It is NOT OK to just munmap memory from malloc :/.

[apt.git] / apt-pkg / contrib / mmap.cc

diff --git a/apt-pkg/contrib/mmap.cc b/apt-pkg/contrib/mmap.cc
index 4dc851c1bee7aa23bf2cf31ecb5749c83a98e3d3..f63f2eea1a9c6080d3df07c0a7e22002603e1c96 100644 (file)
--- a/apt-pkg/contrib/mmap.cc
+++ b/apt-pkg/contrib/mmap.cc
@@ -40,7 +40,6 @@
 MMap::MMap(FileFd &F,unsigned long Flags) : Flags(Flags), iSize(0),
                      Base(nullptr), SyncToFd(nullptr)
 {
-   if ((Flags & NoImmMap) != NoImmMap)
       Map(F);
 }
                                                                        /*}}}*/
@@ -107,14 +106,14 @@ bool MMap::Map(FileFd &Fd)
            if (unlikely(Base == nullptr))
               return _error->Errno("MMap-malloc", _("Couldn't make mmap of %llu bytes"), iSize);
            SyncToFd = new FileFd();
-           return Fd.Read(Base, iSize);
+           return Fd.Seek(0L) && Fd.Read(Base, iSize);
         }
         // FIXME: Writing to compressed fd's ?
         int const dupped_fd = dup(Fd.Fd());
         if (dupped_fd == -1)
            return _error->Errno("mmap", _("Couldn't duplicate file descriptor %i"), Fd.Fd());
 
-        Base = calloc(iSize, 1);
+        Base = malloc(iSize);
         if (unlikely(Base == nullptr))
            return _error->Errno("MMap-calloc", _("Couldn't make mmap of %llu bytes"), iSize);
         SyncToFd = new FileFd (dupped_fd);
@@ -195,7 +194,7 @@ bool MMap::Sync(unsigned long Start,unsigned long Stop)
    {
       if (SyncToFd != 0)
       {
-        if (!SyncToFd->Seek(0) ||
+        if (!SyncToFd->Seek(Start) ||
             !SyncToFd->Write (((char *)Base)+Start, Stop-Start))
            return false;
       }
@@ -203,7 +202,8 @@ bool MMap::Sync(unsigned long Start,unsigned long Stop)
       {
 #ifdef _POSIX_SYNCHRONIZED_IO
         unsigned long long const PSize = sysconf(_SC_PAGESIZE);
-        if (msync((char *)Base+(Start/PSize)*PSize, Stop - Start, MS_SYNC) < 0)
+         Start = (Start/PSize)*PSize;
+        if (msync((char *)Base+Start, Stop - Start, MS_SYNC) < 0)
            return _error->Errno("msync", _("Unable to synchronize mmap"));
 #endif
       }
@@ -217,7 +217,7 @@ bool MMap::Sync(unsigned long Start,unsigned long Stop)
 /* */
 DynamicMMap::DynamicMMap(FileFd &F,unsigned long Flags,unsigned long const &Workspace,
                         unsigned long const &Grow, unsigned long const &Limit) :
-               MMap(F,Flags | NoImmMap), Fd(&F), WorkSpace(Workspace),
+               MMap(Flags), Fd(&F), WorkSpace(Workspace),
                GrowFactor(Grow), Limit(Limit)
 {
    // disable Moveable if we don't grow
@@ -251,7 +251,7 @@ DynamicMMap::DynamicMMap(FileFd &F,unsigned long Flags,unsigned long const &Work
    and could come in handy later than we are able to grow such an mmap */
 DynamicMMap::DynamicMMap(unsigned long Flags,unsigned long const &WorkSpace,
                         unsigned long const &Grow, unsigned long const &Limit) :
-               MMap(Flags | NoImmMap | UnMapped), Fd(0), WorkSpace(WorkSpace),
+               MMap(Flags | UnMapped), Fd(0), WorkSpace(WorkSpace),
                GrowFactor(Grow), Limit(Limit)
 {
        // disable Moveable if we don't grow
@@ -307,10 +307,11 @@ DynamicMMap::~DynamicMMap()
       if (validData() == false)
         return;
 #ifdef _POSIX_MAPPED_FILES
-      munmap(Base, WorkSpace);
-#else
-      free(Base);
+      if ((Flags & Fallback) != Fallback) {
+         munmap(Base, WorkSpace);
+      } else
 #endif
+      free(Base);
       return;
    }
    
@@ -411,7 +412,7 @@ unsigned long DynamicMMap::Allocate(unsigned long ItemSize)
                                                                        /*}}}*/
 // DynamicMMap::WriteString - Write a string to the file               /*{{{*/
 // ---------------------------------------------------------------------
-/* Strings are not aligned to anything */
+/* Strings are aligned to 16 bytes */
 unsigned long DynamicMMap::WriteString(const char *String,
                                       unsigned long Len)
 {
@@ -419,13 +420,20 @@ unsigned long DynamicMMap::WriteString(const char *String,
       Len = strlen(String);
 
    _error->PushToStack();
-   unsigned long const Result = RawAllocate(Len+1,0);
+   unsigned long Result = RawAllocate(Len+1+sizeof(uint16_t),sizeof(uint16_t));
    bool const newError = _error->PendingError();
    _error->MergeWithStack();
 
    if (Base == NULL || (Result == 0 && newError))
       return 0;
 
+   if (Len >= std::numeric_limits<uint16_t>::max())
+      abort();
+
+   uint16_t LenToWrite = Len;
+   memcpy((char *)Base + Result, &LenToWrite, sizeof(LenToWrite));
+   Result += + sizeof(LenToWrite);
+
    memcpy((char *)Base + Result,String,Len);
    ((char *)Base)[Result + Len] = 0;
    return Result;
@@ -482,12 +490,14 @@ bool DynamicMMap::Grow() {
                if ((Flags & Moveable) != Moveable)
                        return false;
 
-               Base = realloc(Base, newSize);
-               if (Base == NULL)
+               auto Temp = realloc(Base, newSize);
+               if (Temp == NULL)
                        return false;
-               else
+               else {
+                       Base = Temp;
                        /* Set new memory to 0 */
                        memset((char*)Base + WorkSpace, 0, newSize - WorkSpace);
+               }
        }
 
        Pools =(Pool*) Base + poolOffset;