* [PATCH] s390: simplify single stepped svc code.
@ 2004-06-11 17:32 Martin Schwidefsky
0 siblings, 0 replies; only message in thread
From: Martin Schwidefsky @ 2004-06-11 17:32 UTC (permalink / raw)
To: akpm, linux-kernel
[PATCH] s390: simplify single stepped svc code.
From: Martin Schwidefsky <schwidefsky@de.ibm.com>
Introduce a TIF_SINGLE_STEP bit that causes do_debugger_trap
to get called at the end of a system call. This way some code
duplication in the program check handler can get removed.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diffstat:
arch/s390/kernel/entry.S | 85 +++++++++------------------------------
arch/s390/kernel/entry64.S | 89 +++++++++--------------------------------
include/asm-s390/thread_info.h | 2
3 files changed, 44 insertions(+), 132 deletions(-)
diff -urN linux-2.6/arch/s390/kernel/entry.S linux-2.6-s390/arch/s390/kernel/entry.S
--- linux-2.6/arch/s390/kernel/entry.S Fri Jun 11 19:09:20 2004
+++ linux-2.6-s390/arch/s390/kernel/entry.S Fri Jun 11 19:09:55 2004
@@ -48,7 +48,8 @@
SP_TRAP = STACK_FRAME_OVERHEAD + __PT_TRAP
SP_SIZE = STACK_FRAME_OVERHEAD + __PT_SIZE
-_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_RESTART_SVC)
+_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
+ _TIF_RESTART_SVC | _TIF_SINGLE_STEP )
_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NEED_RESCHED)
#define BASED(name) name-system_call(%r13)
@@ -230,6 +231,7 @@
lh %r7,0x8a # get svc number from lowcore
sysc_enter:
GET_THREAD_INFO # load pointer to task_struct to R9
+sysc_do_svc:
sla %r7,2 # *4 and test for svc 0
bnz BASED(sysc_nr_ok) # svc number > 0
# svc 0: system call number in %r1
@@ -265,7 +267,6 @@
bz BASED(sysc_leave) # there is no work to do
#
# One of the work bits is on. Find out which one.
-# Checked are: _TIF_SIGPENDING and _TIF_NEED_RESCHED
#
sysc_work:
tm __TI_flags+3(%r9),_TIF_NEED_RESCHED
@@ -274,6 +275,8 @@
bo BASED(sysc_sigpending)
tm __TI_flags+3(%r9),_TIF_RESTART_SVC
bo BASED(sysc_restart)
+ tm __TI_flags+3(%r9),_TIF_SINGLE_STEP
+ bo BASED(sysc_singlestep)
b BASED(sysc_leave)
#
@@ -307,6 +310,17 @@
lm %r2,%r6,SP_R2(%r15) # load svc arguments
b BASED(sysc_do_restart) # restart svc
+#
+# _TIF_SINGLE_STEP is set, call do_debugger_trap
+#
+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
+ 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
+ br %r1 # branch to do_debugger_trap
+
__critical_end:
#
@@ -498,72 +512,15 @@
#
pgm_svcper:
SAVE_ALL __LC_SVC_OLD_PSW,__LC_SAVE_AREA,1
- lh %r7,0x8a # get svc number from lowcore
- GET_THREAD_INFO # load pointer to task_struct to R9
+ lh %r7,0x8a # get svc number from lowcore
+ GET_THREAD_INFO # load pointer to task_struct to R9
l %r1,__TI_task(%r9)
mvc __THREAD_per+__PER_atmid(2,%r1),__LC_PER_ATMID
mvc __THREAD_per+__PER_address(4,%r1),__LC_PER_ADDRESS
mvc __THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID
- stosm 24(%r15),0x03 # reenable interrupts
- sla %r7,2 # *4 and test for svc 0
- bnz BASED(pgm_svcstd) # svc number > 0 ?
- # svc 0: system call number in %r1
- cl %r1,BASED(.Lnr_syscalls)
- bnl BASED(pgm_svcstd)
- lr %r7,%r1 # copy svc number to %r7
- sla %r7,2 # *4
-pgm_svcstd:
- mvc SP_ARGS(4,%r15),SP_R7(%r15)
- tm __TI_flags+3(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)
- l %r8,sys_call_table-system_call(%r7,%r13) # get system call addr.
- bnz BASED(pgm_tracesys)
- basr %r14,%r8 # call sys_xxxx
- st %r2,SP_R2(%r15) # store return value (change R2 on stack)
- # ATTENTION: check sys_execve_glue before
- # changing anything here !!
-
-pgm_svcret:
- tm __TI_flags+3(%r9),_TIF_SIGPENDING
- bno BASED(pgm_svcper_nosig)
- la %r2,SP_PTREGS(%r15) # load pt_regs
- sr %r3,%r3 # clear *oldset
- l %r1,BASED(.Ldo_signal)
- basr %r14,%r1 # call do_signal
-
-pgm_svcper_nosig:
- mvi SP_TRAP+3(%r15),0x28 # set trap indication to pgm check
- la %r2,SP_PTREGS(15) # 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
- br %r1 # branch to do_debugger_trap
-#
-# call trace before and after sys_call
-#
-pgm_tracesys:
- l %r1,BASED(.Ltrace)
- la %r2,SP_PTREGS(%r15) # load pt_regs
- la %r3,0
- srl %r7,2
- st %r7,SP_R2(%r15)
- basr %r14,%r1
- clc SP_R2(4,%r15),BASED(.Lnr_syscalls)
- bnl BASED(pgm_svc_nogo)
- l %r7,SP_R2(%r15) # strace changed the syscall
- sll %r7,2
- l %r8,sys_call_table-system_call(%r7,%r13)
-pgm_svc_go:
- lm %r3,%r6,SP_R3(%r15)
- l %r2,SP_ORIG_R2(%r15)
- basr %r14,%r8 # call sys_xxx
- st %r2,SP_R2(%r15) # store return value
-pgm_svc_nogo:
- tm __TI_flags+3(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)
- bz BASED(pgm_svcret)
- l %r1,BASED(.Ltrace)
- la %r2,SP_PTREGS(%r15) # load pt_regs
- la %r3,1
- la %r14,BASED(pgm_svcret)
- br %r1
+ oi __TI_flags+3(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
+ stosm 24(%r15),0x03 # reenable interrupts
+ b BASED(sysc_do_svc)
/*
* IO interrupt handler routine
diff -urN linux-2.6/arch/s390/kernel/entry64.S linux-2.6-s390/arch/s390/kernel/entry64.S
--- linux-2.6/arch/s390/kernel/entry64.S Fri Jun 11 19:09:20 2004
+++ linux-2.6-s390/arch/s390/kernel/entry64.S Fri Jun 11 19:09:55 2004
@@ -48,7 +48,8 @@
SP_TRAP = STACK_FRAME_OVERHEAD + __PT_TRAP
SP_SIZE = STACK_FRAME_OVERHEAD + __PT_SIZE
-_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_RESTART_SVC)
+_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
+ _TIF_RESTART_SVC | _TIF_SINGLE_STEP )
_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NEED_RESCHED)
/*
@@ -214,6 +215,7 @@
llgh %r7,__LC_SVC_INT_CODE # get svc number from lowcore
sysc_enter:
GET_THREAD_INFO # load pointer to task_struct to R9
+sysc_do_svc:
slag %r7,%r7,2 # *4 and test for svc 0
jnz sysc_nr_ok
# svc 0: system call number in %r1
@@ -257,7 +259,6 @@
jz sysc_leave # there is no work to do
#
# One of the work bits is on. Find out which one.
-# Checked are: _TIF_SIGPENDING and _TIF_NEED_RESCHED
#
sysc_work:
tm __TI_flags+7(%r9),_TIF_NEED_RESCHED
@@ -266,6 +267,8 @@
jo sysc_sigpending
tm __TI_flags+7(%r9),_TIF_RESTART_SVC
jo sysc_restart
+ tm __TI_flags+7(%r9),_TIF_SINGLE_STEP
+ jo sysc_singlestep
j sysc_leave
#
@@ -297,6 +300,17 @@
lmg %r2,%r6,SP_R2(%r15) # load svc arguments
j sysc_do_restart # restart svc
+#
+# _TIF_SINGLE_STEP is set, call do_debugger_trap
+#
+sysc_singlestep:
+ ni __TI_flags+7(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP
+ mvi SP_TRAP+1(%r15),0x28 # set trap indication to pgm check
+ la %r2,SP_PTREGS(%r15) # address of register-save area
+ larl %r14,sysc_return # load adr. of system return
+ jg do_debugger_trap # branch to do_debugger_trap
+
+
__critical_end:
#
@@ -531,76 +545,15 @@
#
pgm_svcper:
SAVE_ALL __LC_SVC_OLD_PSW,__LC_SAVE_AREA,1
- llgh %r7,__LC_SVC_INT_CODE # get svc number from lowcore
- GET_THREAD_INFO # load pointer to task_struct to R9
+ llgh %r7,__LC_SVC_INT_CODE # get svc number from lowcore
+ GET_THREAD_INFO # load pointer to task_struct to R9
lg %r1,__TI_task(%r9)
mvc __THREAD_per+__PER_atmid(2,%r1),__LC_PER_ATMID
mvc __THREAD_per+__PER_address(8,%r1),__LC_PER_ADDRESS
mvc __THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID
- stosm 48(%r15),0x03 # reenable interrupts
- slag %r7,%r7,2 # *4 and test for svc 0
- jnz pgm_svcstd
- # svc 0: system call number in %r1
- lghi %r0,NR_syscalls
- clr %r1,%r0
- slag %r7,%r1,2
-pgm_svcstd:
- mvc SP_ARGS(8,%r15),SP_R7(%r15)
- larl %r10,sys_call_table
-#ifdef CONFIG_S390_SUPPORT
- tm SP_PSW+3(%r15),0x01 # are we running in 31 bit mode ?
- jo pgm_svcper_noemu
- larl %r10,sys_call_table_emu # use 31 bit emulation system calls
-pgm_svcper_noemu:
-#endif
- tm __TI_flags+7(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)
- lgf %r8,0(%r7,%r10) # load address of system call routine
- jnz pgm_tracesys
- basr %r14,%r8 # call sys_xxxx
- stg %r2,SP_R2(%r15) # store return value (change R2 on stack)
- # ATTENTION: check sys_execve_glue before
- # changing anything here !!
-
-pgm_svcret:
- tm __TI_flags+7(%r9),_TIF_SIGPENDING
- jno pgm_svcper_nosig
- la %r2,SP_PTREGS(%r15) # load pt_regs
- sgr %r3,%r3 # clear *oldset
- brasl %r14,do_signal
-
-pgm_svcper_nosig:
- lhi %r0,__LC_PGM_OLD_PSW # set trap indication back to pgm_chk
- st %r0,SP_TRAP(%r15)
- la %r2,SP_PTREGS(15) # address of register-save area
- larl %r14,sysc_return # load adr. of system return
- jg do_debugger_trap
-#
-# call trace before and after sys_call
-#
-pgm_tracesys:
- la %r2,SP_PTREGS(%r15) # load pt_regs
- la %r3,0
- srlg %r7,%r7,2
- stg %r7,SP_R2(%r15)
- brasl %r14,syscall_trace
- lghi %r0,NR_syscalls
- clg %r0,SP_R2(%r15)
- jnh pgm_svc_nogo
- lg %r7,SP_R2(%r15)
- sllg %r7,%r7,2 # strace wants to change the syscall
- lgf %r8,0(%r7,%r10)
-pgm_svc_go:
- lmg %r3,%r6,SP_R3(%r15)
- lg %r2,SP_ORIG_R2(%r15)
- basr %r14,%r8 # call sys_xxx
- stg %r2,SP_R2(%r15) # store return value
-pgm_svc_nogo:
- tm __TI_flags+7(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)
- jz pgm_svcret
- la %r2,SP_PTREGS(%r15) # load pt_regs
- la %r3,1
- larl %r14,pgm_svcret # return point is sysc_return
- jg syscall_trace
+ oi __TI_flags+7(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
+ stosm 48(%r15),0x03 # reenable interrupts
+ j sysc_do_svc
/*
* IO interrupt handler routine
diff -urN linux-2.6/include/asm-s390/thread_info.h linux-2.6-s390/include/asm-s390/thread_info.h
--- linux-2.6/include/asm-s390/thread_info.h Mon May 10 04:32:53 2004
+++ linux-2.6-s390/include/asm-s390/thread_info.h Fri Jun 11 19:09:55 2004
@@ -85,6 +85,7 @@
#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
#define TIF_RESTART_SVC 4 /* restart svc with new svc number */
#define TIF_SYSCALL_AUDIT 5 /* syscall auditing active */
+#define TIF_SINGLE_STEP 6 /* single stepped svc */
#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 */
@@ -96,6 +97,7 @@
#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
#define _TIF_RESTART_SVC (1<<TIF_RESTART_SVC)
#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
+#define _TIF_SINGLE_STEP (1<<TIF_SINGLE_STEP)
#define _TIF_USEDFPU (1<<TIF_USEDFPU)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
#define _TIF_31BIT (1<<TIF_31BIT)
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