https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84761
--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
That won't really work, if you configure against one glibc version and run
against another one, that will still not work properly.
So I think we need something like:
--- libsanitizer/sanitizer_common/sanitizer_linux_libcdep.cc 2017-10-19
13:20:58.972958379 +0200
+++ libsanitizer/sanitizer_common/sanitizer_linux_libcdep.cc 2018-03-19
13:50:41.978147828 +0100
@@ -151,25 +151,35 @@ bool SanitizerGetThreadName(char *name,
!SANITIZER_NETBSD
static uptr g_tls_size;
-#ifdef __i386__
-# define DL_INTERNAL_FUNCTION __attribute__((regparm(3), stdcall))
-#else
-# define DL_INTERNAL_FUNCTION
-#endif
-
void InitTlsSize() {
// all current supported platforms have 16 bytes stack alignment
const size_t kStackAlign = 16;
- typedef void (*get_tls_func)(size_t*, size_t*) DL_INTERNAL_FUNCTION;
- get_tls_func get_tls;
- void *get_tls_static_info_ptr = dlsym(RTLD_NEXT, "_dl_get_tls_static_info");
- CHECK_EQ(sizeof(get_tls), sizeof(get_tls_static_info_ptr));
- internal_memcpy(&get_tls, &get_tls_static_info_ptr,
- sizeof(get_tls_static_info_ptr));
- CHECK_NE(get_tls, 0);
size_t tls_size = 0;
size_t tls_align = 0;
- get_tls(&tls_size, &tls_align);
+ void *get_tls_static_info_ptr = dlsym(RTLD_NEXT, "_dl_get_tls_static_info");
+#ifdef __i386__
+ /* On i?86, _dl_get_tls_static_info used to be regparm(3) before glibc 2.27
+ and is now a normal function. */
+ if (!dlvsym(RTLD_NEXT, "glob", "GLIBC_2.27")) {
+ typedef void (*get_tls_func)(size_t*, size_t*)
+ __attribute__((regparm(3), stdcall));
+ get_tls_func get_tls;
+ CHECK_EQ(sizeof(get_tls), sizeof(get_tls_static_info_ptr));
+ internal_memcpy(&get_tls, &get_tls_static_info_ptr,
+ sizeof(get_tls_static_info_ptr));
+ CHECK_NE(get_tls, 0);
+ get_tls(&tls_size, &tls_align);
+ } else
+#endif
+ {
+ typedef void (*get_tls_func)(size_t*, size_t*);
+ get_tls_func get_tls;
+ CHECK_EQ(sizeof(get_tls), sizeof(get_tls_static_info_ptr));
+ internal_memcpy(&get_tls, &get_tls_static_info_ptr,
+ sizeof(get_tls_static_info_ptr));
+ CHECK_NE(get_tls, 0);
+ get_tls(&tls_size, &tls_align);
+ }
if (tls_align < kStackAlign)
tls_align = kStackAlign;
g_tls_size = RoundUpTo(tls_size, tls_align);
instead. If we only support using the glibc with which gcc has been configured
or later, perhaps that dlvsym call could be avoided if __GLIBC_PREREQ(2, 27).
