105 lines
3.7 KiB
C
105 lines
3.7 KiB
C
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/* Thread-local storage handling in the ELF dynamic linker. s390 version.
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Copyright (C) 2003-2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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/* Type used for the representation of TLS information in the GOT. */
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typedef struct
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{
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unsigned long int ti_module;
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unsigned long int ti_offset;
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} tls_index;
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#ifdef SHARED
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extern unsigned long __tls_get_offset (unsigned long got_offset);
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# if IS_IN (rtld)
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# include <shlib-compat.h>
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/* dl-tls.c declares __tls_get_addr as an exported symbol if it is not defined
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as a macro. It seems suitable to do that in the generic code because all
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architectures other than s390 export __tls_get_addr. The declaration causes
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problems in s390 though, so we define __tls_get_addr here to avoid declaring
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__tls_get_addr again. */
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# define __tls_get_addr __tls_get_addr
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extern void *__tls_get_addr (tls_index *ti) attribute_hidden;
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/* Make a temporary alias of __tls_get_addr to remove the hidden
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attribute. Then export __tls_get_addr as __tls_get_addr_internal
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for use from libc. We do not want to export __tls_get_addr, but we
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do need to use it from libc when looking up the address of a TLS
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variable. We don't use __tls_get_offset because it requires r12 to
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be setup and that might not always be true. Either way it's more
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optimal to use __tls_get_addr directly (that's what
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__tls_get_offset does anyways). */
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strong_alias (__tls_get_addr, __tls_get_addr_internal_tmp);
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versioned_symbol (ld, __tls_get_addr_internal_tmp,
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__tls_get_addr_internal, GLIBC_PRIVATE);
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/* The special thing about the s390 TLS ABI is that we do not have the
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standard __tls_get_addr function but the __tls_get_offset function
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which differs in two important aspects:
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1) __tls_get_offset gets a got offset instead of a pointer to the
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tls_index structure
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2) __tls_get_offset returns the offset of the requested variable to
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the thread descriptor instead of a pointer to the variable.
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*/
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# ifdef __s390x__
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__asm__("\n\
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.text\n\
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.globl __tls_get_offset\n\
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.type __tls_get_offset, @function\n\
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.align 4\n\
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__tls_get_offset:\n\
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la %r2,0(%r2,%r12)\n\
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jg __tls_get_addr\n\
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");
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# elif defined __s390__
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__asm__("\n\
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.text\n\
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.globl __tls_get_offset\n\
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.type __tls_get_offset, @function\n\
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.align 4\n\
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__tls_get_offset:\n\
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basr %r3,0\n\
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0: la %r2,0(%r2,%r12)\n\
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l %r4,1f-0b(%r3)\n\
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b 0(%r4,%r3)\n\
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1: .long __tls_get_addr - 0b\n\
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");
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# endif
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# else /* IS_IN (rtld) */
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extern void *__tls_get_addr_internal (tls_index *ti);
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# endif /* !IS_IN (rtld) */
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# define GET_ADDR_OFFSET \
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(ti->ti_offset - (unsigned long) __builtin_thread_pointer ())
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/* Use the privately exported __tls_get_addr_internal instead of
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__tls_get_offset in order to avoid the __tls_get_offset special
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linkage requiring the GOT pointer to be set up in r12. The
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compiler will take care of setting up r12 only if itself issued the
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__tls_get_offset call. */
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# define __TLS_GET_ADDR(__ti) \
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({ __tls_get_addr_internal (__ti) \
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+ (unsigned long) __builtin_thread_pointer (); })
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#endif
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