[S390] ptrace changes

* System call parameter and result access functions
* Add tracehook calls
* Split syscall_trace into two functions do_syscall_trace_enter and
  do_syscall_trace_exit

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

1 files changed, 32 insertions, 10 deletions

diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index fee10177dbfc..d7ce150453f2 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -52,9 +52,9 @@ SP_SIZE      =	STACK_FRAME_OVERHEAD + __PT_SIZE
 STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
 STACK_SIZE  = 1 << STACK_SHIFT
 
-_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
+_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
                  _TIF_MCCK_PENDING | _TIF_RESTART_SVC | _TIF_SINGLE_STEP )
-_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
+_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
                  _TIF_MCCK_PENDING)
 
 #define BASED(name) name-system_call(%r13)
@@ -310,6 +310,8 @@ sysc_work:
         jo      sysc_reschedule
         tm      __TI_flags+7(%r9),_TIF_SIGPENDING
         jnz     sysc_sigpending
+        tm      __TI_flags+7(%r9),_TIF_NOTIFY_RESUME
+        jnz     sysc_notify_resume
         tm      __TI_flags+7(%r9),_TIF_RESTART_SVC
         jo      sysc_restart
         tm      __TI_flags+7(%r9),_TIF_SINGLE_STEP
@@ -345,6 +347,14 @@ sysc_sigpending:
         j       sysc_work_loop
 
 #
+# _TIF_NOTIFY_RESUME is set, call do_notify_resume
+#
+sysc_notify_resume:
+        la      %r2,SP_PTREGS(%r15)     # load pt_regs
+        larl    %r14,sysc_work_loop
+        jg      do_notify_resume        # call do_notify_resume
+
+#
 # _TIF_RESTART_SVC is set, set up registers and restart svc
 #
 sysc_restart:
@@ -367,20 +377,19 @@ sysc_singlestep:
         jg      do_single_step          # branch to do_sigtrap
 
 #
-# call syscall_trace before and after system call
-# special linkage: %r12 contains the return address for trace_svc
+# call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
+# and after the system call
 #
 sysc_tracesys:
         la      %r2,SP_PTREGS(%r15)     # load pt_regs
         la      %r3,0
         srl     %r7,2
         stg     %r7,SP_R2(%r15)
-        brasl   %r14,syscall_trace
+        brasl   %r14,do_syscall_trace_enter
         lghi    %r0,NR_syscalls
-        clg     %r0,SP_R2(%r15)
+        clgr    %r0,%r2
         jnh     sysc_tracenogo
-        lg      %r7,SP_R2(%r15)         # strace might have changed the
-        sll     %r7,2                   # system call
+        slag    %r7,%r2,2               # *4
         lgf     %r8,0(%r7,%r10)
 sysc_tracego:
         lmg     %r3,%r6,SP_R3(%r15)
@@ -391,9 +400,8 @@ sysc_tracenogo:
         tm      __TI_flags+7(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)
         jz      sysc_return
         la      %r2,SP_PTREGS(%r15)     # load pt_regs
-        la      %r3,1
         larl    %r14,sysc_return        # return point is sysc_return
-        jg      syscall_trace
+        jg      do_syscall_trace_exit
 
 #
 # a new process exits the kernel with ret_from_fork
@@ -672,6 +680,8 @@ io_work_loop:
         jo      io_reschedule
         tm      __TI_flags+7(%r9),_TIF_SIGPENDING
         jnz     io_sigpending
+        tm      __TI_flags+7(%r9),_TIF_NOTIFY_RESUME
+        jnz     io_notify_resume
         j       io_restore
 io_work_done:
 
@@ -712,6 +722,18 @@ io_sigpending:
         TRACE_IRQS_OFF
         j       io_work_loop
 
+#
+# _TIF_NOTIFY_RESUME or is set, call do_notify_resume
+#
+io_notify_resume:
+        TRACE_IRQS_ON
+        stosm   __SF_EMPTY(%r15),0x03   # reenable interrupts
+        la      %r2,SP_PTREGS(%r15)     # load pt_regs
+        brasl   %r14,do_notify_resume   # call do_notify_resume
+        stnsm   __SF_EMPTY(%r15),0xfc   # disable I/O and ext. interrupts
+        TRACE_IRQS_OFF
+        j       io_work_loop
+
 /*
  * External interrupt handler routine
  */