Merge bk://ppc.bkbits.net/for-linus-ppc

into home.transmeta.com:/home/torvalds/v2.5/linux

arch/ppc/kernel/entry.S

@@ -173,8 +173,10 @@ _GLOBAL(DoSyscall)
 	cmpli	0,r0,NR_syscalls
 	bge-	66f
 	rlwinm	r10,r1,0,0,18	/* current_thread_info() */
-	lwz	r10,TI_FLAGS(r10)
-	andi.	r10,r10,_TIF_SYSCALL_TRACE
+	lwz	r11,TI_FLAGS(r10)
+	rlwinm	r11,r11,0,~_TIF_FORCE_NOERROR
+	stw	r11,TI_FLAGS(r10)
+	andi.	r11,r11,_TIF_SYSCALL_TRACE
 	bne-	syscall_dotrace
 syscall_dotrace_cont:
 	lis	r10,sys_call_table@h
@@ -192,7 +194,11 @@ ret_from_syscall:
 	mr	r6,r3
 	li	r11,-_LAST_ERRNO
 	cmpl	0,r3,r11
+	rlwinm	r12,r1,0,0,18	/* current_thread_info() */
 	blt+	30f
+	lwz	r11,TI_FLAGS(r12)
+	andi.	r11,r11,_TIF_FORCE_NOERROR
+	bne	30f
 	neg	r3,r3
 	cmpi	0,r3,ERESTARTNOHAND
 	bne	22f
@@ -205,7 +211,6 @@ ret_from_syscall:
 30:	LOAD_MSR_KERNEL(r10,MSR_KERNEL)	/* doesn't include MSR_EE */
 	SYNC
 	MTMSRD(r10)
-	rlwinm	r12,r1,0,0,18	/* current_thread_info() */
 	lwz	r9,TI_FLAGS(r12)
 	andi.	r0,r9,(_TIF_SYSCALL_TRACE|_TIF_SIGPENDING|_TIF_NEED_RESCHED)
 	bne-	syscall_exit_work

arch/ppc/kernel/process.c

@@ -69,8 +69,6 @@ struct task_struct init_task = INIT_TASK(init_task);
 /* only used to get secondary processor up */
 struct task_struct *current_set[NR_CPUS] = {&init_task, };
 
-static void show_tsk_stack(struct task_struct *tsk, unsigned long sp);
-
 #undef SHOW_TASK_SWITCHES
 #undef CHECK_STACK
 
@@ -296,7 +294,7 @@ void show_regs(struct pt_regs * regs)
 			break;
 	}
 	printk("\n");
-	show_tsk_stack(current, regs->gpr[1]);
+	show_stack(current, (unsigned long *) regs->gpr[1]);
 }
 
 void exit_thread(void)
@@ -494,26 +492,29 @@ int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2,
 	return error;
 }
 
-void show_trace_task(struct task_struct *tsk)
-{
-	show_tsk_stack(tsk, tsk->thread.ksp);
-}
-
 void dump_stack(void)
 {
-	show_tsk_stack(current, _get_SP());
+	show_stack(current, NULL);
 }
 
-static void show_tsk_stack(struct task_struct *tsk, unsigned long sp)
+void show_stack(struct task_struct *tsk, unsigned long *stack)
 {
-	unsigned long stack_top, prev_sp, ret;
+	unsigned long sp, stack_top, prev_sp, ret;
 	int count = 0;
 	unsigned long next_exc = 0;
 	struct pt_regs *regs;
 	extern char ret_from_except, ret_from_except_full, ret_from_syscall;
 
+	sp = (unsigned long) stack;
 	if (tsk == NULL)
-		return;
+		tsk = current;
+	if (sp == 0) {
+		if (tsk == current)
+			asm("mr %0,1" : "=r" (sp));
+		else
+			sp = tsk->thread.ksp;
+	}
+
 	prev_sp = (unsigned long) (tsk->thread_info + 1);
 	stack_top = (unsigned long) tsk->thread_info + THREAD_SIZE;
 	while (count < 16 && sp > prev_sp && sp < stack_top && (sp & 3) == 0) {

include/asm-ppc/hardirq.h

@@ -104,7 +104,5 @@ do {									\
   extern void synchronize_irq(unsigned int irq);
 #endif /* CONFIG_SMP */
 
-extern void show_stack(unsigned long *sp);
-
 #endif /* __ASM_HARDIRQ_H */
 #endif /* __KERNEL__ */

include/asm-ppc/ptrace.h

@@ -49,6 +49,8 @@ struct pt_regs {
 #define instruction_pointer(regs) ((regs)->nip)
 #define user_mode(regs) (((regs)->msr & MSR_PR) != 0)
 
+#define force_successful_syscall_return()   set_thread_flag(TIF_FORCE_NOERROR)
+
 /*
  * We use the least-significant bit of the trap field to indicate
  * whether we have saved the full set of registers, or only a

include/asm-ppc/thread_info.h

@@ -86,6 +86,8 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_NEED_RESCHED	3	/* rescheduling necessary */
 #define TIF_POLLING_NRFLAG	4	/* true if poll_idle() is polling
 					   TIF_NEED_RESCHED */
+#define TIF_FORCE_NOERROR	5	/* don't return error from current
+					   syscall even if result < 0 */
 
 /* as above, but as bit values */
 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
@@ -93,6 +95,7 @@ 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_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
+#define _TIF_FORCE_NOERROR	(1<<TIF_FORCE_NOERROR)
 
 #endif /* __KERNEL__ */