Revert strace hiccups fix.

This reverts commit 40138249 and
ffa9009c.

There are problems with how the flag bytes were rearranged, in
particular we really can't move values down into the lowest
16 bits since those are used for individual state bits.
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc/include/asm/ptrace.h

@@ -202,7 +202,9 @@ struct global_reg_snapshot {
 };
 extern struct global_reg_snapshot global_reg_snapshot[NR_CPUS];
 
-#define force_successful_syscall_return() set_thread_noerror(1)
+#define force_successful_syscall_return()	    \
+do {	current_thread_info()->syscall_noerror = 1; \
+} while (0)
 #define user_mode(regs) (!((regs)->tstate & TSTATE_PRIV))
 #define instruction_pointer(regs) ((regs)->tpc)
 #define instruction_pointer_set(regs, val) ((regs)->tpc = (val))

arch/sparc/include/asm/thread_info_64.h

@@ -18,12 +18,10 @@
 #define TI_FLAG_CWP_SHIFT		40
 #define TI_FLAG_BYTE_CURRENT_DS		3
 #define TI_FLAG_CURRENT_DS_SHIFT	32
-#define TI_FLAG_BYTE_NOERROR		4
-#define TI_FLAG_BYTE_NOERROR_SHIFT	24
-#define TI_FLAG_BYTE_FPDEPTH		5
-#define TI_FLAG_FPDEPTH_SHIFT		16
-#define TI_FLAG_BYTE_WSAVED		6
-#define TI_FLAG_WSAVED_SHIFT		8
+#define TI_FLAG_BYTE_FPDEPTH		4
+#define TI_FLAG_FPDEPTH_SHIFT		24
+#define TI_FLAG_BYTE_WSAVED		5
+#define TI_FLAG_WSAVED_SHIFT		16
 
 #include <asm/page.h>
 
@@ -49,7 +47,7 @@ struct thread_info {
 	struct exec_domain	*exec_domain;
 	int			preempt_count;	/* 0 => preemptable, <0 => BUG */
 	__u8			new_child;
-	__u8			__pad;
+	__u8			syscall_noerror;
 	__u16			cpu;
 
 	unsigned long		*utraps;
@@ -79,7 +77,6 @@ struct thread_info {
 #define TI_CURRENT_DS	(TI_FLAGS + TI_FLAG_BYTE_CURRENT_DS)
 #define TI_FPDEPTH	(TI_FLAGS + TI_FLAG_BYTE_FPDEPTH)
 #define TI_WSAVED	(TI_FLAGS + TI_FLAG_BYTE_WSAVED)
-#define TI_SYS_NOERROR	(TI_FLAGS + TI_FLAG_BYTE_NOERROR)
 #define TI_FPSAVED	0x00000010
 #define TI_KSP		0x00000018
 #define TI_FAULT_ADDR	0x00000020
@@ -87,6 +84,7 @@ struct thread_info {
 #define TI_EXEC_DOMAIN	0x00000030
 #define TI_PRE_COUNT	0x00000038
 #define TI_NEW_CHILD	0x0000003c
+#define TI_SYS_NOERROR	0x0000003d
 #define TI_CPU		0x0000003e
 #define TI_UTRAPS	0x00000040
 #define TI_REG_WINDOW	0x00000048
@@ -157,8 +155,6 @@ register struct thread_info *current_thread_info_reg asm("g6");
 #define set_thread_cwp(val)		(__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_CWP] = (val))
 #define get_thread_current_ds()		(__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_CURRENT_DS])
 #define set_thread_current_ds(val)	(__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_CURRENT_DS] = (val))
-#define get_thread_noerror()		(__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_NOERROR])
-#define set_thread_noerror(val)		(__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_NOERROR] = (val))
 #define get_thread_fpdepth()		(__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_FPDEPTH])
 #define set_thread_fpdepth(val)		(__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_FPDEPTH] = (val))
 #define get_thread_wsaved()		(__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_WSAVED])

arch/sparc/kernel/etrap_64.S

@@ -92,10 +92,8 @@ etrap_save:	save	%g2, -STACK_BIAS, %sp
 		rdpr	%wstate, %g2
 		wrpr	%g0, 0, %canrestore
 		sll	%g2, 3, %g2
-
-		/* Set TI_SYS_FPDEPTH to 1 and clear TI_SYS_NOERROR.  */
 		mov	1, %l5
-		sth	%l5, [%l6 + TI_SYS_NOERROR]
+		stb	%l5, [%l6 + TI_FPDEPTH]
 
 		wrpr	%g3, 0, %otherwin
 		wrpr	%g2, 0, %wstate
@@ -154,9 +152,7 @@ etrap_save:	save	%g2, -STACK_BIAS, %sp
 		add	%l6, TI_FPSAVED + 1, %l4
 		srl	%l5, 1, %l3
 		add	%l5, 2, %l5
-
-		/* Set TI_SYS_FPDEPTH to %l5 and clear TI_SYS_NOERROR.  */
-		sth	%l5, [%l6 + TI_SYS_NOERROR]
+		stb	%l5, [%l6 + TI_FPDEPTH]
 		ba,pt	%xcc, 2b
 		 stb	%g0, [%l4 + %l3]
 		nop

arch/sparc/kernel/syscalls.S

@@ -212,19 +212,24 @@ linux_sparc_syscall:
 3:	stx	%o0, [%sp + PTREGS_OFF + PT_V9_I0]
 ret_sys_call:
 	ldx	[%sp + PTREGS_OFF + PT_V9_TSTATE], %g3
+	ldx	[%sp + PTREGS_OFF + PT_V9_TNPC], %l1 ! pc = npc
 	sra	%o0, 0, %o0
 	mov	%ulo(TSTATE_XCARRY | TSTATE_ICARRY), %g2
 	sllx	%g2, 32, %g2
 
+	/* Check if force_successful_syscall_return()
+	 * was invoked.
+	 */
+	ldub	[%g6 + TI_SYS_NOERROR], %l2
+	brnz,a,pn %l2, 80f
+	 stb	%g0, [%g6 + TI_SYS_NOERROR]
+
 	cmp	%o0, -ERESTART_RESTARTBLOCK
 	bgeu,pn	%xcc, 1f
-	 andcc	%l0, (_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT|_TIF_SYSCALL_TRACEPOINT), %g0
-	ldx	[%sp + PTREGS_OFF + PT_V9_TNPC], %l1 ! pc = npc
-
-2:
+	 andcc	%l0, (_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT|_TIF_SYSCALL_TRACEPOINT), %l6
+80:
 	/* System call success, clear Carry condition code. */
 	andn	%g3, %g2, %g3
-3:
 	stx	%g3, [%sp + PTREGS_OFF + PT_V9_TSTATE]	
 	bne,pn	%icc, linux_syscall_trace2
 	 add	%l1, 0x4, %l2			! npc = npc+4
@@ -233,20 +238,20 @@ ret_sys_call:
 	 stx	%l2, [%sp + PTREGS_OFF + PT_V9_TNPC]
 
 1:
-	/* Check if force_successful_syscall_return()
-	 * was invoked.
-	 */
-	ldub	[%g6 + TI_SYS_NOERROR], %l2
-	brnz,pn %l2, 2b
-	 ldx	[%sp + PTREGS_OFF + PT_V9_TNPC], %l1 ! pc = npc
 	/* System call failure, set Carry condition code.
 	 * Also, get abs(errno) to return to the process.
 	 */
+	andcc	%l0, (_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT|_TIF_SYSCALL_TRACEPOINT), %l6	
 	sub	%g0, %o0, %o0
+	or	%g3, %g2, %g3
 	stx	%o0, [%sp + PTREGS_OFF + PT_V9_I0]
-	ba,pt	%xcc, 3b
-	 or	%g3, %g2, %g3
+	stx	%g3, [%sp + PTREGS_OFF + PT_V9_TSTATE]
+	bne,pn	%icc, linux_syscall_trace2
+	 add	%l1, 0x4, %l2			! npc = npc+4
+	stx	%l1, [%sp + PTREGS_OFF + PT_V9_TPC]
 
+	b,pt	%xcc, rtrap
+	 stx	%l2, [%sp + PTREGS_OFF + PT_V9_TNPC]
 linux_syscall_trace2:
 	call	syscall_trace_leave
 	 add	%sp, PTREGS_OFF, %o0

arch/sparc/kernel/traps_64.c

@@ -2547,6 +2547,8 @@ void __init trap_init(void)
 		     TI_PRE_COUNT != offsetof(struct thread_info,
 					      preempt_count) ||
 		     TI_NEW_CHILD != offsetof(struct thread_info, new_child) ||
+		     TI_SYS_NOERROR != offsetof(struct thread_info,
+						syscall_noerror) ||
 		     TI_RESTART_BLOCK != offsetof(struct thread_info,
 						  restart_block) ||
 		     TI_KUNA_REGS != offsetof(struct thread_info,