diff options
Diffstat (limited to 'sysdeps/s390/dl-tls.h')
| -rw-r--r-- | sysdeps/s390/dl-tls.h | 35 |
1 files changed, 28 insertions, 7 deletions
diff --git a/sysdeps/s390/dl-tls.h b/sysdeps/s390/dl-tls.h index 68a5af4152..52192a26d8 100644 --- a/sysdeps/s390/dl-tls.h +++ b/sysdeps/s390/dl-tls.h @@ -26,11 +26,26 @@ typedef struct #ifdef SHARED -/* This is the prototype for the GNU version. */ -extern void *__tls_get_addr (tls_index *ti) attribute_hidden; + extern unsigned long __tls_get_offset (unsigned long got_offset); # ifdef IS_IN_rtld + +# include <shlib-compat.h> + +extern void *__tls_get_addr (tls_index *ti) attribute_hidden; +/* Make a temporary alias of __tls_get_addr to remove the hidden + attribute. Then export __tls_get_addr as __tls_get_addr_internal + for use from libc. We do not want to export __tls_get_addr, but we + do need to use it from libc when looking up the address of a TLS + variable. We don't use __tls_get_offset because it requires r12 to + be setup and that might not always be true. Either way it's more + optimal to use __tls_get_addr directly (that's what + __tls_get_offset does anyways). */ +strong_alias (__tls_get_addr, __tls_get_addr_internal_tmp); +versioned_symbol (ld, __tls_get_addr_internal_tmp, + __tls_get_addr_internal, GLIBC_PRIVATE); + /* The special thing about the s390 TLS ABI is that we do not have the standard __tls_get_addr function but the __tls_get_offset function which differs in two important aspects: @@ -63,15 +78,21 @@ __tls_get_offset:\n\ 1: .long __tls_get_addr - 0b\n\ "); # endif -# endif +# else /* IS_IN_rtld */ +extern void *__tls_get_addr_internal (tls_index *ti); +# endif /* !IS_IN_rtld */ # define GET_ADDR_OFFSET \ (ti->ti_offset - (unsigned long) __builtin_thread_pointer ()) -# define __TLS_GET_ADDR(__ti) \ - ({ extern char _GLOBAL_OFFSET_TABLE_[] attribute_hidden; \ - (void *) __tls_get_offset ((char *) (__ti) - _GLOBAL_OFFSET_TABLE_) \ - + (unsigned long) __builtin_thread_pointer (); }) +/* Use the privately exported __tls_get_addr_internal instead of + __tls_get_offset in order to avoid the __tls_get_offset special + linkage requiring the GOT pointer to be set up in r12. The + compiler will take care of setting up r12 only if itself issued the + __tls_get_offset call. */ +# define __TLS_GET_ADDR(__ti) \ + ({ (void *) __tls_get_addr_internal ((char *) (__ti)) \ + + (unsigned long) __builtin_thread_pointer (); }) #endif |