diff options
Diffstat (limited to 'sysdeps/hppa/crti.S')
| -rw-r--r-- | sysdeps/hppa/crti.S | 101 |
1 files changed, 92 insertions, 9 deletions
diff --git a/sysdeps/hppa/crti.S b/sysdeps/hppa/crti.S index 6e2bc7d2ba..28550e5758 100644 --- a/sysdeps/hppa/crti.S +++ b/sysdeps/hppa/crti.S @@ -1,5 +1,5 @@ /* Special .init and .fini section support for HPPA - Copyright (C) 2000-2016 Free Software Foundation, Inc. + Copyright (C) 2000-2018 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 @@ -49,28 +49,111 @@ # 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) -#if PREINIT_FUNCTION_WEAK - bl PREINIT_FUNCTION,%rp - copy %r19,%r4 /* delay slot */ -#else - bl PREINIT_FUNCTION,%rp - copy %r19,%r4 /* delay slot */ -#endif - copy %r4,%r19 /* _fini prologue. */ .section .fini,"ax",%progbits .align 4 .globl _fini + .hidden _fini .type _fini,@function _fini: stw %rp,-20(%sp) |