libheaptrace: Fix initialized from TLS to global

The current implementation checks 'initialized' as a TLS variable, but
it's actually incorrect because heaptrace_init() is invoked only once
for each process, not for each thread.

More precisely, it's invoked when exec() invoked to replace its address
map.

Due to this bug, thread allocations are missed and thread deallocations
are also missed so it keeps memory allocation status if the target
backtrace is allocated by a different thread.

This patch makes 'initialized' variable from TLS to global static.

Signed-off-by: Honggyu Kim <[email protected]>

heaptrace.h

@@ -31,9 +31,6 @@ extern FILE *outfp;
 struct thread_flags_t {
 	// to protect unexpected recursive malloc calls
 	bool hook_guard;
-
-	// true only when heaptrace_init is done
-	bool initialized;
 };
 extern thread_local struct thread_flags_t thread_flags;
 

libheaptrace.cc

@@ -46,6 +46,9 @@ static PosixMemalignFunction real_posix_memalign;
 
 thread_local struct thread_flags_t thread_flags;
 
+// true only when heaptrace_init is done
+static bool initialized;
+
 struct opts opts;
 
 FILE *outfp;
@@ -106,7 +109,7 @@ static void heaptrace_init()
 			pid, comm.c_str());
 	}
 
-	tfs->initialized = true;
+	initialized = true;
 }
 
 __destructor
@@ -139,7 +142,7 @@ void* operator new(size_t size)
 {
 	auto* tfs = &thread_flags;
 
-	if (unlikely(tfs->hook_guard || !tfs->initialized))
+	if (unlikely(tfs->hook_guard || !initialized))
 		return __libc_malloc(size);
 
 	tfs->hook_guard = true;
@@ -158,7 +161,7 @@ void* operator new[](size_t size)
 {
 	auto* tfs = &thread_flags;
 
-	if (unlikely(tfs->hook_guard || !tfs->initialized))
+	if (unlikely(tfs->hook_guard || !initialized))
 		return __libc_malloc(size);
 
 	tfs->hook_guard = true;
@@ -177,7 +180,7 @@ void operator delete(void *ptr)
 {
 	auto* tfs = &thread_flags;
 
-	if (unlikely(tfs->hook_guard || !tfs->initialized)) {
+	if (unlikely(tfs->hook_guard || !initialized)) {
 		__libc_free(ptr);
 		return;
 	}
@@ -196,7 +199,7 @@ void operator delete[](void *ptr)
 {
 	auto* tfs = &thread_flags;
 
-	if (unlikely(tfs->hook_guard || !tfs->initialized)) {
+	if (unlikely(tfs->hook_guard || !initialized)) {
 		__libc_free(ptr);
 		return;
 	}
@@ -215,7 +218,7 @@ void* malloc(size_t size)
 {
 	auto* tfs = &thread_flags;
 
-	if (unlikely(tfs->hook_guard || !tfs->initialized))
+	if (unlikely(tfs->hook_guard || !initialized))
 		return __libc_malloc(size);
 
 	tfs->hook_guard = true;
@@ -234,7 +237,7 @@ void free(void *ptr)
 {
 	auto* tfs = &thread_flags;
 
-	if (unlikely(tfs->hook_guard || !tfs->initialized)) {
+	if (unlikely(tfs->hook_guard || !initialized)) {
 		__libc_free(ptr);
 		return;
 	}
@@ -253,7 +256,7 @@ void *calloc(size_t nmemb, size_t size)
 {
 	auto* tfs = &thread_flags;
 
-	if (unlikely(tfs->hook_guard || !tfs->initialized))
+	if (unlikely(tfs->hook_guard || !initialized))
 		return __libc_calloc(nmemb, size);
 
 	tfs->hook_guard = true;
@@ -272,7 +275,7 @@ void *realloc(void *ptr, size_t size)
 {
 	auto* tfs = &thread_flags;
 
-	if (unlikely(tfs->hook_guard || !tfs->initialized))
+	if (unlikely(tfs->hook_guard || !initialized))
 		return __libc_realloc(ptr, size);
 
 	tfs->hook_guard = true;
@@ -292,7 +295,7 @@ void *memalign(size_t alignment, size_t size)
 {
 	auto *tfs = &thread_flags;
 
-	if (unlikely(tfs->hook_guard || !tfs->initialized))
+	if (unlikely(tfs->hook_guard || !initialized))
 		return __libc_memalign(alignment, size);
 
 	tfs->hook_guard = true;
@@ -314,7 +317,7 @@ int posix_memalign(void **memptr, size_t alignment, size_t size)
 	if (unlikely(!real_posix_memalign))
 		real_posix_memalign = (PosixMemalignFunction)dlsym(RTLD_NEXT, "posix_memalign");
 
-	if (unlikely(tfs->hook_guard || !tfs->initialized))
+	if (unlikely(tfs->hook_guard || !initialized))
 		return real_posix_memalign(memptr, alignment, size);
 
 	tfs->hook_guard = true;