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 b2a53a6cb3a342b647f91b474b88705fa89152e4..f63f2eea1a9c6080d3df07c0a7e22002603e1c96 100644 (file)
--- a/apt-pkg/contrib/mmap.cc
+++ b/apt-pkg/contrib/mmap.cc
@@ -16,7 +16,7 @@
    ##################################################################### */
                                                                        /*}}}*/
 // Include Files                                                       /*{{{*/
-#define _BSD_SOURCE
+#define _DEFAULT_SOURCE
 #include <config.h>
 
 #include <apt-pkg/mmap.h>
@@ -38,9 +38,8 @@
 // ---------------------------------------------------------------------
 /* */
 MMap::MMap(FileFd &F,unsigned long Flags) : Flags(Flags), iSize(0),
-                     Base(0), SyncToFd(NULL)
+                     Base(nullptr), SyncToFd(nullptr)
 {
-   if ((Flags & NoImmMap) != NoImmMap)
       Map(F);
 }
                                                                        /*}}}*/
@@ -48,7 +47,7 @@ MMap::MMap(FileFd &F,unsigned long Flags) : Flags(Flags), iSize(0),
 // ---------------------------------------------------------------------
 /* */
 MMap::MMap(unsigned long Flags) : Flags(Flags), iSize(0),
-                     Base(0), SyncToFd(NULL)
+                     Base(nullptr), SyncToFd(nullptr)
 {
 }
                                                                        /*}}}*/
@@ -84,6 +83,8 @@ bool MMap::Map(FileFd &Fd)
       if ((Flags & ReadOnly) != ReadOnly)
         return _error->Error("Compressed file %s can only be mapped readonly", Fd.Name().c_str());
       Base = malloc(iSize);
+      if (unlikely(Base == nullptr))
+        return _error->Errno("MMap-compressed-malloc", _("Couldn't make mmap of %llu bytes"), iSize);
       SyncToFd = new FileFd();
       if (Fd.Seek(0L) == false || Fd.Read(Base, iSize) == false)
         return _error->Error("Compressed file %s can't be read into mmap", Fd.Name().c_str());
@@ -92,7 +93,7 @@ bool MMap::Map(FileFd &Fd)
 
    // Map it.
    Base = (Flags & Fallback) ? MAP_FAILED : mmap(0,iSize,Prot,Map,Fd.Fd(),0);
-   if (Base == (void *)-1)
+   if (Base == MAP_FAILED)
    {
       if (errno == ENODEV || errno == EINVAL || (Flags & Fallback))
       {
@@ -102,22 +103,25 @@ bool MMap::Map(FileFd &Fd)
         {
            // for readonly, we don't need sync, so make it simple
            Base = malloc(iSize);
+           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);
         if (!SyncToFd->Seek(0L) || !SyncToFd->Read(Base, iSize))
            return false;
       }
       else
-        return _error->Errno("mmap",_("Couldn't make mmap of %llu bytes"),
-                             iSize);
+        return _error->Errno("MMap-mmap", _("Couldn't make mmap of %llu bytes"), iSize);
      }
 
    return true;
@@ -190,7 +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;
       }
@@ -198,7 +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
       }
@@ -212,12 +217,9 @@ 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)
 {
-   if (_error->PendingError() == true)
-      return;
-
    // disable Moveable if we don't grow
    if (Grow == 0)
       this->Flags &= ~Moveable;
@@ -249,12 +251,9 @@ 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)
 {
-       if (_error->PendingError() == true)
-               return;
-
        // disable Moveable if we don't grow
        if (Grow == 0)
                this->Flags &= ~Moveable;
@@ -308,10 +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;
    }
    
@@ -390,12 +390,15 @@ unsigned long DynamicMMap::Allocate(unsigned long ItemSize)
       const unsigned long size = 20*1024;
       I->Count = size/ItemSize;
       Pool* oldPools = Pools;
+      _error->PushToStack();
       Result = RawAllocate(size,ItemSize);
+      bool const newError = _error->PendingError();
+      _error->MergeWithStack();
       if (Pools != oldPools)
         I += Pools - oldPools;
 
       // Does the allocation failed ?
-      if (Result == 0 && _error->PendingError())
+      if (Result == 0 && newError)
         return 0;
       I->Start = Result;
    }
@@ -409,18 +412,28 @@ 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)
 {
    if (Len == (unsigned long)-1)
       Len = strlen(String);
 
-   unsigned long const Result = RawAllocate(Len+1,0);
+   _error->PushToStack();
+   unsigned long Result = RawAllocate(Len+1+sizeof(uint16_t),sizeof(uint16_t));
+   bool const newError = _error->PendingError();
+   _error->MergeWithStack();
 
-   if (Base == NULL || (Result == 0 && _error->PendingError()))
+   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;
@@ -477,12 +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;