[PATCH] S/390 port modernization 2/4 (updated)

Ulrich Weigand weigand@i1.informatik.uni-erlangen.de
Fri Dec 5 01:55:00 GMT 2003


Hello,

this is a revised version of patch 2/4 to update the gdb backend.
It incorporates the following changes:

- Fix swapped initial boundaries in s390_fix_watch_points.
- Adapted to changes in patch 1/4.

Retested on s390-ibm-linux and s390x-ibm-linux with no new regressions.

Bye,
Ulrich


ChangeLog:

	* config/s390/nm-linux.h: Update comments.
	(target_insert_watchpoint, target_remove_watchpoint): Redefine.
	(STOPPED_BY_WATCHPOINT): Redefine.
	(TARGET_CAN_USE_HARDWARE_WATCHPOINT): Redefine to 1.
	(s390_insert_watchpoint, s390_remove_watchpoint): Update prototype.
	(s390_stopped_by_watchpoint): Likewise.
	(watch_area_cnt): Remove.
	* s390-nat.c: Update comments.
	(watch_area): Remove typedef.
	Global replace watch_area by struct watch_area.
	(watch_area_cnt, watch_lo_addr, watch_hi_addr): Remove.
	(s390_stopped_by_watchpoint): Remove pid argument, 
	use s390_inferior_tid.  Add short-cut for the no watchpoint case.
	(s390_fix_watch_points): Remove pid argument,
	use s390_inferior_tid.  Recompute area spanned by watchpoints.
	(s390_insert_watchpoint, s390_remove_watchpoint): Remove pid
	argument.  Reimplement.


diff -c -p -r gdb-head/gdb/config/s390/nm-linux.h gdb-head-new/gdb/config/s390/nm-linux.h
*** gdb-head/gdb/config/s390/nm-linux.h	Fri Dec  5 01:32:36 2003
--- gdb-head-new/gdb/config/s390/nm-linux.h	Fri Dec  5 01:40:53 2003
***************
*** 39,71 ****
  extern int kernel_u_size (void);
  
  
! /* WATCHPOINT SPECIFIC STUFF */
  
  #define TARGET_HAS_HARDWARE_WATCHPOINTS
  #define HAVE_CONTINUABLE_WATCHPOINT 1
- #define target_insert_watchpoint(addr, len, type)  \
-   s390_insert_watchpoint (PIDGET (inferior_ptid), addr, len, type)
  
! #define target_remove_watchpoint(addr, len, type)  \
!   s390_remove_watchpoint (PIDGET (inferior_ptid), addr, len)
  
- extern int watch_area_cnt;
- /* gdb if really stupid & calls this all the time without a
-    watchpoint even being set */
- #define STOPPED_BY_WATCHPOINT(W)  \
-   (watch_area_cnt&&s390_stopped_by_watchpoint (PIDGET(inferior_ptid)))
- 
- extern CORE_ADDR s390_stopped_by_watchpoint (int);
- 
- /*
-   Type can be 1 for a read_watchpoint or 2 for an access watchpoint.
-  */
- extern int s390_insert_watchpoint (int pid, CORE_ADDR addr, int len, int rw);
- extern int s390_remove_watchpoint (int pid, CORE_ADDR addr, int len);
- #define TARGET_CAN_USE_HARDWARE_WATCHPOINT(type, cnt, ot) \
- 	 (((type) == bp_hardware_watchpoint)|| \
- 	 ((type) == bp_watchpoint)|| \
- 	 ((type) == bp_read_watchpoint) || \
-          ((type) == bp_access_watchpoint))
  
  #endif /* nm_linux.h */
--- 39,62 ----
  extern int kernel_u_size (void);
  
  
! /* Hardware watchpoints.  */
! 
! extern int s390_stopped_by_watchpoint (void);
! extern int s390_insert_watchpoint (CORE_ADDR addr, int len);
! extern int s390_remove_watchpoint (CORE_ADDR addr, int len);
  
  #define TARGET_HAS_HARDWARE_WATCHPOINTS
+ #define TARGET_CAN_USE_HARDWARE_WATCHPOINT(type, cnt, ot) 1
  #define HAVE_CONTINUABLE_WATCHPOINT 1
  
! #define STOPPED_BY_WATCHPOINT(w) \
!   s390_stopped_by_watchpoint ()
! 
! #define target_insert_watchpoint(addr, len, type) \
!   s390_insert_watchpoint (addr, len)
! 
! #define target_remove_watchpoint(addr, len, type) \
!   s390_remove_watchpoint (addr, len)
  
  
  #endif /* nm_linux.h */
diff -c -p -r gdb-head/gdb/s390-nat.c gdb-head-new/gdb/s390-nat.c
*** gdb-head/gdb/s390-nat.c	Fri Dec  5 01:32:36 2003
--- gdb-head-new/gdb/s390-nat.c	Fri Dec  5 01:40:53 2003
*************** store_inferior_registers (int regnum)
*** 217,271 ****
  }
  
  
! /* watch_areas are required if you put 2 or more watchpoints on the same 
!    address or overlapping areas gdb will call us to delete the watchpoint 
!    more than once when we try to delete them.
!    attempted reference counting to reduce the number of areas unfortunately
!    they didn't shrink when areas had to be split overlapping occurs. */
! struct watch_area;
! typedef struct watch_area watch_area;
  struct watch_area
  {
!   watch_area *next;
    CORE_ADDR lo_addr;
    CORE_ADDR hi_addr;
  };
  
! static watch_area *watch_base = NULL;
! int watch_area_cnt = 0;
! static CORE_ADDR watch_lo_addr = 0, watch_hi_addr = 0;
! 
  
! 
! CORE_ADDR
! s390_stopped_by_watchpoint (int pid)
  {
    per_lowcore_bits per_lowcore;
    ptrace_area parea;
  
    parea.len = sizeof (per_lowcore);
    parea.process_addr = (addr_t) & per_lowcore;
    parea.kernel_addr = offsetof (struct user_regs_struct, per_info.lowcore);
!   ptrace (PTRACE_PEEKUSR_AREA, pid, &parea);
!   return ((per_lowcore.perc_storage_alteration == 1) &&
! 	  (per_lowcore.perc_store_real_address == 0));
! }
  
  
! void
! s390_fix_watch_points (int pid)
  {
    per_struct per_info;
    ptrace_area parea;
  
    parea.len = sizeof (per_info);
    parea.process_addr = (addr_t) & per_info;
!   parea.kernel_addr = PT_CR_9;
!   ptrace (PTRACE_PEEKUSR_AREA, pid, &parea);
!   /* The kernel automatically sets the psw for per depending */
!   /* on whether the per control registers are set for event recording */
!   /* & sets cr9 & cr10 appropriately also */
!   if (watch_area_cnt)
      {
        per_info.control_regs.bits.em_storage_alteration = 1;
        per_info.control_regs.bits.storage_alt_space_ctl = 1;
--- 217,283 ----
  }
  
  
! /* Hardware-assisted watchpoint handling.  */
! 
! /* We maintain a list of all currently active watchpoints in order
!    to properly handle watchpoint removal.
! 
!    The only thing we actually need is the total address space area
!    spanned by the watchpoints.  */
! 
  struct watch_area
  {
!   struct watch_area *next;
    CORE_ADDR lo_addr;
    CORE_ADDR hi_addr;
  };
  
! static struct watch_area *watch_base = NULL;
  
! int
! s390_stopped_by_watchpoint (void)
  {
    per_lowcore_bits per_lowcore;
    ptrace_area parea;
  
+   /* Speed up common case.  */
+   if (!watch_base)
+     return 0;
+ 
    parea.len = sizeof (per_lowcore);
    parea.process_addr = (addr_t) & per_lowcore;
    parea.kernel_addr = offsetof (struct user_regs_struct, per_info.lowcore);
!   if (ptrace (PTRACE_PEEKUSR_AREA, s390_inferior_tid (), &parea) < 0)
!     perror_with_name ("Couldn't retrieve watchpoint status");
  
+   return per_lowcore.perc_storage_alteration == 1
+ 	 && per_lowcore.perc_store_real_address == 0;
+ }
  
! static void
! s390_fix_watch_points (void)
  {
+   int tid = s390_inferior_tid ();
+ 
    per_struct per_info;
    ptrace_area parea;
  
+   CORE_ADDR watch_lo_addr = (CORE_ADDR)-1, watch_hi_addr = 0;
+   struct watch_area *area;
+ 
+   for (area = watch_base; area; area = area->next)
+     {
+       watch_lo_addr = min (watch_lo_addr, area->lo_addr);
+       watch_hi_addr = max (watch_hi_addr, area->hi_addr);
+     }
+ 
    parea.len = sizeof (per_info);
    parea.process_addr = (addr_t) & per_info;
!   parea.kernel_addr = offsetof (struct user_regs_struct, per_info);
!   if (ptrace (PTRACE_PEEKUSR_AREA, tid, &parea) < 0)
!     perror_with_name ("Couldn't retrieve watchpoint status");
! 
!   if (watch_base)
      {
        per_info.control_regs.bits.em_storage_alteration = 1;
        per_info.control_regs.bits.storage_alt_space_ctl = 1;
*************** s390_fix_watch_points (int pid)
*** 277,380 ****
      }
    per_info.starting_addr = watch_lo_addr;
    per_info.ending_addr = watch_hi_addr;
!   ptrace (PTRACE_POKEUSR_AREA, pid, &parea);
  }
  
  int
! s390_insert_watchpoint (int pid, CORE_ADDR addr, int len, int rw)
  {
!   CORE_ADDR hi_addr = addr + len - 1;
!   watch_area *newarea = (watch_area *) xmalloc (sizeof (watch_area));
! 
  
!   if (newarea)
!     {
!       newarea->next = watch_base;
!       watch_base = newarea;
!       watch_lo_addr = min (watch_lo_addr, addr);
!       watch_hi_addr = max (watch_hi_addr, hi_addr);
!       newarea->lo_addr = addr;
!       newarea->hi_addr = hi_addr;
!       if (watch_area_cnt == 0)
! 	{
! 	  watch_lo_addr = newarea->lo_addr;
! 	  watch_hi_addr = newarea->hi_addr;
! 	}
!       watch_area_cnt++;
!       s390_fix_watch_points (pid);
!     }
!   return newarea ? 0 : -1;
  }
  
- 
  int
! s390_remove_watchpoint (int pid, CORE_ADDR addr, int len)
  {
!   watch_area *curr = watch_base, *prev, *matchCurr;
!   CORE_ADDR hi_addr = addr + len - 1;
!   CORE_ADDR watch_second_lo_addr = 0xffffffffUL, watch_second_hi_addr = 0;
!   int lo_addr_ref_cnt, hi_addr_ref_cnt;
!   prev = matchCurr = NULL;
!   lo_addr_ref_cnt = (addr == watch_lo_addr);
!   hi_addr_ref_cnt = (addr == watch_hi_addr);
!   while (curr)
!     {
!       if (matchCurr == NULL)
! 	{
! 	  if (curr->lo_addr == addr && curr->hi_addr == hi_addr)
! 	    {
! 	      matchCurr = curr;
! 	      if (prev)
! 		prev->next = curr->next;
! 	      else
! 		watch_base = curr->next;
! 	    }
! 	  prev = curr;
! 	}
!       if (lo_addr_ref_cnt)
! 	{
! 	  if (watch_lo_addr == curr->lo_addr)
! 	    lo_addr_ref_cnt++;
! 	  if (curr->lo_addr > watch_lo_addr &&
! 	      curr->lo_addr < watch_second_lo_addr)
! 	    watch_second_lo_addr = curr->lo_addr;
! 	}
!       if (hi_addr_ref_cnt)
! 	{
! 	  if (watch_hi_addr == curr->hi_addr)
! 	    hi_addr_ref_cnt++;
! 	  if (curr->hi_addr < watch_hi_addr &&
! 	      curr->hi_addr > watch_second_hi_addr)
! 	    watch_second_hi_addr = curr->hi_addr;
! 	}
!       curr = curr->next;
!     }
!   if (matchCurr)
!     {
!       xfree (matchCurr);
!       watch_area_cnt--;
!       if (watch_area_cnt)
! 	{
! 	  if (lo_addr_ref_cnt == 2)
! 	    watch_lo_addr = watch_second_lo_addr;
! 	  if (hi_addr_ref_cnt == 2)
! 	    watch_hi_addr = watch_second_hi_addr;
! 	}
!       else
! 	{
! 	  watch_lo_addr = watch_hi_addr = 0;
! 	}
!       s390_fix_watch_points (pid);
!       return 0;
!     }
!   else
      {
        fprintf_unfiltered (gdb_stderr,
! 			  "Attempt to remove nonexistent watchpoint in s390_remove_watchpoint\n");
        return -1;
      }
  }
  
  int
  kernel_u_size (void)
  {
--- 289,342 ----
      }
    per_info.starting_addr = watch_lo_addr;
    per_info.ending_addr = watch_hi_addr;
! 
!   if (ptrace (PTRACE_POKEUSR_AREA, tid, &parea) < 0)
!     perror_with_name ("Couldn't modify watchpoint status");
  }
  
  int
! s390_insert_watchpoint (CORE_ADDR addr, int len)
  {
!   struct watch_area *area = xmalloc (sizeof (struct watch_area));
!   if (!area)
!     return -1; 
! 
!   area->lo_addr = addr;
!   area->hi_addr = addr + len - 1;
!  
!   area->next = watch_base;
!   watch_base = area;
  
!   s390_fix_watch_points ();
!   return 0;
  }
  
  int
! s390_remove_watchpoint (CORE_ADDR addr, int len)
  {
!   struct watch_area *area, **parea;
! 
!   for (parea = &watch_base; *parea; parea = &(*parea)->next)
!     if ((*parea)->lo_addr == addr
! 	&& (*parea)->hi_addr == addr + len - 1)
!       break;
! 
!   if (!*parea)
      {
        fprintf_unfiltered (gdb_stderr,
! 			  "Attempt to remove nonexistent watchpoint.\n");
        return -1;
      }
+ 
+   area = *parea;
+   *parea = area->next;
+   xfree (area);
+ 
+   s390_fix_watch_points ();
+   return 0;
  }
  
+ 
  int
  kernel_u_size (void)
  {
-- 
  Dr. Ulrich Weigand
  weigand@informatik.uni-erlangen.de



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