From: Mathieu Desnoyers Date: Fri, 1 Nov 2013 13:42:23 +0000 (-0400) Subject: Fix: tls-compat multi-lib conflict X-Git-Tag: v0.8.1~3 X-Git-Url: http://git.lttng.org/?a=commitdiff_plain;h=ff12c1236f766980d57b1b80e0bd571c21c3df7f;hp=ff12c1236f766980d57b1b80e0bd571c21c3df7f;p=userspace-rcu.git Fix: tls-compat multi-lib conflict When configured with the TLS pthread key fallback either: - explicitly with ./configure --disable-compiler-tls, - or if compiler TLS is not usable, (this can be confirmed by looking at the configure output: Thread Local Storage (TLS): pthread_getspecific().) There is an issue when using multiple flavors of RCU within the same program. Unit tests concerned: tests/unit/test_urcu_multiflavor tests/unit/test_urcu_multiflavor_dynlink Vladimir Nikulichev noticed crashes when using this setup. The problem can be pinpointed to a missing macro expansion in urcu/tls-compat.h: looking at the output of nm tests/unit/.libs/test_urcu_multiflavor : U __tls_access_rcu_reader this seems to be the issue. We're missing macro expansion in tls-compat.h. With this commit, it becomes: U __tls_access_rcu_reader_bp U __tls_access_rcu_reader_mb U __tls_access_rcu_reader_memb U __tls_access_rcu_reader_sig Please note that this affects an unusual configuration of userspace RCU (with TLS pthread key fallback), needed for some BSD that don't support compiler TLS. Strictly speaking, this requires bumping the URCU library soname version major number, because it breaks the ABI presented to applications on those unusual configurations. A following commit will handle the ABI migration: for stable releases (stable-0.7 and stable-0.8 branches), the ABI is kept compatible, and bogus usage are detected. For the upcoming stable-0.9, the soname will simply be bumped. Reported-by: Vladimir Nikulichev Signed-off-by: Mathieu Desnoyers ---