1 files changed, 18 insertions, 1 deletions

diff --git a/compiler-rt/lib/asan/asan_malloc_linux.cc b/compiler-rt/lib/asan/asan_malloc_linux.cc
index 726cc1f4637..7152fe06718 100644
--- a/compiler-rt/lib/asan/asan_malloc_linux.cc
+++ b/compiler-rt/lib/asan/asan_malloc_linux.cc
@@ -31,6 +31,7 @@
 using namespace __asan;  // NOLINT
 
 static uptr allocated_for_dlsym;
+static uptr last_dlsym_alloc_size_in_words;
 static const uptr kDlsymAllocPoolSize = SANITIZER_RTEMS ? 4096 : 1024;
 static uptr alloc_memory_for_dlsym[kDlsymAllocPoolSize];
 
@@ -42,11 +43,25 @@ static INLINE bool IsInDlsymAllocPool(const void *ptr) {
 static void *AllocateFromLocalPool(uptr size_in_bytes) {
   uptr size_in_words = RoundUpTo(size_in_bytes, kWordSize) / kWordSize;
   void *mem = (void*)&alloc_memory_for_dlsym[allocated_for_dlsym];
+  last_dlsym_alloc_size_in_words = size_in_words;
   allocated_for_dlsym += size_in_words;
   CHECK_LT(allocated_for_dlsym, kDlsymAllocPoolSize);
   return mem;
 }
 
+static void DeallocateFromLocalPool(const void *ptr) {
+  // Hack: since glibc 2.27, dlsym longer use stack-allocated memory to store
+  // error messages and instead use malloc followed by free. To avoid pool
+  // exhaustion due to long object filenames, handle that special case here.
+  uptr prev_offset = allocated_for_dlsym - last_dlsym_alloc_size_in_words;
+  void *prev_mem = (void*)&alloc_memory_for_dlsym[prev_offset];
+  if (prev_mem == ptr) {
+    REAL(memset)(prev_mem, 0, last_dlsym_alloc_size_in_words * kWordSize);
+    allocated_for_dlsym = prev_offset;
+    last_dlsym_alloc_size_in_words = 0;
+  }
+}
+
 static int PosixMemalignFromLocalPool(void **memptr, uptr alignment,
                                       uptr size_in_bytes) {
   if (UNLIKELY(!CheckPosixMemalignAlignment(alignment)))
@@ -107,8 +122,10 @@ static void *ReallocFromLocalPool(void *ptr, uptr size) {
 
 INTERCEPTOR(void, free, void *ptr) {
   GET_STACK_TRACE_FREE;
-  if (UNLIKELY(IsInDlsymAllocPool(ptr)))
+  if (UNLIKELY(IsInDlsymAllocPool(ptr))) {
+    DeallocateFromLocalPool(ptr);
     return;
+  }
   asan_free(ptr, &stack, FROM_MALLOC);
 }