From f41dd93ade24f22f8cd1863129ab20c821000134 Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Tue, 8 Dec 2020 10:17:16 -0800 Subject: [PATCH] libgcc: block signals when releasing split-stack memory * generic-morestack-thread.c (free_segments): Block signals during thread exit. --- libgcc/generic-morestack-thread.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/libgcc/generic-morestack-thread.c b/libgcc/generic-morestack-thread.c index 83a65501272..fd391bb2e1f 100644 --- a/libgcc/generic-morestack-thread.c +++ b/libgcc/generic-morestack-thread.c @@ -38,6 +38,7 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see #ifndef inhibit_libc #include +#include #include #include "generic-morestack.h" @@ -54,6 +55,9 @@ extern int pthread_key_create (pthread_key_t *, void (*) (void *)) extern int pthread_setspecific (pthread_key_t, const void *) __attribute__ ((weak)); +extern int pthread_sigmask (int, const sigset_t *, sigset_t *) + __attribute__ ((weak)); + /* The key for the list of stack segments to free when the thread exits. This is created by pthread_key_create. */ @@ -70,6 +74,16 @@ static pthread_once_t create_key_once = PTHREAD_ONCE_INIT; static void free_segments (void* arg) { + /* We must block signals in case the signal handler tries to split + the stack. We leave them blocked while the thread exits. */ + if (pthread_sigmask) + { + sigset_t mask; + + sigfillset (&mask); + pthread_sigmask (SIG_BLOCK, &mask, NULL); + } + __morestack_release_segments ((struct stack_segment **) arg, 1); }