urcu/uatomic/riscv: Mark RISC-V as broken

[urcu.git] / include / urcu / uatomic / riscv.h

diff --git a/include/urcu/uatomic/riscv.h b/include/urcu/uatomic/riscv.h
index a6700e17e2429567fbe1e4e95117bf0c69c7c0f0..66a2b0644c61c65492060f2527392a0498207ab6 100644 (file)
--- a/include/urcu/uatomic/riscv.h
+++ b/include/urcu/uatomic/riscv.h
@@ -22,6 +22,23 @@
  * IN THE SOFTWARE.
  */
 
+/*
+ * See <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104831> for details.
+ *
+ * Until the following patches are backported, Userspace RCU is broken for the
+ * RISC-V architecture when compiled with GCC.
+ *
+ *  - <https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=4990cf84c460f064d6281d0813f20b0ef20c7448>
+ *  - <https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=4990cf84c460f064d6281d0813f20b0ef20c7448>
+ *  - <https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d199d2e56da2379004e7e0457150409c0c99d3e6>
+ */
+#if defined(__GNUC__)
+#  error "Implementations of some atomic operations of GCC for RISC-V \
+          are insufficient for sequential consistency. For this reason \
+          Userspace RCU is currently marked as 'broken' for RISC-V with \
+          GCC. However, it is still possible to use other toolchains."
+#endif
+
 #ifndef _URCU_ARCH_UATOMIC_RISCV_H
 #define _URCU_ARCH_UATOMIC_RISCV_H