From 88ecbe6daa6da4850ea975b635cd1af8e4ca9bfe Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Thu, 6 Sep 2012 09:58:36 -0400 Subject: [PATCH] Document sigaltstack(2) limitation Signed-off-by: Mathieu Desnoyers --- README | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/README b/README index 33038af..303c6ec 100644 --- a/README +++ b/README @@ -189,11 +189,12 @@ Being careful with signals signal(7). The liburcu-mb and liburcu-qsbr versions of the Userspace RCU library do not require any signal. - Read-side critical sections are allowed in a signal handler with - liburcu and liburcu-mb. Be careful, however, to disable these signals + Read-side critical sections are allowed in a signal handler, + except those setup with sigaltstack(2), with liburcu and + liburcu-mb. Be careful, however, to disable these signals between thread creation and calls to rcu_register_thread(), because a - signal handler nesting on an unregistered thread would not be allowed to - call rcu_read_lock(). + signal handler nesting on an unregistered thread would not be + allowed to call rcu_read_lock(). Read-side critical sections are _not_ allowed in a signal handler with liburcu-qsbr, unless signals are disabled explicitly around each -- 2.34.1