commit 63cb679404700c5b7e944d7863d0c4de1ce5eb95
author pasko <pasko@chromium.org> Tue Nov 18 22:31:36 2014 +0900
committer Qijiang Fan <fqj@google.com> Thu Jun 04 17:57:57 2020 +0900
tree aad53b028b3722ee6a1b6c168e0745a959343d94
parent 1e893277f84e73ecb8d819f1edd9ac41c154f872

Intercept base::File Open/Close

When a file descriptor is opened by the base::File, all calls to close(3) from the same dynamic library will hit a CHECK unless they are made from a whitelist of callsites belonging to base::File.

There is a handy protect_file_posix.gypi introduced to make it easy to enable on Chrome-for-Android.

This 'linker magic' is somewhat crazy, so:
1. it will be *removed *when crbug.com/424562 is fixed
2. it should only be used by a whitelist of binaries/libraries (in the opensource part: libchromeshell only)

BUG=424562

Review URL: https://codereview.chromium.org/676873004

Cr-Commit-Position: refs/heads/master@{#304592}


CrOS-Libchrome-Original-Commit: 45a0dc0b75b52e026eb15526ef441edc5dbe9ba5

base/files/file_posix.cc

diff --git a/base/files/file_posix.cc b/base/files/file_posix.cc
index 3d229e4..245ea6a 100644
--- a/base/files/file_posix.cc
+++ b/base/files/file_posix.cc
@@ -10,6 +10,7 @@
 #include <unistd.h>
 
 #include "base/files/file_path.h"
+#include "base/files/file_posix_hooks_internal.h"
 #include "base/logging.h"
 #include "base/metrics/sparse_histogram.h"
 #include "base/posix/eintr_wrapper.h"
@@ -166,6 +167,14 @@
                                   Time::kNanosecondsPerMicrosecond);
 }
 
+// Default implementations of Protect/Unprotect hooks defined as weak symbols
+// where possible.
+void ProtectFileDescriptor(int fd) {
+}
+
+void UnprotectFileDescriptor(int fd) {
+}
+
 // NaCl doesn't implement system calls to open files directly.
 #if !defined(OS_NACL)
 // TODO(erikkay): does it make sense to support FLAG_EXCLUSIVE_* here?
@@ -252,6 +261,7 @@
   async_ = ((flags & FLAG_ASYNC) == FLAG_ASYNC);
   error_details_ = FILE_OK;
   file_.reset(descriptor);
+  ProtectFileDescriptor(descriptor);
 }
 #endif  // !defined(OS_NACL)
 
@@ -264,6 +274,8 @@
 }
 
 PlatformFile File::TakePlatformFile() {
+  if (IsValid())
+    UnprotectFileDescriptor(GetPlatformFile());
   return file_.release();
 }
 
@@ -272,6 +284,7 @@
     return;
 
   base::ThreadRestrictions::AssertIOAllowed();
+  UnprotectFileDescriptor(GetPlatformFile());
   file_.reset();
 }
 
@@ -527,8 +540,10 @@
 }
 
 void File::SetPlatformFile(PlatformFile file) {
-  DCHECK(!file_.is_valid());
+  CHECK(!file_.is_valid());
   file_.reset(file);
+  if (file_.is_valid())
+    ProtectFileDescriptor(GetPlatformFile());
 }
 
 }  // namespace base