Create a new SkShmC segment type for shared memory segments so that we

can ensure they are never merged with adjacent segments. This makes
sure that we can find the right piece of memory to release when the
shmdt system call occurs.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@4854

diff --git a/coregrind/m_aspacemgr/aspacemgr.c b/coregrind/m_aspacemgr/aspacemgr.c
index a95d73f0b9346f9f11f01b5d21ffc9604f856f01..611fd1e4b675656bd4bbce34bbf09044d765574b 100644 (file)
--- a/coregrind/m_aspacemgr/aspacemgr.c
+++ b/coregrind/m_aspacemgr/aspacemgr.c
@@ -441,6 +441,7 @@ static HChar* show_SegKind ( SegKind sk )
       case SkAnonV: return "ANON";
       case SkFileC: return "file";
       case SkFileV: return "FILE";
+      case SkShmC:  return "shm ";
       case SkResvn: return "RSVN";
       default:      return "????";
    }
@@ -523,7 +524,7 @@ static void show_nsegment ( Int logLevel, Int segNo, NSegment* seg )
          );
          break;
 
-      case SkAnonC: case SkAnonV:
+      case SkAnonC: case SkAnonV: case SkShmC:
          VG_(debugLog)(
             logLevel, "aspacem",
             "%3d: %s %010llx-%010llx %s %c%c%c%c%c\n",
@@ -688,7 +689,7 @@ static Bool sane_NSegment ( NSegment* s )
             && !s->hasR && !s->hasW && !s->hasX && !s->hasT
             && !s->isCH;
 
-      case SkAnonC: case SkAnonV:
+      case SkAnonC: case SkAnonV: case SkShmC:
          return 
             s->smode == SmFixed 
             && s->dev == 0 && s->ino == 0 && s->offset == 0 && s->fnIdx == -1
@@ -754,6 +755,9 @@ static Bool maybe_merge_nsegments ( NSegment* s1, NSegment* s2 )
          }
          break;
 
+      case SkShmC:
+         return False;
+
       default:
          break;
    
@@ -890,7 +894,8 @@ static void sync_check_mapping_callback ( Addr addr, SizeT len, UInt prot,
       same = nsegments[i].kind == SkAnonC
              || nsegments[i].kind == SkAnonV
              || nsegments[i].kind == SkFileC
-             || nsegments[i].kind == SkFileV;
+             || nsegments[i].kind == SkFileV
+             || nsegments[i].kind == SkShmC;
 
       seg_prot = 0;
       if (nsegments[i].hasR) seg_prot |= VKI_PROT_READ;
@@ -1106,7 +1111,7 @@ NSegment* VG_(am_next_nsegment) ( NSegment* here, Bool fwds )
          return NULL;
    }
    switch (nsegments[i].kind) {
-      case SkFileC: case SkFileV: 
+      case SkFileC: case SkFileV: case SkShmC:
       case SkAnonC: case SkAnonV: case SkResvn:
          return &nsegments[i];
       default:
@@ -1169,6 +1174,7 @@ Bool is_valid_for_client( Addr start, SizeT len, UInt prot, Bool freeOk )
    for (i = iLo; i <= iHi; i++) {
       if ( (nsegments[i].kind == SkFileC 
             || nsegments[i].kind == SkAnonC
+            || nsegments[i].kind == SkShmC
             || (nsegments[i].kind == SkFree  && freeOk)
             || (nsegments[i].kind == SkResvn && freeOk))
            && (needR ? nsegments[i].hasR : True)
@@ -1638,6 +1644,7 @@ Addr VG_(am_get_advisory) ( MapRequest*  req,
          if (nsegments[i].kind == SkFree
              || nsegments[i].kind == SkFileC
              || nsegments[i].kind == SkAnonC
+             || nsegments[i].kind == SkShmC
              || nsegments[i].kind == SkResvn) {
             /* ok */
          } else {
@@ -1830,6 +1837,37 @@ VG_(am_notify_client_mmap)( Addr a, SizeT len, UInt prot, UInt flags,
    return needDiscard;
 }
 
+/* Notifies aspacem that the client completed a shmat successfully.
+   The segment array is updated accordingly.  If the returned Bool is
+   True, the caller should immediately discard translations from the
+   specified address range. */
+
+Bool
+VG_(am_notify_client_shmat)( Addr a, SizeT len, UInt prot )
+{
+   NSegment seg;
+   Bool     needDiscard;
+
+   aspacem_assert(len > 0);
+   aspacem_assert(VG_IS_PAGE_ALIGNED(a));
+   aspacem_assert(VG_IS_PAGE_ALIGNED(len));
+
+   /* Discard is needed if any of the just-trashed range had T. */
+   needDiscard = any_Ts_in_range( a, len );
+
+   init_nsegment( &seg );
+   seg.kind   = SkShmC;
+   seg.start  = a;
+   seg.end    = a + len - 1;
+   seg.offset = 0;
+   seg.hasR   = toBool(prot & VKI_PROT_READ);
+   seg.hasW   = toBool(prot & VKI_PROT_WRITE);
+   seg.hasX   = toBool(prot & VKI_PROT_EXEC);
+   add_segment( &seg );
+   AM_SANITY_CHECK;
+   return needDiscard;
+}
+
 /* Notifies aspacem that an mprotect was completed successfully.  The
    segment array is updated accordingly.  Note, as with
    VG_(am_notify_munmap), it is not the job of this function to reject
@@ -1866,7 +1904,7 @@ Bool VG_(am_notify_mprotect)( Addr start, SizeT len, UInt prot )
    for (i = iLo; i <= iHi; i++) {
       /* Apply the permissions to all relevant segments. */
       switch (nsegments[i].kind) {
-         case SkAnonC: case SkAnonV: case SkFileC: case SkFileV:
+         case SkAnonC: case SkAnonV: case SkFileC: case SkFileV: case SkShmC:
             nsegments[i].hasR = newR;
             nsegments[i].hasW = newW;
             nsegments[i].hasX = newX;

diff --git a/coregrind/m_syswrap/syswrap-generic.c b/coregrind/m_syswrap/syswrap-generic.c
index 1d03b0c4448b8d53fe083add10404ad35d53a185..4d467fccb66c7fd0df8d87e6c8c6f8722cf66b3c 100644 (file)
--- a/coregrind/m_syswrap/syswrap-generic.c
+++ b/coregrind/m_syswrap/syswrap-generic.c
@@ -1600,8 +1600,7 @@ ML_(generic_POST_sys_shmat) ( ThreadId tid,
          cope with the discrepancy, aspacem's sync checker omits the
          dev/ino correspondence check in cases where V does not know
          the dev/ino. */
-      d = VG_(am_notify_client_mmap)( res, VG_PGROUNDUP(segmentSize), 
-                                      prot, VKI_MAP_ANONYMOUS, 0,0);
+      d = VG_(am_notify_client_shmat)( res, VG_PGROUNDUP(segmentSize), prot );
 
       /* we don't distinguish whether it's read-only or
        * read-write -- it doesn't matter really. */
@@ -1630,7 +1629,11 @@ ML_(generic_POST_sys_shmdt) ( ThreadId tid, UWord res, UWord arg0 )
    if (s != NULL) {
       Addr  s_start = s->start;
       SizeT s_len   = s->end+1 - s->start;
-      Bool  d       = VG_(am_notify_munmap)(s_start, s_len);
+      Bool  d;
+
+      vg_assert(s->kind == SkShmC && s->start == arg0);
+
+      d = VG_(am_notify_munmap)(s_start, s_len);
       s = NULL; /* s is now invalid */
       VG_TRACK( die_mem_munmap, s_start, s_len );
       if (d)

diff --git a/coregrind/pub_core_aspacemgr.h b/coregrind/pub_core_aspacemgr.h
index 6bf343ec4172c3e4c82edd29150995ea91ee8ef5..88b9127bd6322f57f2cd5b7e48eaa3793468e25b 100644 (file)
--- a/coregrind/pub_core_aspacemgr.h
+++ b/coregrind/pub_core_aspacemgr.h
@@ -155,6 +155,12 @@ extern Addr VG_(am_get_advisory_client_simple)
 extern Bool VG_(am_notify_client_mmap)
    ( Addr a, SizeT len, UInt prot, UInt flags, Int fd, Off64T offset );
 
+/* Notifies aspacem that the client completed a shmat successfully.
+   The segment array is updated accordingly.  If the returned Bool is
+   True, the caller should immediately discard translations from the
+   specified address range. */
+extern Bool VG_(am_notify_client_shmat)( Addr a, SizeT len, UInt prot );
+
 /* Notifies aspacem that an mprotect was completed successfully.  The
    segment array is updated accordingly.  Note, as with
    VG_(am_notify_munmap), it is not the job of this function to reject

diff --git a/include/pub_tool_aspacemgr.h b/include/pub_tool_aspacemgr.h
index 51240bb3d7a1c8c96b888e974a1f5b7c1c01b620..160a5aa1d366ca56b4b2f4edec31a50ff1a38021 100644 (file)
--- a/include/pub_tool_aspacemgr.h
+++ b/include/pub_tool_aspacemgr.h
@@ -43,6 +43,7 @@ typedef
       SkAnonV,  // anonymous mapping belonging to valgrind
       SkFileC,  // file mapping belonging to the client
       SkFileV,  // file mapping belonging to valgrind
+      SkShmC,   // shared memory segment belonging to the client
       SkResvn   // reservation
    }
    SegKind;
@@ -73,6 +74,12 @@ typedef
         // there is an associated file
         // segment may have permissions
 
+     kind == SkShmC:
+        // smode==SmFixed
+        // there's no associated file:
+        dev==ino==foff = 0, fnidx == -1
+        // segment may have permissions
+
      kind == SkResvn
         // the segment may be resized if required
         // there's no associated file: