diff options
Diffstat (limited to 'dev-libs/libevent/files/libevent-2.2.1-disable-signalfd.patch')
| -rw-r--r-- | dev-libs/libevent/files/libevent-2.2.1-disable-signalfd.patch | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/dev-libs/libevent/files/libevent-2.2.1-disable-signalfd.patch b/dev-libs/libevent/files/libevent-2.2.1-disable-signalfd.patch new file mode 100644 index 000000000000..6dfce3db3497 --- /dev/null +++ b/dev-libs/libevent/files/libevent-2.2.1-disable-signalfd.patch @@ -0,0 +1,152 @@ +From 594ab34f1dfc73db85e8f95ec51892cadecaa76c Mon Sep 17 00:00:00 2001 +From: Azat Khuzhin <azat@libevent.org> +Date: Mon, 10 Jul 2023 10:40:49 +0200 +Subject: [PATCH] Disable signalfd by default + +signalfd may behave differently to sigaction/signal, so to avoid +breaking libevent users (like [1], [2]) disable it by default. + + [1]: https://github.com/tmux/tmux/pull/3621 + [2]: https://github.com/tmux/tmux/pull/3626 + +Also signalfd is not that perfect: +- you need to SIG_BLOCK the signal before + - blocked signals are not reset on exec + - blocked signals are allowed to coalesce - so in case of multiple + signals sent you may get the signal only once (ok for most of the + signals, but may be a problem for SIGCHLD, though you may call + waitpid() in a loop or use pidfd) +- and also one implementation problem - + sigprocmask is unspecified in a multithreaded process + +Refs: +- https://lwn.net/Articles/415684/ +- https://ldpreload.com/blog/signalfd-is-useless + +Refs: https://github.com/libevent/libevent/issues/1460 +Refs: #1342 (cc @dmantipov) +--- + CMakeLists.txt | 1 + + include/event2/event.h | 6 ++++-- + signalfd.c | 4 ++-- + test/include.am | 2 ++ + test/test.sh | 11 +++++++++-- + 5 files changed, 18 insertions(+), 6 deletions(-) + +diff --git a/CMakeLists.txt b/CMakeLists.txt +index cd41d16e57..9c402ec0c1 100644 +--- a/CMakeLists.txt ++++ b/CMakeLists.txt +@@ -1509,6 +1509,7 @@ if (NOT EVENT__DISABLE_TESTS) + else() + add_backend_test(${BACKEND} "${BACKEND_ENV_VARS}") + endif() ++ add_backend_test(signalfd_${BACKEND} "${BACKEND_ENV_VARS};EVENT_USE_SIGNALFD=1") + endforeach() + + # +diff --git a/include/event2/event.h b/include/event2/event.h +index 384a84178b..9b971edf1d 100644 +--- a/include/event2/event.h ++++ b/include/event2/event.h +@@ -599,9 +599,11 @@ enum event_base_config_flag { + */ + EVENT_BASE_FLAG_EPOLL_DISALLOW_TIMERFD = 0x40, + +- /** Do not use signalfd(2) to handle signals even if supported. ++ /** Use signalfd(2) to handle signals over sigaction/signal. ++ * ++ * But note, that in some edge cases signalfd() may works differently. + */ +- EVENT_BASE_FLAG_DISALLOW_SIGNALFD = 0x80, ++ EVENT_BASE_FLAG_USE_SIGNALFD = 0x80, + }; + + /** +diff --git a/signalfd.c b/signalfd.c +index 376a04d539..ed31014e5f 100644 +--- a/signalfd.c ++++ b/signalfd.c +@@ -205,8 +205,8 @@ sigfd_del(struct event_base *base, int signo, short old, short events, void *p) + int sigfd_init_(struct event_base *base) + { + EVUTIL_ASSERT(base != NULL); +- if ((base->flags & EVENT_BASE_FLAG_DISALLOW_SIGNALFD) || +- getenv("EVENT_DISALLOW_SIGNALFD")) ++ if (!(base->flags & EVENT_BASE_FLAG_USE_SIGNALFD) && ++ !getenv("EVENT_USE_SIGNALFD")) + return -1; + base->evsigsel = &sigfdops; + return 0; +diff --git a/test/include.am b/test/include.am +index e061c937b7..9b50759da7 100644 +--- a/test/include.am ++++ b/test/include.am +@@ -80,6 +80,8 @@ test_runner_changelist: $(top_srcdir)/test/test.sh + $(top_srcdir)/test/test.sh -b "" -c + test_runner_timerfd_changelist: $(top_srcdir)/test/test.sh + $(top_srcdir)/test/test.sh -b "" -T ++test_runner_timerfd_changelist: $(top_srcdir)/test/test.sh ++ $(top_srcdir)/test/test.sh -b "" -S + + DISTCLEANFILES += test/regress.gen.c test/regress.gen.h + +diff --git a/test/test.sh b/test/test.sh +index dfdd2bf098..79362888c5 100755 +--- a/test/test.sh ++++ b/test/test.sh +@@ -50,6 +50,7 @@ setup () { + done + unset EVENT_EPOLL_USE_CHANGELIST + unset EVENT_PRECISE_TIMER ++ unset EVENT_USE_SIGNALFD + } + + announce () { +@@ -138,10 +139,12 @@ do_test() { + EVENT_EPOLL_USE_CHANGELIST=yes; export EVENT_EPOLL_USE_CHANGELIST + elif test "$2" = "(timerfd)" ; then + EVENT_PRECISE_TIMER=1; export EVENT_PRECISE_TIMER ++ elif test "$2" = "(signalfd)" ; then ++ EVENT_USE_SIGNALFD=1; export EVENT_USE_SIGNALFD + elif test "$2" = "(timerfd+changelist)" ; then + EVENT_EPOLL_USE_CHANGELIST=yes; export EVENT_EPOLL_USE_CHANGELIST + EVENT_PRECISE_TIMER=1; export EVENT_PRECISE_TIMER +- fi ++ fi + + run_tests + } +@@ -153,6 +156,7 @@ usage() + -t - run timerfd test + -c - run changelist test + -T - run timerfd+changelist test ++ -S - run signalfd test + EOL + } + main() +@@ -161,13 +165,15 @@ main() + timerfd=0 + changelist=0 + timerfd_changelist=0 ++ signalfd=0 + +- while getopts "b:tcT" c; do ++ while getopts "b:tcTS" c; do + case "$c" in + b) backends="$OPTARG";; + t) timerfd=1;; + c) changelist=1;; + T) timerfd_changelist=1;; ++ S) signalfd=1;; + ?*) usage && exit 1;; + esac + done +@@ -179,6 +185,7 @@ main() + [ $timerfd_changelist -eq 0 ] || do_test EPOLL "(timerfd+changelist)" + for i in $backends; do + do_test $i ++ [ $signalfd -eq 0 ] || do_test $i "(signalfd)" + done + + if test "$FAILED" = "yes"; then |