[DSC] Simplify file mapping to fix intermittent unrelocated pointers

The `FileAccessorCache`'s LRU eviction could discard a file's mapped
data after slide info had already been applied to it. Future accesses to
the file produced a fresh mapping, but failed to reapply the slide info.
This could result in pointers not correctly being slid, such as in
https://github.com/Vector35/binaryninja-api/issues/7689.

The LRU cache existed to stay within OS file descriptor limits, since
the old `MappedFile` held its fd open for the lifetime of the mapping.
There's no real reason for it to hold the file descriptor open like
this. Closing it after `mmap` is sufficient to avoid the file descriptor
limits.

`MappedFileRegion` replaces the combination of `FileAccessorCache`,
`WeakFileAccessor`, and `MappedFileAccessor`. It closes the fd
immediately after mmap, so all files can stay mapped without consuming
descriptors, making the cache unnecessary.

`MappedFileRegion` is owned directly by the `CacheEntry` for its full
lifetime. Slide info is applied exactly once to each `MappedFileRegion`.

1 files changed, 0 insertions, 12 deletions

diff --git a/view/sharedcache/core/SharedCacheView.cpp b/view/sharedcache/core/SharedCacheView.cpp
index dac39278..746bd7eb 100644
--- a/view/sharedcache/core/SharedCacheView.cpp
+++ b/view/sharedcache/core/SharedCacheView.cpp
@@ -3,8 +3,6 @@
 #include <filesystem>
 
 #include "SharedCacheController.h"
-#include "FileAccessorCache.h"
-#include "MappedFileAccessor.h"
 #include "SharedCacheBuilder.h"
 
 using namespace BinaryNinja;
@@ -17,12 +15,6 @@ SharedCacheViewType::SharedCacheViewType() : BinaryViewType(VIEW_NAME, VIEW_NAME
 // We register all our one-shot stuff here, such as the object destructor.
 void SharedCacheViewType::Register()
 {
-	auto fdLimit = AdjustFileDescriptorLimit();
-	LogDebugF("Shared Cache processing initialized with a max file descriptor limit of {}", fdLimit);
-
-	// Adjust the global accessor cache to the fdlimit.
-	FileAccessorCache::Global().SetCacheSize(fdLimit);
-	
 	RegisterSharedCacheControllerDestructor();
 
 	static SharedCacheViewType type;
@@ -874,10 +866,6 @@ bool SharedCacheView::InitController()
 		std::chrono::duration<double> elapsed = endTime - startTime;
 		m_logger->LogInfoF("Processing {} entries took {:.3f} seconds", totalEntries, elapsed.count());
 
-		// If we can't store all of our files for this cache in the accessor cache we might run into issues, warn the user.
-		if (totalEntries > FileAccessorCache::Global().GetCacheSize())
-			m_logger->LogWarn("Cache contains more entries than the allowed number of opened file handles, this may impact reliability.");
-
 		// Verify that we are not missing any entries that were stored in the metadata.
 		// If we are that means we should alert the user that a previously associated cache entry is missing.
 		std::set<std::string> missingCacheEntries = m_secondaryFileNames;