163 lines
4.7 KiB
ArmAsm
163 lines
4.7 KiB
ArmAsm
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/* Special .init and .fini section support for HPPA
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Copyright (C) 2000-2022 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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In addition to the permissions in the GNU Lesser General Public
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License, the Free Software Foundation gives you unlimited
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permission to link the compiled version of this file with other
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programs, and to distribute those programs without any restriction
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coming from the use of this file. (The GNU Lesser General Public
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License restrictions do apply in other respects; for example, they
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cover modification of the file, and distribution when not linked
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into another program.)
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Note that people who make modified versions of this file are not
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obligated to grant this special exception for their modified
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versions; it is their choice whether to do so. The GNU Lesser
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General Public License gives permission to release a modified
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version without this exception; this exception also makes it
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possible to release a modified version which carries forward this
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exception.
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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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/* crti.S puts a function prologue at the beginning of the .init and
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.fini sections and defines global symbols for those addresses, so
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they can be called as functions. The symbols _init and _fini are
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magic and cause the linker to emit DT_INIT and DT_FINI. */
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#include <libc-symbols.h>
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#include <sysdep.h>
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#ifndef PREINIT_FUNCTION
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# define PREINIT_FUNCTION __gmon_start__
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#endif
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#ifndef PREINIT_FUNCTION_WEAK
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# define PREINIT_FUNCTION_WEAK 1
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#endif
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#if PREINIT_FUNCTION_WEAK
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weak_extern (PREINIT_FUNCTION)
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#else
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.hidden PREINIT_FUNCTION
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#endif
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/* If we have working .init_array support, we want to keep the .init
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section empty (apart from the mandatory prologue/epilogue. This
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ensures that the default unwind conventions (return-pointer in b0,
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frame state in ar.pfs, etc.) will do the Right Thing. To ensure
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an empty .init section, we register gmon_initializer() via the
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.init_array.
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--davidm 02/10/29 */
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#if PREINIT_FUNCTION_WEAK
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/* This blob of assembly code is one simple C function:
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static void
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__attribute__ ((used))
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gmon_initializer (void)
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{
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extern void weak_function __gmon_start__ (void);
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if (__gmon_start__)
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(*__gmon_start__)();
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}
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In a final executable, PLABEL32 relocations for function pointers are
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resolved at link time. Typically, binutils/ld resolves __gmon_start__
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using an external shared library. __gmon_start__ is always called if
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it is found at link time. If __gmon_start__ is not found at runtime
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due to a library update, then the function pointer will point at a null
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function descriptor and calling it will cause a segmentation fault.
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So, we call __canonicalize_funcptr_for_compare to obtain the canonicalized
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address of __gmon_start__ and skip calling __gmon_start__ if it is zero.
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*/
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.type __canonicalize_funcptr_for_compare,@function
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.type $$dyncall,@function
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.section .data.rel.ro,"aw",@progbits
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.align 4
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.LC0:
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.type __gmon_start__,@function
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.word P%__gmon_start__
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.text
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.align 4
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.type gmon_initializer,@function
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gmon_initializer:
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.PROC
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.CALLINFO FRAME=64,CALLS,SAVE_RP,ENTRY_GR=4
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.ENTRY
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stw %r2,-20(%r30)
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stwm %r4,64(%r30)
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stw %r3,-60(%r30)
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addil LT'.LC0,%r19
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ldw RT'.LC0(%r1),%r28
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ldw 0(%r28),%r3
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comib,= 0,%r3,1f
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copy %r19,%r4
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stw %r19,-32(%r30)
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bl __canonicalize_funcptr_for_compare,%r2
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copy %r3,%r26
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comib,= 0,%r28,1f
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copy %r4,%r19
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copy %r3,%r22
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.CALL ARGW0=GR
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bl $$dyncall,%r31
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copy %r31,%r2
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1:
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ldw -84(%r30),%r2
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ldw -60(%r30),%r3
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bv %r0(%r2)
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ldwm -64(%r30),%r4
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.EXIT
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.PROCEND
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.size gmon_initializer, .-gmon_initializer
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# undef PREINIT_FUNCTION
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# define PREINIT_FUNCTION gmon_initializer
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#endif
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.section .init_array, "aw"
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.word P% PREINIT_FUNCTION
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/* _init prologue. */
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.section .init, "ax", %progbits
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.align 4
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.globl _init
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.hidden _init
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.type _init,@function
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_init:
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stw %rp,-20(%sp)
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stwm %r4,64(%sp)
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stw %r19,-32(%sp)
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/* _fini prologue. */
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.section .fini,"ax",%progbits
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.align 4
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.globl _fini
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.hidden _fini
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.type _fini,@function
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_fini:
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stw %rp,-20(%sp)
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stwm %r4,64(%sp)
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stw %r19,-32(%sp)
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copy %r19,%r4
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