[S390] ptrace cleanup

Overhaul program event recording and the code dealing with the ptrace
user space interface.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 30 insertions, 40 deletions

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index af8bd3b90a26..648f64239a9d 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -48,7 +48,7 @@ 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 | \
-                 _TIF_MCCK_PENDING | _TIF_RESTART_SVC | _TIF_SINGLE_STEP )
+                 _TIF_MCCK_PENDING | _TIF_RESTART_SVC | _TIF_PER_TRAP )
 _TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
                  _TIF_MCCK_PENDING)
 _TIF_SYSCALL = (_TIF_SYSCALL_TRACE>>8 | _TIF_SYSCALL_AUDIT>>8 | \
@@ -200,31 +200,21 @@ STACK_SIZE  = 1 << STACK_SHIFT
         .globl  __switch_to
 __switch_to:
         basr    %r1,0
-__switch_to_base:
-        tm      __THREAD_per(%r3),0xe8          # new process is using per ?
-        bz      __switch_to_noper-__switch_to_base(%r1) # if not we're fine
-        stctl   %c9,%c11,__SF_EMPTY(%r15)       # We are using per stuff
-        clc     __THREAD_per(12,%r3),__SF_EMPTY(%r15)
-        be      __switch_to_noper-__switch_to_base(%r1) # we got away w/o bashing TLB's
-        lctl    %c9,%c11,__THREAD_per(%r3)      # Nope we didn't
-__switch_to_noper:
-        l       %r4,__THREAD_info(%r2)          # get thread_info of prev
+0:      l       %r4,__THREAD_info(%r2)          # get thread_info of prev
+        l       %r5,__THREAD_info(%r3)          # get thread_info of next
         tm      __TI_flags+3(%r4),_TIF_MCCK_PENDING # machine check pending?
-        bz      __switch_to_no_mcck-__switch_to_base(%r1)
-        ni      __TI_flags+3(%r4),255-_TIF_MCCK_PENDING # clear flag in prev
-        l       %r4,__THREAD_info(%r3)          # get thread_info of next
-        oi      __TI_flags+3(%r4),_TIF_MCCK_PENDING # set it in next
-__switch_to_no_mcck:
-        stm     %r6,%r15,__SF_GPRS(%r15)# store __switch_to registers of prev task
-        st      %r15,__THREAD_ksp(%r2)  # store kernel stack to prev->tss.ksp
-        l       %r15,__THREAD_ksp(%r3)  # load kernel stack from next->tss.ksp
-        lm      %r6,%r15,__SF_GPRS(%r15)# load __switch_to registers of next task
-        st      %r3,__LC_CURRENT        # __LC_CURRENT = current task struct
-        lctl    %c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4
-        l       %r3,__THREAD_info(%r3)  # load thread_info from task struct
-        st      %r3,__LC_THREAD_INFO
-        ahi     %r3,STACK_SIZE
-        st      %r3,__LC_KERNEL_STACK   # __LC_KERNEL_STACK = new kernel stack
+        bz      1f-0b(%r1)
+        ni      __TI_flags+3(%r4),255-_TIF_MCCK_PENDING # clear flag in prev
+        oi      __TI_flags+3(%r5),_TIF_MCCK_PENDING     # set it in next
+1:      stm     %r6,%r15,__SF_GPRS(%r15)        # store gprs of prev task
+        st      %r15,__THREAD_ksp(%r2)          # store kernel stack of prev
+        l       %r15,__THREAD_ksp(%r3)          # load kernel stack of next
+        lctl    %c4,%c4,__TASK_pid(%r3)         # load pid to control reg. 4
+        lm      %r6,%r15,__SF_GPRS(%r15)        # load gprs of next task
+        st      %r3,__LC_CURRENT                # store task struct of next
+        st      %r5,__LC_THREAD_INFO            # store thread info of next
+        ahi     %r5,STACK_SIZE                  # end of kernel stack of next
+        st      %r5,__LC_KERNEL_STACK           # store end of kernel stack
         br      %r14
 
 __critical_start:
@@ -297,7 +287,7 @@ sysc_work_tif:
         bo      BASED(sysc_notify_resume)
         tm      __TI_flags+3(%r12),_TIF_RESTART_SVC
         bo      BASED(sysc_restart)
-        tm      __TI_flags+3(%r12),_TIF_SINGLE_STEP
+        tm      __TI_flags+3(%r12),_TIF_PER_TRAP
         bo      BASED(sysc_singlestep)
         b       BASED(sysc_return)      # beware of critical section cleanup
 
@@ -321,13 +311,13 @@ sysc_mcck_pending:
 # _TIF_SIGPENDING is set, call do_signal
 #
 sysc_sigpending:
-        ni      __TI_flags+3(%r12),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP
+        ni      __TI_flags+3(%r12),255-_TIF_PER_TRAP # clear TIF_PER_TRAP
         la      %r2,SP_PTREGS(%r15)     # load pt_regs
         l       %r1,BASED(.Ldo_signal)
         basr    %r14,%r1                # call do_signal
         tm      __TI_flags+3(%r12),_TIF_RESTART_SVC
         bo      BASED(sysc_restart)
-        tm      __TI_flags+3(%r12),_TIF_SINGLE_STEP
+        tm      __TI_flags+3(%r12),_TIF_PER_TRAP
         bo      BASED(sysc_singlestep)
         b       BASED(sysc_return)
 
@@ -353,15 +343,15 @@ sysc_restart:
         b       BASED(sysc_nr_ok)       # restart svc
 
 #
-# _TIF_SINGLE_STEP is set, call do_single_step
+# _TIF_PER_TRAP is set, call do_per_trap
 #
 sysc_singlestep:
-        ni      __TI_flags+3(%r12),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP
+        ni      __TI_flags+3(%r12),255-_TIF_PER_TRAP # clear TIF_PER_TRAP
         xc      SP_SVCNR(2,%r15),SP_SVCNR(%r15)         # clear svc number
         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_single_step
+        br      %r1                     # branch to do_per_trap
 
 #
 # call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
@@ -520,10 +510,10 @@ pgm_no_vtime2:
         l       %r1,__TI_task(%r12)
         tm      SP_PSW+1(%r15),0x01     # kernel per event ?
         bz      BASED(kernel_per)
-        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
-        oi      __TI_flags+3(%r12),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
+        mvc     __THREAD_per_cause(2,%r1),__LC_PER_CAUSE
+        mvc     __THREAD_per_address(4,%r1),__LC_PER_ADDRESS
+        mvc     __THREAD_per_paid(1,%r1),__LC_PER_PAID
+        oi      __TI_flags+3(%r12),_TIF_PER_TRAP # set TIF_PER_TRAP
         l       %r3,__LC_PGM_ILC        # load program interruption code
         l       %r4,__LC_TRANS_EXC_CODE
         REENABLE_IRQS
@@ -551,10 +541,10 @@ pgm_svcper:
         UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
         mvc     __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
         l       %r8,__TI_task(%r12)
-        mvc     __THREAD_per+__PER_atmid(2,%r8),__LC_PER_ATMID
-        mvc     __THREAD_per+__PER_address(4,%r8),__LC_PER_ADDRESS
-        mvc     __THREAD_per+__PER_access_id(1,%r8),__LC_PER_ACCESS_ID
-        oi      __TI_flags+3(%r12),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
+        mvc     __THREAD_per_cause(2,%r8),__LC_PER_CAUSE
+        mvc     __THREAD_per_address(4,%r8),__LC_PER_ADDRESS
+        mvc     __THREAD_per_paid(1,%r8),__LC_PER_PAID
+        oi      __TI_flags+3(%r12),_TIF_PER_TRAP # set TIF_PER_TRAP
         stosm   __SF_EMPTY(%r15),0x03   # reenable interrupts
         lm      %r2,%r6,SP_R2(%r15)     # load svc arguments
         b       BASED(sysc_do_svc)
@@ -1056,7 +1046,7 @@ cleanup_io_restore_insn:
 .Ldo_signal:    .long   do_signal
 .Ldo_notify_resume:
                 .long   do_notify_resume
-.Lhandle_per:   .long   do_single_step
+.Lhandle_per:   .long   do_per_trap
 .Ldo_execve:    .long   do_execve
 .Lexecve_tail:  .long   execve_tail
 .Ljump_table:   .long   pgm_check_table