Make dlerror(3) thread-safe.
I gave up trying to use the usual thread-local buffer idiom; calls to
calloc(3) and free(3) from any of the "dl" functions -- which live in
the dynamic linker -- end up resolving to the dynamic linker's stubs.
I tried to work around that, but was just making things more complicated.
This alternative costs us a well-known TLS slot (instead of the
dynamically-allocated TLS slot we'd have used otherwise, so no difference
there), plus an extra buffer inside every pthread_internal_t.
Bug: 5404023
Change-Id: Ie9614edd05b6d1eeaf7bf9172792d616c6361767
diff --git a/libc/bionic/pthread_internal.h b/libc/bionic/pthread_internal.h
index 58a809a..4bc81ef 100644
--- a/libc/bionic/pthread_internal.h
+++ b/libc/bionic/pthread_internal.h
@@ -45,6 +45,13 @@
int internal_flags;
__pthread_cleanup_t* cleanup_stack;
void** tls; /* thread-local storage area */
+
+ /*
+ * The dynamic linker implements dlerror(3), which makes it hard for us to implement this
+ * per-thread buffer by simply using malloc(3) and free(3).
+ */
+#define __BIONIC_DLERROR_BUFFER_SIZE 512
+ char dlerror_buffer[__BIONIC_DLERROR_BUFFER_SIZE];
} pthread_internal_t;
int _init_thread(pthread_internal_t* thread, pid_t kernel_id, pthread_attr_t* attr,