%r1,%r24
-
-	b	wrapper_exit
-	LDREG	-RP_OFFSET-FRAME_SIZE(%r30),%r2
-ENDPROC(sys_clone_wrapper)
-
-
-ENTRY(sys_vfork_wrapper)
-	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
-	ldo	TASK_REGS(%r1),%r1	/* get pt regs */
-	reg_save %r1
-	mfctl	%cr27, %r3
-	STREG	%r3, PT_CR27(%r1)
-
-	STREG	%r2,-RP_OFFSET(%r30)
-	ldo	FRAME_SIZE(%r30),%r30
-#ifdef CONFIG_64BIT
-	ldo	-16(%r30),%r29		/* Reference param save area */
-#endif
-
-	STREG	%r2,PT_GR19(%r1)	/* save for child */
-	STREG	%r30,PT_GR21(%r1)
-
-	BL	sys_vfork,%r2
-	copy	%r1,%r26
-
-	b	wrapper_exit
-	LDREG	-RP_OFFSET-FRAME_SIZE(%r30),%r2
-ENDPROC(sys_vfork_wrapper)
-
-	
-	.macro  execve_wrapper execve
-	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
-	ldo	TASK_REGS(%r1),%r1	/* get pt regs */
-
-	/*
-	 * Do we need to save/restore r3-r18 here?
-	 * I don't think so. why would new thread need old
-	 * threads registers?
-	 */
-
-	/* %arg0 - %arg3 are already saved for us. */
-
-	STREG %r2,-RP_OFFSET(%r30)
-	ldo FRAME_SIZE(%r30),%r30
-#ifdef CONFIG_64BIT
-	ldo	-16(%r30),%r29		/* Reference param save area */
-#endif
-	BL \execve,%r2
-	copy %r1,%arg0
-
-	ldo -FRAME_SIZE(%r30),%r30
-	LDREG -RP_OFFSET(%r30),%r2
-
-	/* If exec succeeded we need to load the args */
-
-	ldo -1024(%r0),%r1
-	cmpb,>>= %r28,%r1,error_\execve
-	copy %r2,%r19
-
-error_\execve:
-	bv %r0(%r19)
-	nop
-	.endm
-
-	.import sys_execve
-ENTRY(sys_execve_wrapper)
-	execve_wrapper sys_execve
-ENDPROC(sys_execve_wrapper)
-
-#ifdef CONFIG_64BIT
-	.import sys32_execve
-ENTRY(sys32_execve_wrapper)
-	execve_wrapper sys32_execve
-ENDPROC(sys32_execve_wrapper)
-#endif
-
 ENTRY(sys_rt_sigreturn_wrapper)
 	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r26
 	ldo	TASK_REGS(%r26),%r26	/* get pt regs */
diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c
index cbc37216bf90..d13507246c5d 100644
--- a/arch/parisc/kernel/process.c
+++ b/arch/parisc/kernel/process.c
@@ -52,6 +52,7 @@
 
 #include <asm/io.h>
 #include <asm/asm-offsets.h>
+#include <asm/assembly.h>
 #include <asm/pdc.h>
 #include <asm/pdc_chassis.h>
 #include <asm/pgalloc.h>
@@ -165,23 +166,6 @@ void (*pm_power_off)(void) = machine_power_off;
 EXPORT_SYMBOL(pm_power_off);
 
 /*
- * Create a kernel thread
- */
-
-extern pid_t __kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
-pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
-{
-
-	/*
-	 * FIXME: Once we are sure we don't need any debug here,
-	 *	  kernel_thread can become a #define.
-	 */
-
-	return __kernel_thread(fn, arg, flags);
-}
-EXPORT_SYMBOL(kernel_thread);
-
-/*
  * Free current thread data structures etc..
  */
 void exit_thread(void)
@@ -218,48 +202,11 @@ int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r)
 	return 1;
 }
 
-/* Note that "fork()" is implemented in terms of clone, with
-   parameters (SIGCHLD, regs->gr[30], regs). */
-int
-sys_clone(unsigned long clone_flags, unsigned long usp,
-	  struct pt_regs *regs)
-{
-  	/* Arugments from userspace are:
-	   r26 = Clone flags.
-	   r25 = Child stack.
-	   r24 = parent_tidptr.
-	   r23 = Is the TLS storage descriptor 
-	   r22 = child_tidptr 
-	   
-	   However, these last 3 args are only examined
-	   if the proper flags are set. */
-	int __user *parent_tidptr = (int __user *)regs->gr[24];
-	int __user *child_tidptr  = (int __user *)regs->gr[22];
-
-	/* usp must be word aligned.  This also prevents users from
-	 * passing in the value 1 (which is the signal for a special
-	 * return for a kernel thread) */
-	usp = ALIGN(usp, 4);
-
-	/* A zero value for usp means use the current stack */
-	if (usp == 0)
-	  usp = regs->gr[30];
-
-	return do_fork(clone_flags, usp, regs, 0, parent_tidptr, child_tidptr);
-}
-
-int
-sys_vfork(struct pt_regs *regs)
-{
-	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gr[30], regs, 0, NULL, NULL);
-}
-
 int
 copy_thread(unsigned long clone_flags, unsigned long usp,
-	    unsigned long unused,	/* in ia64 this is "user_stack_size" */
-	    struct task_struct * p, struct pt_regs * pregs)
+	    unsigned long arg, struct task_struct *p)
 {
-	struct pt_regs * cregs = &(p->thread.regs);
+	struct pt_regs *cregs = &(p->thread.regs);
 	void *stack = task_stack_page(p);
 	
 	/* We have to use void * instead of a function pointer, because
@@ -270,48 +217,39 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
 #ifdef CONFIG_HPUX
 	extern void * const hpux_child_return;
 #endif
+	if (unlikely(p->flags & PF_KTHREAD)) {
+		memset(cregs, 0, sizeof(struct pt_regs));
+		if (!usp) /* idle thread */
+			return 0;
 
-	*cregs = *pregs;
-
-	/* Set the return value for the child.  Note that this is not
-           actually restored by the syscall exit path, but we put it
-           here for consistency in case of signals. */
-	cregs->gr[28] = 0; /* child */
-
-	/*
-	 * We need to differentiate between a user fork and a
-	 * kernel fork. We can't use user_mode, because the
-	 * the syscall path doesn't save iaoq. Right now
-	 * We rely on the fact that kernel_thread passes
-	 * in zero for usp.
-	 */
-	if (usp == 1) {
 		/* kernel thread */
-		cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN;
 		/* Must exit via ret_from_kernel_thread in order
 		 * to call schedule_tail()
 		 */
+		cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
 		cregs->kpc = (unsigned long) &ret_from_kernel_thread;
 		/*
 		 * Copy function and argument to be called from
 		 * ret_from_kernel_thread.
 		 */
 #ifdef CONFIG_64BIT
-		cregs->gr[27] = pregs->gr[27];
+		cregs->gr[27] = ((unsigned long *)usp)[3];
+		cregs->gr[26] = ((unsigned long *)usp)[2];
+#else
+		cregs->gr[26] = usp;
 #endif
-		cregs->gr[26] = pregs->gr[26];
-		cregs->gr[25] = pregs->gr[25];
+		cregs->gr[25] = arg;
 	} else {
 		/* user thread */
-		/*
-		 * Note that the fork wrappers are responsible
-		 * for setting gr[21].
-		 */
-
-		/* Use same stack depth as parent */
-		cregs->ksp = (unsigned long)stack
-			+ (pregs->gr[21] & (THREAD_SIZE - 1));
-		cregs->gr[30] = usp;
+		/* usp must be word aligned.  This also prevents users from
+		 * passing in the value 1 (which is the signal for a special
+		 * return for a kernel thread) */
+		if (usp) {
+			usp = ALIGN(usp, 4);
+			if (likely(usp))
+				cregs->gr[30] = usp;
+		}
+		cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
 		if (personality(p->personality) == PER_HPUX) {
 #ifdef CONFIG_HPUX
 			cregs->kpc = (unsigned long) &hpux_child_return;
@@ -323,8 +261,7 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
 		}
 		/* Setup thread TLS area from the 4th parameter in clone */
 		if (clone_flags & CLONE_SETTLS)
-		  cregs->cr27 = pregs->gr[23];
-	
+			cregs->cr27 = cregs->gr[23];
 	}
 
 	return 0;
@@ -335,39 +272,6 @@ unsigned long thread_saved_pc(struct task_struct *t)
 	return t->thread.regs.kpc;
 }
 
-/*
- * sys_execve() executes a new program.
- */
-
-asmlinkage int sys_execve(struct pt_regs *regs)
-{
-	int error;
-	struct filename *filename;
-
-	filename = getname((const char __user *) regs->gr[26]);
-	error = PTR_ERR(filename);
-	if (IS_ERR(filename))
-		goto out;
-	error = do_execve(filename->name,
-			  (const char __user *const __user *) regs->gr[25],
-			  (const char __user *const __user *) regs->gr[24],
-			  regs);
-	putname(filename);
-out:
-
-	return error;
-}
-
-extern int __execve(const char *filename,
-		    const char *const argv[],
-		    const char *const envp[], struct task_struct *task);
-int kernel_execve(const char *filename,
-		  const char *const argv[],
-		  const char *const envp[])
-{
-	return __execve(filename, argv, envp, current);
-}
-
 unsigned long
 get_wchan(struct task_struct *p)
 {
diff --git a/arch/parisc/kernel/sys_parisc32.c b/arch/parisc/kernel/sys_parisc32.c
index bf5b93a885d3..9cfdaa19ab63 100644
--- a/arch/parisc/kernel/sys_parisc32.c
+++ b/arch/parisc/kernel/sys_parisc32.c
@@ -53,28 +53,6 @@
 #define DBG(x)
 #endif
 
-/*
- * sys32_execve() executes a new program.
- */
-
-asmlinkage int sys32_execve(struct pt_regs *regs)
-{
-	int error;
-	struct filename *filename;
-
-	DBG(("sys32_execve(%p) r26 = 0x%lx\n", regs, regs->gr[26]));
-	filename = getname((const char __user *) regs->gr[26]);
-	error = PTR_ERR(filename);
-	if (IS_ERR(filename))
-		goto out;
-	error = compat_do_execve(filename->name, compat_ptr(regs->gr[25]),
-				 compat_ptr(regs->gr[24]), regs);
-	putname(filename);
-out:
-
-	return error;
-}
-
 asmlinkage long sys32_unimplemented(int r26, int r25, int r24, int r23,
 	int r22, int r21, int r20)
 {
diff --git a/arch/parisc/kernel/syscall_table.S b/arch/parisc/kernel/syscall_table.S
index cbf5d59d5d6a..54d950b067b7 100644
--- a/arch/parisc/kernel/syscall_table.S
+++ b/arch/parisc/kernel/syscall_table.S
@@ -66,7 +66,7 @@
 	ENTRY_SAME(creat)
 	ENTRY_SAME(link)
 	ENTRY_SAME(unlink)		/* 10 */
-	ENTRY_DIFF(execve_wrapper)
+	ENTRY_COMP(execve)
 	ENTRY_SAME(chdir)
 	/* See comments in kernel/time.c!!! Maybe we don't need this? */
 	ENTRY_COMP(time)