Files updated, added and removed in order to turn the ERASER branch into HEAD


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@1086 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/coregrind/vg_memory.c b/coregrind/vg_memory.c
index eea79cb..5ea4246 100644
--- a/coregrind/vg_memory.c
+++ b/coregrind/vg_memory.c
@@ -1,7 +1,7 @@
 
 /*--------------------------------------------------------------------*/
-/*--- Maintain bitmaps of memory, tracking the accessibility (A)   ---*/
-/*--- and validity (V) status of each byte.                        ---*/
+/*--- Memory-related stuff: segment initialisation and tracking,   ---*/
+/*--- stack operations                                             ---*/
 /*---                                                  vg_memory.c ---*/
 /*--------------------------------------------------------------------*/
 
@@ -27,1275 +27,208 @@
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
    02111-1307, USA.
 
-   The GNU General Public License is contained in the file LICENSE.
+   The GNU General Public License is contained in the file COPYING.
 */
 
 #include "vg_include.h"
 
-/* Define to debug the mem audit system. */
-/* #define VG_DEBUG_MEMORY */
 
-/* Define to debug the memory-leak-detector. */
-/* #define VG_DEBUG_LEAKCHECK */
+/*--------------------------------------------------------------*/
+/*--- Initialise program data/text etc on program startup.   ---*/
+/*--------------------------------------------------------------*/
 
-/* Define to collect detailed performance info. */
-/* #define VG_PROFILE_MEMORY */
-
-
-/*------------------------------------------------------------*/
-/*--- Low-level support for memory checking.               ---*/
-/*------------------------------------------------------------*/
-
-/* 
-   All reads and writes are checked against a memory map, which
-   records the state of all memory in the process.  The memory map is
-   organised like this:
-
-   The top 16 bits of an address are used to index into a top-level
-   map table, containing 65536 entries.  Each entry is a pointer to a
-   second-level map, which records the accesibililty and validity
-   permissions for the 65536 bytes indexed by the lower 16 bits of the
-   address.  Each byte is represented by nine bits, one indicating
-   accessibility, the other eight validity.  So each second-level map
-   contains 73728 bytes.  This two-level arrangement conveniently
-   divides the 4G address space into 64k lumps, each size 64k bytes.
-
-   All entries in the primary (top-level) map must point to a valid
-   secondary (second-level) map.  Since most of the 4G of address
-   space will not be in use -- ie, not mapped at all -- there is a
-   distinguished secondary map, which indicates `not addressible and
-   not valid' writeable for all bytes.  Entries in the primary map for
-   which the entire 64k is not in use at all point at this
-   distinguished map.
-
-   [...] lots of stuff deleted due to out of date-ness
-
-   As a final optimisation, the alignment and address checks for
-   4-byte loads and stores are combined in a neat way.  The primary
-   map is extended to have 262144 entries (2^18), rather than 2^16.
-   The top 3/4 of these entries are permanently set to the
-   distinguished secondary map.  For a 4-byte load/store, the
-   top-level map is indexed not with (addr >> 16) but instead f(addr),
-   where
-
-    f( XXXX XXXX XXXX XXXX ____ ____ ____ __YZ )
-        = ____ ____ ____ __YZ XXXX XXXX XXXX XXXX  or 
-        = ____ ____ ____ __ZY XXXX XXXX XXXX XXXX
-
-   ie the lowest two bits are placed above the 16 high address bits.
-   If either of these two bits are nonzero, the address is misaligned;
-   this will select a secondary map from the upper 3/4 of the primary
-   map.  Because this is always the distinguished secondary map, a
-   (bogus) address check failure will result.  The failure handling
-   code can then figure out whether this is a genuine addr check
-   failure or whether it is a possibly-legitimate access at a
-   misaligned address.  
-*/
-
-
-/*------------------------------------------------------------*/
-/*--- Crude profiling machinery.                           ---*/
-/*------------------------------------------------------------*/
-
-#ifdef VG_PROFILE_MEMORY
-
-#define N_PROF_EVENTS 150
-
-static UInt event_ctr[N_PROF_EVENTS];
-
-static void init_prof_mem ( void )
-{
-   Int i;
-   for (i = 0; i < N_PROF_EVENTS; i++)
-      event_ctr[i] = 0;
-}
-
-void VG_(done_prof_mem) ( void )
-{
-   Int i;
-   for (i = 0; i < N_PROF_EVENTS; i++) {
-      if ((i % 10) == 0) 
-         VG_(printf)("\n");
-      if (event_ctr[i] > 0)
-         VG_(printf)( "prof mem event %2d: %d\n", i, event_ctr[i] );
+typedef
+   struct _ExeSeg {
+      Addr start;
+      UInt size;
+      struct _ExeSeg* next;
    }
-   VG_(printf)("\n");
-}
+   ExeSeg;
 
-#define PROF_EVENT(ev)                                  \
-   do { vg_assert((ev) >= 0 && (ev) < N_PROF_EVENTS);   \
-        event_ctr[ev]++;                                \
-   } while (False);
+/* The list of current executable segments loaded.  Required so that when a
+   segment is munmap'd, if it's executable we can recognise it as such and
+   invalidate translations for it, and drop any basic-block specific
+   information being stored.  If symbols are being used, this list will have
+   the same segments recorded in it as the SegInfo symbols list (but much
+   less information about each segment).
+*/
+static ExeSeg* exeSegsHead = NULL;
 
-#else
-
-static void init_prof_mem ( void ) { }
-       void VG_(done_prof_mem) ( void ) { }
-
-#define PROF_EVENT(ev) /* */
-
-#endif
-
-/* Event index.  If just the name of the fn is given, this means the
-   number of calls to the fn.  Otherwise it is the specified event.
-
-   10   alloc_secondary_map
-
-   20   get_abit
-   21   get_vbyte
-   22   set_abit
-   23   set_vbyte
-   24   get_abits4_ALIGNED
-   25   get_vbytes4_ALIGNED
-
-   30   set_address_range_perms
-   31   set_address_range_perms(lower byte loop)
-   32   set_address_range_perms(quadword loop)
-   33   set_address_range_perms(upper byte loop)
+/* Prepend it -- mmaps/munmaps likely to follow a stack pattern(?) so this
+   is good.
+   Also check no segments overlap, which would be very bad.  Check is linear
+   for each seg added (quadratic overall) but the total number should be
+   small (konqueror has around 50 --njn). */
+static void add_exe_segment_to_list( a, len ) 
+{
+   Addr lo = a;
+   Addr hi = a + len - 1;
+   ExeSeg* es;
+   ExeSeg* es2;
    
-   35   make_noaccess
-   36   make_writable
-   37   make_readable
+   /* Prepend it */
+   es        = (ExeSeg*)VG_(arena_malloc)(VG_AR_CORE, sizeof(ExeSeg));
+   es->start = a;
+   es->size  = len;
+   es->next  = exeSegsHead;
+   exeSegsHead = es;
 
-   40   copy_address_range_perms
-   41   copy_address_range_perms(byte loop)
-   42   check_writable
-   43   check_writable(byte loop)
-   44   check_readable
-   45   check_readable(byte loop)
-   46   check_readable_asciiz
-   47   check_readable_asciiz(byte loop)
-
-   50   make_aligned_word_NOACCESS
-   51   make_aligned_word_WRITABLE
-
-   60   helperc_LOADV4
-   61   helperc_STOREV4
-   62   helperc_LOADV2
-   63   helperc_STOREV2
-   64   helperc_LOADV1
-   65   helperc_STOREV1
-
-   70   rim_rd_V4_SLOWLY
-   71   rim_wr_V4_SLOWLY
-   72   rim_rd_V2_SLOWLY
-   73   rim_wr_V2_SLOWLY
-   74   rim_rd_V1_SLOWLY
-   75   rim_wr_V1_SLOWLY
-
-   80   fpu_read
-   81   fpu_read aligned 4
-   82   fpu_read aligned 8
-   83   fpu_read 2
-   84   fpu_read 10
-
-   85   fpu_write
-   86   fpu_write aligned 4
-   87   fpu_write aligned 8
-   88   fpu_write 2
-   89   fpu_write 10
-
-   90   fpu_read_check_SLOWLY
-   91   fpu_read_check_SLOWLY(byte loop)
-   92   fpu_write_check_SLOWLY
-   93   fpu_write_check_SLOWLY(byte loop)
-
-   100  is_plausible_stack_addr
-   101  handle_esp_assignment
-   102  handle_esp_assignment(-4)
-   103  handle_esp_assignment(+4)
-   104  handle_esp_assignment(-12)
-   105  handle_esp_assignment(-8)
-   106  handle_esp_assignment(+16)
-   107  handle_esp_assignment(+12)
-   108  handle_esp_assignment(0)
-   109  handle_esp_assignment(+8)
-   110  handle_esp_assignment(-16)
-   111  handle_esp_assignment(+20)
-   112  handle_esp_assignment(-20)
-   113  handle_esp_assignment(+24)
-   114  handle_esp_assignment(-24)
-
-   120  vg_handle_esp_assignment_SLOWLY
-   121  vg_handle_esp_assignment_SLOWLY(normal; move down)
-   122  vg_handle_esp_assignment_SLOWLY(normal; move up)
-   123  vg_handle_esp_assignment_SLOWLY(normal)
-   124  vg_handle_esp_assignment_SLOWLY(>= HUGE_DELTA)
-*/
-
-/*------------------------------------------------------------*/
-/*--- Function declarations.                               ---*/
-/*------------------------------------------------------------*/
-
-/* Set permissions for an address range.  Not speed-critical. */
-void VGM_(make_noaccess) ( Addr a, UInt len );
-void VGM_(make_writable) ( Addr a, UInt len );
-void VGM_(make_readable) ( Addr a, UInt len );
-
-/* Check permissions for an address range.  Not speed-critical. */
-Bool VGM_(check_writable) ( Addr a, UInt len, Addr* bad_addr );
-Bool VGM_(check_readable) ( Addr a, UInt len, Addr* bad_addr );
-Bool VGM_(check_readable_asciiz) ( Addr a, Addr* bad_addr );
-
-static UInt vgm_rd_V4_SLOWLY ( Addr a );
-static UInt vgm_rd_V2_SLOWLY ( Addr a );
-static UInt vgm_rd_V1_SLOWLY ( Addr a );
-static void vgm_wr_V4_SLOWLY ( Addr a, UInt vbytes );
-static void vgm_wr_V2_SLOWLY ( Addr a, UInt vbytes );
-static void vgm_wr_V1_SLOWLY ( Addr a, UInt vbytes );
-static void fpu_read_check_SLOWLY ( Addr addr, Int size );
-static void fpu_write_check_SLOWLY ( Addr addr, Int size );
-
-
-/*------------------------------------------------------------*/
-/*--- Data defns.                                          ---*/
-/*------------------------------------------------------------*/
-
-typedef 
-   struct {
-      UChar abits[8192];
-      UChar vbyte[65536];
-   }
-   SecMap;
-
-/* These two are statically allocated.  Should they be non-public? */
-SecMap* VG_(primary_map)[ /*65536*/ 262144 ];
-static SecMap  vg_distinguished_secondary_map;
-
-#define IS_DISTINGUISHED_SM(smap) \
-   ((smap) == &vg_distinguished_secondary_map)
-
-#define ENSURE_MAPPABLE(addr,caller)                                   \
-   do {                                                                \
-      if (IS_DISTINGUISHED_SM(VG_(primary_map)[(addr) >> 16])) {       \
-         VG_(primary_map)[(addr) >> 16] = alloc_secondary_map(caller); \
-         /* VG_(printf)("new 2map because of %p\n", addr);   */       \
-      }                                                                \
-   } while(0)
-
-#define BITARR_SET(aaa_p,iii_p)                         \
-   do {                                                 \
-      UInt   iii = (UInt)iii_p;                         \
-      UChar* aaa = (UChar*)aaa_p;                       \
-      aaa[iii >> 3] |= (1 << (iii & 7));                \
-   } while (0)
-
-#define BITARR_CLEAR(aaa_p,iii_p)                       \
-   do {                                                 \
-      UInt   iii = (UInt)iii_p;                         \
-      UChar* aaa = (UChar*)aaa_p;                       \
-      aaa[iii >> 3] &= ~(1 << (iii & 7));               \
-   } while (0)
-
-#define BITARR_TEST(aaa_p,iii_p)                        \
-      (0 != (((UChar*)aaa_p)[ ((UInt)iii_p) >> 3 ]      \
-               & (1 << (((UInt)iii_p) & 7))))           \
-
-
-#define VGM_BIT_VALID      0
-#define VGM_BIT_INVALID    1
-
-#define VGM_NIBBLE_VALID   0
-#define VGM_NIBBLE_INVALID 0xF
-
-#define VGM_BYTE_VALID     0
-#define VGM_BYTE_INVALID   0xFF
-
-/* Now in vg_include.h.
-#define VGM_WORD_VALID     0
-#define VGM_WORD_INVALID   0xFFFFFFFF
-*/
-
-#define VGM_EFLAGS_VALID   0xFFFFFFFE
-#define VGM_EFLAGS_INVALID 0xFFFFFFFF
-
-
-#define IS_ALIGNED4_ADDR(aaa_p) (0 == (((UInt)(aaa_p)) & 3))
-
-
-/*------------------------------------------------------------*/
-/*--- Basic bitmap management, reading and writing.        ---*/
-/*------------------------------------------------------------*/
-
-/* Allocate and initialise a secondary map. */
-
-static SecMap* alloc_secondary_map ( __attribute__ ((unused)) 
-                                     Char* caller )
-{
-   SecMap* map;
-   UInt  i;
-   PROF_EVENT(10);
-
-   /* Mark all bytes as invalid access and invalid value. */
-
-   /* It just happens that a SecMap occupies exactly 18 pages --
-      although this isn't important, so the following assert is
-      spurious. */
-   vg_assert(0 == (sizeof(SecMap) % VKI_BYTES_PER_PAGE));
-   map = VG_(get_memory_from_mmap)( sizeof(SecMap), caller );
-
-   for (i = 0; i < 8192; i++)
-      map->abits[i] = VGM_BYTE_INVALID; /* Invalid address */
-   for (i = 0; i < 65536; i++)
-      map->vbyte[i] = VGM_BYTE_INVALID; /* Invalid Value */
-
-   /* VG_(printf)("ALLOC_2MAP(%s)\n", caller ); */
-   return map;
-}
-
-
-/* Basic reading/writing of the bitmaps, for byte-sized accesses. */
-
-static __inline__ UChar get_abit ( Addr a )
-{
-   SecMap* sm     = VG_(primary_map)[a >> 16];
-   UInt    sm_off = a & 0xFFFF;
-   PROF_EVENT(20);
-   return BITARR_TEST(sm->abits, sm_off) 
-             ? VGM_BIT_INVALID : VGM_BIT_VALID;
-}
-
-static __inline__ UChar get_vbyte ( Addr a )
-{
-   SecMap* sm     = VG_(primary_map)[a >> 16];
-   UInt    sm_off = a & 0xFFFF;
-   PROF_EVENT(21);
-   return sm->vbyte[sm_off];
-}
-
-static __inline__ void set_abit ( Addr a, UChar abit )
-{
-   SecMap* sm;
-   UInt    sm_off;
-   PROF_EVENT(22);
-   ENSURE_MAPPABLE(a, "set_abit");
-   sm     = VG_(primary_map)[a >> 16];
-   sm_off = a & 0xFFFF;
-   if (abit) 
-      BITARR_SET(sm->abits, sm_off);
-   else
-      BITARR_CLEAR(sm->abits, sm_off);
-}
-
-static __inline__ void set_vbyte ( Addr a, UChar vbyte )
-{
-   SecMap* sm;
-   UInt    sm_off;
-   PROF_EVENT(23);
-   ENSURE_MAPPABLE(a, "set_vbyte");
-   sm     = VG_(primary_map)[a >> 16];
-   sm_off = a & 0xFFFF;
-   sm->vbyte[sm_off] = vbyte;
-}
-
-
-/* Reading/writing of the bitmaps, for aligned word-sized accesses. */
-
-static __inline__ UChar get_abits4_ALIGNED ( Addr a )
-{
-   SecMap* sm;
-   UInt    sm_off;
-   UChar   abits8;
-   PROF_EVENT(24);
-#  ifdef VG_DEBUG_MEMORY
-   vg_assert(IS_ALIGNED4_ADDR(a));
-#  endif
-   sm     = VG_(primary_map)[a >> 16];
-   sm_off = a & 0xFFFF;
-   abits8 = sm->abits[sm_off >> 3];
-   abits8 >>= (a & 4 /* 100b */);   /* a & 4 is either 0 or 4 */
-   abits8 &= 0x0F;
-   return abits8;
-}
-
-static UInt __inline__ get_vbytes4_ALIGNED ( Addr a )
-{
-   SecMap* sm     = VG_(primary_map)[a >> 16];
-   UInt    sm_off = a & 0xFFFF;
-   PROF_EVENT(25);
-#  ifdef VG_DEBUG_MEMORY
-   vg_assert(IS_ALIGNED4_ADDR(a));
-#  endif
-   return ((UInt*)(sm->vbyte))[sm_off >> 2];
-}
-
-
-/*------------------------------------------------------------*/
-/*--- Setting permissions over address ranges.             ---*/
-/*------------------------------------------------------------*/
-
-static void set_address_range_perms ( Addr a, UInt len, 
-                                      UInt example_a_bit,
-                                      UInt example_v_bit )
-{
-   UChar   vbyte, abyte8;
-   UInt    vword4, sm_off;
-   SecMap* sm;
-
-   PROF_EVENT(30);
-
-   if (len == 0)
-      return;
-
-   if (len > 100 * 1000 * 1000) 
-      VG_(message)(Vg_UserMsg, 
-                   "Warning: set address range perms: "
-                   "large range %d, a %d, v %d",
-                   len, example_a_bit, example_v_bit );
-
-   VGP_PUSHCC(VgpSARP);
-
-   /* Requests to change permissions of huge address ranges may
-      indicate bugs in our machinery.  30,000,000 is arbitrary, but so
-      far all legitimate requests have fallen beneath that size. */
-   /* 4 Mar 02: this is just stupid; get rid of it. */
-   /* vg_assert(len < 30000000); */
-
-   /* Check the permissions make sense. */
-   vg_assert(example_a_bit == VGM_BIT_VALID 
-             || example_a_bit == VGM_BIT_INVALID);
-   vg_assert(example_v_bit == VGM_BIT_VALID 
-             || example_v_bit == VGM_BIT_INVALID);
-   if (example_a_bit == VGM_BIT_INVALID)
-      vg_assert(example_v_bit == VGM_BIT_INVALID);
-
-   /* The validity bits to write. */
-   vbyte = example_v_bit==VGM_BIT_VALID 
-              ? VGM_BYTE_VALID : VGM_BYTE_INVALID;
-
-   /* In order that we can charge through the address space at 8
-      bytes/main-loop iteration, make up some perms. */
-   abyte8 = (example_a_bit << 7)
-            | (example_a_bit << 6)
-            | (example_a_bit << 5)
-            | (example_a_bit << 4)
-            | (example_a_bit << 3)
-            | (example_a_bit << 2)
-            | (example_a_bit << 1)
-            | (example_a_bit << 0);
-   vword4 = (vbyte << 24) | (vbyte << 16) | (vbyte << 8) | vbyte;
-
-#  ifdef VG_DEBUG_MEMORY
-   /* Do it ... */
-   while (True) {
-      PROF_EVENT(31);
-      if (len == 0) break;
-      set_abit ( a, example_a_bit );
-      set_vbyte ( a, vbyte );
-      a++;
-      len--;
-   }
-
-#  else
-   /* Slowly do parts preceding 8-byte alignment. */
-   while (True) {
-      PROF_EVENT(31);
-      if (len == 0) break;
-      if ((a % 8) == 0) break;
-      set_abit ( a, example_a_bit );
-      set_vbyte ( a, vbyte );
-      a++;
-      len--;
-   }   
-
-   if (len == 0) {
-      VGP_POPCC;
-      return;
-   }
-   vg_assert((a % 8) == 0 && len > 0);
-
-   /* Once aligned, go fast. */
-   while (True) {
-      PROF_EVENT(32);
-      if (len < 8) break;
-      ENSURE_MAPPABLE(a, "set_address_range_perms(fast)");
-      sm = VG_(primary_map)[a >> 16];
-      sm_off = a & 0xFFFF;
-      sm->abits[sm_off >> 3] = abyte8;
-      ((UInt*)(sm->vbyte))[(sm_off >> 2) + 0] = vword4;
-      ((UInt*)(sm->vbyte))[(sm_off >> 2) + 1] = vword4;
-      a += 8;
-      len -= 8;
-   }
-
-   if (len == 0) {
-      VGP_POPCC;
-      return;
-   }
-   vg_assert((a % 8) == 0 && len > 0 && len < 8);
-
-   /* Finish the upper fragment. */
-   while (True) {
-      PROF_EVENT(33);
-      if (len == 0) break;
-      set_abit ( a, example_a_bit );
-      set_vbyte ( a, vbyte );
-      a++;
-      len--;
-   }   
-#  endif
-
-   /* Check that zero page and highest page have not been written to
-      -- this could happen with buggy syscall wrappers.  Today
-      (2001-04-26) had precisely such a problem with
-      __NR_setitimer. */
-   vg_assert(VG_(first_and_last_secondaries_look_plausible)());
-   VGP_POPCC;
-}
-
-
-/* Set permissions for address ranges ... */
-
-void VGM_(make_noaccess) ( Addr a, UInt len )
-{
-   PROF_EVENT(35);
-   set_address_range_perms ( a, len, VGM_BIT_INVALID, VGM_BIT_INVALID );
-}
-
-void VGM_(make_writable) ( Addr a, UInt len )
-{
-   PROF_EVENT(36);
-   set_address_range_perms ( a, len, VGM_BIT_VALID, VGM_BIT_INVALID );
-}
-
-void VGM_(make_readable) ( Addr a, UInt len )
-{
-   PROF_EVENT(37);
-   set_address_range_perms ( a, len, VGM_BIT_VALID, VGM_BIT_VALID );
-}
-
-void VGM_(make_readwritable) ( Addr a, UInt len )
-{
-   PROF_EVENT(38);
-   set_address_range_perms ( a, len, VGM_BIT_VALID, VGM_BIT_VALID );
-}
-
-/* Block-copy permissions (needed for implementing realloc()). */
-
-void VGM_(copy_address_range_perms) ( Addr src, Addr dst, UInt len )
-{
-   UInt i;
-   PROF_EVENT(40);
-   for (i = 0; i < len; i++) {
-      UChar abit  = get_abit ( src+i );
-      UChar vbyte = get_vbyte ( src+i );
-      PROF_EVENT(41);
-      set_abit ( dst+i, abit );
-      set_vbyte ( dst+i, vbyte );
-   }
-}
-
-
-/* Check permissions for address range.  If inadequate permissions
-   exist, *bad_addr is set to the offending address, so the caller can
-   know what it is. */
-
-Bool VGM_(check_writable) ( Addr a, UInt len, Addr* bad_addr )
-{
-   UInt  i;
-   UChar abit;
-   PROF_EVENT(42);
-   for (i = 0; i < len; i++) {
-      PROF_EVENT(43);
-      abit = get_abit(a);
-      if (abit == VGM_BIT_INVALID) {
-         if (bad_addr != NULL) *bad_addr = a;
-         return False;
+   /* Check there's no overlap with the rest of the list */
+   for (es2 = es->next; es2 != NULL; es2 = es2->next) {
+      Addr lo2 = es2->start;
+      Addr hi2 = es2->start + es2->size - 1;
+      Bool overlap;
+      vg_assert(lo < hi);
+      vg_assert(lo2 < hi2);
+      /* the main assertion */
+      overlap = (lo <= lo2 && lo2 <= hi)
+                 || (lo <= hi2 && hi2 <= hi);
+      if (overlap) {
+         VG_(printf)("\n\nOVERLAPPING EXE SEGMENTS\n"
+                     "  new: start %p, size %d\n"
+                     "  old: start %p, size %d\n\n",
+                     es->start, es->size, es2->start, es2->size );
+         vg_assert(! overlap);
       }
-      a++;
    }
+}
+
+static Bool remove_if_exe_segment_from_list( Addr a, UInt len )
+{
+   ExeSeg **prev_next_ptr = & exeSegsHead, 
+          *curr = exeSegsHead;
+
+   while (True) {
+      if (curr == NULL) break;
+      if (a == curr->start) break;
+      prev_next_ptr = &curr->next;
+      curr = curr->next;
+   }
+   if (curr == NULL)
+      return False;
+
+   vg_assert(*prev_next_ptr == curr);
+
+   *prev_next_ptr = curr->next;
+
+   VG_(arena_free)(VG_AR_CORE, curr);
    return True;
 }
 
-Bool VGM_(check_readable) ( Addr a, UInt len, Addr* bad_addr )
+/* Records the exe segment in the ExeSeg list (checking for overlaps), and
+   reads debug info if required.  Note the entire /proc/pid/maps file is 
+   read for the debug info, but it just reads symbols for newly added exe
+   segments.  This is required to find out their names if they have one.  So
+   we don't use this at startup because it's overkill and can screw reading
+   of /proc/pid/maps.
+ */
+void VG_(new_exe_segment) ( Addr a, UInt len )
 {
-   UInt  i;
-   UChar abit;
-   UChar vbyte;
-   PROF_EVENT(44);
-   for (i = 0; i < len; i++) {
-      abit  = get_abit(a);
-      vbyte = get_vbyte(a);
-      PROF_EVENT(45);
-      if (abit != VGM_BIT_VALID || vbyte != VGM_BYTE_VALID) {
-         if (bad_addr != NULL) *bad_addr = a;
-         return False;
-      }
-      a++;
-   }
-   return True;
+   // SSS: only bother if size != 0?  Does that happen? (probably can)
+
+   add_exe_segment_to_list( a, len );
+   VG_(maybe_read_symbols)();
 }
 
-
-/* Check a zero-terminated ascii string.  Tricky -- don't want to
-   examine the actual bytes, to find the end, until we're sure it is
-   safe to do so. */
-
-Bool VGM_(check_readable_asciiz) ( Addr a, Addr* bad_addr )
+/* Invalidate translations as necessary (also discarding any basic
+   block-specific info retained by the skin) and unload any debug
+   symbols. */
+// Nb: remove_if_exe_segment_from_list() and VG_(maybe_unload_symbols)()
+// both ignore 'len', but that seems that's ok for most programs...  see
+// comment above vg_syscalls.c:mmap_segment() et al for more details.
+void VG_(remove_if_exe_segment) ( Addr a, UInt len )
 {
-   UChar abit;
-   UChar vbyte;
-   PROF_EVENT(46);
-   while (True) {
-      PROF_EVENT(47);
-      abit  = get_abit(a);
-      vbyte = get_vbyte(a);
-      if (abit != VGM_BIT_VALID || vbyte != VGM_BYTE_VALID) {
-         if (bad_addr != NULL) *bad_addr = a;
-         return False;
-      }
-      /* Ok, a is safe to read. */
-      if (* ((UChar*)a) == 0) return True;
-      a++;
+   if (remove_if_exe_segment_from_list( a, len )) {
+      VG_(invalidate_translations) ( a, len );
+      VG_(maybe_unload_symbols)    ( a, len );
    }
 }
 
 
-/* Setting permissions for aligned words.  This supports fast stack
-   operations. */
-
-static __inline__ void make_aligned_word_NOACCESS ( Addr a )
+static
+void startup_segment_callback ( Addr start, UInt size, 
+                                Char rr, Char ww, Char xx, 
+                                UInt foffset, UChar* filename )
 {
-   SecMap* sm;
-   UInt    sm_off;
-   UChar   mask;
-   PROF_EVENT(50);
-#  ifdef VG_DEBUG_MEMORY
-   vg_assert(IS_ALIGNED4_ADDR(a));
-#  endif
-   ENSURE_MAPPABLE(a, "make_aligned_word_NOACCESS");
-   sm     = VG_(primary_map)[a >> 16];
-   sm_off = a & 0xFFFF;
-   ((UInt*)(sm->vbyte))[sm_off >> 2] = VGM_WORD_INVALID;
-   mask = 0x0F;
-   mask <<= (a & 4 /* 100b */);   /* a & 4 is either 0 or 4 */
-   /* mask now contains 1s where we wish to make address bits
-      invalid (1s). */
-   sm->abits[sm_off >> 3] |= mask;
-}
+   UInt r_esp;
+   Bool is_stack_segment;
 
-static __inline__ void make_aligned_word_WRITABLE ( Addr a )
-{
-   SecMap* sm;
-   UInt    sm_off;
-   UChar   mask;
-   PROF_EVENT(51);
-#  ifdef VG_DEBUG_MEMORY
-   vg_assert(IS_ALIGNED4_ADDR(a));
-#  endif
-   ENSURE_MAPPABLE(a, "make_aligned_word_WRITABLE");
-   sm     = VG_(primary_map)[a >> 16];
-   sm_off = a & 0xFFFF;
-   ((UInt*)(sm->vbyte))[sm_off >> 2] = VGM_WORD_INVALID;
-   mask = 0x0F;
-   mask <<= (a & 4 /* 100b */);   /* a & 4 is either 0 or 4 */
-   /* mask now contains 1s where we wish to make address bits
-      invalid (0s). */
-   sm->abits[sm_off >> 3] &= ~mask;
-}
-
-
-/*------------------------------------------------------------*/
-/*--- Functions called directly from generated code.       ---*/
-/*------------------------------------------------------------*/
-
-static __inline__ UInt rotateRight16 ( UInt x )
-{
-   /* Amazingly, gcc turns this into a single rotate insn. */
-   return (x >> 16) | (x << 16);
-}
-
-
-static __inline__ UInt shiftRight16 ( UInt x )
-{
-   return x >> 16;
-}
-
-
-/* Read/write 1/2/4 sized V bytes, and emit an address error if
-   needed. */
-
-/* VG_(helperc_{LD,ST}V{1,2,4}) handle the common case fast.
-   Under all other circumstances, it defers to the relevant _SLOWLY
-   function, which can handle all situations.
-*/
-UInt VG_(helperc_LOADV4) ( Addr a )
-{
-#  ifdef VG_DEBUG_MEMORY
-   return vgm_rd_V4_SLOWLY(a);
-#  else
-   UInt    sec_no = rotateRight16(a) & 0x3FFFF;
-   SecMap* sm     = VG_(primary_map)[sec_no];
-   UInt    a_off  = (a & 0xFFFF) >> 3;
-   UChar   abits  = sm->abits[a_off];
-   abits >>= (a & 4);
-   abits &= 15;
-   PROF_EVENT(60);
-   if (abits == VGM_NIBBLE_VALID) {
-      /* Handle common case quickly: a is suitably aligned, is mapped,
-         and is addressible. */
-      UInt v_off = a & 0xFFFF;
-      return ((UInt*)(sm->vbyte))[ v_off >> 2 ];
-   } else {
-      /* Slow but general case. */
-      return vgm_rd_V4_SLOWLY(a);
-   }
-#  endif
-}
-
-void VG_(helperc_STOREV4) ( Addr a, UInt vbytes )
-{
-#  ifdef VG_DEBUG_MEMORY
-   vgm_wr_V4_SLOWLY(a, vbytes);
-#  else
-   UInt    sec_no = rotateRight16(a) & 0x3FFFF;
-   SecMap* sm     = VG_(primary_map)[sec_no];
-   UInt    a_off  = (a & 0xFFFF) >> 3;
-   UChar   abits  = sm->abits[a_off];
-   abits >>= (a & 4);
-   abits &= 15;
-   PROF_EVENT(61);
-   if (abits == VGM_NIBBLE_VALID) {
-      /* Handle common case quickly: a is suitably aligned, is mapped,
-         and is addressible. */
-      UInt v_off = a & 0xFFFF;
-      ((UInt*)(sm->vbyte))[ v_off >> 2 ] = vbytes;
-   } else {
-      /* Slow but general case. */
-      vgm_wr_V4_SLOWLY(a, vbytes);
-   }
-#  endif
-}
-
-UInt VG_(helperc_LOADV2) ( Addr a )
-{
-#  ifdef VG_DEBUG_MEMORY
-   return vgm_rd_V2_SLOWLY(a);
-#  else
-   UInt    sec_no = rotateRight16(a) & 0x1FFFF;
-   SecMap* sm     = VG_(primary_map)[sec_no];
-   UInt    a_off  = (a & 0xFFFF) >> 3;
-   PROF_EVENT(62);
-   if (sm->abits[a_off] == VGM_BYTE_VALID) {
-      /* Handle common case quickly. */
-      UInt v_off = a & 0xFFFF;
-      return 0xFFFF0000 
-             |  
-             (UInt)( ((UShort*)(sm->vbyte))[ v_off >> 1 ] );
-   } else {
-      /* Slow but general case. */
-      return vgm_rd_V2_SLOWLY(a);
-   }
-#  endif
-}
-
-void VG_(helperc_STOREV2) ( Addr a, UInt vbytes )
-{
-#  ifdef VG_DEBUG_MEMORY
-   vgm_wr_V2_SLOWLY(a, vbytes);
-#  else
-   UInt    sec_no = rotateRight16(a) & 0x1FFFF;
-   SecMap* sm     = VG_(primary_map)[sec_no];
-   UInt    a_off  = (a & 0xFFFF) >> 3;
-   PROF_EVENT(63);
-   if (sm->abits[a_off] == VGM_BYTE_VALID) {
-      /* Handle common case quickly. */
-      UInt v_off = a & 0xFFFF;
-      ((UShort*)(sm->vbyte))[ v_off >> 1 ] = vbytes & 0x0000FFFF;
-   } else {
-      /* Slow but general case. */
-      vgm_wr_V2_SLOWLY(a, vbytes);
-   }
-#  endif
-}
-
-UInt VG_(helperc_LOADV1) ( Addr a )
-{
-#  ifdef VG_DEBUG_MEMORY
-   return vgm_rd_V1_SLOWLY(a);
-#  else
-   UInt    sec_no = shiftRight16(a);
-   SecMap* sm     = VG_(primary_map)[sec_no];
-   UInt    a_off  = (a & 0xFFFF) >> 3;
-   PROF_EVENT(64);
-   if (sm->abits[a_off] == VGM_BYTE_VALID) {
-      /* Handle common case quickly. */
-      UInt v_off = a & 0xFFFF;
-      return 0xFFFFFF00
-             |
-             (UInt)( ((UChar*)(sm->vbyte))[ v_off ] );
-   } else {
-      /* Slow but general case. */
-      return vgm_rd_V1_SLOWLY(a);
-   }
-#  endif
-}
-
-void VG_(helperc_STOREV1) ( Addr a, UInt vbytes )
-{
-#  ifdef VG_DEBUG_MEMORY
-   vgm_wr_V1_SLOWLY(a, vbytes);
-#  else
-   UInt    sec_no = shiftRight16(a);
-   SecMap* sm     = VG_(primary_map)[sec_no];
-   UInt    a_off  = (a & 0xFFFF) >> 3;
-   PROF_EVENT(65);
-   if (sm->abits[a_off] == VGM_BYTE_VALID) {
-      /* Handle common case quickly. */
-      UInt v_off = a & 0xFFFF;
-      ((UChar*)(sm->vbyte))[ v_off ] = vbytes & 0x000000FF;
-   } else {
-      /* Slow but general case. */
-      vgm_wr_V1_SLOWLY(a, vbytes);
-   }
-#  endif
-}
-
-
-/*------------------------------------------------------------*/
-/*--- Fallback functions to handle cases that the above    ---*/
-/*--- VG_(helperc_{LD,ST}V{1,2,4}) can't manage.           ---*/
-/*------------------------------------------------------------*/
-
-static UInt vgm_rd_V4_SLOWLY ( Addr a )
-{
-   Bool a0ok, a1ok, a2ok, a3ok;
-   UInt vb0, vb1, vb2, vb3;
-
-   PROF_EVENT(70);
-
-   /* First establish independently the addressibility of the 4 bytes
-      involved. */
-   a0ok = get_abit(a+0) == VGM_BIT_VALID;
-   a1ok = get_abit(a+1) == VGM_BIT_VALID;
-   a2ok = get_abit(a+2) == VGM_BIT_VALID;
-   a3ok = get_abit(a+3) == VGM_BIT_VALID;
-
-   /* Also get the validity bytes for the address. */
-   vb0 = (UInt)get_vbyte(a+0);
-   vb1 = (UInt)get_vbyte(a+1);
-   vb2 = (UInt)get_vbyte(a+2);
-   vb3 = (UInt)get_vbyte(a+3);
-
-   /* Now distinguish 3 cases */
-
-   /* Case 1: the address is completely valid, so:
-      - no addressing error
-      - return V bytes as read from memory
-   */
-   if (a0ok && a1ok && a2ok && a3ok) {
-      UInt vw = VGM_WORD_INVALID;
-      vw <<= 8; vw |= vb3;
-      vw <<= 8; vw |= vb2;
-      vw <<= 8; vw |= vb1;
-      vw <<= 8; vw |= vb0;
-      return vw;
-   }
-
-   /* Case 2: the address is completely invalid.  
-      - emit addressing error
-      - return V word indicating validity.  
-      This sounds strange, but if we make loads from invalid addresses 
-      give invalid data, we also risk producing a number of confusing
-      undefined-value errors later, which confuses the fact that the
-      error arose in the first place from an invalid address. 
-   */
-   /* VG_(printf)("%p (%d %d %d %d)\n", a, a0ok, a1ok, a2ok, a3ok); */
-   if (!VG_(clo_partial_loads_ok) 
-       || ((a & 3) != 0)
-       || (!a0ok && !a1ok && !a2ok && !a3ok)) {
-      VG_(record_address_error)( a, 4, False );
-      return (VGM_BYTE_VALID << 24) | (VGM_BYTE_VALID << 16) 
-             | (VGM_BYTE_VALID << 8) | VGM_BYTE_VALID;
-   }
-
-   /* Case 3: the address is partially valid.  
-      - no addressing error
-      - returned V word is invalid where the address is invalid, 
-        and contains V bytes from memory otherwise. 
-      Case 3 is only allowed if VG_(clo_partial_loads_ok) is True
-      (which is the default), and the address is 4-aligned.  
-      If not, Case 2 will have applied.
-   */
-   vg_assert(VG_(clo_partial_loads_ok));
-   {
-      UInt vw = VGM_WORD_INVALID;
-      vw <<= 8; vw |= (a3ok ? vb3 : VGM_BYTE_INVALID);
-      vw <<= 8; vw |= (a2ok ? vb2 : VGM_BYTE_INVALID);
-      vw <<= 8; vw |= (a1ok ? vb1 : VGM_BYTE_INVALID);
-      vw <<= 8; vw |= (a0ok ? vb0 : VGM_BYTE_INVALID);
-      return vw;
-   }
-}
-
-static void vgm_wr_V4_SLOWLY ( Addr a, UInt vbytes )
-{
-   /* Check the address for validity. */
-   Bool aerr = False;
-   PROF_EVENT(71);
-
-   if (get_abit(a+0) != VGM_BIT_VALID) aerr = True;
-   if (get_abit(a+1) != VGM_BIT_VALID) aerr = True;
-   if (get_abit(a+2) != VGM_BIT_VALID) aerr = True;
-   if (get_abit(a+3) != VGM_BIT_VALID) aerr = True;
-
-   /* Store the V bytes, remembering to do it little-endian-ly. */
-   set_vbyte( a+0, vbytes & 0x000000FF ); vbytes >>= 8;
-   set_vbyte( a+1, vbytes & 0x000000FF ); vbytes >>= 8;
-   set_vbyte( a+2, vbytes & 0x000000FF ); vbytes >>= 8;
-   set_vbyte( a+3, vbytes & 0x000000FF );
-
-   /* If an address error has happened, report it. */
-   if (aerr)
-      VG_(record_address_error)( a, 4, True );
-}
-
-static UInt vgm_rd_V2_SLOWLY ( Addr a )
-{
-   /* Check the address for validity. */
-   UInt vw   = VGM_WORD_INVALID;
-   Bool aerr = False;
-   PROF_EVENT(72);
-
-   if (get_abit(a+0) != VGM_BIT_VALID) aerr = True;
-   if (get_abit(a+1) != VGM_BIT_VALID) aerr = True;
-
-   /* Fetch the V bytes, remembering to do it little-endian-ly. */
-   vw <<= 8; vw |= (UInt)get_vbyte(a+1);
-   vw <<= 8; vw |= (UInt)get_vbyte(a+0);
-
-   /* If an address error has happened, report it. */
-   if (aerr) {
-      VG_(record_address_error)( a, 2, False );
-      vw = (VGM_BYTE_INVALID << 24) | (VGM_BYTE_INVALID << 16) 
-           | (VGM_BYTE_VALID << 8) | (VGM_BYTE_VALID);
-   }
-   return vw;   
-}
-
-static void vgm_wr_V2_SLOWLY ( Addr a, UInt vbytes )
-{
-   /* Check the address for validity. */
-   Bool aerr = False;
-   PROF_EVENT(73);
-
-   if (get_abit(a+0) != VGM_BIT_VALID) aerr = True;
-   if (get_abit(a+1) != VGM_BIT_VALID) aerr = True;
-
-   /* Store the V bytes, remembering to do it little-endian-ly. */
-   set_vbyte( a+0, vbytes & 0x000000FF ); vbytes >>= 8;
-   set_vbyte( a+1, vbytes & 0x000000FF );
-
-   /* If an address error has happened, report it. */
-   if (aerr)
-      VG_(record_address_error)( a, 2, True );
-}
-
-static UInt vgm_rd_V1_SLOWLY ( Addr a )
-{
-   /* Check the address for validity. */
-   UInt vw   = VGM_WORD_INVALID;
-   Bool aerr = False;
-   PROF_EVENT(74);
-
-   if (get_abit(a+0) != VGM_BIT_VALID) aerr = True;
-
-   /* Fetch the V byte. */
-   vw <<= 8; vw |= (UInt)get_vbyte(a+0);
-
-   /* If an address error has happened, report it. */
-   if (aerr) {
-      VG_(record_address_error)( a, 1, False );
-      vw = (VGM_BYTE_INVALID << 24) | (VGM_BYTE_INVALID << 16) 
-           | (VGM_BYTE_INVALID << 8) | (VGM_BYTE_VALID);
-   }
-   return vw;   
-}
-
-static void vgm_wr_V1_SLOWLY ( Addr a, UInt vbytes )
-{
-   /* Check the address for validity. */
-   Bool aerr = False;
-   PROF_EVENT(75);
-   if (get_abit(a+0) != VGM_BIT_VALID) aerr = True;
-
-   /* Store the V bytes, remembering to do it little-endian-ly. */
-   set_vbyte( a+0, vbytes & 0x000000FF );
-
-   /* If an address error has happened, report it. */
-   if (aerr)
-      VG_(record_address_error)( a, 1, True );
-}
-
-
-/* ---------------------------------------------------------------------
-   Called from generated code, or from the assembly helpers.
-   Handlers for value check failures.
-   ------------------------------------------------------------------ */
-
-void VG_(helperc_value_check0_fail) ( void )
-{
-   VG_(record_value_error) ( 0 );
-}
-
-void VG_(helperc_value_check1_fail) ( void )
-{
-   VG_(record_value_error) ( 1 );
-}
-
-void VG_(helperc_value_check2_fail) ( void )
-{
-   VG_(record_value_error) ( 2 );
-}
-
-void VG_(helperc_value_check4_fail) ( void )
-{
-   VG_(record_value_error) ( 4 );
-}
-
-
-/* ---------------------------------------------------------------------
-   FPU load and store checks, called from generated code.
-   ------------------------------------------------------------------ */
-
-void VGM_(fpu_read_check) ( Addr addr, Int size )
-{
-   /* Ensure the read area is both addressible and valid (ie,
-      readable).  If there's an address error, don't report a value
-      error too; but if there isn't an address error, check for a
-      value error. 
-
-      Try to be reasonably fast on the common case; wimp out and defer
-      to fpu_read_check_SLOWLY for everything else.  */
-
-   SecMap* sm;
-   UInt    sm_off, v_off, a_off;
-   Addr    addr4;
-
-   PROF_EVENT(80);
-
-#  ifdef VG_DEBUG_MEMORY
-   fpu_read_check_SLOWLY ( addr, size );
-#  else
-
-   if (size == 4) {
-      if (!IS_ALIGNED4_ADDR(addr)) goto slow4;
-      PROF_EVENT(81);
-      /* Properly aligned. */
-      sm     = VG_(primary_map)[addr >> 16];
-      sm_off = addr & 0xFFFF;
-      a_off  = sm_off >> 3;
-      if (sm->abits[a_off] != VGM_BYTE_VALID) goto slow4;
-      /* Properly aligned and addressible. */
-      v_off = addr & 0xFFFF;
-      if (((UInt*)(sm->vbyte))[ v_off >> 2 ] != VGM_WORD_VALID) 
-         goto slow4;
-      /* Properly aligned, addressible and with valid data. */
-      return;
-     slow4:
-      fpu_read_check_SLOWLY ( addr, 4 );
-      return;
-   }
-
-   if (size == 8) {
-      if (!IS_ALIGNED4_ADDR(addr)) goto slow8;
-      PROF_EVENT(82);
-      /* Properly aligned.  Do it in two halves. */
-      addr4 = addr + 4;
-      /* First half. */
-      sm     = VG_(primary_map)[addr >> 16];
-      sm_off = addr & 0xFFFF;
-      a_off  = sm_off >> 3;
-      if (sm->abits[a_off] != VGM_BYTE_VALID) goto slow8;
-      /* First half properly aligned and addressible. */
-      v_off = addr & 0xFFFF;
-      if (((UInt*)(sm->vbyte))[ v_off >> 2 ] != VGM_WORD_VALID) 
-         goto slow8;
-      /* Second half. */
-      sm     = VG_(primary_map)[addr4 >> 16];
-      sm_off = addr4 & 0xFFFF;
-      a_off  = sm_off >> 3;
-      if (sm->abits[a_off] != VGM_BYTE_VALID) goto slow8;
-      /* Second half properly aligned and addressible. */
-      v_off = addr4 & 0xFFFF;
-      if (((UInt*)(sm->vbyte))[ v_off >> 2 ] != VGM_WORD_VALID) 
-         goto slow8;
-      /* Both halves properly aligned, addressible and with valid
-         data. */
-      return;
-     slow8:
-      fpu_read_check_SLOWLY ( addr, 8 );
-      return;
-   }
-
-   /* Can't be bothered to huff'n'puff to make these (allegedly) rare
-      cases go quickly.  */
-   if (size == 2) {
-      PROF_EVENT(83);
-      fpu_read_check_SLOWLY ( addr, 2 );
-      return;
-   }
-
-   if (size == 10) {
-      PROF_EVENT(84);
-      fpu_read_check_SLOWLY ( addr, 10 );
-      return;
-   }
-
-   if (size == 28) {
-      PROF_EVENT(84); /* XXX assign correct event number */
-      fpu_read_check_SLOWLY ( addr, 28 );
-      return;
-   }
-
-   VG_(printf)("size is %d\n", size);
-   VG_(panic)("vgm_fpu_read_check: unhandled size");
-#  endif
-}
-
-
-void VGM_(fpu_write_check) ( Addr addr, Int size )
-{
-   /* Ensure the written area is addressible, and moan if otherwise.
-      If it is addressible, make it valid, otherwise invalid. 
-   */
-
-   SecMap* sm;
-   UInt    sm_off, v_off, a_off;
-   Addr    addr4;
-
-   PROF_EVENT(85);
-
-#  ifdef VG_DEBUG_MEMORY
-   fpu_write_check_SLOWLY ( addr, size );
-#  else
-
-   if (size == 4) {
-      if (!IS_ALIGNED4_ADDR(addr)) goto slow4;
-      PROF_EVENT(86);
-      /* Properly aligned. */
-      sm     = VG_(primary_map)[addr >> 16];
-      sm_off = addr & 0xFFFF;
-      a_off  = sm_off >> 3;
-      if (sm->abits[a_off] != VGM_BYTE_VALID) goto slow4;
-      /* Properly aligned and addressible.  Make valid. */
-      v_off = addr & 0xFFFF;
-      ((UInt*)(sm->vbyte))[ v_off >> 2 ] = VGM_WORD_VALID;
-      return;
-     slow4:
-      fpu_write_check_SLOWLY ( addr, 4 );
-      return;
-   }
-
-   if (size == 8) {
-      if (!IS_ALIGNED4_ADDR(addr)) goto slow8;
-      PROF_EVENT(87);
-      /* Properly aligned.  Do it in two halves. */
-      addr4 = addr + 4;
-      /* First half. */
-      sm     = VG_(primary_map)[addr >> 16];
-      sm_off = addr & 0xFFFF;
-      a_off  = sm_off >> 3;
-      if (sm->abits[a_off] != VGM_BYTE_VALID) goto slow8;
-      /* First half properly aligned and addressible.  Make valid. */
-      v_off = addr & 0xFFFF;
-      ((UInt*)(sm->vbyte))[ v_off >> 2 ] = VGM_WORD_VALID;
-      /* Second half. */
-      sm     = VG_(primary_map)[addr4 >> 16];
-      sm_off = addr4 & 0xFFFF;
-      a_off  = sm_off >> 3;
-      if (sm->abits[a_off] != VGM_BYTE_VALID) goto slow8;
-      /* Second half properly aligned and addressible. */
-      v_off = addr4 & 0xFFFF;
-      ((UInt*)(sm->vbyte))[ v_off >> 2 ] = VGM_WORD_VALID;
-      /* Properly aligned, addressible and with valid data. */
-      return;
-     slow8:
-      fpu_write_check_SLOWLY ( addr, 8 );
-      return;
-   }
-
-   /* Can't be bothered to huff'n'puff to make these (allegedly) rare
-      cases go quickly.  */
-   if (size == 2) {
-      PROF_EVENT(88);
-      fpu_write_check_SLOWLY ( addr, 2 );
-      return;
-   }
-
-   if (size == 10) {
-      PROF_EVENT(89);
-      fpu_write_check_SLOWLY ( addr, 10 );
-      return;
-   }
-
-   if (size == 28) {
-      PROF_EVENT(89); /* XXX assign correct event number */
-      fpu_write_check_SLOWLY ( addr, 28 );
-      return;
-   }
-
-   VG_(printf)("size is %d\n", size);
-   VG_(panic)("vgm_fpu_write_check: unhandled size");
-#  endif
-}
-
-
-/* ---------------------------------------------------------------------
-   Slow, general cases for FPU load and store checks.
-   ------------------------------------------------------------------ */
-
-/* Generic version.  Test for both addr and value errors, but if
-   there's an addr error, don't report a value error even if it
-   exists. */
-
-void fpu_read_check_SLOWLY ( Addr addr, Int size )
-{
-   Int  i;
-   Bool aerr = False;
-   Bool verr = False;
-   PROF_EVENT(90);
-   for (i = 0; i < size; i++) {
-      PROF_EVENT(91);
-      if (get_abit(addr+i) != VGM_BIT_VALID)
-         aerr = True;
-      if (get_vbyte(addr+i) != VGM_BYTE_VALID)
-         verr = True;
-   }
-
-   if (aerr) {
-      VG_(record_address_error)( addr, size, False );
-   } else {
-     if (verr)
-        VG_(record_value_error)( size );
-   }
-}
-
-
-/* Generic version.  Test for addr errors.  Valid addresses are
-   given valid values, and invalid addresses invalid values. */
-
-void fpu_write_check_SLOWLY ( Addr addr, Int size )
-{
-   Int  i;
-   Addr a_here;
-   Bool a_ok;
-   Bool aerr = False;
-   PROF_EVENT(92);
-   for (i = 0; i < size; i++) {
-      PROF_EVENT(93);
-      a_here = addr+i;
-      a_ok = get_abit(a_here) == VGM_BIT_VALID;
-      if (a_ok) {
-	set_vbyte(a_here, VGM_BYTE_VALID);
-      } else {
-	set_vbyte(a_here, VGM_BYTE_INVALID);
-        aerr = True;
+   /* Sanity check ... if this is the executable's text segment,
+      ensure it is loaded where we think it ought to be.  Any file
+      name which doesn't contain ".so" is assumed to be the
+      executable. */
+   if (filename != NULL
+       && xx == 'x'
+       && VG_(strstr(filename, ".so")) == NULL
+      ) {
+      /* We assume this is the executable. */
+      if (start != VG_ASSUMED_EXE_BASE) {
+         VG_(message)(Vg_UserMsg,
+                      "FATAL: executable base addr not as assumed.");
+         VG_(message)(Vg_UserMsg, "name %s, actual %p, assumed %p.",
+                      filename, start, VG_ASSUMED_EXE_BASE);
+         VG_(message)(Vg_UserMsg,
+            "One reason this could happen is that you have a shared object");
+         VG_(message)(Vg_UserMsg,
+            " whose name doesn't contain the characters \".so\", so Valgrind ");
+         VG_(message)(Vg_UserMsg,
+            "naively assumes it is the executable.  ");
+         VG_(message)(Vg_UserMsg,
+            "In that case, rename it appropriately.");
+         VG_(panic)("VG_ASSUMED_EXE_BASE doesn't match reality");
       }
    }
-   if (aerr) {
-      VG_(record_address_error)( addr, size, True );
+
+   if (0)
+      VG_(message)(Vg_DebugMsg,
+                   "initial map %8x-%8x %c%c%c? %8x (%d) (%s)",
+                   start,start+size,rr,ww,xx,foffset,
+                   size, filename?filename:(UChar*)"NULL");
+
+   if (rr != 'r' && xx != 'x' && ww != 'w') {
+      VG_(printf)("No permissions on the segment named %s\n", filename);
+      VG_(panic)("Non-readable, writable, executable segment at startup");
    }
+
+   /* This parallels what happens when we mmap some new memory */
+   if (filename != NULL && xx == 'x') {
+      VG_(new_exe_segment)( start, size );
+   }
+   VG_TRACK( new_mem_startup, start, size, rr=='r', ww=='w', xx=='x' );
+
+   /* If this is the stack segment mark all below %esp as noaccess. */
+   r_esp = VG_(baseBlock)[VGOFF_(m_esp)];
+   is_stack_segment = start <= r_esp && r_esp < start+size;
+   if (is_stack_segment) {
+      if (0)
+         VG_(message)(Vg_DebugMsg, "invalidating stack area: %x .. %x",
+                      start,r_esp);
+      VG_TRACK( die_mem_stack, start, r_esp-start );
+   }
+}
+
+
+/* 1. Records exe segments from /proc/pid/maps -- always necessary, because 
+      if they're munmap()ed we need to know if they were executable in order
+      to discard translations.  Also checks there's no exe segment overlaps.
+
+   2. Marks global variables that might be accessed from generated code;
+
+   3. Sets up the end of the data segment so that vg_syscalls.c can make
+      sense of calls to brk().
+ */
+void VG_(init_memory) ( void )
+{
+   /* 1 and 2 */
+   VG_(read_procselfmaps) ( startup_segment_callback );
+
+   /* 3 */
+   VG_TRACK( post_mem_write, (Addr) & VG_(running_on_simd_CPU), 1 );
+   VG_TRACK( post_mem_write, (Addr) & VG_(clo_trace_malloc),    1 );
+   VG_TRACK( post_mem_write, (Addr) & VG_(clo_sloppy_malloc),   1 );
+
+   /* 4 */
+   VG_(init_dataseg_end_for_brk)();
 }
 
 
@@ -1340,7 +273,7 @@
 Bool is_plausible_stack_addr ( ThreadState* tst, Addr aa )
 {
    UInt a = (UInt)aa;
-   PROF_EVENT(100);
+   //PROF_EVENT(100);   PPP
    if (a <= tst->stack_highest_word && 
        a > tst->stack_highest_word - VG_PLAUSIBLE_STACK_SIZE)
       return True;
@@ -1349,18 +282,6 @@
 }
 
 
-/* Is this address within some small distance below %ESP?  Used only
-   for the --workaround-gcc296-bugs kludge. */
-Bool VG_(is_just_below_ESP)( Addr esp, Addr aa )
-{
-   if ((UInt)esp > (UInt)aa
-       && ((UInt)esp - (UInt)aa) <= VG_GCC296_BUG_STACK_SLOP)
-      return True;
-   else
-      return False;
-}
-
-
 /* Kludgey ... how much does %esp have to change before we reckon that
    the application is switching stacks ? */
 #define VG_HUGE_DELTA (VG_PLAUSIBLE_STACK_SIZE / 4)
@@ -1370,133 +291,59 @@
    return a & ~(VKI_BYTES_PER_PAGE-1);
 }
 
+static void vg_handle_esp_assignment_SLOWLY ( Addr old_esp, Addr new_esp );
 
-static void vg_handle_esp_assignment_SLOWLY ( Addr );
-
-void VGM_(handle_esp_assignment) ( Addr new_espA )
+__attribute__ ((regparm (1)))
+void VG_(handle_esp_assignment) ( Addr new_esp )
 {
-   UInt old_esp = VG_(baseBlock)[VGOFF_(m_esp)];
-   UInt new_esp = (UInt)new_espA;
-   Int  delta   = ((Int)new_esp) - ((Int)old_esp);
+   UInt old_esp;
+   Int  delta;
 
-   PROF_EVENT(101);
+   VGP_MAYBE_PUSHCC(VgpStack);
+
+   old_esp = VG_(baseBlock)[VGOFF_(m_esp)];
+   delta = ((Int)new_esp) - ((Int)old_esp);
+
+   /* Update R_ESP */
+   VG_(baseBlock)[VGOFF_(m_esp)] = new_esp;
+
+   //PROF_EVENT(101);   PPP
 
 #  ifndef VG_DEBUG_MEMORY
 
-   if (IS_ALIGNED4_ADDR(old_esp)) {
+   if (IS_ALIGNED4_ADDR(old_esp) &&  IS_ALIGNED4_ADDR(new_esp)) {
 
       /* Deal with the most common cases fast.  These are ordered in
          the sequence most common first. */
 
-      if (delta == -4) {
-         /* Moving down by 4 and properly aligned.. */
-         PROF_EVENT(102);
-         make_aligned_word_WRITABLE(new_esp);
-         return;
+#     ifdef VG_PROFILE_MEMORY
+      // PPP
+      if      (delta = - 4) PROF_EVENT(102);
+      else if (delta =   4) PROF_EVENT(103);
+      else if (delta = -12) PROF_EVENT(104);
+      else if (delta = - 8) PROF_EVENT(105);
+      else if (delta =  16) PROF_EVENT(106);
+      else if (delta =  12) PROF_EVENT(107);
+      else if (delta =   0) PROF_EVENT(108);
+      else if (delta =   8) PROF_EVENT(109);
+      else if (delta = -16) PROF_EVENT(110);
+      else if (delta =  20) PROF_EVENT(111);
+      else if (delta = -20) PROF_EVENT(112);
+      else if (delta =  24) PROF_EVENT(113);
+      else if (delta = -24) PROF_EVENT(114);
+      else if (delta > 0)   PROF_EVENT(115); // PPP: new: aligned_big_pos
+      else                  PROF_EVENT(116); // PPP: new: aligned_big_neg
+#     endif
+      
+      if (delta < 0) {
+         VG_TRACK(new_mem_stack_aligned, new_esp, -delta);
+      } else if (delta > 0) {
+         VG_TRACK(die_mem_stack_aligned, old_esp, delta);
       }
+      /* Do nothing if (delta==0) */
 
-      if (delta == 4) {
-         /* Moving up by 4 and properly aligned. */
-         PROF_EVENT(103);
-         make_aligned_word_NOACCESS(old_esp);
-         return;
-      }
-
-      if (delta == -12) {
-         PROF_EVENT(104);
-         make_aligned_word_WRITABLE(new_esp);
-         make_aligned_word_WRITABLE(new_esp+4);
-         make_aligned_word_WRITABLE(new_esp+8);
-         return;
-      }
-
-      if (delta == -8) {
-         PROF_EVENT(105);
-         make_aligned_word_WRITABLE(new_esp);
-         make_aligned_word_WRITABLE(new_esp+4);
-         return;
-      }
-
-      if (delta == 16) {
-         PROF_EVENT(106);
-         make_aligned_word_NOACCESS(old_esp);
-         make_aligned_word_NOACCESS(old_esp+4);
-         make_aligned_word_NOACCESS(old_esp+8);
-         make_aligned_word_NOACCESS(old_esp+12);
-         return;
-      }
-
-      if (delta == 12) {
-         PROF_EVENT(107);
-         make_aligned_word_NOACCESS(old_esp);
-         make_aligned_word_NOACCESS(old_esp+4);
-         make_aligned_word_NOACCESS(old_esp+8);
-         return;
-      }
-
-      if (delta == 0) {
-         PROF_EVENT(108);
-         return;
-      }
-
-      if (delta == 8) {
-         PROF_EVENT(109);
-         make_aligned_word_NOACCESS(old_esp);
-         make_aligned_word_NOACCESS(old_esp+4);
-         return;
-      }
-
-      if (delta == -16) {
-         PROF_EVENT(110);
-         make_aligned_word_WRITABLE(new_esp);
-         make_aligned_word_WRITABLE(new_esp+4);
-         make_aligned_word_WRITABLE(new_esp+8);
-         make_aligned_word_WRITABLE(new_esp+12);
-         return;
-      }
-
-      if (delta == 20) {
-         PROF_EVENT(111);
-         make_aligned_word_NOACCESS(old_esp);
-         make_aligned_word_NOACCESS(old_esp+4);
-         make_aligned_word_NOACCESS(old_esp+8);
-         make_aligned_word_NOACCESS(old_esp+12);
-         make_aligned_word_NOACCESS(old_esp+16);
-         return;
-      }
-
-      if (delta == -20) {
-         PROF_EVENT(112);
-         make_aligned_word_WRITABLE(new_esp);
-         make_aligned_word_WRITABLE(new_esp+4);
-         make_aligned_word_WRITABLE(new_esp+8);
-         make_aligned_word_WRITABLE(new_esp+12);
-         make_aligned_word_WRITABLE(new_esp+16);
-         return;
-      }
-
-      if (delta == 24) {
-         PROF_EVENT(113);
-         make_aligned_word_NOACCESS(old_esp);
-         make_aligned_word_NOACCESS(old_esp+4);
-         make_aligned_word_NOACCESS(old_esp+8);
-         make_aligned_word_NOACCESS(old_esp+12);
-         make_aligned_word_NOACCESS(old_esp+16);
-         make_aligned_word_NOACCESS(old_esp+20);
-         return;
-      }
-
-      if (delta == -24) {
-         PROF_EVENT(114);
-         make_aligned_word_WRITABLE(new_esp);
-         make_aligned_word_WRITABLE(new_esp+4);
-         make_aligned_word_WRITABLE(new_esp+8);
-         make_aligned_word_WRITABLE(new_esp+12);
-         make_aligned_word_WRITABLE(new_esp+16);
-         make_aligned_word_WRITABLE(new_esp+20);
-         return;
-      }
-
+      VGP_MAYBE_POPCC(VgpStack);
+      return;
    }
 
 #  endif
@@ -1504,33 +351,35 @@
    /* The above special cases handle 90% to 95% of all the stack
       adjustments.  The rest we give to the slow-but-general
       mechanism. */
-   vg_handle_esp_assignment_SLOWLY ( new_espA );
+   vg_handle_esp_assignment_SLOWLY ( old_esp, new_esp );
+   VGP_MAYBE_POPCC(VgpStack);
 }
 
 
-static void vg_handle_esp_assignment_SLOWLY ( Addr new_espA )
+static void vg_handle_esp_assignment_SLOWLY ( Addr old_esp, Addr new_esp )
 {
-   UInt old_esp = VG_(baseBlock)[VGOFF_(m_esp)];
-   UInt new_esp = (UInt)new_espA;
-   Int  delta   = ((Int)new_esp) - ((Int)old_esp);
-   //   VG_(printf)("%d ", delta);
-   PROF_EVENT(120);
+   Int  delta;
+   
+   delta = ((Int)new_esp) - ((Int)old_esp);
+   //VG_(printf)("delta %d (%x) %x --> %x\n", delta, delta, old_esp, new_esp);
+   //PROF_EVENT(120);   PPP
    if (-(VG_HUGE_DELTA) < delta && delta < VG_HUGE_DELTA) {
       /* "Ordinary" stack change. */
       if (new_esp < old_esp) {
          /* Moving down; the stack is growing. */
-         PROF_EVENT(121);
-         VGM_(make_writable) ( new_esp, old_esp - new_esp );
-         return;
-      }
-      if (new_esp > old_esp) {
+         //PROF_EVENT(121); PPP
+         VG_TRACK( new_mem_stack, new_esp, -delta );
+      
+      } else if (new_esp > old_esp) {
          /* Moving up; the stack is shrinking. */
-         PROF_EVENT(122);
-         VGM_(make_noaccess) ( old_esp, new_esp - old_esp );
-         return;
+         //PROF_EVENT(122); PPP
+         VG_TRACK( die_mem_stack, old_esp, delta );
+
+      } else {
+         /* when old_esp == new_esp */
+         //PROF_EVENT(123);    PPP
       }
-      PROF_EVENT(123);
-      return; /* when old_esp == new_esp */
+      return;
    }
 
    /* %esp has changed by more than HUGE_DELTA.  We take this to mean
@@ -1552,863 +401,21 @@
      Addr valid_up_to     = get_page_base(new_esp) + VKI_BYTES_PER_PAGE
                             + 0 * VKI_BYTES_PER_PAGE;
      ThreadState* tst     = VG_(get_current_thread_state)();
-     PROF_EVENT(124);
+     //PROF_EVENT(124); PPP
      if (VG_(clo_verbosity) > 1)
         VG_(message)(Vg_UserMsg, "Warning: client switching stacks?  "
-                                 "%%esp: %p --> %p",
-                                  old_esp, new_esp);
+                                 "%%esp: %p --> %p", old_esp, new_esp);
      /* VG_(printf)("na %p,   %%esp %p,   wr %p\n",
                     invalid_down_to, new_esp, valid_up_to ); */
-     VGM_(make_noaccess) ( invalid_down_to, new_esp - invalid_down_to );
+     VG_TRACK( die_mem_stack, invalid_down_to, new_esp - invalid_down_to );
      if (!is_plausible_stack_addr(tst, new_esp)) {
-        VGM_(make_readable) ( new_esp, valid_up_to - new_esp );
+        VG_TRACK( post_mem_write, new_esp, valid_up_to - new_esp );
      }
    }
 }
 
 
-/*--------------------------------------------------------------*/
-/*--- Initialise the memory audit system on program startup. ---*/
-/*--------------------------------------------------------------*/
-
-/* Handle one entry derived from /proc/self/maps. */
-
-static
-void init_memory_audit_callback ( 
-        Addr start, UInt size, 
-        Char rr, Char ww, Char xx, 
-        UInt foffset, UChar* filename )
-{
-   UChar example_a_bit;
-   UChar example_v_bit;
-   UInt  r_esp;
-   Bool  is_stack_segment;
-
-   /* Sanity check ... if this is the executable's text segment,
-      ensure it is loaded where we think it ought to be.  Any file
-      name which doesn't contain ".so" is assumed to be the
-      executable. */
-   if (filename != NULL
-       && xx == 'x'
-       && VG_(strstr(filename, ".so")) == NULL
-      ) {
-      /* We assume this is the executable. */
-      if (start != VG_ASSUMED_EXE_BASE) {
-         VG_(message)(Vg_UserMsg,
-                      "FATAL: executable base addr not as assumed.");
-         VG_(message)(Vg_UserMsg, "name %s, actual %p, assumed %p.",
-                      filename, start, VG_ASSUMED_EXE_BASE);
-         VG_(message)(Vg_UserMsg,
-            "One reason this could happen is that you have a shared object");
-         VG_(message)(Vg_UserMsg,
-            " whose name doesn't contain the characters \".so\", so Valgrind ");
-         VG_(message)(Vg_UserMsg,
-            "naively assumes it is the executable.  ");
-         VG_(message)(Vg_UserMsg,
-            "In that case, rename it appropriately.");
-         VG_(panic)("VG_ASSUMED_EXE_BASE doesn't match reality");
-      }
-   }
-    
-   if (0)
-      VG_(message)(Vg_DebugMsg, 
-                   "initial map %8x-%8x %c%c%c? %8x (%d) (%s)",
-                   start,start+size,rr,ww,xx,foffset,
-                   size, filename?filename:(UChar*)"NULL");
-
-   r_esp = VG_(baseBlock)[VGOFF_(m_esp)];
-   is_stack_segment = start <= r_esp && r_esp < start+size;
-
-   /* Figure out the segment's permissions.
-
-      All segments are addressible -- since a process can read its
-      own text segment.
-
-      A read-but-not-write segment presumably contains initialised
-      data, so is all valid.  Read-write segments presumably contains
-      uninitialised data, so is all invalid.  */
-
-   /* ToDo: make this less bogus. */
-   if (rr != 'r' && xx != 'x' && ww != 'w') {
-      /* Very bogus; this path never gets taken. */
-      /* A no, V no */
-      example_a_bit = VGM_BIT_INVALID;
-      example_v_bit = VGM_BIT_INVALID;
-   } else {
-      /* A yes, V yes */
-      example_a_bit = VGM_BIT_VALID;
-      example_v_bit = VGM_BIT_VALID;
-      /* Causes a lot of errs for unknown reasons. 
-         if (filename is valgrind.so 
-               [careful about end conditions on filename]) {
-            example_a_bit = VGM_BIT_INVALID;
-            example_v_bit = VGM_BIT_INVALID;
-         }
-      */
-   }
-
-   set_address_range_perms ( start, size, 
-                             example_a_bit, example_v_bit );
-
-   if (is_stack_segment) {
-      /* This is the stack segment.  Mark all below %esp as
-         noaccess. */
-      if (0)
-         VG_(message)(Vg_DebugMsg, 
-                      "invalidating stack area: %x .. %x",
-                      start,r_esp);
-      VGM_(make_noaccess)( start, r_esp-start );
-   }
-}
-
-
-/* Initialise the memory audit system. */
-void VGM_(init_memory_audit) ( void )
-{
-   Int i;
-
-   init_prof_mem();
-
-   for (i = 0; i < 8192; i++)
-      vg_distinguished_secondary_map.abits[i] 
-         = VGM_BYTE_INVALID; /* Invalid address */
-   for (i = 0; i < 65536; i++)
-      vg_distinguished_secondary_map.vbyte[i] 
-         = VGM_BYTE_INVALID; /* Invalid Value */
-
-   /* These entries gradually get overwritten as the used address
-      space expands. */
-   for (i = 0; i < 65536; i++)
-      VG_(primary_map)[i] = &vg_distinguished_secondary_map;
-   /* These ones should never change; it's a bug in Valgrind if they
-      do. */
-   for (i = 65536; i < 262144; i++)
-      VG_(primary_map)[i] = &vg_distinguished_secondary_map;
-
-   /* Read the initial memory mapping from the /proc filesystem, and
-      set up our own maps accordingly. */
-   VG_(read_procselfmaps) ( init_memory_audit_callback );
-
-   /* Last but not least, set up the shadow regs with reasonable (sic)
-      values.  All regs are claimed to have valid values.
-   */
-   VG_(baseBlock)[VGOFF_(sh_esp)]    = VGM_WORD_VALID;
-   VG_(baseBlock)[VGOFF_(sh_ebp)]    = VGM_WORD_VALID;
-   VG_(baseBlock)[VGOFF_(sh_eax)]    = VGM_WORD_VALID;
-   VG_(baseBlock)[VGOFF_(sh_ecx)]    = VGM_WORD_VALID;
-   VG_(baseBlock)[VGOFF_(sh_edx)]    = VGM_WORD_VALID;
-   VG_(baseBlock)[VGOFF_(sh_ebx)]    = VGM_WORD_VALID;
-   VG_(baseBlock)[VGOFF_(sh_esi)]    = VGM_WORD_VALID;
-   VG_(baseBlock)[VGOFF_(sh_edi)]    = VGM_WORD_VALID;
-   VG_(baseBlock)[VGOFF_(sh_eflags)] = VGM_EFLAGS_VALID;
-
-   /* Record the end of the data segment, so that vg_syscall_mem.c
-      can make sense of calls to brk(). 
-   */
-   VGM_(curr_dataseg_end) = (Addr)VG_(brk)(0);
-   if (VGM_(curr_dataseg_end) == (Addr)(-1))
-      VG_(panic)("vgm_init_memory_audit: can't determine data-seg end");
-
-   if (0)
-      VG_(printf)("DS END is %p\n", (void*)VGM_(curr_dataseg_end));
-
-   /* Read the list of errors to suppress.  This should be found in
-      the file specified by vg_clo_suppressions. */
-   VG_(load_suppressions)();
-}
-
-
-/*------------------------------------------------------------*/
-/*--- Low-level address-space scanning, for the leak       ---*/
-/*--- detector.                                            ---*/
-/*------------------------------------------------------------*/
-
-static 
-jmp_buf memscan_jmpbuf;
-
-static
-void vg_scan_all_valid_memory_sighandler ( Int sigNo )
-{
-   __builtin_longjmp(memscan_jmpbuf, 1);
-}
-
-UInt VG_(scan_all_valid_memory) ( void (*notify_word)( Addr, UInt ) )
-{
-   /* All volatile, because some gccs seem paranoid about longjmp(). */
-   volatile UInt res, numPages, page, vbytes, primaryMapNo, nWordsNotified;
-   volatile Addr pageBase, addr;
-   volatile SecMap* sm;
-   volatile UChar abits;
-   volatile UInt page_first_word;
-
-   vki_ksigaction sigbus_saved;
-   vki_ksigaction sigbus_new;
-   vki_ksigaction sigsegv_saved;
-   vki_ksigaction sigsegv_new;
-   vki_ksigset_t  blockmask_saved;
-   vki_ksigset_t  unblockmask_new;
-
-   /* Temporarily install a new sigsegv and sigbus handler, and make
-      sure SIGBUS, SIGSEGV and SIGTERM are unblocked.  (Perhaps the
-      first two can never be blocked anyway?)  */
-
-   sigbus_new.ksa_handler = vg_scan_all_valid_memory_sighandler;
-   sigbus_new.ksa_flags = VKI_SA_ONSTACK | VKI_SA_RESTART;
-   sigbus_new.ksa_restorer = NULL;
-   res = VG_(ksigemptyset)( &sigbus_new.ksa_mask );
-   vg_assert(res == 0);
-
-   sigsegv_new.ksa_handler = vg_scan_all_valid_memory_sighandler;
-   sigsegv_new.ksa_flags = VKI_SA_ONSTACK | VKI_SA_RESTART;
-   sigsegv_new.ksa_restorer = NULL;
-   res = VG_(ksigemptyset)( &sigsegv_new.ksa_mask );
-   vg_assert(res == 0+0);
-
-   res =  VG_(ksigemptyset)( &unblockmask_new );
-   res |= VG_(ksigaddset)( &unblockmask_new, VKI_SIGBUS );
-   res |= VG_(ksigaddset)( &unblockmask_new, VKI_SIGSEGV );
-   res |= VG_(ksigaddset)( &unblockmask_new, VKI_SIGTERM );
-   vg_assert(res == 0+0+0);
-
-   res = VG_(ksigaction)( VKI_SIGBUS, &sigbus_new, &sigbus_saved );
-   vg_assert(res == 0+0+0+0);
-
-   res = VG_(ksigaction)( VKI_SIGSEGV, &sigsegv_new, &sigsegv_saved );
-   vg_assert(res == 0+0+0+0+0);
-
-   res = VG_(ksigprocmask)( VKI_SIG_UNBLOCK, &unblockmask_new, &blockmask_saved );
-   vg_assert(res == 0+0+0+0+0+0);
-
-   /* The signal handlers are installed.  Actually do the memory scan. */
-   numPages = 1 << (32-VKI_BYTES_PER_PAGE_BITS);
-   vg_assert(numPages == 1048576);
-   vg_assert(4096 == (1 << VKI_BYTES_PER_PAGE_BITS));
-
-   nWordsNotified = 0;
-
-   for (page = 0; page < numPages; page++) {
-      pageBase = page << VKI_BYTES_PER_PAGE_BITS;
-      primaryMapNo = pageBase >> 16;
-      sm = VG_(primary_map)[primaryMapNo];
-      if (IS_DISTINGUISHED_SM(sm)) continue;
-      if (__builtin_setjmp(memscan_jmpbuf) == 0) {
-         /* try this ... */
-         page_first_word = * (volatile UInt*)pageBase;
-         /* we get here if we didn't get a fault */
-         /* Scan the page */
-         for (addr = pageBase; addr < pageBase+VKI_BYTES_PER_PAGE; addr += 4) {
-            abits  = get_abits4_ALIGNED(addr);
-            vbytes = get_vbytes4_ALIGNED(addr);
-            if (abits == VGM_NIBBLE_VALID 
-                && vbytes == VGM_WORD_VALID) {
-               nWordsNotified++;
-               notify_word ( addr, *(UInt*)addr );
-	    }
-         }
-      } else {
-         /* We get here if reading the first word of the page caused a
-            fault, which in turn caused the signal handler to longjmp.
-            Ignore this page. */
-         if (0)
-         VG_(printf)(
-            "vg_scan_all_valid_memory_sighandler: ignoring page at %p\n",
-            (void*)pageBase 
-         );
-      }
-   }
-
-   /* Restore signal state to whatever it was before. */
-   res = VG_(ksigaction)( VKI_SIGBUS, &sigbus_saved, NULL );
-   vg_assert(res == 0 +0);
-
-   res = VG_(ksigaction)( VKI_SIGSEGV, &sigsegv_saved, NULL );
-   vg_assert(res == 0 +0 +0);
-
-   res = VG_(ksigprocmask)( VKI_SIG_SETMASK, &blockmask_saved, NULL );
-   vg_assert(res == 0 +0 +0 +0);
-
-   return nWordsNotified;
-}
-
-
-/*------------------------------------------------------------*/
-/*--- Detecting leaked (unreachable) malloc'd blocks.      ---*/
-/*------------------------------------------------------------*/
-
-/* A block is either 
-   -- Proper-ly reached; a pointer to its start has been found
-   -- Interior-ly reached; only an interior pointer to it has been found
-   -- Unreached; so far, no pointers to any part of it have been found. 
-*/
-typedef 
-   enum { Unreached, Interior, Proper } 
-   Reachedness;
-
-/* A block record, used for generating err msgs. */
-typedef
-   struct _LossRecord {
-      struct _LossRecord* next;
-      /* Where these lost blocks were allocated. */
-      ExeContext*  allocated_at;
-      /* Their reachability. */
-      Reachedness  loss_mode;
-      /* Number of blocks and total # bytes involved. */
-      UInt         total_bytes;
-      UInt         num_blocks;
-   }
-   LossRecord;
-
-
-/* Find the i such that ptr points at or inside the block described by
-   shadows[i].  Return -1 if none found.  This assumes that shadows[]
-   has been sorted on the ->data field. */
-
-#ifdef VG_DEBUG_LEAKCHECK
-/* Used to sanity-check the fast binary-search mechanism. */
-static Int find_shadow_for_OLD ( Addr          ptr, 
-                                 ShadowChunk** shadows,
-                                 Int           n_shadows )
-
-{
-   Int  i;
-   Addr a_lo, a_hi;
-   PROF_EVENT(70);
-   for (i = 0; i < n_shadows; i++) {
-      PROF_EVENT(71);
-      a_lo = shadows[i]->data;
-      a_hi = ((Addr)shadows[i]->data) + shadows[i]->size - 1;
-      if (a_lo <= ptr && ptr <= a_hi)
-         return i;
-   }
-   return -1;
-}
-#endif
-
-
-static Int find_shadow_for ( Addr          ptr, 
-                             ShadowChunk** shadows,
-                             Int           n_shadows )
-{
-   Addr a_mid_lo, a_mid_hi;
-   Int lo, mid, hi, retVal;
-   PROF_EVENT(70);
-   /* VG_(printf)("find shadow for %p = ", ptr); */
-   retVal = -1;
-   lo = 0;
-   hi = n_shadows-1;
-   while (True) {
-      PROF_EVENT(71);
-
-      /* invariant: current unsearched space is from lo to hi,
-         inclusive. */
-      if (lo > hi) break; /* not found */
-
-      mid      = (lo + hi) / 2;
-      a_mid_lo = shadows[mid]->data;
-      a_mid_hi = ((Addr)shadows[mid]->data) + shadows[mid]->size - 1;
-
-      if (ptr < a_mid_lo) {
-         hi = mid-1;
-         continue;
-      } 
-      if (ptr > a_mid_hi) {
-         lo = mid+1;
-         continue;
-      }
-      vg_assert(ptr >= a_mid_lo && ptr <= a_mid_hi);
-      retVal = mid;
-      break;
-   }
-
-#  ifdef VG_DEBUG_LEAKCHECK
-   vg_assert(retVal == find_shadow_for_OLD ( ptr, shadows, n_shadows ));
-#  endif
-   /* VG_(printf)("%d\n", retVal); */
-   return retVal;
-}
-
-
-
-static void sort_malloc_shadows ( ShadowChunk** shadows, UInt n_shadows )
-{
-   Int   incs[14] = { 1, 4, 13, 40, 121, 364, 1093, 3280,
-                      9841, 29524, 88573, 265720,
-                      797161, 2391484 };
-   Int          lo = 0;
-   Int          hi = n_shadows-1;
-   Int          i, j, h, bigN, hp;
-   ShadowChunk* v;
-
-   PROF_EVENT(72);
-   bigN = hi - lo + 1; if (bigN < 2) return;
-   hp = 0; while (incs[hp] < bigN) hp++; hp--;
-
-   for (; hp >= 0; hp--) {
-      PROF_EVENT(73);
-      h = incs[hp];
-      i = lo + h;
-      while (1) {
-         PROF_EVENT(74);
-         if (i > hi) break;
-         v = shadows[i];
-         j = i;
-         while (shadows[j-h]->data > v->data) {
-            PROF_EVENT(75);
-            shadows[j] = shadows[j-h];
-            j = j - h;
-            if (j <= (lo + h - 1)) break;
-         }
-         shadows[j] = v;
-         i++;
-      }
-   }
-}
-
-/* Globals, for the callback used by VG_(detect_memory_leaks). */
-
-static ShadowChunk** vglc_shadows;
-static Int           vglc_n_shadows;
-static Reachedness*  vglc_reachedness;
-static Addr          vglc_min_mallocd_addr;
-static Addr          vglc_max_mallocd_addr;
-
-static 
-void vg_detect_memory_leaks_notify_addr ( Addr a, UInt word_at_a )
-{
-   Int  sh_no;
-   Addr ptr;
-
-   /* Rule out some known causes of bogus pointers.  Mostly these do
-      not cause much trouble because only a few false pointers can
-      ever lurk in these places.  This mainly stops it reporting that
-      blocks are still reachable in stupid test programs like this
-
-         int main (void) { char* a = malloc(100); return 0; }
-
-      which people seem inordinately fond of writing, for some reason.  
-
-      Note that this is a complete kludge.  It would be better to
-      ignore any addresses corresponding to valgrind.so's .bss and
-      .data segments, but I cannot think of a reliable way to identify
-      where the .bss segment has been put.  If you can, drop me a
-      line.  
-   */
-   if (a >= ((Addr)(&VG_(stack)))
-       && a <= ((Addr)(&VG_(stack))) + sizeof(VG_(stack))) {
-      return;
-   }
-   if (a >= ((Addr)(&VG_(m_state_static)))
-       && a <= ((Addr)(&VG_(m_state_static))) + sizeof(VG_(m_state_static))) {
-      return;
-   }
-   if (a == (Addr)(&vglc_min_mallocd_addr))
-      return;
-   if (a == (Addr)(&vglc_max_mallocd_addr))
-      return;
-
-   /* OK, let's get on and do something Useful for a change. */
-
-   ptr = (Addr)word_at_a;
-   if (ptr >= vglc_min_mallocd_addr && ptr <= vglc_max_mallocd_addr) {
-      /* Might be legitimate; we'll have to investigate further. */
-      sh_no = find_shadow_for ( ptr, vglc_shadows, vglc_n_shadows );
-      if (sh_no != -1) {
-         /* Found a block at/into which ptr points. */
-         vg_assert(sh_no >= 0 && sh_no < vglc_n_shadows);
-         vg_assert(ptr < vglc_shadows[sh_no]->data 
-                         + vglc_shadows[sh_no]->size);
-         /* Decide whether Proper-ly or Interior-ly reached. */
-         if (ptr == vglc_shadows[sh_no]->data) {
-            if (0) VG_(printf)("pointer at %p to %p\n", a, word_at_a );
-            vglc_reachedness[sh_no] = Proper;
-         } else {
-            if (vglc_reachedness[sh_no] == Unreached)
-               vglc_reachedness[sh_no] = Interior;
-         }
-      }
-   }
-}
-
-
-void VG_(detect_memory_leaks) ( void )
-{
-   Int    i;
-   Int    blocks_leaked, bytes_leaked;
-   Int    blocks_dubious, bytes_dubious;
-   Int    blocks_reachable, bytes_reachable;
-   Int    n_lossrecords;
-   UInt   bytes_notified;
-   
-   LossRecord*  errlist;
-   LossRecord*  p;
-
-   Bool (*ec_comparer_fn) ( ExeContext*, ExeContext* );
-   PROF_EVENT(76);
-   vg_assert(VG_(clo_instrument));
-
-   /* Decide how closely we want to match ExeContexts in leak
-      records. */
-   switch (VG_(clo_leak_resolution)) {
-      case 2: 
-         ec_comparer_fn = VG_(eq_ExeContext_top2); 
-         break;
-      case 4: 
-         ec_comparer_fn = VG_(eq_ExeContext_top4); 
-         break;
-      case VG_DEEPEST_BACKTRACE: 
-         ec_comparer_fn = VG_(eq_ExeContext_all); 
-         break;
-      default: 
-         VG_(panic)("VG_(detect_memory_leaks): "
-                    "bad VG_(clo_leak_resolution)");
-         break;
-   }
-
-   /* vg_get_malloc_shadows allocates storage for shadows */
-   vglc_shadows = VG_(get_malloc_shadows)( &vglc_n_shadows );
-   if (vglc_n_shadows == 0) {
-      vg_assert(vglc_shadows == NULL);
-      VG_(message)(Vg_UserMsg, 
-                   "No malloc'd blocks -- no leaks are possible.\n");
-      return;
-   }
-
-   VG_(message)(Vg_UserMsg, 
-                "searching for pointers to %d not-freed blocks.", 
-                vglc_n_shadows );
-   sort_malloc_shadows ( vglc_shadows, vglc_n_shadows );
-
-   /* Sanity check; assert that the blocks are now in order and that
-      they don't overlap. */
-   for (i = 0; i < vglc_n_shadows-1; i++) {
-      vg_assert( ((Addr)vglc_shadows[i]->data)
-                 < ((Addr)vglc_shadows[i+1]->data) );
-      vg_assert( ((Addr)vglc_shadows[i]->data) + vglc_shadows[i]->size
-                 < ((Addr)vglc_shadows[i+1]->data) );
-   }
-
-   vglc_min_mallocd_addr = ((Addr)vglc_shadows[0]->data);
-   vglc_max_mallocd_addr = ((Addr)vglc_shadows[vglc_n_shadows-1]->data)
-                         + vglc_shadows[vglc_n_shadows-1]->size - 1;
-
-   vglc_reachedness 
-      = VG_(malloc)( VG_AR_PRIVATE, vglc_n_shadows * sizeof(Reachedness) );
-   for (i = 0; i < vglc_n_shadows; i++)
-      vglc_reachedness[i] = Unreached;
-
-   /* Do the scan of memory. */
-   bytes_notified
-       = VG_(scan_all_valid_memory)( &vg_detect_memory_leaks_notify_addr )
-         * VKI_BYTES_PER_WORD;
-
-   VG_(message)(Vg_UserMsg, "checked %d bytes.", bytes_notified);
-
-   blocks_leaked    = bytes_leaked    = 0;
-   blocks_dubious   = bytes_dubious   = 0;
-   blocks_reachable = bytes_reachable = 0;
-
-   for (i = 0; i < vglc_n_shadows; i++) {
-      if (vglc_reachedness[i] == Unreached) {
-         blocks_leaked++;
-         bytes_leaked += vglc_shadows[i]->size;
-      }
-      else if (vglc_reachedness[i] == Interior) {
-         blocks_dubious++;
-         bytes_dubious += vglc_shadows[i]->size;
-      }
-      else if (vglc_reachedness[i] == Proper) {
-         blocks_reachable++;
-         bytes_reachable += vglc_shadows[i]->size;
-      }
-   }
-
-   VG_(message)(Vg_UserMsg, "");
-   VG_(message)(Vg_UserMsg, "definitely lost: %d bytes in %d blocks.", 
-                            bytes_leaked, blocks_leaked );
-   VG_(message)(Vg_UserMsg, "possibly lost:   %d bytes in %d blocks.", 
-                            bytes_dubious, blocks_dubious );
-   VG_(message)(Vg_UserMsg, "still reachable: %d bytes in %d blocks.", 
-                            bytes_reachable, blocks_reachable );
-
-
-   /* Common up the lost blocks so we can print sensible error
-      messages. */
-
-   n_lossrecords = 0;
-   errlist       = NULL;
-   for (i = 0; i < vglc_n_shadows; i++) {
-      for (p = errlist; p != NULL; p = p->next) {
-         if (p->loss_mode == vglc_reachedness[i]
-             && ec_comparer_fn (
-                   p->allocated_at, 
-                   vglc_shadows[i]->where) ) {
-            break;
-	 }
-      }
-      if (p != NULL) {
-         p->num_blocks  ++;
-         p->total_bytes += vglc_shadows[i]->size;
-      } else {
-         n_lossrecords ++;
-         p = VG_(malloc)(VG_AR_PRIVATE, sizeof(LossRecord));
-         p->loss_mode    = vglc_reachedness[i];
-         p->allocated_at = vglc_shadows[i]->where;
-         p->total_bytes  = vglc_shadows[i]->size;
-         p->num_blocks   = 1;
-         p->next         = errlist;
-         errlist         = p;
-      }
-   }
-   
-   for (i = 0; i < n_lossrecords; i++) {
-      LossRecord* p_min = NULL;
-      UInt        n_min = 0xFFFFFFFF;
-      for (p = errlist; p != NULL; p = p->next) {
-         if (p->num_blocks > 0 && p->total_bytes < n_min) {
-            n_min = p->total_bytes;
-            p_min = p;
-         }
-      }
-      vg_assert(p_min != NULL);
-
-      if ( (!VG_(clo_show_reachable)) && p_min->loss_mode == Proper) {
-         p_min->num_blocks = 0;
-         continue;
-      }
-
-      VG_(message)(Vg_UserMsg, "");
-      VG_(message)(
-         Vg_UserMsg,
-         "%d bytes in %d blocks are %s in loss record %d of %d",
-         p_min->total_bytes, p_min->num_blocks,
-         p_min->loss_mode==Unreached ? "definitely lost" :
-            (p_min->loss_mode==Interior ? "possibly lost"
-                                        : "still reachable"),
-         i+1, n_lossrecords
-      );
-      VG_(pp_ExeContext)(p_min->allocated_at);
-      p_min->num_blocks = 0;
-   }
-
-   VG_(message)(Vg_UserMsg, "");
-   VG_(message)(Vg_UserMsg, "LEAK SUMMARY:");
-   VG_(message)(Vg_UserMsg, "   definitely lost: %d bytes in %d blocks.", 
-                            bytes_leaked, blocks_leaked );
-   VG_(message)(Vg_UserMsg, "   possibly lost:   %d bytes in %d blocks.", 
-                            bytes_dubious, blocks_dubious );
-   VG_(message)(Vg_UserMsg, "   still reachable: %d bytes in %d blocks.", 
-                            bytes_reachable, blocks_reachable );
-   if (!VG_(clo_show_reachable)) {
-      VG_(message)(Vg_UserMsg, 
-         "Reachable blocks (those to which a pointer was found) are not shown.");
-      VG_(message)(Vg_UserMsg, 
-         "To see them, rerun with: --show-reachable=yes");
-   }
-   VG_(message)(Vg_UserMsg, "");
-
-   VG_(free) ( VG_AR_PRIVATE, vglc_shadows );
-   VG_(free) ( VG_AR_PRIVATE, vglc_reachedness );
-}
-
-
-/* ---------------------------------------------------------------------
-   Sanity check machinery (permanently engaged).
-   ------------------------------------------------------------------ */
-
-/* Check that nobody has spuriously claimed that the first or last 16
-   pages (64 KB) of address space have become accessible.  Failure of
-   the following do not per se indicate an internal consistency
-   problem, but they are so likely to that we really want to know
-   about it if so. */
-
-Bool VG_(first_and_last_secondaries_look_plausible) ( void )
-{
-   if (IS_DISTINGUISHED_SM(VG_(primary_map)[0])
-       && IS_DISTINGUISHED_SM(VG_(primary_map)[65535])) {
-      return True;
-   } else {
-      return False;
-   }
-}
-
-
-/* A fast sanity check -- suitable for calling circa once per
-   millisecond. */
-
-void VG_(do_sanity_checks) ( Bool force_expensive )
-{
-   Int          i;
-   Bool         do_expensive_checks;
-
-   if (VG_(sanity_level) < 1) return;
-
-   /* --- First do all the tests that we can do quickly. ---*/
-
-   VG_(sanity_fast_count)++;
-
-   /* Check that we haven't overrun our private stack. */
-   for (i = 0; i < 10; i++) {
-      vg_assert(VG_(stack)[i]
-                == ((UInt)(&VG_(stack)[i]) ^ 0xA4B3C2D1));
-      vg_assert(VG_(stack)[10000-1-i] 
-                == ((UInt)(&VG_(stack)[10000-i-1]) ^ 0xABCD4321));
-   }
-
-   /* Check stuff pertaining to the memory check system. */
-
-   if (VG_(clo_instrument)) {
-
-      /* Check that nobody has spuriously claimed that the first or
-         last 16 pages of memory have become accessible [...] */
-      vg_assert(VG_(first_and_last_secondaries_look_plausible)());
-   }
-
-   /* --- Now some more expensive checks. ---*/
-
-   /* Once every 25 times, check some more expensive stuff. */
-
-   do_expensive_checks = False;
-   if (force_expensive) 
-      do_expensive_checks = True;
-   if (VG_(sanity_level) > 1) 
-      do_expensive_checks = True;
-   if (VG_(sanity_level) == 1 
-       && (VG_(sanity_fast_count) % 25) == 0)
-      do_expensive_checks = True;
-
-   if (do_expensive_checks) {
-      VG_(sanity_slow_count)++;
-
-#     if 0
-      { void zzzmemscan(void); zzzmemscan(); }
-#     endif
-
-      if ((VG_(sanity_fast_count) % 250) == 0)
-         VG_(sanity_check_tc_tt)();
-
-      if (VG_(clo_instrument)) {
-         /* Make sure nobody changed the distinguished secondary. */
-         for (i = 0; i < 8192; i++)
-            vg_assert(vg_distinguished_secondary_map.abits[i] 
-                      == VGM_BYTE_INVALID);
-         for (i = 0; i < 65536; i++)
-            vg_assert(vg_distinguished_secondary_map.vbyte[i] 
-                      == VGM_BYTE_INVALID);
-
-         /* Make sure that the upper 3/4 of the primary map hasn't
-            been messed with. */
-         for (i = 65536; i < 262144; i++)
-            vg_assert(VG_(primary_map)[i] 
-                      == & vg_distinguished_secondary_map);
-      }
-      /* 
-      if ((VG_(sanity_fast_count) % 500) == 0) VG_(mallocSanityCheckAll)(); 
-      */
-   }
-
-   if (VG_(sanity_level) > 1) {
-      /* Check sanity of the low-level memory manager.  Note that bugs
-         in the client's code can cause this to fail, so we don't do
-         this check unless specially asked for.  And because it's
-         potentially very expensive. */
-      VG_(mallocSanityCheckAll)();
-   }
-}
-
-
-/* ---------------------------------------------------------------------
-   Debugging machinery (turn on to debug).  Something of a mess.
-   ------------------------------------------------------------------ */
-
-/* Print the value tags on the 8 integer registers & flag reg. */
-
-static void uint_to_bits ( UInt x, Char* str )
-{
-   Int i;
-   Int w = 0;
-   /* str must point to a space of at least 36 bytes. */
-   for (i = 31; i >= 0; i--) {
-      str[w++] = (x & ( ((UInt)1) << i)) ? '1' : '0';
-      if (i == 24 || i == 16 || i == 8)
-         str[w++] = ' ';
-   }
-   str[w++] = 0;
-   vg_assert(w == 36);
-}
-
-/* Caution!  Not vthread-safe; looks in VG_(baseBlock), not the thread
-   state table. */
-
-void VG_(show_reg_tags) ( void )
-{
-   Char buf1[36];
-   Char buf2[36];
-   UInt z_eax, z_ebx, z_ecx, z_edx, 
-        z_esi, z_edi, z_ebp, z_esp, z_eflags;
-
-   z_eax    = VG_(baseBlock)[VGOFF_(sh_eax)];
-   z_ebx    = VG_(baseBlock)[VGOFF_(sh_ebx)];
-   z_ecx    = VG_(baseBlock)[VGOFF_(sh_ecx)];
-   z_edx    = VG_(baseBlock)[VGOFF_(sh_edx)];
-   z_esi    = VG_(baseBlock)[VGOFF_(sh_esi)];
-   z_edi    = VG_(baseBlock)[VGOFF_(sh_edi)];
-   z_ebp    = VG_(baseBlock)[VGOFF_(sh_ebp)];
-   z_esp    = VG_(baseBlock)[VGOFF_(sh_esp)];
-   z_eflags = VG_(baseBlock)[VGOFF_(sh_eflags)];
-   
-   uint_to_bits(z_eflags, buf1);
-   VG_(message)(Vg_DebugMsg, "efl %\n", buf1);
-
-   uint_to_bits(z_eax, buf1);
-   uint_to_bits(z_ebx, buf2);
-   VG_(message)(Vg_DebugMsg, "eax %s   ebx %s\n", buf1, buf2);
-
-   uint_to_bits(z_ecx, buf1);
-   uint_to_bits(z_edx, buf2);
-   VG_(message)(Vg_DebugMsg, "ecx %s   edx %s\n", buf1, buf2);
-
-   uint_to_bits(z_esi, buf1);
-   uint_to_bits(z_edi, buf2);
-   VG_(message)(Vg_DebugMsg, "esi %s   edi %s\n", buf1, buf2);
-
-   uint_to_bits(z_ebp, buf1);
-   uint_to_bits(z_esp, buf2);
-   VG_(message)(Vg_DebugMsg, "ebp %s   esp %s\n", buf1, buf2);
-}
-
-
-#if 0
-/* For debugging only.  Scan the address space and touch all allegedly
-   addressible words.  Useful for establishing where Valgrind's idea of
-   addressibility has diverged from what the kernel believes. */
-
-static 
-void zzzmemscan_notify_word ( Addr a, UInt w )
-{
-}
-
-void zzzmemscan ( void )
-{
-   Int n_notifies
-      = VG_(scan_all_valid_memory)( zzzmemscan_notify_word );
-   VG_(printf)("zzzmemscan: n_bytes = %d\n", 4 * n_notifies );
-}
-#endif
-
-
-
-
-#if 0
-static Int zzz = 0;
-
-void show_bb ( Addr eip_next )
-{
-   VG_(printf)("[%4d] ", zzz);
-   VG_(show_reg_tags)( &VG_(m_shadow );
-   VG_(translate) ( eip_next, NULL, NULL, NULL );
-}
-#endif /* 0 */
-
 /*--------------------------------------------------------------------*/
 /*--- end                                              vg_memory.c ---*/
 /*--------------------------------------------------------------------*/
+