From 0256e4f0f5e10f0a15cbba2cd64e252dfa864e4a Mon Sep 17 00:00:00 2001 From: Yusuke Endoh Date: Fri, 6 Mar 2020 21:32:42 +0900 Subject: thread_pthread.c: allocate sigaltstack before pthread_create A new (not-initialized-yet) pthread attempts to allocate sigaltstack by using xmalloc. It may cause GC, but because the thread is not initialized yet, ruby_native_thread_p() returns false, which leads to "[FATAL] failed to allocate memory" and exit. In fact, we can observe the error message in the log of OpenBSD CI: https://rubyci.org/logs/rubyci.s3.amazonaws.com/openbsd-current/ruby-master/log/20200306T083005Z.log.html.gz This changeset allocates sigaltstack before pthread is created. --- signal.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) (limited to 'signal.c') diff --git a/signal.c b/signal.c index ab4eadc7ee..650c59a084 100644 --- a/signal.c +++ b/signal.c @@ -547,14 +547,25 @@ rb_sigaltstack_size(void) return size; } +static int rb_sigaltstack_size_value = 0; + +void * +rb_allocate_sigaltstack(void) +{ + if (!rb_sigaltstack_size_value) { + rb_sigaltstack_size_value = rb_sigaltstack_size(); + } + return xmalloc(rb_sigaltstack_size_value); +} + /* alternate stack for SIGSEGV */ void * -rb_register_sigaltstack(void) +rb_register_sigaltstack(void *altstack) { stack_t newSS, oldSS; - newSS.ss_size = rb_sigaltstack_size(); - newSS.ss_sp = xmalloc(newSS.ss_size); + newSS.ss_size = rb_sigaltstack_size_value; + newSS.ss_sp = altstack; newSS.ss_flags = 0; sigaltstack(&newSS, &oldSS); /* ignore error. */ @@ -1561,7 +1572,7 @@ Init_signal(void) force_install_sighandler(SIGILL, (sighandler_t)sigill, &default_sigill_handler); #endif #ifdef SIGSEGV - RB_ALTSTACK_INIT(GET_VM()->main_altstack); + RB_ALTSTACK_INIT(GET_VM()->main_altstack, rb_allocate_sigaltstack()); force_install_sighandler(SIGSEGV, (sighandler_t)sigsegv, &default_sigsegv_handler); #endif } -- cgit v1.2.1