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

Pull pile 2 of execve and kernel_thread unification work from Al Viro:
 "Stuff in there: kernel_thread/kernel_execve/sys_execve conversions for
  several more architectures plus assorted signal fixes and cleanups.

  There'll be more (in particular, real fixes for the alpha
  do_notify_resume() irq mess)..."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (43 commits)
  alpha: don't open-code trace_report_syscall_{enter,exit}
  Uninclude linux/freezer.h
  m32r: trim masks
  avr32: trim masks
  tile: don't bother with SIGTRAP in setup_frame
  microblaze: don't bother with SIGTRAP in setup_rt_frame()
  mn10300: don't bother with SIGTRAP in setup_frame()
  frv: no need to raise SIGTRAP in setup_frame()
  x86: get rid of duplicate code in case of CONFIG_VM86
  unicore32: remove pointless test
  h8300: trim _TIF_WORK_MASK
  parisc: decide whether to go to slow path (tracesys) based on thread flags
  parisc: don't bother looping in do_signal()
  parisc: fix double restarts
  bury the rest of TIF_IRET
  sanitize tsk_is_polling()
  bury _TIF_RESTORE_SIGMASK
  unicore32: unobfuscate _TIF_WORK_MASK
  mips: NOTIFY_RESUME is not needed in TIF masks
  mips: merge the identical "return from syscall" per-ABI code
  ...

Conflicts:
	arch/arm/include/asm/thread_info.h

arch/alpha/include/asm/thread_info.h

@@ -84,7 +84,6 @@ register struct thread_info *__current_thread_info __asm__("$8");
 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
 #define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
-#define _TIF_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)
 #define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
 
 /* Work to do on interrupt/exception return.  */
@@ -117,5 +116,7 @@ register struct thread_info *__current_thread_info __asm__("$8");
 		 (int __user *)(value));				\
 	})
 
+#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
+
 #endif /* __KERNEL__ */
 #endif /* _ALPHA_THREAD_INFO_H */

arch/alpha/kernel/entry.S

@@ -418,11 +418,10 @@ $work_notifysig:
 strace:
 	/* set up signal stack, call syscall_trace */
 	bsr	$1, do_switch_stack
-	jsr	$26, syscall_trace
+	jsr	$26, syscall_trace_enter /* returns the syscall number */
 	bsr	$1, undo_switch_stack
 
-	/* get the system call number and the arguments back.. */
-	ldq	$0, 0($sp)
+	/* get the arguments back.. */
 	ldq	$16, SP_OFF+24($sp)
 	ldq	$17, SP_OFF+32($sp)
 	ldq	$18, SP_OFF+40($sp)
@@ -449,7 +448,7 @@ $strace_success:
 	stq	$0, 0($sp)		/* save return value */
 
 	bsr	$1, do_switch_stack
-	jsr	$26, syscall_trace
+	jsr	$26, syscall_trace_leave
 	bsr	$1, undo_switch_stack
 	br	$31, ret_from_sys_call
 
@@ -467,7 +466,7 @@ $strace_error:
 	bsr	$1, do_switch_stack
 	mov	$19, $9		/* save old syscall number */
 	mov	$20, $10	/* save old a3 */
-	jsr	$26, syscall_trace
+	jsr	$26, syscall_trace_leave
 	mov	$9, $19
 	mov	$10, $20
 	bsr	$1, undo_switch_stack
@@ -698,7 +697,7 @@ sys_sigreturn:
 	lda	$sp, -SWITCH_STACK_SIZE($sp)
 	jsr	$26, do_sigreturn
 	bne	$9, 1f
-	jsr	$26, syscall_trace
+	jsr	$26, syscall_trace_leave
 1:	br	$1, undo_switch_stack
 	br	ret_from_sys_call
 .end sys_sigreturn
@@ -715,7 +714,7 @@ sys_rt_sigreturn:
 	lda	$sp, -SWITCH_STACK_SIZE($sp)
 	jsr	$26, do_rt_sigreturn
 	bne	$9, 1f
-	jsr	$26, syscall_trace
+	jsr	$26, syscall_trace_leave
 1:	br	$1, undo_switch_stack
 	br	ret_from_sys_call
 .end sys_rt_sigreturn

arch/alpha/kernel/ptrace.c

@@ -13,6 +13,7 @@
 #include <linux/user.h>
 #include <linux/security.h>
 #include <linux/signal.h>
+#include <linux/tracehook.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -312,25 +313,18 @@ long arch_ptrace(struct task_struct *child, long request,
 	return ret;
 }
 
-asmlinkage void
-syscall_trace(void)
+asmlinkage unsigned long syscall_trace_enter(void)
 {
-	if (!test_thread_flag(TIF_SYSCALL_TRACE))
-		return;
-	if (!(current->ptrace & PT_PTRACED))
-		return;
-	/* The 0x80 provides a way for the tracing parent to distinguish
-	   between a syscall stop and SIGTRAP delivery */
-	ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
-				 ? 0x80 : 0));
+	unsigned long ret = 0;
+	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
+	    tracehook_report_syscall_entry(current_pt_regs()))
+		ret = -1UL;
+	return ret ?: current_pt_regs()->r0;
+}
 
-	/*
-	 * This isn't the same as continuing with a signal, but it will do
-	 * for normal use.  strace only continues with a signal if the
-	 * stopping signal is not SIGTRAP.  -brl
-	 */
-	if (current->exit_code) {
-		send_sig(current->exit_code, current, 1);
-		current->exit_code = 0;
-	}
+asmlinkage void
+syscall_trace_leave(void)
+{
+	if (test_thread_flag(TIF_SYSCALL_TRACE))
+		tracehook_report_syscall_exit(current_pt_regs(), 0);
 }

arch/arm/include/asm/thread_info.h

@@ -151,7 +151,6 @@ extern int vfp_restore_user_hwstate(struct user_vfp __user *,
 #define TIF_SYSCALL_TRACE	8
 #define TIF_SYSCALL_AUDIT	9
 #define TIF_SYSCALL_TRACEPOINT	10
-#define TIF_POLLING_NRFLAG	16
 #define TIF_USING_IWMMXT	17
 #define TIF_MEMDIE		18	/* is terminating due to OOM killer */
 #define TIF_RESTORE_SIGMASK	20
@@ -164,7 +163,6 @@ extern int vfp_restore_user_hwstate(struct user_vfp __user *,
 #define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
 #define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)
 #define _TIF_SYSCALL_TRACEPOINT	(1 << TIF_SYSCALL_TRACEPOINT)
-#define _TIF_POLLING_NRFLAG	(1 << TIF_POLLING_NRFLAG)
 #define _TIF_USING_IWMMXT	(1 << TIF_USING_IWMMXT)
 #define _TIF_SECCOMP		(1 << TIF_SECCOMP)
 

arch/arm/kernel/signal.c

@@ -10,7 +10,6 @@
 #include <linux/errno.h>
 #include <linux/signal.h>
 #include <linux/personality.h>
-#include <linux/freezer.h>
 #include <linux/uaccess.h>
 #include <linux/tracehook.h>
 

arch/avr32/include/asm/thread_info.h

@@ -77,8 +77,6 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_SYSCALL_TRACE       0       /* syscall trace active */
 #define TIF_SIGPENDING          1       /* signal pending */
 #define TIF_NEED_RESCHED        2       /* rescheduling necessary */
-#define TIF_POLLING_NRFLAG      3       /* true if poll_idle() is polling
-					   TIF_NEED_RESCHED */
 #define TIF_BREAKPOINT		4	/* enter monitor mode on return */
 #define TIF_SINGLE_STEP		5	/* single step in progress */
 #define TIF_MEMDIE		6	/* is terminating due to OOM killer */
@@ -91,10 +89,9 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
 #define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
-#define _TIF_POLLING_NRFLAG	(1 << TIF_POLLING_NRFLAG)
+#define _TIF_BREAKPOINT		(1 << TIF_BREAKPOINT)
 #define _TIF_SINGLE_STEP	(1 << TIF_SINGLE_STEP)
 #define _TIF_MEMDIE		(1 << TIF_MEMDIE)
-#define _TIF_RESTORE_SIGMASK	(1 << TIF_RESTORE_SIGMASK)
 #define _TIF_CPU_GOING_TO_SLEEP (1 << TIF_CPU_GOING_TO_SLEEP)
 #define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
 
@@ -102,17 +99,14 @@ static inline struct thread_info *current_thread_info(void)
 
 /* work to do on interrupt/exception return */
 #define _TIF_WORK_MASK				\
-	((1 << TIF_SIGPENDING)			\
+	(_TIF_SIGPENDING			\
 	 | _TIF_NOTIFY_RESUME			\
-	 | (1 << TIF_NEED_RESCHED)		\
-	 | (1 << TIF_POLLING_NRFLAG)		\
-	 | (1 << TIF_BREAKPOINT)		\
-	 | (1 << TIF_RESTORE_SIGMASK))
+	 | _TIF_NEED_RESCHED			\
+	 | _TIF_BREAKPOINT)
 
 /* work to do on any return to userspace */
-#define _TIF_ALLWORK_MASK	(_TIF_WORK_MASK | (1 << TIF_SYSCALL_TRACE) | \
-				 _TIF_NOTIFY_RESUME)
+#define _TIF_ALLWORK_MASK	(_TIF_WORK_MASK | _TIF_SYSCALL_TRACE)
 /* work to do on return from debug mode */
-#define _TIF_DBGWORK_MASK	(_TIF_WORK_MASK & ~(1 << TIF_BREAKPOINT))
+#define _TIF_DBGWORK_MASK	(_TIF_WORK_MASK & ~_TIF_BREAKPOINT)
 
 #endif /* __ASM_AVR32_THREAD_INFO_H */

arch/avr32/kernel/signal.c

@@ -15,7 +15,6 @@
 #include <linux/errno.h>
 #include <linux/ptrace.h>
 #include <linux/unistd.h>
-#include <linux/freezer.h>
 #include <linux/tracehook.h>
 
 #include <asm/uaccess.h>

arch/blackfin/include/asm/thread_info.h

@@ -96,8 +96,6 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_SYSCALL_TRACE	0	/* syscall trace active */
 #define TIF_SIGPENDING		1	/* signal pending */
 #define TIF_NEED_RESCHED	2	/* rescheduling necessary */
-#define TIF_POLLING_NRFLAG	3	/* true if poll_idle() is polling
-					   TIF_NEED_RESCHED */
 #define TIF_MEMDIE		4	/* is terminating due to OOM killer */
 #define TIF_RESTORE_SIGMASK	5	/* restore signal mask in do_signal() */
 #define TIF_IRQ_SYNC		7	/* sync pipeline stage */
@@ -108,8 +106,6 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
-#define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
-#define _TIF_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)
 #define _TIF_IRQ_SYNC		(1<<TIF_IRQ_SYNC)
 #define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
 #define _TIF_SINGLESTEP		(1<<TIF_SINGLESTEP)

arch/blackfin/kernel/signal.c

@@ -10,7 +10,6 @@
 #include <linux/tty.h>
 #include <linux/personality.h>
 #include <linux/binfmts.h>
-#include <linux/freezer.h>
 #include <linux/uaccess.h>
 #include <linux/tracehook.h>
 

arch/c6x/Kconfig

@@ -17,6 +17,7 @@ config C6X
 	select OF
 	select OF_EARLY_FLATTREE
 	select GENERIC_CLOCKEVENTS
+	select GENERIC_KERNEL_THREAD
 
 config MMU
 	def_bool n

arch/c6x/include/asm/processor.h

@@ -92,8 +92,6 @@ static inline void release_thread(struct task_struct *dead_task)
 {
 }
 
-extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
-
 #define copy_segments(tsk, mm)		do { } while (0)
 #define release_segments(mm)		do { } while (0)
 

arch/c6x/include/asm/syscalls.h

@@ -44,11 +44,6 @@ extern int sys_cache_sync(unsigned long s, unsigned long e);
 struct pt_regs;
 
 extern asmlinkage long sys_c6x_clone(struct pt_regs *regs);
-extern asmlinkage long sys_c6x_execve(const char __user *name,
-				      const char __user *const __user *argv,
-				      const char __user *const __user *envp,
-				      struct pt_regs *regs);
-
 
 #include <asm-generic/syscalls.h>
 

arch/c6x/include/asm/thread_info.h

@@ -97,7 +97,6 @@ struct thread_info *current_thread_info(void)
 #define TIF_NEED_RESCHED	3	/* rescheduling necessary */
 #define TIF_RESTORE_SIGMASK	4	/* restore signal mask in do_signal() */
 
-#define TIF_POLLING_NRFLAG	16	/* true if polling TIF_NEED_RESCHED */
 #define TIF_MEMDIE		17	/* OOM killer killed process */
 
 #define TIF_WORK_MASK		0x00007FFE /* work on irq/exception return */

arch/c6x/include/asm/unistd.h

@@ -14,6 +14,9 @@
  *   more details.
  */
 
+#define __ARCH_WANT_KERNEL_EXECVE
+#define __ARCH_WANT_SYS_EXECVE
+
 /* Use the standard ABI for syscalls. */
 #include <asm-generic/unistd.h>
 

arch/c6x/kernel/asm-offsets.c

@@ -116,7 +116,6 @@ void foo(void)
 	DEFINE(_TIF_NOTIFY_RESUME, (1<<TIF_NOTIFY_RESUME));
 	DEFINE(_TIF_SIGPENDING, (1<<TIF_SIGPENDING));
 	DEFINE(_TIF_NEED_RESCHED, (1<<TIF_NEED_RESCHED));
-	DEFINE(_TIF_POLLING_NRFLAG, (1<<TIF_POLLING_NRFLAG));
 
 	DEFINE(_TIF_ALLWORK_MASK, TIF_ALLWORK_MASK);
 	DEFINE(_TIF_WORK_MASK, TIF_WORK_MASK);

arch/c6x/kernel/entry.S

@@ -400,6 +400,32 @@ ret_from_fork_2:
 	STW	.D2T2	B0,*+SP(REGS_A4+8)
 ENDPROC(ret_from_fork)
 
+ENTRY(ret_from_kernel_thread)
+#ifdef CONFIG_C6X_BIG_KERNEL
+	MVKL	.S1	schedule_tail,A0
+	MVKH	.S1	schedule_tail,A0
+	B	.S2X	A0
+#else
+	B	.S2	schedule_tail
+#endif
+	LDW	.D2T2	*+SP(REGS_A0+8),B10 /* get fn  */
+	ADDKPC	.S2	0f,B3,3
+0:
+	B	.S2	B10		   /* call fn */
+	LDW	.D2T1	*+SP(REGS_A1+8),A4 /* get arg */
+	MVKL	.S2	sys_exit,B11
+	MVKH	.S2	sys_exit,B11
+	ADDKPC	.S2	0f,B3,1
+0:
+	BNOP	.S2	B11,5	/* jump to sys_exit */
+ENDPROC(ret_from_kernel_thread)
+
+ENTRY(ret_from_kernel_execve)
+	GET_THREAD_INFO A12
+	BNOP	.S2	syscall_exit,4
+	ADD	.D2X	A4,-8,SP
+ENDPROC(ret_from_kernel_execve)
+
 	;;
 	;; These are the interrupt handlers, responsible for calling __do_IRQ()
 	;; int6 is used for syscalls (see _system_call entry)
@@ -593,13 +619,6 @@ ENTRY(sys_sigaltstack)
 	NOP	4
 ENDPROC(sys_sigaltstack)
 
-	;; kernel_execve
-ENTRY(kernel_execve)
-	MVK	.S2	__NR_execve,B0
-	SWE
-	BNOP	.S2	B3,5
-ENDPROC(kernel_execve)
-
 	;;
 	;; Special system calls
 	;; return address is in B3
@@ -628,29 +647,6 @@ ENTRY(sys_rt_sigreturn)
 #endif
 ENDPROC(sys_rt_sigreturn)
 
-ENTRY(sys_execve)
-	ADDAW	.D2	SP,2,B6		; put regs addr in 4th parameter
-					; & adjust regs stack addr
-	LDW	.D2T2	*+SP(REGS_B4+8),B4
-
-	;; c6x_execve(char *name, char **argv,
-	;;            char **envp, struct pt_regs *regs)
-#ifdef CONFIG_C6X_BIG_KERNEL
- ||	MVKL	.S1	sys_c6x_execve,A0
-	MVKH	.S1	sys_c6x_execve,A0
-	B	.S2X	A0
-#else
- ||	B	.S2	sys_c6x_execve
-#endif
-	STW	.D2T2	B3,*SP--[2]
-	ADDKPC	.S2	ret_from_c6x_execve,B3,3
-
-ret_from_c6x_execve:
-	LDW	.D2T2	*++SP[2],B3
-	NOP	4
-	BNOP	.S2	B3,5
-ENDPROC(sys_execve)
-
 ENTRY(sys_pread_c6x)
 	MV	.D2X	A8,B7
 #ifdef CONFIG_C6X_BIG_KERNEL

arch/c6x/kernel/process.c

@@ -25,6 +25,7 @@ void	(*c6x_restart)(void);
 void	(*c6x_halt)(void);
 
 extern asmlinkage void ret_from_fork(void);
+extern asmlinkage void ret_from_kernel_thread(void);
 
 /*
  * power off function, if any
@@ -103,37 +104,6 @@ void machine_power_off(void)
 	halt_loop();
 }
 
-static void kernel_thread_helper(int dummy, void *arg, int (*fn)(void *))
-{
-	do_exit(fn(arg));
-}
-
-/*
- * Create a kernel thread
- */
-int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
-{
-	struct pt_regs regs;
-
-	/*
-	 * copy_thread sets a4 to zero (child return from fork)
-	 * so we can't just set things up to directly return to
-	 * fn.
-	 */
-	memset(&regs, 0, sizeof(regs));
-	regs.b4 = (unsigned long) arg;
-	regs.a6 = (unsigned long) fn;
-	regs.pc = (unsigned long) kernel_thread_helper;
-	local_save_flags(regs.csr);
-	regs.csr |= 1;
-	regs.tsr = 5; /* Set GEE and GIE in TSR */
-
-	/* Ok, create the new process.. */
-	return do_fork(flags | CLONE_VM | CLONE_UNTRACED, -1, &regs,
-		       0, NULL, NULL);
-}
-EXPORT_SYMBOL(kernel_thread);
-
 void flush_thread(void)
 {
 }
@@ -191,22 +161,24 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 
 	childregs = task_pt_regs(p);
 
-	*childregs = *regs;
-	childregs->a4 = 0;
-
-	if (usp == -1)
+	if (!regs) {
 		/* case of  __kernel_thread: we return to supervisor space */
+		memset(childregs, 0, sizeof(struct pt_regs));
 		childregs->sp = (unsigned long)(childregs + 1);
-	else
+		p->thread.pc = (unsigned long) ret_from_kernel_thread;
+		childregs->a0 = usp;		/* function */
+		childregs->a1 = ustk_size;	/* argument */
+	} else {
 		/* Otherwise use the given stack */
+		*childregs = *regs;
 		childregs->sp = usp;
+		p->thread.pc = (unsigned long) ret_from_fork;
+	}
 
 	/* Set usp/ksp */
 	p->thread.usp = childregs->sp;
-	/* switch_to uses stack to save/restore 14 callee-saved regs */
 	thread_saved_ksp(p) = (unsigned long)childregs - 8;
-	p->thread.pc = (unsigned int) ret_from_fork;
-	p->thread.wchan	= (unsigned long) ret_from_fork;
+	p->thread.wchan	= p->thread.pc;
 #ifdef __DSBT__
 	{
 		unsigned long dp;
@@ -221,28 +193,6 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 	return 0;
 }
 
-/*
- * c6x_execve() executes a new program.
- */
-SYSCALL_DEFINE4(c6x_execve, const char __user *, name,
-		const char __user *const __user *, argv,
-		const char __user *const __user *, envp,
-		struct pt_regs *, regs)
-{
-	int error;
-	char *filename;
-
-	filename = getname(name);
-	error = PTR_ERR(filename);
-	if (IS_ERR(filename))
-		goto out;
-
-	error = do_execve(filename, argv, envp, regs);
-	putname(filename);
-out:
-	return error;
-}
-
 unsigned long get_wchan(struct task_struct *p)
 {
 	return p->thread.wchan;

arch/cris/include/asm/thread_info.h

@@ -78,15 +78,12 @@ struct thread_info {
 #define TIF_SIGPENDING		2	/* signal pending */
 #define TIF_NEED_RESCHED	3	/* rescheduling necessary */
 #define TIF_RESTORE_SIGMASK	9	/* restore signal mask in do_signal() */
-#define TIF_POLLING_NRFLAG	16	/* true if poll_idle() is polling TIF_NEED_RESCHED */
 #define TIF_MEMDIE		17	/* is terminating due to OOM killer */
 
 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
 #define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
-#define _TIF_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)
-#define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
 
 #define _TIF_WORK_MASK		0x0000FFFE	/* work to do on interrupt/exception return */
 #define _TIF_ALLWORK_MASK	0x0000FFFF	/* work to do on any return to u-space */

arch/frv/Kconfig

@@ -12,6 +12,7 @@ config FRV
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select GENERIC_CPU_DEVICES
 	select ARCH_WANT_IPC_PARSE_VERSION
+	select GENERIC_KERNEL_THREAD
 
 config ZONE_DMA
 	bool

arch/frv/include/asm/processor.h

@@ -92,14 +92,12 @@ extern struct task_struct *__kernel_current_task;
 
 /*
  * do necessary setup to start up a newly executed thread.
- * - need to discard the frame stacked by init() invoking the execve syscall
  */
 #define start_thread(_regs, _pc, _usp)			\
 do {							\
-	__frame = __kernel_frame0_ptr;			\
-	__frame->pc	= (_pc);			\
-	__frame->psr	&= ~PSR_S;			\
-	__frame->sp	= (_usp);			\
+	_regs->pc	= (_pc);			\
+	_regs->psr	&= ~PSR_S;			\
+	_regs->sp	= (_usp);			\
 } while(0)
 
 /* Free all resources held by a thread. */
@@ -107,7 +105,6 @@ static inline void release_thread(struct task_struct *dead_task)
 {
 }
 
-extern asmlinkage int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
 extern asmlinkage void save_user_regs(struct user_context *target);
 extern asmlinkage void *restore_user_regs(const struct user_context *target, ...);
 

arch/frv/include/asm/ptrace.h

@@ -76,6 +76,7 @@ register struct pt_regs *__frame asm("gr28");
 #define user_mode(regs)			(!((regs)->psr & PSR_S))
 #define instruction_pointer(regs)	((regs)->pc)
 #define user_stack_pointer(regs)	((regs)->sp)
+#define current_pt_regs()		(__frame)
 
 extern unsigned long user_stack(const struct pt_regs *);
 #define profile_pc(regs) ((regs)->pc)

arch/frv/include/asm/thread_info.h

@@ -94,7 +94,6 @@ register struct thread_info *__current_thread_info asm("gr15");
 #define TIF_NEED_RESCHED	3	/* rescheduling necessary */
 #define TIF_SINGLESTEP		4	/* restore singlestep on return to user mode */
 #define TIF_RESTORE_SIGMASK	5	/* restore signal mask in do_signal() */
-#define TIF_POLLING_NRFLAG	6	/* true if poll_idle() is polling TIF_NEED_RESCHED */
 #define TIF_MEMDIE		7	/* is terminating due to OOM killer */
 
 #define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
@@ -102,8 +101,6 @@ register struct thread_info *__current_thread_info asm("gr15");
 #define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
 #define _TIF_SINGLESTEP		(1 << TIF_SINGLESTEP)
-#define _TIF_RESTORE_SIGMASK	(1 << TIF_RESTORE_SIGMASK)
-#define _TIF_POLLING_NRFLAG	(1 << TIF_POLLING_NRFLAG)
 
 /* work to do on interrupt/exception return */
 #define _TIF_WORK_MASK		\

arch/frv/include/asm/unistd.h

@@ -372,6 +372,8 @@
 #define __ARCH_WANT_SYS_SIGPROCMASK
 #define __ARCH_WANT_SYS_RT_SIGACTION
 #define __ARCH_WANT_SYS_RT_SIGSUSPEND
+#define __ARCH_WANT_SYS_EXECVE
+#define __ARCH_WANT_KERNEL_EXECVE
 
 /*
  * "Conditional" syscalls

arch/frv/kernel/Makefile

@@ -7,8 +7,8 @@ heads-$(CONFIG_MMU)		:= head-mmu-fr451.o
 
 extra-y:= head.o vmlinux.lds
 
-obj-y := $(heads-y) entry.o entry-table.o break.o switch_to.o kernel_thread.o \
-	 kernel_execve.o process.o traps.o ptrace.o signal.o dma.o \
+obj-y := $(heads-y) entry.o entry-table.o break.o switch_to.o \
+	 process.o traps.o ptrace.o signal.o dma.o \
 	 sys_frv.o time.o setup.o frv_ksyms.o \
 	 debug-stub.o irq.o sleep.o uaccess.o
 

arch/frv/kernel/entry.S

@@ -863,6 +863,19 @@ ret_from_fork:
 	setlos.p	#0,gr8
 	bra		__syscall_exit
 
+	.globl		ret_from_kernel_thread
+ret_from_kernel_thread:
+	lddi.p		@(gr28,#REG_GR(8)),gr20
+	call		schedule_tail
+	or.p		gr20,gr20,gr8
+	calll		@(gr21,gr0)
+	bra		sys_exit
+
+	.globl		ret_from_kernel_execve
+ret_from_kernel_execve:
+	ori		gr28,0,sp
+	bra		__syscall_exit
+
 ###################################################################################################
 #
 # Return to user mode is not as complex as all this looks,

arch/frv/kernel/frv_ksyms.c

@@ -30,7 +30,6 @@ EXPORT_SYMBOL(ip_fast_csum);
 EXPORT_SYMBOL(local_irq_count);
 EXPORT_SYMBOL(local_bh_count);
 #endif
-EXPORT_SYMBOL(kernel_thread);
 
 EXPORT_SYMBOL(__res_bus_clock_speed_HZ);
 EXPORT_SYMBOL(__page_offset);

arch/frv/kernel/kernel_execve.S

-/* in-kernel program execution
- *
- * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- */
-
-#include <linux/linkage.h>
-#include <asm/unistd.h>
-
-###############################################################################
-#
-# Do a system call from kernel instead of calling sys_execve so we end up with
-# proper pt_regs.
-#
-# int kernel_execve(const char *filename, char *const argv[], char *const envp[])
-#
-# On entry: GR8/GR9/GR10: arguments to function
-# On return: GR8: syscall return.
-#
-###############################################################################
-	.globl		kernel_execve
-	.type		kernel_execve,@function
-kernel_execve:
-	setlos		__NR_execve,gr7
-	tira		gr0,#0
-	bralr
-
-	.size		kernel_execve,.-kernel_execve

arch/frv/kernel/kernel_thread.S

-/* kernel_thread.S: kernel thread creation
- *
- * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- */
-
-#include <linux/linkage.h>
-#include <linux/kern_levels.h>
-#include <asm/unistd.h>
-
-#define CLONE_VM	0x00000100	/* set if VM shared between processes */
-
-	.section .rodata
-kernel_thread_emsg:
-	.asciz	KERN_ERR "failed to create kernel thread: error=%d\n"
-
-	.text
-	.balign		4
-
-###############################################################################
-#
-# Create a kernel thread
-#
-# int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
-#
-###############################################################################
-	.globl		kernel_thread
-	.type		kernel_thread,@function
-kernel_thread:
-	or.p		gr8,gr0,gr4
-	or		gr9,gr0,gr5
-
-	# start by forking the current process, but with shared VM
-	setlos.p	#__NR_clone,gr7		; syscall number
-	ori		gr10,#CLONE_VM,gr8	; first syscall arg	[clone_flags]
-	sethi.p		#0xe4e4,gr9		; second syscall arg	[newsp]
-	setlo		#0xe4e4,gr9
-	setlos.p	#0,gr10			; third syscall arg	[parent_tidptr]
-	setlos		#0,gr11			; fourth syscall arg	[child_tidptr]
-	tira		gr0,#0
-	setlos.p	#4095,gr7
-	andcc		gr8,gr8,gr0,icc0
-	addcc.p		gr8,gr7,gr0,icc1
-	bnelr		icc0,#2
-	bc		icc1,#0,kernel_thread_error
-
-	# now invoke the work function
-	or		gr5,gr0,gr8
-	calll		@(gr4,gr0)
-
-	# and finally exit the thread
-	setlos		#__NR_exit,gr7		; syscall number
-	tira		gr0,#0
-
-kernel_thread_error:
-	subi		sp,#8,sp
-	movsg		lr,gr4
-	sti		gr8,@(sp,#0)
-	sti.p		gr4,@(sp,#4)
-
-	or		gr8,gr0,gr9
-	sethi.p		%hi(kernel_thread_emsg),gr8
-	setlo		%lo(kernel_thread_emsg),gr8
-
-	call		printk
-
-	ldi		@(sp,#4),gr4
-	ldi		@(sp,#0),gr8
-	subi		sp,#8,sp
-	jmpl		@(gr4,gr0)
-
-	.size		kernel_thread,.-kernel_thread

arch/frv/kernel/process.c

@@ -38,6 +38,7 @@
 #include "local.h"
 
 asmlinkage void ret_from_fork(void);
+asmlinkage void ret_from_kernel_thread(void);
 
 #include <asm/pgalloc.h>
 
@@ -172,32 +173,13 @@ asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
  * set up the kernel stack and exception frames for a new process
  */
 int copy_thread(unsigned long clone_flags,
-		unsigned long usp, unsigned long topstk,
+		unsigned long usp, unsigned long arg,
 		struct task_struct *p, struct pt_regs *regs)
 {
-	struct pt_regs *childregs0, *childregs, *regs0;
+	struct pt_regs *childregs;
 
-	regs0 = __kernel_frame0_ptr;
-	childregs0 = (struct pt_regs *)
+	childregs = (struct pt_regs *)
 		(task_stack_page(p) + THREAD_SIZE - FRV_FRAME0_SIZE);
-	childregs = childregs0;
-
-	/* set up the userspace frame (the only place that the USP is stored) */
-	*childregs0 = *regs0;
-
-	childregs0->gr8		= 0;
-	childregs0->sp		= usp;
-	childregs0->next_frame	= NULL;
-
-	/* set up the return kernel frame if called from kernel_thread() */
-	if (regs != regs0) {
-		childregs--;
-		*childregs = *regs;
-		childregs->sp = (unsigned long) childregs0;
-		childregs->next_frame = childregs0;
-		childregs->gr15 = (unsigned long) task_thread_info(p);
-		childregs->gr29 = (unsigned long) p;
-	}
 
 	p->set_child_tid = p->clear_child_tid = NULL;
 
@@ -206,8 +188,25 @@ int copy_thread(unsigned long clone_flags,
 	p->thread.sp	 = (unsigned long) childregs;
 	p->thread.fp	 = 0;
 	p->thread.lr	 = 0;
+	p->thread.frame0 = childregs;
+
+	if (unlikely(!regs)) {
+		memset(childregs, 0, sizeof(struct pt_regs));
+		childregs->gr9 = usp; /* function */
+		childregs->gr8 = arg;
+		chilregs->psr = PSR_S;
+		p->thread.pc = (unsigned long) ret_from_kernel_thread;
+		save_user_regs(p->thread.user);
+		return 0;
+	}
+
+	/* set up the userspace frame (the only place that the USP is stored) */
+	*childregs = *regs;
+
+	childregs->sp		= usp;
+	childregs->next_frame	= NULL;
+
 	p->thread.pc = (unsigned long) ret_from_fork;
-	p->thread.frame0 = childregs0;
 
 	/* the new TLS pointer is passed in as arg #5 to sys_clone() */
 	if (clone_flags & CLONE_SETTLS)
@@ -218,25 +217,6 @@ int copy_thread(unsigned long clone_flags,
 	return 0;
 } /* end copy_thread() */
 
-/*
- * 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;
-	char * filename;
-
-	filename = getname(name);
-	error = PTR_ERR(filename);
-	if (IS_ERR(filename))
-		return error;
-	error = do_execve(filename, argv, envp, __frame);
-	putname(filename);
-	return error;
-}
-
 unsigned long get_wchan(struct task_struct *p)
 {
 	struct pt_regs *regs0;

arch/frv/kernel/signal.c

@@ -20,7 +20,6 @@
 #include <linux/ptrace.h>
 #include <linux/unistd.h>
 #include <linux/personality.h>
-#include <linux/freezer.h>
 #include <linux/tracehook.h>
 #include <asm/ucontext.h>
 #include <asm/uaccess.h>
@@ -298,10 +297,6 @@ static int setup_frame(int sig, struct k_sigaction *ka, sigset_t *set)
 	__frame->lr   = (unsigned long) &frame->retcode;
 	__frame->gr8  = sig;
 
-	/* the tracer may want to single-step inside the handler */
-	if (test_thread_flag(TIF_SINGLESTEP))
-		ptrace_notify(SIGTRAP);
-
 #if DEBUG_SIG
 	printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
 	       sig, current->comm, current->pid, frame, __frame->pc,
@@ -400,10 +395,6 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	__frame->gr8 = sig;
 	__frame->gr9 = (unsigned long) &frame->info;
 
-	/* the tracer may want to single-step inside the handler */
-	if (test_thread_flag(TIF_SINGLESTEP))
-		ptrace_notify(SIGTRAP);
-
 #if DEBUG_SIG
 	printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
 	       sig, current->comm, current->pid, frame, __frame->pc,

arch/h8300/include/asm/thread_info.h

@@ -85,8 +85,6 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_SYSCALL_TRACE	0	/* syscall trace active */
 #define TIF_SIGPENDING		1	/* signal pending */
 #define TIF_NEED_RESCHED	2	/* rescheduling necessary */
-#define TIF_POLLING_NRFLAG	3	/* true if poll_idle() is polling
-					   TIF_NEED_RESCHED */
 #define TIF_MEMDIE		4	/* is terminating due to OOM killer */
 #define TIF_RESTORE_SIGMASK	5	/* restore signal mask in do_signal() */
 #define TIF_NOTIFY_RESUME	6	/* callback before returning to user */
@@ -95,11 +93,10 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
-#define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
-#define _TIF_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)
 #define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
 
-#define _TIF_WORK_MASK		0x0000FFFE	/* work to do on interrupt/exception return */
+#define _TIF_WORK_MASK		(_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
+				 _TIF_NOTIFY_RESUME)
 
 #endif /* __KERNEL__ */
 

arch/h8300/kernel/signal.c

@@ -38,7 +38,6 @@
 #include <linux/personality.h>
 #include <linux/tty.h>
 #include <linux/binfmts.h>
-#include <linux/freezer.h>
 #include <linux/tracehook.h>
 
 #include <asm/setup.h>

arch/hexagon/include/asm/thread_info.h

@@ -120,10 +120,8 @@ register struct thread_info *__current_thread_info asm(QUOTED_THREADINFO_REG);
 #define TIF_SIGPENDING          2       /* signal pending */
 #define TIF_NEED_RESCHED        3       /* rescheduling necessary */
 #define TIF_SINGLESTEP          4       /* restore ss @ return to usr mode */
-#define TIF_IRET                5       /* return with iret */
 #define TIF_RESTORE_SIGMASK     6       /* restore sig mask in do_signal() */
 /* true if poll_idle() is polling TIF_NEED_RESCHED */
-#define TIF_POLLING_NRFLAG      16
 #define TIF_MEMDIE              17      /* OOM killer killed process */
 
 #define _TIF_SYSCALL_TRACE      (1 << TIF_SYSCALL_TRACE)
@@ -131,9 +129,6 @@ register struct thread_info *__current_thread_info asm(QUOTED_THREADINFO_REG);
 #define _TIF_SIGPENDING         (1 << TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED       (1 << TIF_NEED_RESCHED)
 #define _TIF_SINGLESTEP         (1 << TIF_SINGLESTEP)
-#define _TIF_IRET               (1 << TIF_IRET)
-#define _TIF_RESTORE_SIGMASK    (1 << TIF_RESTORE_SIGMASK)
-#define _TIF_POLLING_NRFLAG     (1 << TIF_POLLING_NRFLAG)
 
 /* work to do on interrupt/exception return - All but TIF_SYSCALL_TRACE */
 #define _TIF_WORK_MASK          (0x0000FFFF & ~_TIF_SYSCALL_TRACE)

arch/hexagon/kernel/signal.c

@@ -20,7 +20,6 @@
 
 #include <linux/linkage.h>
 #include <linux/syscalls.h>
-#include <linux/freezer.h>
 #include <linux/tracehook.h>
 #include <asm/registers.h>
 #include <asm/thread_info.h>

arch/ia64/include/asm/thread_info.h

@@ -106,7 +106,6 @@ struct thread_info {
 #define TIF_SYSCALL_AUDIT	3	/* syscall auditing active */
 #define TIF_SINGLESTEP		4	/* restore singlestep on return to user mode */
 #define TIF_NOTIFY_RESUME	6	/* resumption notification requested */
-#define TIF_POLLING_NRFLAG	16	/* true if poll_idle() is polling TIF_NEED_RESCHED */
 #define TIF_MEMDIE		17	/* is terminating due to OOM killer */
 #define TIF_MCA_INIT		18	/* this task is processing MCA or INIT */
 #define TIF_DB_DISABLED		19	/* debug trap disabled for fsyscall */
@@ -119,7 +118,6 @@ struct thread_info {
 #define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
 #define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
-#define _TIF_POLLING_NRFLAG	(1 << TIF_POLLING_NRFLAG)
 #define _TIF_MCA_INIT		(1 << TIF_MCA_INIT)
 #define _TIF_DB_DISABLED	(1 << TIF_DB_DISABLED)
 #define _TIF_RESTORE_RSE	(1 << TIF_RESTORE_RSE)

arch/ia64/kernel/signal.c

@@ -437,14 +437,6 @@ ia64_do_signal (struct sigscratch *scr, long in_syscall)
 	long restart = in_syscall;
 	long errno = scr->pt.r8;
 
-	/*
-	 * In the ia64_leave_kernel code path, we want the common case to go fast, which
-	 * is why we may in certain cases get here from kernel mode. Just return without
-	 * doing anything if so.
-	 */
-	if (!user_mode(&scr->pt))
-		return;
-
 	/*
 	 * This only loops in the rare cases of handle_signal() failing, in which case we
 	 * need to push through a forced SIGSEGV.

arch/m32r/include/asm/thread_info.h

@@ -119,25 +119,20 @@ static inline unsigned int get_thread_fault_code(void)
 #define TIF_SIGPENDING		1	/* signal pending */
 #define TIF_NEED_RESCHED	2	/* rescheduling necessary */
 #define TIF_SINGLESTEP		3	/* restore singlestep on return to user mode */
-#define TIF_IRET		4	/* return with iret */
 #define TIF_NOTIFY_RESUME	5	/* callback before returning to user */
 #define TIF_RESTORE_SIGMASK	8	/* restore signal mask in do_signal() */
 #define TIF_USEDFPU		16	/* FPU was used by this task this quantum (SMP) */
-#define TIF_POLLING_NRFLAG	17	/* true if poll_idle() is polling TIF_NEED_RESCHED */
 #define TIF_MEMDIE		18	/* is terminating due to OOM killer */
 
 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
 #define _TIF_SINGLESTEP		(1<<TIF_SINGLESTEP)
-#define _TIF_IRET		(1<<TIF_IRET)
 #define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
-#define _TIF_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)
 #define _TIF_USEDFPU		(1<<TIF_USEDFPU)
-#define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
 
-#define _TIF_WORK_MASK		0x0000FFFE	/* work to do on interrupt/exception return */
-#define _TIF_ALLWORK_MASK	0x0000FFFF	/* work to do on any return to u-space */
+#define _TIF_WORK_MASK		(_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_NOTIFY_RESUME)
+#define _TIF_ALLWORK_MASK	(_TIF_WORK_MASK | _TIF_SYSCALL_TRACE)
 
 /*
  * Thread-synchronous status.

arch/m32r/kernel/signal.c

@@ -20,7 +20,6 @@
 #include <linux/unistd.h>
 #include <linux/stddef.h>
 #include <linux/personality.h>
-#include <linux/freezer.h>
 #include <linux/tracehook.h>
 #include <asm/cacheflush.h>
 #include <asm/ucontext.h>
@@ -366,6 +365,4 @@ void do_notify_resume(struct pt_regs *regs, __u32 thread_info_flags)
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
 	}
-
-	clear_thread_flag(TIF_IRET);
 }

arch/m68k/Kconfig

@@ -15,6 +15,7 @@ config M68K
 	select FPU if MMU
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select ARCH_USES_GETTIMEOFFSET if MMU && !COLDFIRE
+	select GENERIC_KERNEL_THREAD
 
 config RWSEM_GENERIC_SPINLOCK
 	bool

arch/m68k/include/asm/processor.h

@@ -100,6 +100,16 @@ struct thread_struct {
 	.fs	= __KERNEL_DS,						\
 }
 
+/*
+ * ColdFire stack format sbould be 0x4 for an aligned usp (will always be
+ * true on thread creation). We need to set this explicitly.
+ */
+#ifdef CONFIG_COLDFIRE
+#define setframeformat(_regs)	do { (_regs)->format = 0x4; } while(0)
+#else
+#define setframeformat(_regs)	do { } while (0)
+#endif
+
 #ifdef CONFIG_MMU
 /*
  * Do necessary setup to start up a newly executed thread.
@@ -109,6 +119,7 @@ static inline void start_thread(struct pt_regs * regs, unsigned long pc,
 {
 	regs->pc = pc;
 	regs->sr &= ~0x2000;
+	setframeformat(regs);
 	wrusp(usp);
 }
 
@@ -116,21 +127,11 @@ extern int handle_kernel_fault(struct pt_regs *regs);
 
 #else
 
-/*
- * Coldfire stacks need to be re-aligned on trap exit, conventional
- * 68k can handle this case cleanly.
- */
-#ifdef CONFIG_COLDFIRE
-#define reformat(_regs)		do { (_regs)->format = 0x4; } while(0)
-#else
-#define reformat(_regs)		do { } while (0)
-#endif
-
 #define start_thread(_regs, _pc, _usp)                  \
 do {                                                    \
 	(_regs)->pc = (_pc);                            \
 	((struct switch_stack *)(_regs))[-1].a6 = 0;    \
-	reformat(_regs);                                \
+	setframeformat(_regs);                          \
 	if (current->mm)                                \
 		(_regs)->d5 = current->mm->start_data;  \
 	(_regs)->sr &= ~0x2000;                         \
@@ -153,8 +154,6 @@ 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..
  */

arch/m68k/include/asm/ptrace.h

@@ -85,6 +85,8 @@ struct switch_stack {
 #define user_mode(regs) (!((regs)->sr & PS_S))
 #define instruction_pointer(regs) ((regs)->pc)
 #define profile_pc(regs) instruction_pointer(regs)
+#define current_pt_regs() \
+	(struct pt_regs *)((char *)current_thread_info() + THREAD_SIZE) - 1
 
 #define arch_has_single_step()	(1)
 

arch/m68k/include/asm/unistd.h

@@ -382,6 +382,8 @@
 #define __ARCH_WANT_SYS_SIGPROCMASK
 #define __ARCH_WANT_SYS_RT_SIGACTION
 #define __ARCH_WANT_SYS_RT_SIGSUSPEND
+#define __ARCH_WANT_SYS_EXECVE
+#define __ARCH_WANT_KERNEL_EXECVE
 
 /*
  * "Conditional" syscalls

arch/m68k/kernel/entry.S

@@ -111,6 +111,22 @@ ENTRY(ret_from_fork)
 	addql	#4,%sp
 	jra	ret_from_exception
 
+ENTRY(ret_from_kernel_thread)
+	| a3 contains the kernel thread payload, d7 - its argument
+	movel	%d1,%sp@-
+	jsr	schedule_tail
+	GET_CURRENT(%d0)
+	movel	%d7,(%sp)
+	jsr	%a3@
+	addql	#4,%sp
+	movel	%d0,(%sp)
+	jra	sys_exit
+
+ENTRY(ret_from_kernel_execve)
+	movel	4(%sp), %sp
+	GET_CURRENT(%d0)
+	jra	ret_from_exception
+
 #if defined(CONFIG_COLDFIRE) || !defined(CONFIG_MMU)
 
 #ifdef TRAP_DBG_INTERRUPT

arch/m68k/kernel/process.c

@@ -35,6 +35,7 @@
 
 
 asmlinkage void ret_from_fork(void);
+asmlinkage void ret_from_kernel_thread(void);
 
 
 /*
@@ -123,51 +124,6 @@ void show_regs(struct pt_regs * regs)
 		printk("USP: %08lx\n", rdusp());
 }
 
-/*
- * Create a kernel thread
- */
-int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
-{
-	int pid;
-	mm_segment_t fs;
-
-	fs = get_fs();
-	set_fs (KERNEL_DS);
-
-	{
-	register long retval __asm__ ("d0");
-	register long clone_arg __asm__ ("d1") = flags | CLONE_VM | CLONE_UNTRACED;
-
-	retval = __NR_clone;
-	__asm__ __volatile__
-	  ("clrl %%d2\n\t"
-	   "trap #0\n\t"		/* Linux/m68k system call */
-	   "tstl %0\n\t"		/* child or parent */
-	   "jne 1f\n\t"			/* parent - jump */
-#ifdef CONFIG_MMU
-	   "lea %%sp@(%c7),%6\n\t"	/* reload current */
-	   "movel %6@,%6\n\t"
-#endif
-	   "movel %3,%%sp@-\n\t"	/* push argument */
-	   "jsr %4@\n\t"		/* call fn */
-	   "movel %0,%%d1\n\t"		/* pass exit value */
-	   "movel %2,%%d0\n\t"		/* exit */
-	   "trap #0\n"
-	   "1:"
-	   : "+d" (retval)
-	   : "i" (__NR_clone), "i" (__NR_exit),
-	     "r" (arg), "a" (fn), "d" (clone_arg), "r" (current),
-	     "i" (-THREAD_SIZE)
-	   : "d2");
-
-	pid = retval;
-	}
-
-	set_fs (fs);
-	return pid;
-}
-EXPORT_SYMBOL(kernel_thread);
-
 void flush_thread(void)
 {
 	current->thread.fs = __USER_DS;
@@ -219,30 +175,18 @@ asmlinkage int m68k_clone(struct pt_regs *regs)
 }
 
 int copy_thread(unsigned long clone_flags, unsigned long usp,
-		 unsigned long unused,
+		 unsigned long arg,
 		 struct task_struct * p, struct pt_regs * regs)
 {
 	struct pt_regs * childregs;
-	struct switch_stack * childstack, *stack;
-	unsigned long *retp;
+	struct switch_stack *childstack;
 
 	childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
-
-	*childregs = *regs;
-	childregs->d0 = 0;
-
-	retp = ((unsigned long *) regs);
-	stack = ((struct switch_stack *) retp) - 1;
-
 	childstack = ((struct switch_stack *) childregs) - 1;
-	*childstack = *stack;
-	childstack->retpc = (unsigned long)ret_from_fork;
 
 	p->thread.usp = usp;
 	p->thread.ksp = (unsigned long)childstack;
-
-	if (clone_flags & CLONE_SETTLS)
-		task_thread_info(p)->tp_value = regs->d5;
+	p->thread.esp0 = (unsigned long)childregs;
 
 	/*
 	 * Must save the current SFC/DFC value, NOT the value when
@@ -250,6 +194,26 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 	 */
 	p->thread.fs = get_fs().seg;
 
+	if (unlikely(!regs)) {
+		/* kernel thread */
+		memset(childstack, 0,
+			sizeof(struct switch_stack) + sizeof(struct pt_regs));
+		childregs->sr = PS_S;
+		childstack->a3 = usp; /* function */
+		childstack->d7 = arg;
+		childstack->retpc = (unsigned long)ret_from_kernel_thread;
+		p->thread.usp = 0;
+		return 0;
+	}
+	*childregs = *regs;
+	childregs->d0 = 0;
+
+	*childstack = ((struct switch_stack *) regs)[-1];
+	childstack->retpc = (unsigned long)ret_from_fork;
+
+	if (clone_flags & CLONE_SETTLS)
+		task_thread_info(p)->tp_value = regs->d5;
+
 #ifdef CONFIG_FPU
 	if (!FPU_IS_EMU) {
 		/* Copy the current fpu state */
@@ -337,26 +301,6 @@ int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
 EXPORT_SYMBOL(dump_fpu);
 #endif /* CONFIG_FPU */
 
-/*
- * 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;
-	char * filename;
-	struct pt_regs *regs = (struct pt_regs *) &name;
-
-	filename = getname(name);
-	error = PTR_ERR(filename);
-	if (IS_ERR(filename))
-		return error;
-	error = do_execve(filename, argv, envp, regs);
-	putname(filename);
-	return error;
-}
-
 unsigned long get_wchan(struct task_struct *p)
 {
 	unsigned long fp, pc;

arch/m68k/kernel/sys_m68k.c

@@ -549,23 +549,6 @@ asmlinkage int sys_getpagesize(void)
 	return PAGE_SIZE;
 }
 
-/*
- * Do a system call from kernel instead of calling sys_execve so we
- * end up with proper pt_regs.
- */
-int kernel_execve(const char *filename,
-		  const char *const argv[],
-		  const char *const envp[])
-{
-	register long __res asm ("%d0") = __NR_execve;
-	register long __a asm ("%d1") = (long)(filename);
-	register long __b asm ("%d2") = (long)(argv);
-	register long __c asm ("%d3") = (long)(envp);
-	asm volatile ("trap  #0" : "+d" (__res)
-			: "d" (__a), "d" (__b), "d" (__c));
-	return __res;
-}
-
 asmlinkage unsigned long sys_get_thread_area(void)
 {
 	return current_thread_info()->tp_value;

arch/microblaze/include/asm/thread_info.h

@@ -121,7 +121,6 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_NEED_RESCHED	3 /* rescheduling necessary */
 /* restore singlestep on return to user mode */
 #define TIF_SINGLESTEP		4
-#define TIF_IRET		5 /* return with iret */
 #define TIF_MEMDIE		6	/* is terminating due to OOM killer */
 #define TIF_SYSCALL_AUDIT	9       /* syscall auditing active */
 #define TIF_SECCOMP		10      /* secure computing */
@@ -134,7 +133,6 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
 #define _TIF_SINGLESTEP		(1 << TIF_SINGLESTEP)
-#define _TIF_IRET		(1 << TIF_IRET)
 #define _TIF_POLLING_NRFLAG	(1 << TIF_POLLING_NRFLAG)
 #define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)
 #define _TIF_SECCOMP		(1 << TIF_SECCOMP)
@@ -184,6 +182,7 @@ static inline bool test_and_clear_restore_sigmask(void)
 	ti->status &= ~TS_RESTORE_SIGMASK;
 	return true;
 }
+#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
 #endif
 
 #endif /* __KERNEL__ */

arch/microblaze/kernel/signal.c

@@ -254,10 +254,6 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 
 	set_fs(USER_DS);
 
-	/* the tracer may want to single-step inside the handler */
-	if (test_thread_flag(TIF_SINGLESTEP))
-		ptrace_notify(SIGTRAP);
-
 #ifdef DEBUG_SIG
 	printk(KERN_INFO "SIG deliver (%s:%d): sp=%p pc=%08lx\n",
 		current->comm, current->pid, frame, regs->pc);
@@ -315,7 +311,8 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,
 	if (ret)
 		return;
 
-	signal_delivered(sig, info, ka, regs, 0);
+	signal_delivered(sig, info, ka, regs,
+			test_thread_flag(TIF_SINGLESTEP));
 }
 
 /*

arch/mips/include/asm/thread_info.h

@@ -103,7 +103,6 @@ register struct thread_info *__current_thread_info __asm__("$28");
 #define TIF_NOTIFY_RESUME	5	/* callback before returning to user */
 #define TIF_RESTORE_SIGMASK	9	/* restore signal mask in do_signal() */
 #define TIF_USEDFPU		16	/* FPU was used by this task this quantum (SMP) */
-#define TIF_POLLING_NRFLAG	17	/* true if poll_idle() is polling TIF_NEED_RESCHED */
 #define TIF_MEMDIE		18	/* is terminating due to OOM killer */
 #define TIF_FIXADE		20	/* Fix address errors in software */
 #define TIF_LOGADE		21	/* Log address errors to syslog */
@@ -125,9 +124,7 @@ register struct thread_info *__current_thread_info __asm__("$28");
 #define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)
 #define _TIF_SECCOMP		(1<<TIF_SECCOMP)
 #define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
-#define _TIF_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)
 #define _TIF_USEDFPU		(1<<TIF_USEDFPU)
-#define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
 #define _TIF_FIXADE		(1<<TIF_FIXADE)
 #define _TIF_LOGADE		(1<<TIF_LOGADE)
 #define _TIF_32BIT_REGS		(1<<TIF_32BIT_REGS)

arch/mn10300/Kconfig

@@ -8,6 +8,7 @@ config MN10300
 	select HAVE_ARCH_KGDB
 	select HAVE_NMI_WATCHDOG if MN10300_WD_TIMER
 	select GENERIC_CLOCKEVENTS
+	select GENERIC_KERNEL_THREAD
 
 config AM33_2
 	def_bool n

arch/mn10300/include/asm/frame.inc

@@ -61,7 +61,7 @@
 ###############################################################################
 .macro RESTORE_ALL
 	# peel back the stack to the calling frame
-	# - this permits execve() to discard extra frames due to kernel syscalls
+	# - we need that when returning from interrupts to kernel mode
 	GET_THREAD_INFO a0
 	mov	(TI_frame,a0),fp
 	mov	fp,sp

arch/mn10300/include/asm/processor.h

@@ -119,31 +119,19 @@ struct thread_struct {
 
 /*
  * do necessary setup to start up a newly executed thread
- * - need to discard the frame stacked by the kernel thread invoking the execve
- *   syscall (see RESTORE_ALL macro)
  */
 static inline void start_thread(struct pt_regs *regs,
 				unsigned long new_pc, unsigned long new_sp)
 {
-	struct thread_info *ti = current_thread_info();
-	struct pt_regs *frame0;
-
-	frame0 = thread_info_to_uregs(ti);
-	frame0->epsw = EPSW_nSL | EPSW_IE | EPSW_IM;
-	frame0->pc = new_pc;
-	frame0->sp = new_sp;
-	ti->frame = frame0;
+	regs->epsw = EPSW_nSL | EPSW_IE | EPSW_IM;
+	regs->pc = new_pc;
+	regs->sp = new_sp;
 }
 
 
 /* Free all resources held by a thread. */
 extern void release_thread(struct task_struct *);
 
-/*
- * create a kernel thread without removing it from tasklists
- */
-extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
-
 /*
  * Return saved PC of a blocked thread.
  */

arch/mn10300/include/asm/ptrace.h

@@ -86,6 +86,7 @@ struct pt_regs {
 #define user_mode(regs)			(((regs)->epsw & EPSW_nSL) == EPSW_nSL)
 #define instruction_pointer(regs)	((regs)->pc)
 #define user_stack_pointer(regs)	((regs)->sp)
+#define current_pt_regs()		current_frame()
 
 #define arch_has_single_step()	(1)
 

arch/mn10300/include/asm/thread_info.h

@@ -160,12 +160,13 @@ void arch_release_thread_info(struct thread_info *ti);
 #define _TIF_SIGPENDING		+(1 << TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	+(1 << TIF_NEED_RESCHED)
 #define _TIF_SINGLESTEP		+(1 << TIF_SINGLESTEP)
-#define _TIF_RESTORE_SIGMASK	+(1 << TIF_RESTORE_SIGMASK)
 #define _TIF_POLLING_NRFLAG	+(1 << TIF_POLLING_NRFLAG)
 
 #define _TIF_WORK_MASK		0x0000FFFE	/* work to do on interrupt/exception return */
 #define _TIF_ALLWORK_MASK	0x0000FFFF	/* work to do on any return to u-space */
 
+#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
+
 #endif /* __KERNEL__ */
 
 #endif /* _ASM_THREAD_INFO_H */

arch/mn10300/include/asm/unistd.h

@@ -382,6 +382,8 @@
 #define __ARCH_WANT_SYS_SIGPROCMASK
 #define __ARCH_WANT_SYS_RT_SIGACTION
 #define __ARCH_WANT_SYS_RT_SIGSUSPEND
+#define __ARCH_WANT_SYS_EXECVE
+#define __ARCH_WANT_KERNEL_EXECVE
 
 /*
  * "Conditional" syscalls

arch/mn10300/kernel/Makefile

@@ -7,8 +7,8 @@ fpu-obj-y := fpu-nofpu.o fpu-nofpu-low.o
 fpu-obj-$(CONFIG_FPU) := fpu.o fpu-low.o
 
 obj-y   := process.o signal.o entry.o traps.o irq.o \
-	   ptrace.o setup.o time.o sys_mn10300.o io.o kthread.o \
-	   switch_to.o mn10300_ksyms.o kernel_execve.o $(fpu-obj-y) \
+	   ptrace.o setup.o time.o sys_mn10300.o io.o \
+	   switch_to.o mn10300_ksyms.o $(fpu-obj-y) \
 	   csrc-mn10300.o cevt-mn10300.o
 
 obj-$(CONFIG_SMP) += smp.o smp-low.o

arch/mn10300/kernel/entry.S

@@ -55,6 +55,20 @@ ENTRY(ret_from_fork)
 	mov	d0,(REG_D0,fp)
 	jmp	syscall_exit
 
+ENTRY(ret_from_kernel_thread)
+	call	schedule_tail[],0
+	mov	(REG_D0,fp),d0
+	mov	(REG_A0,fp),a0
+	calls	(a0)
+	jmp	sys_exit
+
+ENTRY(ret_from_kernel_execve)
+	add	-12,d0	/* pt_regs -> frame */
+	mov	d0,sp
+	GET_THREAD_INFO a2
+	clr	d0
+	jmp	syscall_exit
+
 ###############################################################################
 #
 # system call handler
@@ -94,6 +108,10 @@ restore_all:
 ###############################################################################
 	ALIGN
 syscall_exit_work:
+	mov	(REG_EPSW,fp),d0
+	and	EPSW_nSL,d0
+	beq	resume_kernel		# returning to supervisor mode
+
 	btst	_TIF_SYSCALL_TRACE,d2
 	beq	work_pending
 	LOCAL_IRQ_ENABLE		# could let syscall_trace_exit() call

arch/mn10300/kernel/internal.h

@@ -14,15 +14,11 @@
 struct clocksource;
 struct clock_event_device;
 
-/*
- * kthread.S
- */
-extern int kernel_thread_helper(int);
-
 /*
  * entry.S
  */
 extern void ret_from_fork(struct task_struct *) __attribute__((noreturn));
+extern void ret_from_kernel_thread(struct task_struct *) __attribute__((noreturn));
 
 /*
  * smp-low.S

arch/mn10300/kernel/kernel_execve.S

-/* MN10300 In-kernel program execution
- *
- * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public Licence
- * as published by the Free Software Foundation; either version
- * 2 of the Licence, or (at your option) any later version.
- */
-#include <linux/linkage.h>
-#include <asm/unistd.h>
-
-###############################################################################
-#
-# Do a system call from kernel instead of calling sys_execve so we end up with
-# proper pt_regs.
-#
-# int kernel_execve(const char *filename, char *const argv[],
-#		    char *const envp[])
-#
-# On entry: D0/D1/8(SP): arguments to function
-# On return: D0: syscall return.
-#
-###############################################################################
-	.globl		kernel_execve
-	.type		kernel_execve,@function
-kernel_execve:
-	mov		a3,a1
-	mov		d0,a0
-	mov		(12,sp),a3
-	mov		+__NR_execve,d0
-	syscall		0
-	mov		a1,a3
-	rets
-
-	.size		kernel_execve,.-kernel_execve

arch/mn10300/kernel/kthread.S

-/* MN10300 Kernel thread trampoline function
- *
- * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
- * Written by Mark Salter (msalter@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public Licence
- * as published by the Free Software Foundation; either version
- * 2 of the Licence, or (at your option) any later version.
- */
-	.text
-
-###############################################################################
-#
-# kernel_thread_helper - trampoline for kernel_thread()
-#
-# On entry:
-#   A2 = address of function to call
-#   D2 = function argument
-#
-###############################################################################
-	.globl	kernel_thread_helper
-	.type	kernel_thread_helper,@function
-kernel_thread_helper:
-	mov	do_exit,d1
-	mov	d1,(sp)
-	mov	d1,mdr
-	mov	d2,d0
-	jmp	(a2)
-
-	.size	kernel_thread_helper,.-kernel_thread_helper

arch/mn10300/kernel/process.c

@@ -164,27 +164,6 @@ void show_regs(struct pt_regs *regs)
 {
 }
 
-/*
- * create a kernel thread
- */
-int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
-{
-	struct pt_regs regs;
-
-	memset(&regs, 0, sizeof(regs));
-
-	regs.a2 = (unsigned long) fn;
-	regs.d2 = (unsigned long) arg;
-	regs.pc = (unsigned long) kernel_thread_helper;
-	local_save_flags(regs.epsw);
-	regs.epsw |= EPSW_IE | EPSW_IM_7;
-
-	/* Ok, create the new process.. */
-	return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0,
-		       NULL, NULL);
-}
-EXPORT_SYMBOL(kernel_thread);
-
 /*
  * free current thread data structures etc..
  */
@@ -230,50 +209,42 @@ int copy_thread(unsigned long clone_flags,
 		struct task_struct *p, struct pt_regs *kregs)
 {
 	struct thread_info *ti = task_thread_info(p);
-	struct pt_regs *c_uregs, *c_kregs, *uregs;
+	struct pt_regs *c_regs;
 	unsigned long c_ksp;
 
-	uregs = current->thread.uregs;
-
 	c_ksp = (unsigned long) task_stack_page(p) + THREAD_SIZE;
 
 	/* allocate the userspace exception frame and set it up */
 	c_ksp -= sizeof(struct pt_regs);
-	c_uregs = (struct pt_regs *) c_ksp;
+	c_regs = (struct pt_regs *) c_ksp;
+	c_ksp -= 12; /* allocate function call ABI slack */
 
-	p->thread.uregs = c_uregs;
-	*c_uregs = *uregs;
-	c_uregs->sp = c_usp;
-	c_uregs->epsw &= ~EPSW_FE; /* my FPU */
+	/* set up things up so the scheduler can start the new task */
+	p->thread.uregs = c_regs;
+	ti->frame	= c_regs;
+	p->thread.a3	= (unsigned long) c_regs;
+	p->thread.sp	= c_ksp;
+	p->thread.wchan	= p->thread.pc;
+	p->thread.usp	= c_usp;
 
-	c_ksp -= 12; /* allocate function call ABI slack */
+	if (unlikely(!kregs)) {
+		memset(c_regs, 0, sizeof(struct pt_regs));
+		c_regs->a0 = c_usp; /* function */
+		c_regs->d0 = ustk_size; /* argument */
+		local_save_flags(c_regs->epsw);
+		c_regs->epsw |= EPSW_IE | EPSW_IM_7;
+		p->thread.pc	= (unsigned long) ret_from_kernel_thread;
+		return 0;
+	}
+	*c_regs = *kregs;
+	c_regs->sp = c_usp;
+	c_regs->epsw &= ~EPSW_FE; /* my FPU */
 
 	/* the new TLS pointer is passed in as arg #5 to sys_clone() */
 	if (clone_flags & CLONE_SETTLS)
-		c_uregs->e2 = current_frame()->d3;
-
-	/* set up the return kernel frame if called from kernel_thread() */
-	c_kregs = c_uregs;
-	if (kregs != uregs) {
-		c_ksp -= sizeof(struct pt_regs);
-		c_kregs = (struct pt_regs *) c_ksp;
-		*c_kregs = *kregs;
-		c_kregs->sp = c_usp;
-		c_kregs->next = c_uregs;
-#ifdef CONFIG_MN10300_CURRENT_IN_E2
-		c_kregs->e2 = (unsigned long) p; /* current */
-#endif
-
-		c_ksp -= 12; /* allocate function call ABI slack */
-	}
+		c_regs->e2 = current_frame()->d3;
 
-	/* set up things up so the scheduler can start the new task */
-	ti->frame	= c_kregs;
-	p->thread.a3	= (unsigned long) c_kregs;
-	p->thread.sp	= c_ksp;
 	p->thread.pc	= (unsigned long) ret_from_fork;
-	p->thread.wchan	= (unsigned long) ret_from_fork;
-	p->thread.usp	= c_usp;
 
 	return 0;
 }
@@ -302,22 +273,6 @@ asmlinkage long sys_vfork(void)
 		       current_frame(), 0, NULL, NULL);
 }
 
-asmlinkage long sys_execve(const char __user *name,
-			   const char __user *const __user *argv,
-			   const char __user *const __user *envp)
-{
-	char *filename;
-	int error;
-
-	filename = getname(name);
-	error = PTR_ERR(filename);
-	if (IS_ERR(filename))
-		return error;
-	error = do_execve(filename, argv, envp, current_frame());
-	putname(filename);
-	return error;
-}
-
 unsigned long get_wchan(struct task_struct *p)
 {
 	return p->thread.wchan;

arch/mn10300/kernel/signal.c

@@ -317,10 +317,6 @@ static int setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
 	regs->d0 = sig;
 	regs->d1 = (unsigned long) &frame->sc;
 
-	/* the tracer may want to single-step inside the handler */
-	if (test_thread_flag(TIF_SINGLESTEP))
-		ptrace_notify(SIGTRAP);
-
 #if DEBUG_SIG
 	printk(KERN_DEBUG "SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
 	       sig, current->comm, current->pid, frame, regs->pc,
@@ -398,10 +394,6 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	regs->d0 = sig;
 	regs->d1 = (long) &frame->info;
 
-	/* the tracer may want to single-step inside the handler */
-	if (test_thread_flag(TIF_SINGLESTEP))
-		ptrace_notify(SIGTRAP);
-
 #if DEBUG_SIG
 	printk(KERN_DEBUG "SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
 	       sig, current->comm, current->pid, frame, regs->pc,
@@ -475,11 +467,6 @@ static void do_signal(struct pt_regs *regs)
 	siginfo_t info;
 	int signr;
 
-	/* we want the common case to go fast, which is why we may in certain
-	 * cases get here from kernel mode */
-	if (!user_mode(regs))
-		return;
-
 	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 	if (signr > 0) {
 		if (handle_signal(signr, &info, &ka, regs) == 0) {

arch/openrisc/include/asm/thread_info.h

@@ -121,7 +121,6 @@ register struct thread_info *current_thread_info_reg asm("r10");
 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
 #define _TIF_SINGLESTEP		(1<<TIF_SINGLESTEP)
-#define _TIF_RESTORE_SIGMASK     (1<<TIF_RESTORE_SIGMASK)
 #define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
 
 
@@ -129,6 +128,8 @@ register struct thread_info *current_thread_info_reg asm("r10");
 /* For OpenRISC, this is anything in the LSW other than syscall trace */
 #define _TIF_WORK_MASK (0xff & ~(_TIF_SYSCALL_TRACE|_TIF_SINGLESTEP))
 
+#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
+
 #endif /* __KERNEL__ */
 
 #endif /* _ASM_THREAD_INFO_H */

arch/parisc/hpux/gate.S

@@ -71,7 +71,7 @@ ENTRY(hpux_gateway_page)
 	STREG	%r26, TASK_PT_GR26(%r1)	 	/* 1st argument */
 	STREG	%r27, TASK_PT_GR27(%r1)		/* user dp */
 	STREG   %r28, TASK_PT_GR28(%r1)         /* return value 0 */
-	STREG   %r28, TASK_PT_ORIG_R28(%r1)     /* return value 0 (saved for signals) */
+	STREG   %r0, TASK_PT_ORIG_R28(%r1)     /* don't prohibit restarts */
 	STREG   %r29, TASK_PT_GR29(%r1)         /* 8th argument */
 	STREG	%r31, TASK_PT_GR31(%r1)		/* preserve syscall return ptr */
 	

arch/parisc/include/asm/thread_info.h

@@ -68,13 +68,16 @@ struct thread_info {
 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
 #define _TIF_POLLING_NRFLAG	(1 << TIF_POLLING_NRFLAG)
 #define _TIF_32BIT		(1 << TIF_32BIT)
-#define _TIF_RESTORE_SIGMASK	(1 << TIF_RESTORE_SIGMASK)
 #define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
 #define _TIF_SINGLESTEP		(1 << TIF_SINGLESTEP)
 #define _TIF_BLOCKSTEP		(1 << TIF_BLOCKSTEP)
 
 #define _TIF_USER_WORK_MASK     (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | \
                                  _TIF_NEED_RESCHED)
+#define _TIF_SYSCALL_TRACE_MASK (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP |	\
+				 _TIF_BLOCKSTEP)
+
+#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
 
 #endif /* __KERNEL__ */
 

arch/parisc/kernel/signal.c

@@ -113,6 +113,8 @@ sys_rt_sigreturn(struct pt_regs *regs, int in_syscall)
 		(usp - sigframe_size);
 	DBG(2,"sys_rt_sigreturn: frame is %p\n", frame);
 
+	regs->orig_r28 = 1; /* no restarts for sigreturn */
+
 #ifdef CONFIG_64BIT
 	compat_frame = (struct compat_rt_sigframe __user *)frame;
 	
@@ -437,7 +439,7 @@ setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
  * OK, we're invoking a handler.
  */	
 
-static long
+static void
 handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
 		struct pt_regs *regs, int in_syscall)
 {
@@ -447,7 +449,7 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
 	
 	/* Set up the stack frame */
 	if (!setup_rt_frame(sig, ka, info, oldset, regs, in_syscall))
-		return 0;
+		return;
 
 	signal_delivered(sig, info, ka, regs, 
 		test_thread_flag(TIF_SINGLESTEP) ||
@@ -455,13 +457,14 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
 
 	DBG(1,KERN_DEBUG "do_signal: Exit (success), regs->gr[28] = %ld\n",
 		regs->gr[28]);
-
-	return 1;
 }
 
 static inline void
 syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
 {
+	if (regs->orig_r28)
+		return;
+	regs->orig_r28 = 1; /* no more restarts */
 	/* Check the return code */
 	switch (regs->gr[28]) {
 	case -ERESTART_RESTARTBLOCK:
@@ -482,8 +485,6 @@ syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
 		 * we have to do is fiddle the return pointer.
 		 */
 		regs->gr[31] -= 8; /* delayed branching */
-		/* Preserve original r28. */
-		regs->gr[28] = regs->orig_r28;
 		break;
 	}
 }
@@ -491,6 +492,9 @@ syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
 static inline void
 insert_restart_trampoline(struct pt_regs *regs)
 {
+	if (regs->orig_r28)
+		return;
+	regs->orig_r28 = 1; /* no more restarts */
 	switch(regs->gr[28]) {
 	case -ERESTART_RESTARTBLOCK: {
 		/* Restart the system call - no handlers present */
@@ -525,9 +529,6 @@ insert_restart_trampoline(struct pt_regs *regs)
 		flush_user_icache_range(regs->gr[30], regs->gr[30] + 4);
 
 		regs->gr[31] = regs->gr[30] + 8;
-		/* Preserve original r28. */
-		regs->gr[28] = regs->orig_r28;
-
 		return;
 	}
 	case -ERESTARTNOHAND:
@@ -539,9 +540,6 @@ insert_restart_trampoline(struct pt_regs *regs)
 		 * slot of the branch external instruction.
 		 */
 		regs->gr[31] -= 8;
-		/* Preserve original r28. */
-		regs->gr[28] = regs->orig_r28;
-
 		return;
 	}
 	default:
@@ -570,30 +568,17 @@ do_signal(struct pt_regs *regs, long in_syscall)
 	DBG(1,"\ndo_signal: regs=0x%p, sr7 %#lx, in_syscall=%d\n",
 	       regs, regs->sr[7], in_syscall);
 
-	/* Everyone else checks to see if they are in kernel mode at
-	   this point and exits if that's the case.  I'm not sure why
-	   we would be called in that case, but for some reason we
-	   are. */
-
-	/* May need to force signal if handle_signal failed to deliver */
-	while (1) {
 	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 	DBG(3,"do_signal: signr = %d, regs->gr[28] = %ld\n", signr, regs->gr[28]); 
 	
-		if (signr <= 0)
-		  break;
-		
+	if (signr > 0) {
 		/* Restart a system call if necessary. */
 		if (in_syscall)
 			syscall_restart(regs, &ka);
 
-		/* Whee!  Actually deliver the signal.  If the
-		   delivery failed, we need to continue to iterate in
-		   this loop so we can deliver the SIGSEGV... */
-		if (handle_signal(signr, &info, &ka, regs, in_syscall))
+		handle_signal(signr, &info, &ka, regs, in_syscall);
 		return;
 	}
-	/* end of while(1) looping forever if we can't force a signal */
 
 	/* Did we come from a system call? */
 	if (in_syscall)

arch/parisc/kernel/syscall.S

@@ -156,7 +156,7 @@ linux_gateway_entry:
 	STREG	%r26, TASK_PT_GR26(%r1)	 	/* 1st argument */
 	STREG	%r27, TASK_PT_GR27(%r1)		/* user dp */
 	STREG   %r28, TASK_PT_GR28(%r1)         /* return value 0 */
-	STREG   %r28, TASK_PT_ORIG_R28(%r1)     /* return value 0 (saved for signals) */
+	STREG   %r0, TASK_PT_ORIG_R28(%r1)      /* don't prohibit restarts */
 	STREG	%r29, TASK_PT_GR29(%r1)		/* return value 1 */
 	STREG	%r31, TASK_PT_GR31(%r1)		/* preserve syscall return ptr */
 	
@@ -180,9 +180,10 @@ linux_gateway_entry:
 
 	/* Are we being ptraced? */
 	mfctl	%cr30, %r1
-	LDREG	TI_TASK(%r1),%r1
-	ldw	TASK_PTRACE(%r1), %r1
-	bb,<,n	%r1,31,.Ltracesys
+	LDREG	TI_FLAGS(%r1),%r1
+	ldi	_TIF_SYSCALL_TRACE_MASK, %r19
+	and,COND(=) %r1, %r19, %r0
+	b,n	.Ltracesys
 	
 	/* Note!  We cannot use the syscall table that is mapped
 	nearby since the gateway page is mapped execute-only. */

arch/powerpc/Kconfig

@@ -141,6 +141,7 @@ config PPC
 	select GENERIC_CLOCKEVENTS
 	select GENERIC_STRNCPY_FROM_USER
 	select GENERIC_STRNLEN_USER
+	select GENERIC_KERNEL_THREAD
 
 config EARLY_PRINTK
 	bool

arch/powerpc/include/asm/processor.h

@@ -74,9 +74,6 @@ struct task_struct;
 void start_thread(struct pt_regs *regs, unsigned long fdptr, unsigned long sp);
 void release_thread(struct task_struct *);
 
-/* Create a new kernel thread. */
-extern long kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
-
 /* Lazy FPU handling on uni-processor */
 extern struct task_struct *last_task_used_math;
 extern struct task_struct *last_task_used_altivec;

arch/powerpc/include/asm/ptrace.h

@@ -125,6 +125,8 @@ extern unsigned long ptrace_get_reg(struct task_struct *task, int regno);
 extern int ptrace_put_reg(struct task_struct *task, int regno,
 			  unsigned long data);
 
+#define current_pt_regs() \
+	((struct pt_regs *)((unsigned long)current_thread_info() + THREAD_SIZE) - 1)
 /*
  * We use the least-significant bit of the trap field to indicate
  * whether we have saved the full set of registers, or only a

arch/powerpc/include/asm/syscalls.h

@@ -17,9 +17,6 @@ asmlinkage unsigned long sys_mmap(unsigned long addr, size_t len,
 asmlinkage unsigned long sys_mmap2(unsigned long addr, size_t len,
 		unsigned long prot, unsigned long flags,
 		unsigned long fd, unsigned long pgoff);
-asmlinkage 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);
 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long usp,
 		int __user *parent_tidp, void __user *child_threadptr,
 		int __user *child_tidp, int p6, struct pt_regs *regs);

arch/powerpc/include/asm/thread_info.h

@@ -182,6 +182,8 @@ static inline bool test_thread_local_flags(unsigned int flags)
 #define is_32bit_task()	(1)
 #endif
 
+#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
+
 #endif	/* !__ASSEMBLY__ */
 
 #endif /* __KERNEL__ */

arch/powerpc/include/asm/unistd.h

@@ -421,6 +421,8 @@
 #define __ARCH_WANT_SYS_NEWFSTATAT
 #define __ARCH_WANT_COMPAT_SYS_SENDFILE
 #endif
+#define __ARCH_WANT_SYS_EXECVE
+#define __ARCH_WANT_KERNEL_EXECVE
 
 /*
  * "Conditional" syscalls

arch/powerpc/kernel/entry_32.S

@@ -435,6 +435,22 @@ ret_from_fork:
 	li	r3,0
 	b	ret_from_syscall
 
+	.globl	ret_from_kernel_thread
+ret_from_kernel_thread:
+	REST_NVGPRS(r1)
+	bl	schedule_tail
+	mtlr	r14
+	mr	r3,r15
+	PPC440EP_ERR42
+	blrl
+	li	r3,0
+	b	do_exit		# no return
+
+	.globl	__ret_from_kernel_execve
+__ret_from_kernel_execve:
+	addi	r1,r3,-STACK_FRAME_OVERHEAD
+	b	ret_from_syscall
+
 /* Traced system call support */
 syscall_dotrace:
 	SAVE_NVGPRS(r1)

arch/powerpc/kernel/entry_64.S

@@ -370,6 +370,22 @@ _GLOBAL(ret_from_fork)
 	li	r3,0
 	b	syscall_exit
 
+_GLOBAL(ret_from_kernel_thread)
+	bl	.schedule_tail
+	REST_NVGPRS(r1)
+	REST_GPR(2,r1)
+	mtlr	r14
+	mr	r3,r15
+	blrl
+	li	r3,0
+	b	.do_exit	# no return
+
+_GLOBAL(__ret_from_kernel_execve)
+	addi	r1,r3,-STACK_FRAME_OVERHEAD
+	li	r10,1
+	std	r10,SOFTE(r1)
+	b	syscall_exit
+
 	.section	".toc","aw"
 DSCR_DEFAULT:
 	.tc dscr_default[TC],dscr_default

arch/powerpc/kernel/misc.S

@@ -54,13 +54,6 @@ _GLOBAL(add_reloc_offset)
 	.align	3
 2:	PPC_LONG 1b
 
-_GLOBAL(kernel_execve)
-	li	r0,__NR_execve
-	sc
-	bnslr
-	neg	r3,r3
-	blr
-
 _GLOBAL(setjmp)
 	mflr	r0
 	PPC_STL	r0,0(r3)

arch/powerpc/kernel/misc_32.S

@@ -663,39 +663,6 @@ _GLOBAL(abs)
 	sub	r3,r3,r4
 	blr
 
-/*
- * Create a kernel thread
- *   kernel_thread(fn, arg, flags)
- */
-_GLOBAL(kernel_thread)
-	stwu	r1,-16(r1)
-	stw	r30,8(r1)
-	stw	r31,12(r1)
-	mr	r30,r3		/* function */
-	mr	r31,r4		/* argument */
-	ori	r3,r5,CLONE_VM	/* flags */
-	oris	r3,r3,CLONE_UNTRACED>>16
-	li	r4,0		/* new sp (unused) */
-	li	r0,__NR_clone
-	sc
-	bns+	1f		/* did system call indicate error? */
-	neg	r3,r3		/* if so, make return code negative */
-1:	cmpwi	0,r3,0		/* parent or child? */
-	bne	2f		/* return if parent */
-	li	r0,0		/* make top-level stack frame */
-	stwu	r0,-16(r1)
-	mtlr	r30		/* fn addr in lr */
-	mr	r3,r31		/* load arg and call fn */
-	PPC440EP_ERR42
-	blrl
-	li	r0,__NR_exit	/* exit if function returns */
-	li	r3,0
-	sc
-2:	lwz	r30,8(r1)
-	lwz	r31,12(r1)
-	addi	r1,r1,16
-	blr
-
 #ifdef CONFIG_SMP
 _GLOBAL(start_secondary_resume)
 	/* Reset stack */

arch/powerpc/kernel/misc_64.S

@@ -406,40 +406,6 @@ _GLOBAL(scom970_write)
 #endif /* CONFIG_CPU_FREQ_PMAC64 || CONFIG_CPU_FREQ_MAPLE */
 
 
-/*
- * Create a kernel thread
- *   kernel_thread(fn, arg, flags)
- */
-_GLOBAL(kernel_thread)
-	std	r29,-24(r1)
-	std	r30,-16(r1)
-	stdu	r1,-STACK_FRAME_OVERHEAD(r1)
-	mr	r29,r3
-	mr	r30,r4
-	ori	r3,r5,CLONE_VM	/* flags */
-	oris	r3,r3,(CLONE_UNTRACED>>16)
-	li	r4,0		/* new sp (unused) */
-	li	r0,__NR_clone
-	sc
-	bns+	1f		/* did system call indicate error? */
-	neg	r3,r3		/* if so, make return code negative */
-1:	cmpdi	0,r3,0		/* parent or child? */
-	bne	2f		/* return if parent */
-	li	r0,0
-	stdu	r0,-STACK_FRAME_OVERHEAD(r1)
-	ld	r2,8(r29)
-	ld	r29,0(r29)
-	mtlr	r29              /* fn addr in lr */
-	mr	r3,r30	        /* load arg and call fn */
-	blrl
-	li	r0,__NR_exit	/* exit after child exits */
-        li	r3,0
-	sc
-2:	addi	r1,r1,STACK_FRAME_OVERHEAD
-	ld	r29,-24(r1)
-	ld	r30,-16(r1)
-	blr
-
 /*
  * disable_kernel_fp()
  * Disable the FPU.

arch/powerpc/kernel/ppc_ksyms.c

@@ -94,7 +94,6 @@ EXPORT_SYMBOL(pci_dram_offset);
 #endif /* CONFIG_PCI */
 
 EXPORT_SYMBOL(start_thread);
-EXPORT_SYMBOL(kernel_thread);
 
 EXPORT_SYMBOL(giveup_fpu);
 #ifdef CONFIG_ALTIVEC

arch/powerpc/kernel/process.c

@@ -733,30 +733,39 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 extern unsigned long dscr_default; /* defined in arch/powerpc/kernel/sysfs.c */
 
 int copy_thread(unsigned long clone_flags, unsigned long usp,
-		unsigned long unused, struct task_struct *p,
+		unsigned long arg, struct task_struct *p,
 		struct pt_regs *regs)
 {
 	struct pt_regs *childregs, *kregs;
 	extern void ret_from_fork(void);
+	extern void ret_from_kernel_thread(void);
+	void (*f)(void);
 	unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
 
-	CHECK_FULL_REGS(regs);
 	/* Copy registers */
 	sp -= sizeof(struct pt_regs);
 	childregs = (struct pt_regs *) sp;
-	*childregs = *regs;
-	if ((childregs->msr & MSR_PR) == 0) {
+	if (!regs) {
 		/* for kernel thread, set `current' and stackptr in new task */
+		memset(childregs, 0, sizeof(struct pt_regs));
 		childregs->gpr[1] = sp + sizeof(struct pt_regs);
-#ifdef CONFIG_PPC32
-		childregs->gpr[2] = (unsigned long) p;
-#else
+#ifdef CONFIG_PPC64
+		childregs->gpr[14] = *(unsigned long *)usp;
+		childregs->gpr[2] = ((unsigned long *)usp)[1],
 		clear_tsk_thread_flag(p, TIF_32BIT);
+#else
+		childregs->gpr[14] = usp;	/* function */
+		childregs->gpr[2] = (unsigned long) p;
 #endif
+		childregs->gpr[15] = arg;
 		p->thread.regs = NULL;	/* no user register state */
+		f = ret_from_kernel_thread;
 	} else {
+		CHECK_FULL_REGS(regs);
+		*childregs = *regs;
 		childregs->gpr[1] = usp;
 		p->thread.regs = childregs;
+		childregs->gpr[3] = 0;  /* Result from fork() */
 		if (clone_flags & CLONE_SETTLS) {
 #ifdef CONFIG_PPC64
 			if (!is_32bit_task())
@@ -765,8 +774,9 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 #endif
 				childregs->gpr[2] = childregs->gpr[6];
 		}
+
+		f = ret_from_fork;
 	}
-	childregs->gpr[3] = 0;  /* Result from fork() */
 	sp -= STACK_FRAME_OVERHEAD;
 
 	/*
@@ -805,7 +815,6 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 		p->thread.dscr = current->thread.dscr;
 	}
 #endif
-
 	/*
 	 * The PPC64 ABI makes use of a TOC to contain function 
 	 * pointers.  The function (ret_from_except) is actually a pointer
@@ -813,11 +822,10 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 	 * function.
 	 */
 #ifdef CONFIG_PPC64
-	kregs->nip = *((unsigned long *)ret_from_fork);
+	kregs->nip = *((unsigned long *)f);
 #else
-	kregs->nip = (unsigned long)ret_from_fork;
+	kregs->nip = (unsigned long)f;
 #endif
-
 	return 0;
 }
 
@@ -1055,26 +1063,13 @@ 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,

arch/powerpc/kernel/signal_32.c

@@ -35,7 +35,6 @@
 #include <linux/stddef.h>
 #include <linux/tty.h>
 #include <linux/binfmts.h>
-#include <linux/freezer.h>
 #endif
 
 #include <asm/uaccess.h>

arch/powerpc/kernel/sys_ppc32.c

@@ -156,28 +156,6 @@ asmlinkage long compat_sys_sendfile64_wrapper(u32 out_fd, u32 in_fd,
 			    (off_t __user *)offset, count);
 }
 
-long compat_sys_execve(unsigned long a0, unsigned long a1, unsigned long a2,
-		  unsigned long a3, unsigned long a4, unsigned long a5,
-		  struct pt_regs *regs)
-{
-	int error;
-	char * filename;
-	
-	filename = getname((char __user *) a0);
-	error = PTR_ERR(filename);
-	if (IS_ERR(filename))
-		goto out;
-	flush_fp_to_thread(current);
-	flush_altivec_to_thread(current);
-
-	error = compat_do_execve(filename, compat_ptr(a1), compat_ptr(a2), regs);
-
-	putname(filename);
-
-out:
-	return error;
-}
-
 /* Note: it is necessary to treat option as an unsigned int, 
  * with the corresponding cast to a signed int to insure that the 
  * proper conversion (sign extension) between the register representation of a signed int (msr in 32-bit mode)

arch/s390/include/asm/thread_info.h

@@ -91,8 +91,6 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_SYSCALL_AUDIT	9	/* syscall auditing active */
 #define TIF_SECCOMP		10	/* secure computing */
 #define TIF_SYSCALL_TRACEPOINT	11	/* syscall tracepoint instrumentation */
-#define TIF_POLLING_NRFLAG	16	/* true if poll_idle() is polling
-					   TIF_NEED_RESCHED */
 #define TIF_31BIT		17	/* 32bit process */
 #define TIF_MEMDIE		18	/* is terminating due to OOM killer */
 #define TIF_RESTORE_SIGMASK	19	/* restore signal mask in do_signal() */
@@ -100,7 +98,6 @@ static inline struct thread_info *current_thread_info(void)
 
 #define _TIF_SYSCALL		(1<<TIF_SYSCALL)
 #define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
-#define _TIF_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)
 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
 #define _TIF_PER_TRAP		(1<<TIF_PER_TRAP)
@@ -109,7 +106,6 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)
 #define _TIF_SECCOMP		(1<<TIF_SECCOMP)
 #define _TIF_SYSCALL_TRACEPOINT	(1<<TIF_SYSCALL_TRACEPOINT)
-#define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
 #define _TIF_31BIT		(1<<TIF_31BIT)
 #define _TIF_SINGLE_STEP	(1<<TIF_SINGLE_STEP)
 

arch/score/include/asm/thread_info.h

@@ -86,16 +86,12 @@ register struct thread_info *__current_thread_info __asm__("r28");
 #define TIF_NEED_RESCHED	2	/* rescheduling necessary */
 #define TIF_NOTIFY_RESUME	5	/* callback before returning to user */
 #define TIF_RESTORE_SIGMASK	9	/* restore signal mask in do_signal() */
-#define TIF_POLLING_NRFLAG	17	/* true if poll_idle() is polling
-						 TIF_NEED_RESCHED */
 #define TIF_MEMDIE		18	/* is terminating due to OOM killer */
 
 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
 #define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
-#define _TIF_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)
-#define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
 
 #define _TIF_WORK_MASK		(0x0000ffff)
 

arch/score/kernel/signal.c

@@ -174,6 +174,7 @@ score_rt_sigreturn(struct pt_regs *regs)
 	/* It is more difficult to avoid calling this function than to
 	   call it and ignore errors.  */
 	do_sigaltstack((stack_t __user *)&st, NULL, regs->regs[0]);
+	regs->is_syscall = 0;
 
 	__asm__ __volatile__(
 		"mv\tr0, %0\n\t"

arch/sh/include/asm/thread_info.h

@@ -206,6 +206,9 @@ static inline bool test_and_clear_restore_sigmask(void)
 	ti->status &= ~TS_RESTORE_SIGMASK;
 	return true;
 }
+
+#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
+
 #endif	/* !__ASSEMBLY__ */
 
 #endif /* __KERNEL__ */

arch/sh/kernel/signal_32.c

@@ -22,7 +22,6 @@
 #include <linux/elf.h>
 #include <linux/personality.h>
 #include <linux/binfmts.h>
-#include <linux/freezer.h>
 #include <linux/io.h>
 #include <linux/tracehook.h>
 #include <asm/ucontext.h>

arch/sh/kernel/signal_64.c

@@ -18,7 +18,6 @@
 #include <linux/errno.h>
 #include <linux/wait.h>
 #include <linux/personality.h>
-#include <linux/freezer.h>
 #include <linux/ptrace.h>
 #include <linux/unistd.h>
 #include <linux/stddef.h>

arch/sparc/include/asm/thread_info_32.h

@@ -126,13 +126,14 @@ register struct thread_info *current_thread_info_reg asm("g6");
 #define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
-#define _TIF_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)
 #define _TIF_USEDFPU		(1<<TIF_USEDFPU)
 #define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
 
 #define _TIF_DO_NOTIFY_RESUME_MASK	(_TIF_NOTIFY_RESUME | \
 					 _TIF_SIGPENDING)
 
+#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
+
 #endif /* __KERNEL__ */
 
 #endif /* _ASM_THREAD_INFO_H */

arch/sparc/include/asm/thread_info_64.h

@@ -256,6 +256,9 @@ static inline bool test_and_clear_restore_sigmask(void)
 	ti->status &= ~TS_RESTORE_SIGMASK;
 	return true;
 }
+
+#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
+
 #endif	/* !__ASSEMBLY__ */
 
 #endif /* __KERNEL__ */

arch/tile/kernel/compat_signal.c

@@ -354,15 +354,6 @@ int compat_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	regs->regs[1] = ptr_to_compat_reg(&frame->info);
 	regs->regs[2] = ptr_to_compat_reg(&frame->uc);
 	regs->flags |= PT_FLAGS_CALLER_SAVES;
-
-	/*
-	 * Notify any tracer that was single-stepping it.
-	 * The tracer may want to single-step inside the
-	 * handler too.
-	 */
-	if (test_thread_flag(TIF_SINGLESTEP))
-		ptrace_notify(SIGTRAP);
-
 	return 0;
 
 give_sigsegv:

arch/tile/kernel/signal.c

@@ -219,15 +219,6 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	regs->regs[1] = (unsigned long) &frame->info;
 	regs->regs[2] = (unsigned long) &frame->uc;
 	regs->flags |= PT_FLAGS_CALLER_SAVES;
-
-	/*
-	 * Notify any tracer that was single-stepping it.
-	 * The tracer may want to single-step inside the
-	 * handler too.
-	 */
-	if (test_thread_flag(TIF_SINGLESTEP))
-		ptrace_notify(SIGTRAP);
-
 	return 0;
 
 give_sigsegv:
@@ -278,7 +269,8 @@ static void handle_signal(unsigned long sig, siginfo_t *info,
 		ret = setup_rt_frame(sig, ka, info, oldset, regs);
 	if (ret)
 		return;
-	signal_delivered(sig, info, ka, regs, 0);
+	signal_delivered(sig, info, ka, regs,
+			test_thread_flag(TIF_SINGLESTEP));
 }
 
 /*

arch/um/include/asm/thread_info.h

@@ -65,8 +65,6 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_SYSCALL_TRACE	0	/* syscall trace active */
 #define TIF_SIGPENDING		1	/* signal pending */
 #define TIF_NEED_RESCHED	2	/* rescheduling necessary */
-#define TIF_POLLING_NRFLAG      3       /* true if poll_idle() is polling
-					 * TIF_NEED_RESCHED */
 #define TIF_RESTART_BLOCK	4
 #define TIF_MEMDIE		5	/* is terminating due to OOM killer */
 #define TIF_SYSCALL_AUDIT	6
@@ -76,7 +74,6 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
 #define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
-#define _TIF_POLLING_NRFLAG     (1 << TIF_POLLING_NRFLAG)
 #define _TIF_MEMDIE		(1 << TIF_MEMDIE)
 #define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)
 

arch/unicore32/include/asm/thread_info.h

@@ -141,12 +141,12 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
 #define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
 #define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
-#define _TIF_RESTORE_SIGMASK	(1 << TIF_RESTORE_SIGMASK)
 
 /*
  * Change these and you break ASM code in entry-common.S
  */
-#define _TIF_WORK_MASK		0x000000ff
+#define _TIF_WORK_MASK \
+	(_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_NOTIFY_RESUME)
 
 #endif /* __KERNEL__ */
 #endif /* __UNICORE_THREAD_INFO_H__ */

arch/unicore32/kernel/entry.S

@@ -544,8 +544,6 @@ fast_work_pending:
 work_pending:
 	cand.a	r1, #_TIF_NEED_RESCHED
 	bne	work_resched
-	cand.a	r1, #_TIF_SIGPENDING|_TIF_NOTIFY_RESUME
-	beq	no_work_pending
 	mov	r0, sp				@ 'regs'
 	mov	r2, why				@ 'syscall'
 	cand.a	r1, #_TIF_SIGPENDING		@ delivering a signal?

arch/unicore32/kernel/signal.c

@@ -12,7 +12,6 @@
 #include <linux/errno.h>
 #include <linux/signal.h>
 #include <linux/personality.h>
-#include <linux/freezer.h>
 #include <linux/uaccess.h>
 #include <linux/tracehook.h>
 #include <linux/elf.h>

arch/x86/kernel/entry_32.S

@@ -622,6 +622,10 @@ work_notifysig:				# deal with pending signals and
 	movl %esp, %eax
 	jne work_notifysig_v86		# returning to kernel-space or
 					# vm86-space
+1:
+#else
+	movl %esp, %eax
+#endif
 	TRACE_IRQS_ON
 	ENABLE_INTERRUPTS(CLBR_NONE)
 	movb PT_CS(%esp), %bl
@@ -632,24 +636,15 @@ work_notifysig:				# deal with pending signals and
 	call do_notify_resume
 	jmp resume_userspace
 
+#ifdef CONFIG_VM86
 	ALIGN
 work_notifysig_v86:
 	pushl_cfi %ecx			# save ti_flags for do_notify_resume
 	call save_v86_state		# %eax contains pt_regs pointer
 	popl_cfi %ecx
 	movl %eax, %esp
-#else
-	movl %esp, %eax
+	jmp 1b
 #endif
-	TRACE_IRQS_ON
-	ENABLE_INTERRUPTS(CLBR_NONE)
-	movb PT_CS(%esp), %bl
-	andb $SEGMENT_RPL_MASK, %bl
-	cmpb $USER_RPL, %bl
-	jb resume_kernel
-	xorl %edx, %edx
-	call do_notify_resume
-	jmp resume_userspace
 END(work_pending)
 
 	# perform syscall exit tracing

arch/xtensa/include/asm/thread_info.h

@@ -128,19 +128,14 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_SIGPENDING		1	/* signal pending */
 #define TIF_NEED_RESCHED	2	/* rescheduling necessary */
 #define TIF_SINGLESTEP		3	/* restore singlestep on return to user mode */
-#define TIF_IRET		4	/* return with iret */
 #define TIF_MEMDIE		5	/* is terminating due to OOM killer */
 #define TIF_RESTORE_SIGMASK	6	/* restore signal mask in do_signal() */
 #define TIF_NOTIFY_RESUME	7	/* callback before returning to user */
-#define TIF_POLLING_NRFLAG	16	/* true if poll_idle() is polling TIF_NEED_RESCHED */
 
 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
 #define _TIF_SINGLESTEP		(1<<TIF_SINGLESTEP)
-#define _TIF_IRET		(1<<TIF_IRET)
-#define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
-#define _TIF_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)
 
 #define _TIF_WORK_MASK		0x0000FFFE	/* work to do on interrupt/exception return */
 #define _TIF_ALLWORK_MASK	0x0000FFFF	/* work to do on any return to u-space */

arch/xtensa/kernel/signal.c

@@ -19,7 +19,6 @@
 #include <linux/errno.h>
 #include <linux/ptrace.h>
 #include <linux/personality.h>
-#include <linux/freezer.h>
 #include <linux/tracehook.h>
 
 #include <asm/ucontext.h>
@@ -527,9 +526,6 @@ static void do_signal(struct pt_regs *regs)
 
 void do_notify_resume(struct pt_regs *regs)
 {
-	if (!user_mode(regs))
-		return;
-
 	if (test_thread_flag(TIF_SIGPENDING))
 		do_signal(regs);
 

kernel/sched/core.c

@@ -505,7 +505,7 @@ static inline void init_hrtick(void)
 #ifdef CONFIG_SMP
 
 #ifndef tsk_is_polling
-#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
+#define tsk_is_polling(t) 0
 #endif
 
 void resched_task(struct task_struct *p)