aarch64: blacklist gcc prior to 5.1

[urcu.git] / README.md

diff --git a/README.md b/README.md
index 7a33cd7ea044c138618d886f50325661ff757105..8dfd5e96a62ab2cc048e54e26a111bcc7b357894 100644 (file)
--- a/README.md
+++ b/README.md
@@ -86,6 +86,8 @@ supported, with the following exceptions:
   - Alpha, ia64 and ARM architectures depend on GCC 4.x with atomic builtins
     support. For ARM this was introduced with GCC 4.4:
     http://gcc.gnu.org/gcc-4.4/changes.html.
   - Alpha, ia64 and ARM architectures depend on GCC 4.x with atomic builtins
     support. For ARM this was introduced with GCC 4.4:
     http://gcc.gnu.org/gcc-4.4/changes.html.

+  - Linux aarch64 depends on GCC 5.1 or better because prior versions
+    perform unsafe access to deallocated stack.

 
 Clang version 3.0 (based on LLVM 3.0) is supported.
 
 
 Clang version 3.0 (based on LLVM 3.0) is supported.
 


@@ -224,10 +226,11 @@ be overridden with `-DSIGRCU` by modifying `Makefile.build.inc`.
 
 The BP library flavor stands for "bulletproof". It is specifically
 designed to help tracing library to hook on applications without
 
 The BP library flavor stands for "bulletproof". It is specifically
 designed to help tracing library to hook on applications without

-requiring to modify these applications. `urcu_bp_init()`,
-`urcu_bp_register_thread()` and `urcu_bp_unregister_thread()` all become
-nops. The state is dealt with by the library internally at the expense
-of read-side and write-side performance.
+requiring to modify these applications. `urcu_bp_init()`, and
+`urcu_bp_unregister_thread()` all become nops, whereas calling
+`urcu_bp_register_thread()` becomes optional. The state is dealt with by
+the library internally at the expense of read-side and write-side
+performance.

 
 
 ### Initialization
 
 
 ### Initialization


@@ -387,7 +390,7 @@ For always-on debugging self-checks:
        ./configure --enable-rcu-debug
 
 For fine grained enabling of debugging self-checks, build
        ./configure --enable-rcu-debug
 
 For fine grained enabling of debugging self-checks, build

-urserspace-rcu with DEBUG_RCU defined and compile dependent
+userspace-rcu with DEBUG_RCU defined and compile dependent

 applications with DEBUG_RCU defined when necessary.
 
 Warning: Enabling this feature result in a performance penalty.
 applications with DEBUG_RCU defined when necessary.
 
 Warning: Enabling this feature result in a performance penalty.


@@ -410,6 +413,20 @@ systems can be disabled with:
 theoretically yielding slightly better performance.
 
 
 theoretically yielding slightly better performance.
 
 

+### Usage of `--enable-cds-lfht-iter-debug`
+
+By default the library is configured with extra debugging checks for
+lock-free hash table iterator traversal disabled.
+
+Building liburcu with --enable-cds-lfht-iter-debug and rebuilding
+application to match the ABI change allows finding cases where the hash
+table iterator is re-purposed to be used on a different hash table while
+still being used to iterate on a hash table.
+
+This option alters the rculfhash ABI. Make sure to compile both library
+and application with matching configuration.
+
+

 Make targets
 ------------
 
 Make targets
 ------------