[cfi] Support for dlopen and dlclose.

Add dlopen/dlclose interceptors to update CFI shadow for loaded/unloaded libraries.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@258857 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 5 insertions, 0 deletions

diff --git a/lib/sanitizer_common/sanitizer_common.h b/lib/sanitizer_common/sanitizer_common.h
index c41dc9f09..c40c1f369 100644
--- a/lib/sanitizer_common/sanitizer_common.h
+++ b/lib/sanitizer_common/sanitizer_common.h
@@ -93,6 +93,7 @@ void *MmapAlignedOrDie(uptr size, uptr alignment, const char *mem_type);
 // Disallow access to a memory range.  Use MmapNoAccess to allocate an
 // unaccessible memory.
 bool MprotectNoAccess(uptr addr, uptr size);
+bool MprotectReadOnly(uptr addr, uptr size);
 
 // Used to check if we can map shadow memory to a fixed location.
 bool MemoryRangeIsAvailable(uptr range_start, uptr range_end);
diff --git a/lib/sanitizer_common/sanitizer_posix.cc b/lib/sanitizer_common/sanitizer_posix.cc
index 5ae68663d..62671f5c4 100644
--- a/lib/sanitizer_common/sanitizer_posix.cc
+++ b/lib/sanitizer_common/sanitizer_posix.cc
@@ -171,6 +171,10 @@ bool MprotectNoAccess(uptr addr, uptr size) {
   return 0 == internal_mprotect((void*)addr, size, PROT_NONE);
 }
 
+bool MprotectReadOnly(uptr addr, uptr size) {
+  return 0 == internal_mprotect((void *)addr, size, PROT_READ);
+}
+
 fd_t OpenFile(const char *filename, FileAccessMode mode, error_t *errno_p) {
   int flags;
   switch (mode) {