runtime/cgo: provide backward compatibility with old glibc for cgo

Fixes: golang#65625
Before go1.22, the example in golang#65625 can be run successfully, though
the core issue is in old version glibc, but it will be better to
provide this backward compatibility to let people can upgrade to
go 1.22+.

Signed-off-by: lifubang <[email protected]>

src/runtime/cgo/gcc_stack_unix.c

@@ -17,24 +17,45 @@ x_cgo_getstackbound(uintptr bounds[2])
  pthread_attr_t attr;
  void *addr;
  size_t size;
+ bool noinit;
+ int err;
 
 #if defined(__GLIBC__) || (defined(__sun) && !defined(__illumos__))
  // pthread_getattr_np is a GNU extension supported in glibc.
  // Solaris is not glibc but does support pthread_getattr_np
  // (and the fallback doesn't work...). Illumos does not.
- pthread_getattr_np(pthread_self(), &attr); // GNU extension
- pthread_attr_getstack(&attr, &addr, &size); // low address
+ err = pthread_getattr_np(pthread_self(), &attr); // GNU extension
+ if (err != 0) {
+ noinit = true;
+ goto failback;
+ }
+ err = pthread_attr_getstack(&attr, &addr, &size); // low address
+ if (err != 0) {
+ goto failback;
+ }
+ goto ret;
 #elif defined(__illumos__)
  pthread_attr_init(&attr);
- pthread_attr_get_np(pthread_self(), &attr);
- pthread_attr_getstack(&attr, &addr, &size); // low address
-#else
+ err = pthread_attr_get_np(pthread_self(), &attr);
+ if (err != 0) {
+ goto failback;
+ }
+ err = pthread_attr_getstack(&attr, &addr, &size); // low address
+ if (err != 0) {
+ goto failback;
+ }
+ goto ret;
+#endif
+failback:
  // We don't know how to get the current stacks, so assume they are the
  // same as the default stack bounds.
+ if (!noinit) {
+ pthread_attr_destroy(&attr);
+ }
  pthread_attr_init(&attr);
  pthread_attr_getstacksize(&attr, &size);
  addr = __builtin_frame_address(0) + 4096 - size;
-#endif
+ret:
  pthread_attr_destroy(&attr);
 
  bounds[0] = (uintptr)addr;

src/runtime/cgo/libcgo.h

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+#include <stdbool.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <stdio.h>