Index: lib/asan/asan_interceptors.cc =================================================================== --- lib/asan/asan_interceptors.cc +++ lib/asan/asan_interceptors.cc @@ -275,7 +275,15 @@ uptr stack, ssize; ReadContextStack(ucp, &stack, &ssize); ClearShadowMemoryForContextStack(stack, ssize); +#if __has_attribute(__indirect_return__) && \ + (defined(__x86_64__) || defined(__i386__)) + int (*real_swapcontext)(struct ucontext_t *, struct ucontext_t *) + __attribute__((__indirect_return__)) + = REAL(swapcontext); + int res = real_swapcontext(oucp, ucp); +#else int res = REAL(swapcontext)(oucp, ucp); +#endif // swapcontext technically does not return, but program may swap context to // "oucp" later, that would look as if swapcontext() returned 0. // We need to clear shadow for ucp once again, as it may be in arbitrary Index: lib/sanitizer_common/sanitizer_internal_defs.h =================================================================== --- lib/sanitizer_common/sanitizer_internal_defs.h +++ lib/sanitizer_common/sanitizer_internal_defs.h @@ -122,6 +122,11 @@ # define __has_feature(x) 0 #endif +// Older GCCs do not understand __has_attribute. +#if !defined(__has_attribute) +# define __has_attribute)(x) 0 +#endif + // For portability reasons we do not include stddef.h, stdint.h or any other // system header, but we do need some basic types that are not defined // in a portable way by the language itself.