diff options
Diffstat (limited to 'REORG.TODO/sysdeps/s390/dl-tls.h')
-rw-r--r-- | REORG.TODO/sysdeps/s390/dl-tls.h | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/s390/dl-tls.h b/REORG.TODO/sysdeps/s390/dl-tls.h new file mode 100644 index 0000000000..3298acfbcf --- /dev/null +++ b/REORG.TODO/sysdeps/s390/dl-tls.h @@ -0,0 +1,104 @@ +/* Thread-local storage handling in the ELF dynamic linker. s390 version. + Copyright (C) 2003-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + + +/* Type used for the representation of TLS information in the GOT. */ +typedef struct +{ + unsigned long int ti_module; + unsigned long int ti_offset; +} tls_index; + + +#ifdef SHARED + +extern unsigned long __tls_get_offset (unsigned long got_offset); + +# if IS_IN (rtld) + +# include <shlib-compat.h> + +/* dl-tls.c declares __tls_get_addr as an exported symbol if it is not defined + as a macro. It seems suitable to do that in the generic code because all + architectures other than s390 export __tls_get_addr. The declaration causes + problems in s390 though, so we define __tls_get_addr here to avoid declaring + __tls_get_addr again. */ +# define __tls_get_addr __tls_get_addr + +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: + 1) __tls_get_offset gets a got offset instead of a pointer to the + tls_index structure + 2) __tls_get_offset returns the offset of the requested variable to + the thread descriptor instead of a pointer to the variable. + */ +# ifdef __s390x__ +__asm__("\n\ + .text\n\ + .globl __tls_get_offset\n\ + .type __tls_get_offset, @function\n\ + .align 4\n\ +__tls_get_offset:\n\ + la %r2,0(%r2,%r12)\n\ + jg __tls_get_addr\n\ +"); +# elif defined __s390__ +__asm__("\n\ + .text\n\ + .globl __tls_get_offset\n\ + .type __tls_get_offset, @function\n\ + .align 4\n\ +__tls_get_offset:\n\ + basr %r3,0\n\ +0: la %r2,0(%r2,%r12)\n\ + l %r4,1f-0b(%r3)\n\ + b 0(%r4,%r3)\n\ +1: .long __tls_get_addr - 0b\n\ +"); +# 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 ()) + +/* 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) \ + ({ __tls_get_addr_internal (__ti) \ + + (unsigned long) __builtin_thread_pointer (); }) + +#endif |