Improve stack overflow diagnostics (take 2).
This reverts commits eb1b07469f2b5a392dc1bfd8adc211aea8c72bc5 and
d14dc3b87fbf80553f1cafa453816b7f11366627, and fixes the bug where
we were calling mmap (which might cause errno to be set) before
__set_tls (which is required to implement errno).
Bug: 8557703
Change-Id: I2c36d00240c56e156e1bb430d8c22a73a068b70c
diff --git a/libc/bionic/pthread.c b/libc/bionic/pthread.c
index 8589cd6..92e2c27 100644
--- a/libc/bionic/pthread.c
+++ b/libc/bionic/pthread.c
@@ -31,6 +31,7 @@
#include <errno.h>
#include <limits.h>
#include <sys/atomics.h>
+#include <sys/mman.h>
#include <unistd.h>
#include "bionic_atomic_inline.h"
@@ -102,6 +103,18 @@
// space (see pthread_key_delete)
pthread_key_clean_all();
+ if (thread->alternate_signal_stack != NULL) {
+ // Tell the kernel to stop using the alternate signal stack.
+ stack_t ss;
+ ss.ss_sp = NULL;
+ ss.ss_flags = SS_DISABLE;
+ sigaltstack(&ss, NULL);
+
+ // Free it.
+ munmap(thread->alternate_signal_stack, SIGSTKSZ);
+ thread->alternate_signal_stack = NULL;
+ }
+
// if the thread is detached, destroy the pthread_internal_t
// otherwise, keep it in memory and signal any joiners.
pthread_mutex_lock(&gThreadListLock);