| /* Thread-local storage handling in the ELF dynamic linker. s390 version. |
| Copyright (C) 2003-2018 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 |