/* Special .init and .fini section support for HPPA Copyright (C) 2000-2021 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. In addition to the permissions in the GNU Lesser General Public License, the Free Software Foundation gives you unlimited permission to link the compiled version of this file with other programs, and to distribute those programs without any restriction coming from the use of this file. (The GNU Lesser General Public License restrictions do apply in other respects; for example, they cover modification of the file, and distribution when not linked into another program.) Note that people who make modified versions of this file are not obligated to grant this special exception for their modified versions; it is their choice whether to do so. The GNU Lesser General Public License gives permission to release a modified version without this exception; this exception also makes it possible to release a modified version which carries forward this exception. 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 <https://www.gnu.org/licenses/>. */ /* crti.S puts a function prologue at the beginning of the .init and .fini sections and defines global symbols for those addresses, so they can be called as functions. The symbols _init and _fini are magic and cause the linker to emit DT_INIT and DT_FINI. */ #include <libc-symbols.h> #include <sysdep.h> #ifndef PREINIT_FUNCTION # define PREINIT_FUNCTION __gmon_start__ #endif #ifndef PREINIT_FUNCTION_WEAK # define PREINIT_FUNCTION_WEAK 1 #endif #if PREINIT_FUNCTION_WEAK weak_extern (PREINIT_FUNCTION) #else .hidden PREINIT_FUNCTION #endif /* If we have working .init_array support, we want to keep the .init section empty (apart from the mandatory prologue/epilogue. This ensures that the default unwind conventions (return-pointer in b0, frame state in ar.pfs, etc.) will do the Right Thing. To ensure an empty .init section, we register gmon_initializer() via the .init_array. --davidm 02/10/29 */ #if PREINIT_FUNCTION_WEAK /* This blob of assembly code is one simple C function: static void __attribute__ ((used)) gmon_initializer (void) { extern void weak_function __gmon_start__ (void); if (__gmon_start__) (*__gmon_start__)(); } In a final executable, PLABEL32 relocations for function pointers are resolved at link time. Typically, binutils/ld resolves __gmon_start__ using an external shared library. __gmon_start__ is always called if it is found at link time. If __gmon_start__ is not found at runtime due to a library update, then the function pointer will point at a null function descriptor and calling it will cause a segmentation fault. So, we call __canonicalize_funcptr_for_compare to obtain the canonicalized address of __gmon_start__ and skip calling __gmon_start__ if it is zero. */ .type __canonicalize_funcptr_for_compare,@function .type $$dyncall,@function .section .data.rel.ro,"aw",@progbits .align 4 .LC0: .type __gmon_start__,@function .word P%__gmon_start__ .text .align 4 .type gmon_initializer,@function gmon_initializer: .PROC .CALLINFO FRAME=64,CALLS,SAVE_RP,ENTRY_GR=4 .ENTRY stw %r2,-20(%r30) stwm %r4,64(%r30) stw %r3,-60(%r30) addil LT'.LC0,%r19 ldw RT'.LC0(%r1),%r28 ldw 0(%r28),%r3 comib,= 0,%r3,1f copy %r19,%r4 stw %r19,-32(%r30) bl __canonicalize_funcptr_for_compare,%r2 copy %r3,%r26 comib,= 0,%r28,1f copy %r4,%r19 copy %r3,%r22 .CALL ARGW0=GR bl $$dyncall,%r31 copy %r31,%r2 1: ldw -84(%r30),%r2 ldw -60(%r30),%r3 bv %r0(%r2) ldwm -64(%r30),%r4 .EXIT .PROCEND .size gmon_initializer, .-gmon_initializer # undef PREINIT_FUNCTION # define PREINIT_FUNCTION gmon_initializer #endif .section .init_array, "aw" .word P% PREINIT_FUNCTION /* _init prologue. */ .section .init, "ax", %progbits .align 4 .globl _init .hidden _init .type _init,@function _init: stw %rp,-20(%sp) stwm %r4,64(%sp) stw %r19,-32(%sp) /* _fini prologue. */ .section .fini,"ax",%progbits .align 4 .globl _fini .hidden _fini .type _fini,@function _fini: stw %rp,-20(%sp) stwm %r4,64(%sp) stw %r19,-32(%sp) copy %r19,%r4