[ipfire-2.x.git] / src / patches / suse-2.6.27.39 / patches.trace / s390-syscall-get-nr.diff

Subject: [PATCH] fix syscall_get_nr.

From: Martin Schwidefsky <schwidefsky@de.ibm.com>

syscall_get_nr() currently returns a valid result only if the call
chain of the traced process includes do_syscall_trace_enter(). But
collect_syscall() can be called for any sleeping task, the result of
syscall_get_nr() in general is completely bogus.

To make syscall_get_nr() work for any sleeping task the traps field
in pt_regs is replace with svcnr - the system call number the process
is executing. If svcnr == 0 the process is not on a system call path.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: John Jolly <jjolly@novell.com>
---

 arch/s390/include/asm/ptrace.h   |    2 +-
 arch/s390/include/asm/syscall.h  |    4 +---
 arch/s390/kernel/asm-offsets.c   |    2 +-
 arch/s390/kernel/compat_signal.c |    2 +-
 arch/s390/kernel/entry.S         |   21 +++++++++++----------
 arch/s390/kernel/entry64.S       |   23 ++++++++++-------------
 arch/s390/kernel/ptrace.c        |    2 +-
 arch/s390/kernel/signal.c        |    6 +++---
 8 files changed, 29 insertions(+), 33 deletions(-)

--- a/arch/s390/include/asm/ptrace.h
+++ b/arch/s390/include/asm/ptrace.h
@@ -321,8 +321,8 @@ struct pt_regs 
 	psw_t psw;
 	unsigned long gprs[NUM_GPRS];
 	unsigned long orig_gpr2;
+	unsigned short svcnr;
 	unsigned short ilc;
-	unsigned short trap;
 };
 #endif
 
--- a/arch/s390/include/asm/syscall.h
+++ b/arch/s390/include/asm/syscall.h
@@ -17,9 +17,7 @@
 static inline long syscall_get_nr(struct task_struct *task,
 				  struct pt_regs *regs)
 {
-	if (regs->trap != __LC_SVC_OLD_PSW)
-		return -1;
-	return regs->gprs[2];
+	return regs->svcnr ? regs->svcnr : -1;
 }
 
 static inline void syscall_rollback(struct task_struct *task,
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -32,7 +32,7 @@ int main(void)
 	DEFINE(__PT_GPRS, offsetof(struct pt_regs, gprs));
 	DEFINE(__PT_ORIG_GPR2, offsetof(struct pt_regs, orig_gpr2));
 	DEFINE(__PT_ILC, offsetof(struct pt_regs, ilc));
-	DEFINE(__PT_TRAP, offsetof(struct pt_regs, trap));
+	DEFINE(__PT_SVCNR, offsetof(struct pt_regs, svcnr));
 	DEFINE(__PT_SIZE, sizeof(struct pt_regs));
 	BLANK();
 	DEFINE(__SF_BACKCHAIN, offsetof(struct stack_frame, back_chain));
--- a/arch/s390/kernel/compat_signal.c
+++ b/arch/s390/kernel/compat_signal.c
@@ -340,7 +340,7 @@ static int restore_sigregs32(struct pt_r
 		return err;
 
 	restore_fp_regs(&current->thread.fp_regs);
-	regs->trap = -1;	/* disable syscall checks */
+	regs->svcnr = 0;	/* disable syscall checks */
 	return 0;
 }
 
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -46,7 +46,7 @@ SP_R14	     =	STACK_FRAME_OVERHEAD + __P
 SP_R15	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 120
 SP_ORIG_R2   =	STACK_FRAME_OVERHEAD + __PT_ORIG_GPR2
 SP_ILC	     =	STACK_FRAME_OVERHEAD + __PT_ILC
-SP_TRAP      =	STACK_FRAME_OVERHEAD + __PT_TRAP
+SP_SVCNR      =	STACK_FRAME_OVERHEAD + __PT_SVCNR
 SP_SIZE      =	STACK_FRAME_OVERHEAD + __PT_SIZE
 
 STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
@@ -168,11 +168,10 @@ _TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_
 	.macro	CREATE_STACK_FRAME psworg,savearea
 	aghi	%r15,-SP_SIZE		# make room for registers & psw
 	mvc	SP_PSW(16,%r15),0(%r12)	# move user PSW to stack
-	la	%r12,\psworg
 	stg	%r2,SP_ORIG_R2(%r15)	# store original content of gpr 2
-	icm	%r12,12,__LC_SVC_ILC
+	icm	%r12,3,__LC_SVC_ILC
 	stmg	%r0,%r11,SP_R0(%r15)	# store gprs %r0-%r11 to kernel stack
-	st	%r12,SP_ILC(%r15)
+	st	%r12,SP_SVCNR(%r15)
 	mvc	SP_R12(32,%r15),\savearea # move %r12-%r15 to stack
 	la	%r12,0
 	stg	%r12,__SF_BACKCHAIN(%r15)
@@ -247,16 +246,17 @@ sysc_update:
 #endif
 sysc_do_svc:
 	lg	%r9,__LC_THREAD_INFO	# load pointer to thread_info struct
-	slag	%r7,%r7,2	# *4 and test for svc 0
+	ltgr	%r7,%r7		# test for svc 0
 	jnz	sysc_nr_ok
 	# svc 0: system call number in %r1
 	cl	%r1,BASED(.Lnr_syscalls)
 	jnl	sysc_nr_ok
 	lgfr	%r7,%r1 	# clear high word in r1
-	slag	%r7,%r7,2	# svc 0: system call number in %r1
 sysc_nr_ok:
 	mvc	SP_ARGS(8,%r15),SP_R7(%r15)
 sysc_do_restart:
+	sth	%r7,SP_SVCNR(%r15)
+	sllg	%r7,%r7,2	# svc number * 4
 	larl	%r10,sys_call_table
 #ifdef CONFIG_COMPAT
 	tm	__TI_flags+5(%r9),(_TIF_31BIT>>16)  # running in 31 bit mode ?
@@ -360,7 +360,6 @@ sysc_notify_resume:
 sysc_restart:
 	ni	__TI_flags+7(%r9),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC
 	lg	%r7,SP_R2(%r15)		# load new svc number
-	slag	%r7,%r7,2		# *4
 	mvc	SP_R2(8,%r15),SP_ORIG_R2(%r15) # restore first argument
 	lmg	%r2,%r6,SP_R2(%r15)	# load svc arguments
 	j	sysc_do_restart 	# restart svc
@@ -369,9 +368,8 @@ sysc_restart:
 # _TIF_SINGLE_STEP is set, call do_single_step
 #
 sysc_singlestep:
-	ni	__TI_flags+7(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP
-	lhi	%r0,__LC_PGM_OLD_PSW
-	sth	%r0,SP_TRAP(%r15)	# set trap indication to pgm check
+	ni	__TI_flags+7(%r9),255-_TIF_SINGLE_STEP	# clear TIF_SINGLE_STEP
+	xc	SP_SVCNR(2,%r15),SP_SVCNR(%r15)		# clear svc number
 	la	%r2,SP_PTREGS(%r15)	# address of register-save area
 	larl	%r14,sysc_return	# load adr. of system return
 	jg	do_single_step		# branch to do_sigtrap
@@ -389,7 +387,7 @@ sysc_tracesys:
 	lghi	%r0,NR_syscalls
 	clgr	%r0,%r2
 	jnh	sysc_tracenogo
-	slag	%r7,%r2,2		# *4
+	sllg	%r7,%r2,2		# svc number *4
 	lgf	%r8,0(%r7,%r10)
 sysc_tracego:
 	lmg	%r3,%r6,SP_R3(%r15)
@@ -564,8 +562,7 @@ pgm_svcper:
 # per was called from kernel, must be kprobes
 #
 kernel_per:
-	lhi	%r0,__LC_PGM_OLD_PSW
-	sth	%r0,SP_TRAP(%r15)	# set trap indication to pgm check
+	xc	SP_SVCNR(2,%r15),SP_SVCNR(%r15)	# clear svc number
 	la	%r2,SP_PTREGS(%r15)	# address of register-save area
 	larl	%r14,sysc_restore	# load adr. of system ret, no work
 	jg	do_single_step		# branch to do_single_step
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -46,7 +46,7 @@ SP_R14	     =	STACK_FRAME_OVERHEAD + __P
 SP_R15	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 60
 SP_ORIG_R2   =	STACK_FRAME_OVERHEAD + __PT_ORIG_GPR2
 SP_ILC	     =	STACK_FRAME_OVERHEAD + __PT_ILC
-SP_TRAP      =	STACK_FRAME_OVERHEAD + __PT_TRAP
+SP_SVCNR     =	STACK_FRAME_OVERHEAD + __PT_SVCNR
 SP_SIZE      =	STACK_FRAME_OVERHEAD + __PT_SIZE
 
 _TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
@@ -180,11 +180,10 @@ STACK_SIZE  = 1 << STACK_SHIFT
 	.macro	CREATE_STACK_FRAME psworg,savearea
 	s	%r15,BASED(.Lc_spsize)	# make room for registers & psw
 	mvc	SP_PSW(8,%r15),0(%r12)	# move user PSW to stack
-	la	%r12,\psworg
 	st	%r2,SP_ORIG_R2(%r15)	# store original content of gpr 2
-	icm	%r12,12,__LC_SVC_ILC
+	icm	%r12,3,__LC_SVC_ILC
 	stm	%r0,%r11,SP_R0(%r15)	# store gprs %r0-%r11 to kernel stack
-	st	%r12,SP_ILC(%r15)
+	st	%r12,SP_SVCNR(%r15)
 	mvc	SP_R12(16,%r15),\savearea # move %r12-%r15 to stack
 	la	%r12,0
 	st	%r12,__SF_BACKCHAIN(%r15)	# clear back chain
@@ -261,16 +260,17 @@ sysc_update:
 #endif
 sysc_do_svc:
 	l	%r9,__LC_THREAD_INFO	# load pointer to thread_info struct
-	sla	%r7,2			# *4 and test for svc 0
+	ltr	%r7,%r7			# test for svc 0
 	bnz	BASED(sysc_nr_ok)	# svc number > 0
 	# svc 0: system call number in %r1
 	cl	%r1,BASED(.Lnr_syscalls)
 	bnl	BASED(sysc_nr_ok)
 	lr	%r7,%r1 	  # copy svc number to %r7
-	sla	%r7,2		  # *4
 sysc_nr_ok:
 	mvc	SP_ARGS(4,%r15),SP_R7(%r15)
 sysc_do_restart:
+	sth	%r7,SP_SVCNR(%r15)
+	sll	%r7,2		  # svc number *4
 	l	%r8,BASED(.Lsysc_table)
 	tm	__TI_flags+3(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)
 	l	%r8,0(%r7,%r8)	  # get system call addr.
@@ -373,7 +373,6 @@ sysc_notify_resume:
 sysc_restart:
 	ni	__TI_flags+3(%r9),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC
 	l	%r7,SP_R2(%r15) 	# load new svc number
-	sla	%r7,2
 	mvc	SP_R2(4,%r15),SP_ORIG_R2(%r15) # restore first argument
 	lm	%r2,%r6,SP_R2(%r15)	# load svc arguments
 	b	BASED(sysc_do_restart)	# restart svc
@@ -383,7 +382,8 @@ sysc_restart:
 #
 sysc_singlestep:
 	ni	__TI_flags+3(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP
-	mvi	SP_TRAP+1(%r15),0x28	# set trap indication to pgm check
+	mvi	SP_SVCNR(%r15),0xff	# set trap indication to pgm check
+	mvi	SP_SVCNR+1(%r15),0xff
 	la	%r2,SP_PTREGS(%r15)	# address of register-save area
 	l	%r1,BASED(.Lhandle_per)	# load adr. of per handler
 	la	%r14,BASED(sysc_return)	# load adr. of system return
@@ -404,7 +404,7 @@ sysc_tracesys:
 	bnl	BASED(sysc_tracenogo)
 	l	%r8,BASED(.Lsysc_table)
 	lr	%r7,%r2
-	sll	%r7,2			# *4
+	sll	%r7,2			# svc number *4
 	l	%r8,0(%r7,%r8)
 sysc_tracego:
 	lm	%r3,%r6,SP_R3(%r15)
@@ -583,7 +583,8 @@ pgm_svcper:
 # per was called from kernel, must be kprobes
 #
 kernel_per:
-	mvi	SP_TRAP+1(%r15),0x28	# set trap indication to pgm check
+	mvi	SP_SVCNR(%r15),0xff	# set trap indication to pgm check
+	mvi	SP_SVCNR+1(%r15),0xff
 	la	%r2,SP_PTREGS(%r15)	# address of register-save area
 	l	%r1,BASED(.Lhandle_per)	# load adr. of per handler
 	la	%r14,BASED(sysc_restore)# load adr. of system return
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -671,7 +671,7 @@ asmlinkage long do_syscall_trace_enter(s
 		 * debugger stored an invalid system call number. Skip
 		 * the system call and the system call restart handling.
 		 */
-		regs->trap = -1;
+		regs->svcnr = 0;
 		ret = -1;
 	}
 
--- a/arch/s390/kernel/signal.c
+++ b/arch/s390/kernel/signal.c
@@ -157,7 +157,7 @@ static int restore_sigregs(struct pt_reg
 	current->thread.fp_regs.fpc &= FPC_VALID_MASK;
 
 	restore_fp_regs(&current->thread.fp_regs);
-	regs->trap = -1;	/* disable syscall checks */
+	regs->svcnr = 0;	/* disable syscall checks */
 	return 0;
 }
 
@@ -442,7 +442,7 @@ void do_signal(struct pt_regs *regs)
 		oldset = &current->blocked;
 
 	/* Are we from a system call? */
-	if (regs->trap == __LC_SVC_OLD_PSW) {
+	if (regs->svcnr) {
 		continue_addr = regs->psw.addr;
 		restart_addr = continue_addr - regs->ilc;
 		retval = regs->gprs[2];
@@ -459,7 +459,7 @@ void do_signal(struct pt_regs *regs)
 		case -ERESTART_RESTARTBLOCK:
 			regs->gprs[2] = -EINTR;
 		}
-		regs->trap = -1;	/* Don't deal with this again. */
+		regs->svcnr = 0;	/* Don't deal with this again. */
 	}
 
 	/* Get signal to deliver.  When running under ptrace, at this point
Commit	Line	Data
4d1e5b62 AF	1	Subject: [PATCH] fix syscall_get_nr.
	2
	3	From: Martin Schwidefsky <schwidefsky@de.ibm.com>
	4
	5	syscall_get_nr() currently returns a valid result only if the call
	6	chain of the traced process includes do_syscall_trace_enter(). But
	7	collect_syscall() can be called for any sleeping task, the result of
	8	syscall_get_nr() in general is completely bogus.
	9
	10	To make syscall_get_nr() work for any sleeping task the traps field
	11	in pt_regs is replace with svcnr - the system call number the process
	12	is executing. If svcnr == 0 the process is not on a system call path.
	13
	14	Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
	15	Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
	16	Acked-by: John Jolly <jjolly@novell.com>
	17	---
	18
	19	arch/s390/include/asm/ptrace.h \| 2 +-
	20	arch/s390/include/asm/syscall.h \| 4 +---
	21	arch/s390/kernel/asm-offsets.c \| 2 +-
	22	arch/s390/kernel/compat_signal.c \| 2 +-
	23	arch/s390/kernel/entry.S \| 21 +++++++++++----------
	24	arch/s390/kernel/entry64.S \| 23 ++++++++++-------------
	25	arch/s390/kernel/ptrace.c \| 2 +-
	26	arch/s390/kernel/signal.c \| 6 +++---
	27	8 files changed, 29 insertions(+), 33 deletions(-)
	28
	29	--- a/arch/s390/include/asm/ptrace.h
	30	+++ b/arch/s390/include/asm/ptrace.h
	31	@@ -321,8 +321,8 @@ struct pt_regs
	32	psw_t psw;
	33	unsigned long gprs[NUM_GPRS];
	34	unsigned long orig_gpr2;
	35	+ unsigned short svcnr;
	36	unsigned short ilc;
	37	- unsigned short trap;
	38	};
	39	#endif
	40
	41	--- a/arch/s390/include/asm/syscall.h
	42	+++ b/arch/s390/include/asm/syscall.h
	43	@@ -17,9 +17,7 @@
	44	static inline long syscall_get_nr(struct task_struct *task,
	45	struct pt_regs *regs)
	46	{
	47	- if (regs->trap != __LC_SVC_OLD_PSW)
	48	- return -1;
	49	- return regs->gprs[2];
	50	+ return regs->svcnr ? regs->svcnr : -1;
	51	}
	52
	53	static inline void syscall_rollback(struct task_struct *task,
	54	--- a/arch/s390/kernel/asm-offsets.c
	55	+++ b/arch/s390/kernel/asm-offsets.c
	56	@@ -32,7 +32,7 @@ int main(void)
	57	DEFINE(__PT_GPRS, offsetof(struct pt_regs, gprs));
	58	DEFINE(__PT_ORIG_GPR2, offsetof(struct pt_regs, orig_gpr2));
	59	DEFINE(__PT_ILC, offsetof(struct pt_regs, ilc));
	60	- DEFINE(__PT_TRAP, offsetof(struct pt_regs, trap));
	61	+ DEFINE(__PT_SVCNR, offsetof(struct pt_regs, svcnr));
	62	DEFINE(__PT_SIZE, sizeof(struct pt_regs));
	63	BLANK();
	64	DEFINE(__SF_BACKCHAIN, offsetof(struct stack_frame, back_chain));
65	--- a/arch/s390/kernel/compat_signal.c
66	+++ b/arch/s390/kernel/compat_signal.c
67	@@ -340,7 +340,7 @@ static int restore_sigregs32(struct pt_r
68	return err;
69
70	restore_fp_regs(&current->thread.fp_regs);
71	- regs->trap = -1; /* disable syscall checks */
72	+ regs->svcnr = 0; /* disable syscall checks */
73	return 0;
74	}
75
76	--- a/arch/s390/kernel/entry64.S
77	+++ b/arch/s390/kernel/entry64.S
78	@@ -46,7 +46,7 @@ SP_R14 = STACK_FRAME_OVERHEAD + __P
79	SP_R15 = STACK_FRAME_OVERHEAD + __PT_GPRS + 120
80	SP_ORIG_R2 = STACK_FRAME_OVERHEAD + __PT_ORIG_GPR2
81	SP_ILC = STACK_FRAME_OVERHEAD + __PT_ILC
82	-SP_TRAP = STACK_FRAME_OVERHEAD + __PT_TRAP
83	+SP_SVCNR = STACK_FRAME_OVERHEAD + __PT_SVCNR
84	SP_SIZE = STACK_FRAME_OVERHEAD + __PT_SIZE
85
86	STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
87	@@ -168,11 +168,10 @@ _TIF_WORK_INT = (_TIF_SIGPENDING \| _TIF_
88	.macro CREATE_STACK_FRAME psworg,savearea
89	aghi %r15,-SP_SIZE # make room for registers & psw
90	mvc SP_PSW(16,%r15),0(%r12) # move user PSW to stack
91	- la %r12,\psworg
92	stg %r2,SP_ORIG_R2(%r15) # store original content of gpr 2
93	- icm %r12,12,__LC_SVC_ILC
94	+ icm %r12,3,__LC_SVC_ILC
95	stmg %r0,%r11,SP_R0(%r15) # store gprs %r0-%r11 to kernel stack
96	- st %r12,SP_ILC(%r15)
97	+ st %r12,SP_SVCNR(%r15)
98	mvc SP_R12(32,%r15),\savearea # move %r12-%r15 to stack
99	la %r12,0
100	stg %r12,__SF_BACKCHAIN(%r15)
101	@@ -247,16 +246,17 @@ sysc_update:
102	#endif
103	sysc_do_svc:
104	lg %r9,__LC_THREAD_INFO # load pointer to thread_info struct
105	- slag %r7,%r7,2 # *4 and test for svc 0
106	+ ltgr %r7,%r7 # test for svc 0
107	jnz sysc_nr_ok
108	# svc 0: system call number in %r1
109	cl %r1,BASED(.Lnr_syscalls)
110	jnl sysc_nr_ok
111	lgfr %r7,%r1 # clear high word in r1
112	- slag %r7,%r7,2 # svc 0: system call number in %r1
113	sysc_nr_ok:
114	mvc SP_ARGS(8,%r15),SP_R7(%r15)
115	sysc_do_restart:
116	+ sth %r7,SP_SVCNR(%r15)
117	+ sllg %r7,%r7,2 # svc number * 4
118	larl %r10,sys_call_table
119	#ifdef CONFIG_COMPAT
120	tm __TI_flags+5(%r9),(_TIF_31BIT>>16) # running in 31 bit mode ?
121	@@ -360,7 +360,6 @@ sysc_notify_resume:
122	sysc_restart:
123	ni __TI_flags+7(%r9),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC
124	lg %r7,SP_R2(%r15) # load new svc number
125	- slag %r7,%r7,2 # *4
126	mvc SP_R2(8,%r15),SP_ORIG_R2(%r15) # restore first argument
127	lmg %r2,%r6,SP_R2(%r15) # load svc arguments
128	j sysc_do_restart # restart svc
129	@@ -369,9 +368,8 @@ sysc_restart:
130	# _TIF_SINGLE_STEP is set, call do_single_step
131	#
132	sysc_singlestep:
133	- ni __TI_flags+7(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP
134	- lhi %r0,__LC_PGM_OLD_PSW
135	- sth %r0,SP_TRAP(%r15) # set trap indication to pgm check
136	+ ni __TI_flags+7(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP
137	+ xc SP_SVCNR(2,%r15),SP_SVCNR(%r15) # clear svc number
138	la %r2,SP_PTREGS(%r15) # address of register-save area
139	larl %r14,sysc_return # load adr. of system return
140	jg do_single_step # branch to do_sigtrap
141	@@ -389,7 +387,7 @@ sysc_tracesys:
142	lghi %r0,NR_syscalls
143	clgr %r0,%r2
144	jnh sysc_tracenogo
145	- slag %r7,%r2,2 # *4
146	+ sllg %r7,%r2,2 # svc number *4
147	lgf %r8,0(%r7,%r10)
148	sysc_tracego:
149	lmg %r3,%r6,SP_R3(%r15)
150	@@ -564,8 +562,7 @@ pgm_svcper:
151	# per was called from kernel, must be kprobes
152	#
153	kernel_per:
154	- lhi %r0,__LC_PGM_OLD_PSW
155	- sth %r0,SP_TRAP(%r15) # set trap indication to pgm check
156	+ xc SP_SVCNR(2,%r15),SP_SVCNR(%r15) # clear svc number
157	la %r2,SP_PTREGS(%r15) # address of register-save area
158	larl %r14,sysc_restore # load adr. of system ret, no work
159	jg do_single_step # branch to do_single_step
160	--- a/arch/s390/kernel/entry.S
161	+++ b/arch/s390/kernel/entry.S
162	@@ -46,7 +46,7 @@ SP_R14 = STACK_FRAME_OVERHEAD + __P
163	SP_R15 = STACK_FRAME_OVERHEAD + __PT_GPRS + 60
164	SP_ORIG_R2 = STACK_FRAME_OVERHEAD + __PT_ORIG_GPR2
165	SP_ILC = STACK_FRAME_OVERHEAD + __PT_ILC
166	-SP_TRAP = STACK_FRAME_OVERHEAD + __PT_TRAP
167	+SP_SVCNR = STACK_FRAME_OVERHEAD + __PT_SVCNR
168	SP_SIZE = STACK_FRAME_OVERHEAD + __PT_SIZE
169
170	_TIF_WORK_SVC = (_TIF_SIGPENDING \| _TIF_NOTIFY_RESUME \| _TIF_NEED_RESCHED \| \
171	@@ -180,11 +180,10 @@ STACK_SIZE = 1 << STACK_SHIFT
172	.macro CREATE_STACK_FRAME psworg,savearea
173	s %r15,BASED(.Lc_spsize) # make room for registers & psw
174	mvc SP_PSW(8,%r15),0(%r12) # move user PSW to stack
175	- la %r12,\psworg
176	st %r2,SP_ORIG_R2(%r15) # store original content of gpr 2
177	- icm %r12,12,__LC_SVC_ILC
178	+ icm %r12,3,__LC_SVC_ILC
179	stm %r0,%r11,SP_R0(%r15) # store gprs %r0-%r11 to kernel stack
180	- st %r12,SP_ILC(%r15)
181	+ st %r12,SP_SVCNR(%r15)
182	mvc SP_R12(16,%r15),\savearea # move %r12-%r15 to stack
183	la %r12,0
184	st %r12,__SF_BACKCHAIN(%r15) # clear back chain
185	@@ -261,16 +260,17 @@ sysc_update:
186	#endif
187	sysc_do_svc:
188	l %r9,__LC_THREAD_INFO # load pointer to thread_info struct
189	- sla %r7,2 # *4 and test for svc 0
190	+ ltr %r7,%r7 # test for svc 0
191	bnz BASED(sysc_nr_ok) # svc number > 0
192	# svc 0: system call number in %r1
193	cl %r1,BASED(.Lnr_syscalls)
194	bnl BASED(sysc_nr_ok)
195	lr %r7,%r1 # copy svc number to %r7
196	- sla %r7,2 # *4
197	sysc_nr_ok:
198	mvc SP_ARGS(4,%r15),SP_R7(%r15)
199	sysc_do_restart:
200	+ sth %r7,SP_SVCNR(%r15)
201	+ sll %r7,2 # svc number *4
202	l %r8,BASED(.Lsysc_table)
203	tm __TI_flags+3(%r9),(_TIF_SYSCALL_TRACE\|_TIF_SYSCALL_AUDIT)
204	l %r8,0(%r7,%r8) # get system call addr.
205	@@ -373,7 +373,6 @@ sysc_notify_resume:
206	sysc_restart:
207	ni __TI_flags+3(%r9),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC
208	l %r7,SP_R2(%r15) # load new svc number
209	- sla %r7,2
210	mvc SP_R2(4,%r15),SP_ORIG_R2(%r15) # restore first argument
211	lm %r2,%r6,SP_R2(%r15) # load svc arguments
212	b BASED(sysc_do_restart) # restart svc
213	@@ -383,7 +382,8 @@ sysc_restart:
214	#
215	sysc_singlestep:
216	ni __TI_flags+3(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP
217	- mvi SP_TRAP+1(%r15),0x28 # set trap indication to pgm check
218	+ mvi SP_SVCNR(%r15),0xff # set trap indication to pgm check
219	+ mvi SP_SVCNR+1(%r15),0xff
220	la %r2,SP_PTREGS(%r15) # address of register-save area
221	l %r1,BASED(.Lhandle_per) # load adr. of per handler
222	la %r14,BASED(sysc_return) # load adr. of system return
223	@@ -404,7 +404,7 @@ sysc_tracesys:
224	bnl BASED(sysc_tracenogo)
225	l %r8,BASED(.Lsysc_table)
226	lr %r7,%r2
227	- sll %r7,2 # *4
228	+ sll %r7,2 # svc number *4
229	l %r8,0(%r7,%r8)
230	sysc_tracego:
231	lm %r3,%r6,SP_R3(%r15)
232	@@ -583,7 +583,8 @@ pgm_svcper:
233	# per was called from kernel, must be kprobes
234	#
235	kernel_per:
236	- mvi SP_TRAP+1(%r15),0x28 # set trap indication to pgm check
237	+ mvi SP_SVCNR(%r15),0xff # set trap indication to pgm check
238	+ mvi SP_SVCNR+1(%r15),0xff
239	la %r2,SP_PTREGS(%r15) # address of register-save area
240	l %r1,BASED(.Lhandle_per) # load adr. of per handler
241	la %r14,BASED(sysc_restore)# load adr. of system return
242	--- a/arch/s390/kernel/ptrace.c
243	+++ b/arch/s390/kernel/ptrace.c
244	@@ -671,7 +671,7 @@ asmlinkage long do_syscall_trace_enter(s
245	* debugger stored an invalid system call number. Skip
246	* the system call and the system call restart handling.
247	*/
248	- regs->trap = -1;
249	+ regs->svcnr = 0;
250	ret = -1;
251	}
252
253	--- a/arch/s390/kernel/signal.c
254	+++ b/arch/s390/kernel/signal.c
255	@@ -157,7 +157,7 @@ static int restore_sigregs(struct pt_reg
256	current->thread.fp_regs.fpc &= FPC_VALID_MASK;
257
258	restore_fp_regs(&current->thread.fp_regs);
259	- regs->trap = -1; /* disable syscall checks */
260	+ regs->svcnr = 0; /* disable syscall checks */
261	return 0;
262	}
263
264	@@ -442,7 +442,7 @@ void do_signal(struct pt_regs *regs)
265	oldset = &current->blocked;
266
267	/* Are we from a system call? */
268	- if (regs->trap == __LC_SVC_OLD_PSW) {
269	+ if (regs->svcnr) {
270	continue_addr = regs->psw.addr;
271	restart_addr = continue_addr - regs->ilc;
272	retval = regs->gprs[2];
273	@@ -459,7 +459,7 @@ void do_signal(struct pt_regs *regs)
274	case -ERESTART_RESTARTBLOCK:
275	regs->gprs[2] = -EINTR;
276	}
277	- regs->trap = -1; /* Don't deal with this again. */
278	+ regs->svcnr = 0; /* Don't deal with this again. */
279	}
280
281	/* Get signal to deliver. When running under ptrace, at this point