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697 lines
19 KiB
697 lines
19 KiB
/* SPDX-License-Identifier: GPL-2.0-only */ |
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/* |
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* recordmcount.h |
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* |
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* This code was taken out of recordmcount.c written by |
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* Copyright 2009 John F. Reiser <[email protected]>. All rights reserved. |
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* |
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* The original code had the same algorithms for both 32bit |
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* and 64bit ELF files, but the code was duplicated to support |
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* the difference in structures that were used. This |
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* file creates a macro of everything that is different between |
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* the 64 and 32 bit code, such that by including this header |
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* twice we can create both sets of functions by including this |
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* header once with RECORD_MCOUNT_64 undefined, and again with |
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* it defined. |
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* |
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* This conversion to macros was done by: |
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* Copyright 2010 Steven Rostedt <[email protected]>, Red Hat Inc. |
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*/ |
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#undef append_func |
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#undef is_fake_mcount |
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#undef fn_is_fake_mcount |
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#undef MIPS_is_fake_mcount |
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#undef mcount_adjust |
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#undef sift_rel_mcount |
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#undef nop_mcount |
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#undef find_secsym_ndx |
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#undef __has_rel_mcount |
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#undef has_rel_mcount |
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#undef tot_relsize |
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#undef get_mcountsym |
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#undef find_symtab |
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#undef get_shnum |
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#undef set_shnum |
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#undef get_shstrndx |
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#undef get_symindex |
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#undef get_sym_str_and_relp |
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#undef do_func |
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#undef Elf_Addr |
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#undef Elf_Ehdr |
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#undef Elf_Shdr |
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#undef Elf_Rel |
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#undef Elf_Rela |
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#undef Elf_Sym |
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#undef ELF_R_SYM |
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#undef Elf_r_sym |
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#undef ELF_R_INFO |
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#undef Elf_r_info |
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#undef ELF_ST_BIND |
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#undef ELF_ST_TYPE |
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#undef fn_ELF_R_SYM |
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#undef fn_ELF_R_INFO |
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#undef uint_t |
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#undef _w |
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#undef _align |
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#undef _size |
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|
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#ifdef RECORD_MCOUNT_64 |
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# define append_func append64 |
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# define sift_rel_mcount sift64_rel_mcount |
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# define nop_mcount nop_mcount_64 |
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# define find_secsym_ndx find64_secsym_ndx |
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# define __has_rel_mcount __has64_rel_mcount |
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# define has_rel_mcount has64_rel_mcount |
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# define tot_relsize tot64_relsize |
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# define find_symtab find_symtab64 |
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# define get_shnum get_shnum64 |
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# define set_shnum set_shnum64 |
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# define get_shstrndx get_shstrndx64 |
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# define get_symindex get_symindex64 |
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# define get_sym_str_and_relp get_sym_str_and_relp_64 |
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# define do_func do64 |
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# define get_mcountsym get_mcountsym_64 |
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# define is_fake_mcount is_fake_mcount64 |
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# define fn_is_fake_mcount fn_is_fake_mcount64 |
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# define MIPS_is_fake_mcount MIPS64_is_fake_mcount |
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# define mcount_adjust mcount_adjust_64 |
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# define Elf_Addr Elf64_Addr |
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# define Elf_Ehdr Elf64_Ehdr |
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# define Elf_Shdr Elf64_Shdr |
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# define Elf_Rel Elf64_Rel |
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# define Elf_Rela Elf64_Rela |
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# define Elf_Sym Elf64_Sym |
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# define ELF_R_SYM ELF64_R_SYM |
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# define Elf_r_sym Elf64_r_sym |
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# define ELF_R_INFO ELF64_R_INFO |
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# define Elf_r_info Elf64_r_info |
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# define ELF_ST_BIND ELF64_ST_BIND |
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# define ELF_ST_TYPE ELF64_ST_TYPE |
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# define fn_ELF_R_SYM fn_ELF64_R_SYM |
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# define fn_ELF_R_INFO fn_ELF64_R_INFO |
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# define uint_t uint64_t |
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# define _w w8 |
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# define _align 7u |
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# define _size 8 |
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#else |
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# define append_func append32 |
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# define sift_rel_mcount sift32_rel_mcount |
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# define nop_mcount nop_mcount_32 |
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# define find_secsym_ndx find32_secsym_ndx |
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# define __has_rel_mcount __has32_rel_mcount |
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# define has_rel_mcount has32_rel_mcount |
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# define tot_relsize tot32_relsize |
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# define find_symtab find_symtab32 |
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# define get_shnum get_shnum32 |
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# define set_shnum set_shnum32 |
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# define get_shstrndx get_shstrndx32 |
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# define get_symindex get_symindex32 |
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# define get_sym_str_and_relp get_sym_str_and_relp_32 |
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# define do_func do32 |
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# define get_mcountsym get_mcountsym_32 |
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# define is_fake_mcount is_fake_mcount32 |
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# define fn_is_fake_mcount fn_is_fake_mcount32 |
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# define MIPS_is_fake_mcount MIPS32_is_fake_mcount |
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# define mcount_adjust mcount_adjust_32 |
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# define Elf_Addr Elf32_Addr |
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# define Elf_Ehdr Elf32_Ehdr |
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# define Elf_Shdr Elf32_Shdr |
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# define Elf_Rel Elf32_Rel |
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# define Elf_Rela Elf32_Rela |
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# define Elf_Sym Elf32_Sym |
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# define ELF_R_SYM ELF32_R_SYM |
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# define Elf_r_sym Elf32_r_sym |
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# define ELF_R_INFO ELF32_R_INFO |
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# define Elf_r_info Elf32_r_info |
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# define ELF_ST_BIND ELF32_ST_BIND |
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# define ELF_ST_TYPE ELF32_ST_TYPE |
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# define fn_ELF_R_SYM fn_ELF32_R_SYM |
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# define fn_ELF_R_INFO fn_ELF32_R_INFO |
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# define uint_t uint32_t |
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# define _w w |
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# define _align 3u |
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# define _size 4 |
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#endif |
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|
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/* Functions and pointers that do_file() may override for specific e_machine. */ |
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static int fn_is_fake_mcount(Elf_Rel const *rp) |
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{ |
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return 0; |
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} |
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static int (*is_fake_mcount)(Elf_Rel const *rp) = fn_is_fake_mcount; |
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|
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static uint_t fn_ELF_R_SYM(Elf_Rel const *rp) |
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{ |
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return ELF_R_SYM(_w(rp->r_info)); |
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} |
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static uint_t (*Elf_r_sym)(Elf_Rel const *rp) = fn_ELF_R_SYM; |
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static void fn_ELF_R_INFO(Elf_Rel *const rp, unsigned sym, unsigned type) |
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{ |
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rp->r_info = _w(ELF_R_INFO(sym, type)); |
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} |
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static void (*Elf_r_info)(Elf_Rel *const rp, unsigned sym, unsigned type) = fn_ELF_R_INFO; |
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static int mcount_adjust = 0; |
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/* |
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* MIPS mcount long call has 2 _mcount symbols, only the position of the 1st |
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* _mcount symbol is needed for dynamic function tracer, with it, to disable |
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* tracing(ftrace_make_nop), the instruction in the position is replaced with |
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* the "b label" instruction, to enable tracing(ftrace_make_call), replace the |
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* instruction back. So, here, we set the 2nd one as fake and filter it. |
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* |
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* c: 3c030000 lui v1,0x0 <--> b label |
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* c: R_MIPS_HI16 _mcount |
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* c: R_MIPS_NONE *ABS* |
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* c: R_MIPS_NONE *ABS* |
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* 10: 64630000 daddiu v1,v1,0 |
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* 10: R_MIPS_LO16 _mcount |
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* 10: R_MIPS_NONE *ABS* |
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* 10: R_MIPS_NONE *ABS* |
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* 14: 03e0082d move at,ra |
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* 18: 0060f809 jalr v1 |
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* label: |
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*/ |
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#define MIPS_FAKEMCOUNT_OFFSET 4 |
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static int MIPS_is_fake_mcount(Elf_Rel const *rp) |
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{ |
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static Elf_Addr old_r_offset = ~(Elf_Addr)0; |
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Elf_Addr current_r_offset = _w(rp->r_offset); |
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int is_fake; |
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is_fake = (old_r_offset != ~(Elf_Addr)0) && |
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(current_r_offset - old_r_offset == MIPS_FAKEMCOUNT_OFFSET); |
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old_r_offset = current_r_offset; |
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return is_fake; |
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} |
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static unsigned int get_symindex(Elf_Sym const *sym, Elf32_Word const *symtab, |
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Elf32_Word const *symtab_shndx) |
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{ |
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unsigned long offset; |
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unsigned short shndx = w2(sym->st_shndx); |
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int index; |
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if (shndx > SHN_UNDEF && shndx < SHN_LORESERVE) |
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return shndx; |
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if (shndx == SHN_XINDEX) { |
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offset = (unsigned long)sym - (unsigned long)symtab; |
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index = offset / sizeof(*sym); |
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return w(symtab_shndx[index]); |
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} |
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return 0; |
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} |
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static unsigned int get_shnum(Elf_Ehdr const *ehdr, Elf_Shdr const *shdr0) |
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{ |
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if (shdr0 && !ehdr->e_shnum) |
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return w(shdr0->sh_size); |
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return w2(ehdr->e_shnum); |
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} |
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static void set_shnum(Elf_Ehdr *ehdr, Elf_Shdr *shdr0, unsigned int new_shnum) |
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{ |
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if (new_shnum >= SHN_LORESERVE) { |
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ehdr->e_shnum = 0; |
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shdr0->sh_size = w(new_shnum); |
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} else |
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ehdr->e_shnum = w2(new_shnum); |
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} |
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static int get_shstrndx(Elf_Ehdr const *ehdr, Elf_Shdr const *shdr0) |
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{ |
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if (ehdr->e_shstrndx != SHN_XINDEX) |
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return w2(ehdr->e_shstrndx); |
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return w(shdr0->sh_link); |
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} |
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static void find_symtab(Elf_Ehdr *const ehdr, Elf_Shdr const *shdr0, |
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unsigned const nhdr, Elf32_Word **symtab, |
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Elf32_Word **symtab_shndx) |
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{ |
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Elf_Shdr const *relhdr; |
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unsigned k; |
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*symtab = NULL; |
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*symtab_shndx = NULL; |
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for (relhdr = shdr0, k = nhdr; k; --k, ++relhdr) { |
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if (relhdr->sh_type == SHT_SYMTAB) |
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*symtab = (void *)ehdr + relhdr->sh_offset; |
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else if (relhdr->sh_type == SHT_SYMTAB_SHNDX) |
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*symtab_shndx = (void *)ehdr + relhdr->sh_offset; |
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if (*symtab && *symtab_shndx) |
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break; |
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} |
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} |
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/* Append the new shstrtab, Elf_Shdr[], __mcount_loc and its relocations. */ |
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static int append_func(Elf_Ehdr *const ehdr, |
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Elf_Shdr *const shstr, |
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uint_t const *const mloc0, |
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uint_t const *const mlocp, |
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Elf_Rel const *const mrel0, |
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Elf_Rel const *const mrelp, |
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unsigned int const rel_entsize, |
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unsigned int const symsec_sh_link) |
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{ |
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/* Begin constructing output file */ |
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Elf_Shdr mcsec; |
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char const *mc_name = (sizeof(Elf_Rela) == rel_entsize) |
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? ".rela__mcount_loc" |
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: ".rel__mcount_loc"; |
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uint_t const old_shoff = _w(ehdr->e_shoff); |
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uint_t const old_shstr_sh_size = _w(shstr->sh_size); |
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uint_t const old_shstr_sh_offset = _w(shstr->sh_offset); |
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Elf_Shdr *const shdr0 = (Elf_Shdr *)(old_shoff + (void *)ehdr); |
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unsigned int const old_shnum = get_shnum(ehdr, shdr0); |
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unsigned int const new_shnum = 2 + old_shnum; /* {.rel,}__mcount_loc */ |
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uint_t t = 1 + strlen(mc_name) + _w(shstr->sh_size); |
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uint_t new_e_shoff; |
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shstr->sh_size = _w(t); |
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shstr->sh_offset = _w(sb.st_size); |
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t += sb.st_size; |
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t += (_align & -t); /* word-byte align */ |
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new_e_shoff = t; |
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set_shnum(ehdr, shdr0, new_shnum); |
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/* body for new shstrtab */ |
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if (ulseek(sb.st_size, SEEK_SET) < 0) |
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return -1; |
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if (uwrite(old_shstr_sh_offset + (void *)ehdr, old_shstr_sh_size) < 0) |
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return -1; |
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if (uwrite(mc_name, 1 + strlen(mc_name)) < 0) |
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return -1; |
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/* old(modified) Elf_Shdr table, word-byte aligned */ |
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if (ulseek(t, SEEK_SET) < 0) |
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return -1; |
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t += sizeof(Elf_Shdr) * old_shnum; |
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if (uwrite(old_shoff + (void *)ehdr, |
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sizeof(Elf_Shdr) * old_shnum) < 0) |
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return -1; |
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/* new sections __mcount_loc and .rel__mcount_loc */ |
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t += 2*sizeof(mcsec); |
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mcsec.sh_name = w((sizeof(Elf_Rela) == rel_entsize) + strlen(".rel") |
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+ old_shstr_sh_size); |
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mcsec.sh_type = w(SHT_PROGBITS); |
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mcsec.sh_flags = _w(SHF_ALLOC); |
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mcsec.sh_addr = 0; |
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mcsec.sh_offset = _w(t); |
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mcsec.sh_size = _w((void *)mlocp - (void *)mloc0); |
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mcsec.sh_link = 0; |
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mcsec.sh_info = 0; |
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mcsec.sh_addralign = _w(_size); |
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mcsec.sh_entsize = _w(_size); |
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if (uwrite(&mcsec, sizeof(mcsec)) < 0) |
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return -1; |
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mcsec.sh_name = w(old_shstr_sh_size); |
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mcsec.sh_type = (sizeof(Elf_Rela) == rel_entsize) |
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? w(SHT_RELA) |
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: w(SHT_REL); |
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mcsec.sh_flags = 0; |
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mcsec.sh_addr = 0; |
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mcsec.sh_offset = _w((void *)mlocp - (void *)mloc0 + t); |
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mcsec.sh_size = _w((void *)mrelp - (void *)mrel0); |
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mcsec.sh_link = w(symsec_sh_link); |
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mcsec.sh_info = w(old_shnum); |
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mcsec.sh_addralign = _w(_size); |
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mcsec.sh_entsize = _w(rel_entsize); |
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if (uwrite(&mcsec, sizeof(mcsec)) < 0) |
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return -1; |
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if (uwrite(mloc0, (void *)mlocp - (void *)mloc0) < 0) |
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return -1; |
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if (uwrite(mrel0, (void *)mrelp - (void *)mrel0) < 0) |
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return -1; |
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ehdr->e_shoff = _w(new_e_shoff); |
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if (ulseek(0, SEEK_SET) < 0) |
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return -1; |
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if (uwrite(ehdr, sizeof(*ehdr)) < 0) |
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return -1; |
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return 0; |
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} |
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static unsigned get_mcountsym(Elf_Sym const *const sym0, |
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Elf_Rel const *relp, |
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char const *const str0) |
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{ |
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unsigned mcountsym = 0; |
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Elf_Sym const *const symp = |
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&sym0[Elf_r_sym(relp)]; |
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char const *symname = &str0[w(symp->st_name)]; |
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char const *mcount = gpfx == '_' ? "_mcount" : "mcount"; |
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char const *fentry = "__fentry__"; |
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if (symname[0] == '.') |
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++symname; /* ppc64 hack */ |
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if (strcmp(mcount, symname) == 0 || |
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(altmcount && strcmp(altmcount, symname) == 0) || |
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(strcmp(fentry, symname) == 0)) |
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mcountsym = Elf_r_sym(relp); |
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return mcountsym; |
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} |
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static void get_sym_str_and_relp(Elf_Shdr const *const relhdr, |
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Elf_Ehdr const *const ehdr, |
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Elf_Sym const **sym0, |
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char const **str0, |
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Elf_Rel const **relp) |
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{ |
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Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff) |
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+ (void *)ehdr); |
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unsigned const symsec_sh_link = w(relhdr->sh_link); |
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Elf_Shdr const *const symsec = &shdr0[symsec_sh_link]; |
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Elf_Shdr const *const strsec = &shdr0[w(symsec->sh_link)]; |
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Elf_Rel const *const rel0 = (Elf_Rel const *)(_w(relhdr->sh_offset) |
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+ (void *)ehdr); |
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*sym0 = (Elf_Sym const *)(_w(symsec->sh_offset) |
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+ (void *)ehdr); |
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*str0 = (char const *)(_w(strsec->sh_offset) |
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+ (void *)ehdr); |
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*relp = rel0; |
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} |
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/* |
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* Look at the relocations in order to find the calls to mcount. |
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* Accumulate the section offsets that are found, and their relocation info, |
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* onto the end of the existing arrays. |
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*/ |
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static uint_t *sift_rel_mcount(uint_t *mlocp, |
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unsigned const offbase, |
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Elf_Rel **const mrelpp, |
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Elf_Shdr const *const relhdr, |
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Elf_Ehdr const *const ehdr, |
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unsigned const recsym, |
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uint_t const recval, |
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unsigned const reltype) |
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{ |
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uint_t *const mloc0 = mlocp; |
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Elf_Rel *mrelp = *mrelpp; |
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Elf_Sym const *sym0; |
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char const *str0; |
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Elf_Rel const *relp; |
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unsigned rel_entsize = _w(relhdr->sh_entsize); |
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unsigned const nrel = _w(relhdr->sh_size) / rel_entsize; |
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unsigned mcountsym = 0; |
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unsigned t; |
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get_sym_str_and_relp(relhdr, ehdr, &sym0, &str0, &relp); |
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for (t = nrel; t; --t) { |
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if (!mcountsym) |
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mcountsym = get_mcountsym(sym0, relp, str0); |
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if (mcountsym && mcountsym == Elf_r_sym(relp) && |
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!is_fake_mcount(relp)) { |
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uint_t const addend = |
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_w(_w(relp->r_offset) - recval + mcount_adjust); |
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mrelp->r_offset = _w(offbase |
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+ ((void *)mlocp - (void *)mloc0)); |
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Elf_r_info(mrelp, recsym, reltype); |
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if (rel_entsize == sizeof(Elf_Rela)) { |
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((Elf_Rela *)mrelp)->r_addend = addend; |
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*mlocp++ = 0; |
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} else |
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*mlocp++ = addend; |
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mrelp = (Elf_Rel *)(rel_entsize + (void *)mrelp); |
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} |
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relp = (Elf_Rel const *)(rel_entsize + (void *)relp); |
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} |
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*mrelpp = mrelp; |
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return mlocp; |
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} |
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/* |
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* Read the relocation table again, but this time its called on sections |
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* that are not going to be traced. The mcount calls here will be converted |
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* into nops. |
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*/ |
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static int nop_mcount(Elf_Shdr const *const relhdr, |
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Elf_Ehdr const *const ehdr, |
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const char *const txtname) |
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{ |
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Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff) |
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+ (void *)ehdr); |
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Elf_Sym const *sym0; |
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char const *str0; |
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Elf_Rel const *relp; |
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Elf_Shdr const *const shdr = &shdr0[w(relhdr->sh_info)]; |
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unsigned rel_entsize = _w(relhdr->sh_entsize); |
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unsigned const nrel = _w(relhdr->sh_size) / rel_entsize; |
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unsigned mcountsym = 0; |
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unsigned t; |
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int once = 0; |
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get_sym_str_and_relp(relhdr, ehdr, &sym0, &str0, &relp); |
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for (t = nrel; t; --t) { |
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int ret = -1; |
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if (!mcountsym) |
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mcountsym = get_mcountsym(sym0, relp, str0); |
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if (mcountsym == Elf_r_sym(relp) && !is_fake_mcount(relp)) { |
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if (make_nop) |
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ret = make_nop((void *)ehdr, _w(shdr->sh_offset) + _w(relp->r_offset)); |
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if (warn_on_notrace_sect && !once) { |
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printf("Section %s has mcount callers being ignored\n", |
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txtname); |
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once = 1; |
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/* just warn? */ |
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if (!make_nop) |
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return 0; |
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} |
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} |
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|
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/* |
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* If we successfully removed the mcount, mark the relocation |
|
* as a nop (don't do anything with it). |
|
*/ |
|
if (!ret) { |
|
Elf_Rel rel; |
|
rel = *(Elf_Rel *)relp; |
|
Elf_r_info(&rel, Elf_r_sym(relp), rel_type_nop); |
|
if (ulseek((void *)relp - (void *)ehdr, SEEK_SET) < 0) |
|
return -1; |
|
if (uwrite(&rel, sizeof(rel)) < 0) |
|
return -1; |
|
} |
|
relp = (Elf_Rel const *)(rel_entsize + (void *)relp); |
|
} |
|
return 0; |
|
} |
|
|
|
/* |
|
* Find a symbol in the given section, to be used as the base for relocating |
|
* the table of offsets of calls to mcount. A local or global symbol suffices, |
|
* but avoid a Weak symbol because it may be overridden; the change in value |
|
* would invalidate the relocations of the offsets of the calls to mcount. |
|
* Often the found symbol will be the unnamed local symbol generated by |
|
* GNU 'as' for the start of each section. For example: |
|
* Num: Value Size Type Bind Vis Ndx Name |
|
* 2: 00000000 0 SECTION LOCAL DEFAULT 1 |
|
*/ |
|
static int find_secsym_ndx(unsigned const txtndx, |
|
char const *const txtname, |
|
uint_t *const recvalp, |
|
unsigned int *sym_index, |
|
Elf_Shdr const *const symhdr, |
|
Elf32_Word const *symtab, |
|
Elf32_Word const *symtab_shndx, |
|
Elf_Ehdr const *const ehdr) |
|
{ |
|
Elf_Sym const *const sym0 = (Elf_Sym const *)(_w(symhdr->sh_offset) |
|
+ (void *)ehdr); |
|
unsigned const nsym = _w(symhdr->sh_size) / _w(symhdr->sh_entsize); |
|
Elf_Sym const *symp; |
|
unsigned t; |
|
|
|
for (symp = sym0, t = nsym; t; --t, ++symp) { |
|
unsigned int const st_bind = ELF_ST_BIND(symp->st_info); |
|
|
|
if (txtndx == get_symindex(symp, symtab, symtab_shndx) |
|
/* avoid STB_WEAK */ |
|
&& (STB_LOCAL == st_bind || STB_GLOBAL == st_bind)) { |
|
/* function symbols on ARM have quirks, avoid them */ |
|
if (w2(ehdr->e_machine) == EM_ARM |
|
&& ELF_ST_TYPE(symp->st_info) == STT_FUNC) |
|
continue; |
|
|
|
*recvalp = _w(symp->st_value); |
|
*sym_index = symp - sym0; |
|
return 0; |
|
} |
|
} |
|
fprintf(stderr, "Cannot find symbol for section %u: %s.\n", |
|
txtndx, txtname); |
|
return -1; |
|
} |
|
|
|
/* Evade ISO C restriction: no declaration after statement in has_rel_mcount. */ |
|
static char const * __has_rel_mcount(Elf_Shdr const *const relhdr, /* reltype */ |
|
Elf_Shdr const *const shdr0, |
|
char const *const shstrtab, |
|
char const *const fname) |
|
{ |
|
/* .sh_info depends on .sh_type == SHT_REL[,A] */ |
|
Elf_Shdr const *const txthdr = &shdr0[w(relhdr->sh_info)]; |
|
char const *const txtname = &shstrtab[w(txthdr->sh_name)]; |
|
|
|
if (strcmp("__mcount_loc", txtname) == 0) { |
|
fprintf(stderr, "warning: __mcount_loc already exists: %s\n", |
|
fname); |
|
return already_has_rel_mcount; |
|
} |
|
if (w(txthdr->sh_type) != SHT_PROGBITS || |
|
!(_w(txthdr->sh_flags) & SHF_EXECINSTR)) |
|
return NULL; |
|
return txtname; |
|
} |
|
|
|
static char const *has_rel_mcount(Elf_Shdr const *const relhdr, |
|
Elf_Shdr const *const shdr0, |
|
char const *const shstrtab, |
|
char const *const fname) |
|
{ |
|
if (w(relhdr->sh_type) != SHT_REL && w(relhdr->sh_type) != SHT_RELA) |
|
return NULL; |
|
return __has_rel_mcount(relhdr, shdr0, shstrtab, fname); |
|
} |
|
|
|
|
|
static unsigned tot_relsize(Elf_Shdr const *const shdr0, |
|
unsigned nhdr, |
|
const char *const shstrtab, |
|
const char *const fname) |
|
{ |
|
unsigned totrelsz = 0; |
|
Elf_Shdr const *shdrp = shdr0; |
|
char const *txtname; |
|
|
|
for (; nhdr; --nhdr, ++shdrp) { |
|
txtname = has_rel_mcount(shdrp, shdr0, shstrtab, fname); |
|
if (txtname == already_has_rel_mcount) { |
|
totrelsz = 0; |
|
break; |
|
} |
|
if (txtname && is_mcounted_section_name(txtname)) |
|
totrelsz += _w(shdrp->sh_size); |
|
} |
|
return totrelsz; |
|
} |
|
|
|
/* Overall supervision for Elf32 ET_REL file. */ |
|
static int do_func(Elf_Ehdr *const ehdr, char const *const fname, |
|
unsigned const reltype) |
|
{ |
|
Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff) |
|
+ (void *)ehdr); |
|
unsigned const nhdr = get_shnum(ehdr, shdr0); |
|
Elf_Shdr *const shstr = &shdr0[get_shstrndx(ehdr, shdr0)]; |
|
char const *const shstrtab = (char const *)(_w(shstr->sh_offset) |
|
+ (void *)ehdr); |
|
|
|
Elf_Shdr const *relhdr; |
|
unsigned k; |
|
|
|
Elf32_Word *symtab; |
|
Elf32_Word *symtab_shndx; |
|
|
|
/* Upper bound on space: assume all relevant relocs are for mcount. */ |
|
unsigned totrelsz; |
|
|
|
Elf_Rel * mrel0; |
|
Elf_Rel * mrelp; |
|
|
|
uint_t * mloc0; |
|
uint_t * mlocp; |
|
|
|
unsigned rel_entsize = 0; |
|
unsigned symsec_sh_link = 0; |
|
|
|
int result = 0; |
|
|
|
totrelsz = tot_relsize(shdr0, nhdr, shstrtab, fname); |
|
if (totrelsz == 0) |
|
return 0; |
|
mrel0 = umalloc(totrelsz); |
|
mrelp = mrel0; |
|
if (!mrel0) |
|
return -1; |
|
|
|
/* 2*sizeof(address) <= sizeof(Elf_Rel) */ |
|
mloc0 = umalloc(totrelsz>>1); |
|
mlocp = mloc0; |
|
if (!mloc0) { |
|
free(mrel0); |
|
return -1; |
|
} |
|
|
|
find_symtab(ehdr, shdr0, nhdr, &symtab, &symtab_shndx); |
|
|
|
for (relhdr = shdr0, k = nhdr; k; --k, ++relhdr) { |
|
char const *const txtname = has_rel_mcount(relhdr, shdr0, |
|
shstrtab, fname); |
|
if (txtname == already_has_rel_mcount) { |
|
result = 0; |
|
file_updated = 0; |
|
goto out; /* Nothing to be done; don't append! */ |
|
} |
|
if (txtname && is_mcounted_section_name(txtname)) { |
|
unsigned int recsym; |
|
uint_t recval = 0; |
|
|
|
symsec_sh_link = w(relhdr->sh_link); |
|
result = find_secsym_ndx(w(relhdr->sh_info), txtname, |
|
&recval, &recsym, |
|
&shdr0[symsec_sh_link], |
|
symtab, symtab_shndx, |
|
ehdr); |
|
if (result) |
|
goto out; |
|
|
|
rel_entsize = _w(relhdr->sh_entsize); |
|
mlocp = sift_rel_mcount(mlocp, |
|
(void *)mlocp - (void *)mloc0, &mrelp, |
|
relhdr, ehdr, recsym, recval, reltype); |
|
} else if (txtname && (warn_on_notrace_sect || make_nop)) { |
|
/* |
|
* This section is ignored by ftrace, but still |
|
* has mcount calls. Convert them to nops now. |
|
*/ |
|
if (nop_mcount(relhdr, ehdr, txtname) < 0) { |
|
result = -1; |
|
goto out; |
|
} |
|
} |
|
} |
|
if (!result && mloc0 != mlocp) |
|
result = append_func(ehdr, shstr, mloc0, mlocp, mrel0, mrelp, |
|
rel_entsize, symsec_sh_link); |
|
out: |
|
free(mrel0); |
|
free(mloc0); |
|
return result; |
|
}
|
|
|