[compiler-rt] tsan: Refine conditions to intercept pthread_cond_t functions (PR #154268)

[Fangrui Song via llvm-commits]

https://github.com/MaskRay created https://github.com/llvm/llvm-project/pull/154268

On glibc x86-64, functions like pthread_cond_init exist in two versions:
2.2 (older pthread_cond_t) and 2.3.2 (newer pthread_cond_t). In glibc
versions prior to 2.36, using an unversioned interceptor
(`dlsym(RTLD_NEXT, "pthread_cond_init")`) retrieves the older 2.2
symbol, which is not desired
(https://sourceware.org/bugzilla/show_bug.cgi?id=14932).

For newer architectures, such as aarch64 (introduced in glibc 2.17) and
riscv64 (introduced in glibc 2.27), a versioned interceptor is
unnecessary.


>From f8bf9da5c0a517316324fb1795c779e6046a0452 Mon Sep 17 00:00:00 2001
From: Fangrui Song <i at maskray.me>
Date: Mon, 18 Aug 2025 21:59:21 -0700
Subject: [PATCH] =?UTF-8?q?[=F0=9D=98=80=F0=9D=97=BD=F0=9D=97=BF]=20initia?=
 =?UTF-8?q?l=20version?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Created using spr 1.3.5-bogner
---
 .../lib/tsan/rtl/tsan_interceptors_posix.cpp  | 31 +++++++++----------
 1 file changed, 15 insertions(+), 16 deletions(-)

diff --git a/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp b/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
index e9f8d311bbce1..1e05c00ca85a6 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
@@ -79,17 +79,6 @@ struct ucontext_t {
 };
 #endif
 
-#if defined(__x86_64__) || defined(__mips__) || SANITIZER_PPC64V1 || \
-    defined(__s390x__)
-#define PTHREAD_ABI_BASE  "GLIBC_2.3.2"
-#elif defined(__aarch64__) || SANITIZER_PPC64V2
-#define PTHREAD_ABI_BASE  "GLIBC_2.17"
-#elif SANITIZER_LOONGARCH64
-#define PTHREAD_ABI_BASE  "GLIBC_2.36"
-#elif SANITIZER_RISCV64
-#  define PTHREAD_ABI_BASE "GLIBC_2.27"
-#endif
-
 extern "C" int pthread_attr_init(void *attr);
 extern "C" int pthread_attr_destroy(void *attr);
 DECLARE_REAL(int, pthread_attr_getdetachstate, void *, void *)
@@ -341,11 +330,6 @@ void ScopedInterceptor::DisableIgnoresImpl() {
 }
 
 #define TSAN_INTERCEPT(func) INTERCEPT_FUNCTION(func)
-#if SANITIZER_FREEBSD || SANITIZER_NETBSD
-#  define TSAN_INTERCEPT_VER(func, ver) INTERCEPT_FUNCTION(func)
-#else
-#  define TSAN_INTERCEPT_VER(func, ver) INTERCEPT_FUNCTION_VER(func, ver)
-#endif
 #if SANITIZER_FREEBSD
 #  define TSAN_MAYBE_INTERCEPT_FREEBSD_ALIAS(func) \
     INTERCEPT_FUNCTION(_pthread_##func)
@@ -3041,12 +3025,27 @@ void InitializeInterceptors() {
   TSAN_INTERCEPT(pthread_timedjoin_np);
   #endif
 
+  // In glibc versions older than 2.36, dlsym(RTLD_NEXT, "pthread_cond_init")
+  // may return an outdated symbol (max(2.2,base_version)) if the port was
+  // introduced before 2.3.2 (when the new pthread_cond_t was introduced).
+#if SANITIZER_GLIBC && !__GLIBC_PREREQ(2, 36) &&                      \
+    (defined(__x86_64__) || defined(__mips__) || SANITIZER_PPC64V1 || \
+     defined(__s390x__))
+#  define PTHREAD_ABI_BASE "GLIBC_2.3.2"
   TSAN_INTERCEPT_VER(pthread_cond_init, PTHREAD_ABI_BASE);
   TSAN_INTERCEPT_VER(pthread_cond_signal, PTHREAD_ABI_BASE);
   TSAN_INTERCEPT_VER(pthread_cond_broadcast, PTHREAD_ABI_BASE);
   TSAN_INTERCEPT_VER(pthread_cond_wait, PTHREAD_ABI_BASE);
   TSAN_INTERCEPT_VER(pthread_cond_timedwait, PTHREAD_ABI_BASE);
   TSAN_INTERCEPT_VER(pthread_cond_destroy, PTHREAD_ABI_BASE);
+#else
+  TSAN_INTERCEPT(pthread_cond_init);
+  TSAN_INTERCEPT(pthread_cond_signal);
+  TSAN_INTERCEPT(pthread_cond_broadcast);
+  TSAN_INTERCEPT(pthread_cond_wait);
+  TSAN_INTERCEPT(pthread_cond_timedwait);
+  TSAN_INTERCEPT(pthread_cond_destroy);
+#endif
 
   TSAN_MAYBE_PTHREAD_COND_CLOCKWAIT;