/* * recordmcount.h * * This code was taken out of recordmcount.c written by * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>.  All rights reserved. * * The original code had the same algorithms for both 32bit * and 64bit ELF files, but the code was duplicated to support * the difference in structures that were used. This * file creates a macro of everything that is different between * the 64 and 32 bit code, such that by including this header * twice we can create both sets of functions by including this * header once with RECORD_MCOUNT_64 undefined, and again with * it defined. * * This conversion to macros was done by: * Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc. * * Licensed under the GNU General Public License, version 2 (GPLv2). */#undef append_func#undef is_fake_mcount#undef fn_is_fake_mcount#undef MIPS_is_fake_mcount#undef mcount_adjust#undef sift_rel_mcount#undef nop_mcount#undef find_secsym_ndx#undef __has_rel_mcount#undef has_rel_mcount#undef tot_relsize#undef get_mcountsym#undef get_sym_str_and_relp#undef do_func#undef Elf_Addr#undef Elf_Ehdr#undef Elf_Shdr#undef Elf_Rel#undef Elf_Rela#undef Elf_Sym#undef ELF_R_SYM#undef Elf_r_sym#undef ELF_R_INFO#undef Elf_r_info#undef ELF_ST_BIND#undef ELF_ST_TYPE#undef fn_ELF_R_SYM#undef fn_ELF_R_INFO#undef uint_t#undef _w#undef _align#undef _size #ifdef RECORD_MCOUNT_64# define append_func		append64# define sift_rel_mcount	sift64_rel_mcount# define nop_mcount		nop_mcount_64# define find_secsym_ndx	find64_secsym_ndx# define __has_rel_mcount	__has64_rel_mcount# define has_rel_mcount		has64_rel_mcount# define tot_relsize		tot64_relsize# define get_sym_str_and_relp	get_sym_str_and_relp_64# define do_func		do64# define get_mcountsym		get_mcountsym_64# define is_fake_mcount		is_fake_mcount64# define fn_is_fake_mcount	fn_is_fake_mcount64# define MIPS_is_fake_mcount	MIPS64_is_fake_mcount# define mcount_adjust		mcount_adjust_64# define Elf_Addr		Elf64_Addr# define Elf_Ehdr		Elf64_Ehdr# define Elf_Shdr		Elf64_Shdr# define Elf_Rel		Elf64_Rel# define Elf_Rela		Elf64_Rela# define Elf_Sym		Elf64_Sym# define ELF_R_SYM		ELF64_R_SYM# define Elf_r_sym		Elf64_r_sym# define ELF_R_INFO		ELF64_R_INFO# define Elf_r_info		Elf64_r_info# define ELF_ST_BIND		ELF64_ST_BIND# define ELF_ST_TYPE		ELF64_ST_TYPE# define fn_ELF_R_SYM		fn_ELF64_R_SYM# define fn_ELF_R_INFO		fn_ELF64_R_INFO# define uint_t			uint64_t# define _w			w8# define _align			7u# define _size			8#else# define append_func		append32# define sift_rel_mcount	sift32_rel_mcount# define nop_mcount		nop_mcount_32# define find_secsym_ndx	find32_secsym_ndx# define __has_rel_mcount	__has32_rel_mcount# define has_rel_mcount		has32_rel_mcount# define tot_relsize		tot32_relsize# define get_sym_str_and_relp	get_sym_str_and_relp_32# define do_func		do32# define get_mcountsym		get_mcountsym_32# define is_fake_mcount		is_fake_mcount32# define fn_is_fake_mcount	fn_is_fake_mcount32# define MIPS_is_fake_mcount	MIPS32_is_fake_mcount# define mcount_adjust		mcount_adjust_32# define Elf_Addr		Elf32_Addr# define Elf_Ehdr		Elf32_Ehdr# define Elf_Shdr		Elf32_Shdr# define Elf_Rel		Elf32_Rel# define Elf_Rela		Elf32_Rela# define Elf_Sym		Elf32_Sym# define ELF_R_SYM		ELF32_R_SYM# define Elf_r_sym		Elf32_r_sym# define ELF_R_INFO		ELF32_R_INFO# define Elf_r_info		Elf32_r_info# define ELF_ST_BIND		ELF32_ST_BIND# define ELF_ST_TYPE		ELF32_ST_TYPE# define fn_ELF_R_SYM		fn_ELF32_R_SYM# define fn_ELF_R_INFO		fn_ELF32_R_INFO# define uint_t			uint32_t# define _w			w# define _align			3u# define _size			4#endif /* Functions and pointers that do_file() may override for specific e_machine. */static int fn_is_fake_mcount(Elf_Rel const *rp){	return 0;}static int (*is_fake_mcount)(Elf_Rel const *rp) = fn_is_fake_mcount; static uint_t fn_ELF_R_SYM(Elf_Rel const *rp){	return ELF_R_SYM(_w(rp->r_info));}static uint_t (*Elf_r_sym)(Elf_Rel const *rp) = fn_ELF_R_SYM; static void fn_ELF_R_INFO(Elf_Rel *const rp, unsigned sym, unsigned type){	rp->r_info = _w(ELF_R_INFO(sym, type));}static void (*Elf_r_info)(Elf_Rel *const rp, unsigned sym, unsigned type) = fn_ELF_R_INFO; static int mcount_adjust = 0; /* * MIPS mcount long call has 2 _mcount symbols, only the position of the 1st * _mcount symbol is needed for dynamic function tracer, with it, to disable * tracing(ftrace_make_nop), the instruction in the position is replaced with * the "b label" instruction, to enable tracing(ftrace_make_call), replace the * instruction back. So, here, we set the 2nd one as fake and filter it. * * c:	3c030000	lui	v1,0x0		<-->	b	label *		c: R_MIPS_HI16	_mcount *		c: R_MIPS_NONE	*ABS* *		c: R_MIPS_NONE	*ABS* * 10:	64630000	daddiu	v1,v1,0 *		10: R_MIPS_LO16	_mcount *		10: R_MIPS_NONE	*ABS* *		10: R_MIPS_NONE	*ABS* * 14:	03e0082d	move	at,ra * 18:	0060f809	jalr	v1 * label: */#define MIPS_FAKEMCOUNT_OFFSET	4 static int MIPS_is_fake_mcount(Elf_Rel const *rp){	static Elf_Addr old_r_offset;	Elf_Addr current_r_offset = _w(rp->r_offset);	int is_fake; 	is_fake = old_r_offset &&		(current_r_offset - old_r_offset == MIPS_FAKEMCOUNT_OFFSET);	old_r_offset = current_r_offset; 	return is_fake;} /* Append the new shstrtab, Elf_Shdr[], __mcount_loc and its relocations. */static void append_func(Elf_Ehdr *const ehdr,			Elf_Shdr *const shstr,			uint_t const *const mloc0,			uint_t const *const mlocp,			Elf_Rel const *const mrel0,			Elf_Rel const *const mrelp,			unsigned int const rel_entsize,			unsigned int const symsec_sh_link){	/* Begin constructing output file */	Elf_Shdr mcsec;	char const *mc_name = (sizeof(Elf_Rela) == rel_entsize)		? ".rela__mcount_loc"		:  ".rel__mcount_loc";	unsigned const old_shnum = w2(ehdr->e_shnum);	uint_t const old_shoff = _w(ehdr->e_shoff);	uint_t const old_shstr_sh_size   = _w(shstr->sh_size);	uint_t const old_shstr_sh_offset = _w(shstr->sh_offset);	uint_t t = 1 + strlen(mc_name) + _w(shstr->sh_size);	uint_t new_e_shoff; 	shstr->sh_size = _w(t);	shstr->sh_offset = _w(sb.st_size);	t += sb.st_size;	t += (_align & -t);  /* word-byte align */	new_e_shoff = t; 	/* body for new shstrtab */	ulseek(fd_map, sb.st_size, SEEK_SET);	uwrite(fd_map, old_shstr_sh_offset + (void *)ehdr, old_shstr_sh_size);	uwrite(fd_map, mc_name, 1 + strlen(mc_name)); 	/* old(modified) Elf_Shdr table, word-byte aligned */	ulseek(fd_map, t, SEEK_SET);	t += sizeof(Elf_Shdr) * old_shnum;	uwrite(fd_map, old_shoff + (void *)ehdr,	       sizeof(Elf_Shdr) * old_shnum); 	/* new sections __mcount_loc and .rel__mcount_loc */	t += 2*sizeof(mcsec);	mcsec.sh_name = w((sizeof(Elf_Rela) == rel_entsize) + strlen(".rel")		+ old_shstr_sh_size);	mcsec.sh_type = w(SHT_PROGBITS);	mcsec.sh_flags = _w(SHF_ALLOC);	mcsec.sh_addr = 0;	mcsec.sh_offset = _w(t);	mcsec.sh_size = _w((void *)mlocp - (void *)mloc0);	mcsec.sh_link = 0;	mcsec.sh_info = 0;	mcsec.sh_addralign = _w(_size);	mcsec.sh_entsize = _w(_size);	uwrite(fd_map, &mcsec, sizeof(mcsec)); 	mcsec.sh_name = w(old_shstr_sh_size);	mcsec.sh_type = (sizeof(Elf_Rela) == rel_entsize)		? w(SHT_RELA)		: w(SHT_REL);	mcsec.sh_flags = 0;	mcsec.sh_addr = 0;	mcsec.sh_offset = _w((void *)mlocp - (void *)mloc0 + t);	mcsec.sh_size   = _w((void *)mrelp - (void *)mrel0);	mcsec.sh_link = w(symsec_sh_link);	mcsec.sh_info = w(old_shnum);	mcsec.sh_addralign = _w(_size);	mcsec.sh_entsize = _w(rel_entsize);	uwrite(fd_map, &mcsec, sizeof(mcsec)); 	uwrite(fd_map, mloc0, (void *)mlocp - (void *)mloc0);	uwrite(fd_map, mrel0, (void *)mrelp - (void *)mrel0); 	ehdr->e_shoff = _w(new_e_shoff);	ehdr->e_shnum = w2(2 + w2(ehdr->e_shnum));  /* {.rel,}__mcount_loc */	ulseek(fd_map, 0, SEEK_SET);	uwrite(fd_map, ehdr, sizeof(*ehdr));} static unsigned get_mcountsym(Elf_Sym const *const sym0,			      Elf_Rel const *relp,			      char const *const str0){	unsigned mcountsym = 0; 	Elf_Sym const *const symp =		&sym0[Elf_r_sym(relp)];	char const *symname = &str0[w(symp->st_name)];	char const *mcount = gpfx == '_' ? "_mcount" : "mcount"; 	if (symname[0] == '.')		++symname;  /* ppc64 hack */	if (strcmp(mcount, symname) == 0 ||	    (altmcount && strcmp(altmcount, symname) == 0))		mcountsym = Elf_r_sym(relp); 	return mcountsym;} static void get_sym_str_and_relp(Elf_Shdr const *const relhdr,				 Elf_Ehdr const *const ehdr,				 Elf_Sym const **sym0,				 char const **str0,				 Elf_Rel const **relp){	Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)		+ (void *)ehdr);	unsigned const symsec_sh_link = w(relhdr->sh_link);	Elf_Shdr const *const symsec = &shdr0[symsec_sh_link];	Elf_Shdr const *const strsec = &shdr0[w(symsec->sh_link)];	Elf_Rel const *const rel0 = (Elf_Rel const *)(_w(relhdr->sh_offset)		+ (void *)ehdr); 	*sym0 = (Elf_Sym const *)(_w(symsec->sh_offset)				  + (void *)ehdr); 	*str0 = (char const *)(_w(strsec->sh_offset)			       + (void *)ehdr); 	*relp = rel0;} /* * Look at the relocations in order to find the calls to mcount. * Accumulate the section offsets that are found, and their relocation info, * onto the end of the existing arrays. */static uint_t *sift_rel_mcount(uint_t *mlocp,			       unsigned const offbase,			       Elf_Rel **const mrelpp,			       Elf_Shdr const *const relhdr,			       Elf_Ehdr const *const ehdr,			       unsigned const recsym,			       uint_t const recval,			       unsigned const reltype){	uint_t *const mloc0 = mlocp;	Elf_Rel *mrelp = *mrelpp;	Elf_Sym const *sym0;	char const *str0;	Elf_Rel const *relp;	unsigned rel_entsize = _w(relhdr->sh_entsize);	unsigned const nrel = _w(relhdr->sh_size) / rel_entsize;	unsigned mcountsym = 0;	unsigned t; 	get_sym_str_and_relp(relhdr, ehdr, &sym0, &str0, &relp); 	for (t = nrel; t; --t) {		if (!mcountsym)			mcountsym = get_mcountsym(sym0, relp, str0); 		if (mcountsym == Elf_r_sym(relp) && !is_fake_mcount(relp)) {			uint_t const addend =				_w(_w(relp->r_offset) - recval + mcount_adjust);			mrelp->r_offset = _w(offbase				+ ((void *)mlocp - (void *)mloc0));			Elf_r_info(mrelp, recsym, reltype);			if (rel_entsize == sizeof(Elf_Rela)) {				((Elf_Rela *)mrelp)->r_addend = addend;				*mlocp++ = 0;			} else				*mlocp++ = addend; 			mrelp = (Elf_Rel *)(rel_entsize + (void *)mrelp);		}		relp = (Elf_Rel const *)(rel_entsize + (void *)relp);	}	*mrelpp = mrelp;	return mlocp;} /* * Read the relocation table again, but this time its called on sections * that are not going to be traced. The mcount calls here will be converted * into nops. */static void nop_mcount(Elf_Shdr const *const relhdr,		       Elf_Ehdr const *const ehdr,		       const char *const txtname){	Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)		+ (void *)ehdr);	Elf_Sym const *sym0;	char const *str0;	Elf_Rel const *relp;	Elf_Shdr const *const shdr = &shdr0[w(relhdr->sh_info)];	unsigned rel_entsize = _w(relhdr->sh_entsize);	unsigned const nrel = _w(relhdr->sh_size) / rel_entsize;	unsigned mcountsym = 0;	unsigned t;	int once = 0; 	get_sym_str_and_relp(relhdr, ehdr, &sym0, &str0, &relp); 	for (t = nrel; t; --t) {		int ret = -1; 		if (!mcountsym)			mcountsym = get_mcountsym(sym0, relp, str0); 		if (mcountsym == Elf_r_sym(relp) && !is_fake_mcount(relp)) {			if (make_nop)				ret = make_nop((void *)ehdr, shdr->sh_offset + relp->r_offset);			if (warn_on_notrace_sect && !once) {				printf("Section %s has mcount callers being ignored\n",				       txtname);				once = 1;				/* just warn? */				if (!make_nop)					return;			}		} 		/*		 * 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);			ulseek(fd_map, (void *)relp - (void *)ehdr, SEEK_SET);			uwrite(fd_map, &rel, sizeof(rel));		}		relp = (Elf_Rel const *)(rel_entsize + (void *)relp);	}}  /* * 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 unsigned find_secsym_ndx(unsigned const txtndx,				char const *const txtname,				uint_t *const recvalp,				Elf_Shdr const *const symhdr,				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 == w2(symp->st_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);			return symp - sym0;		}	}	fprintf(stderr, "Cannot find symbol for section %d: %s.\n",		txtndx, txtname);	fail_file();}  /* Evade ISO C restriction: no declaration after statement in has_rel_mcount. */static char const *__has_rel_mcount(Elf_Shdr const *const relhdr,  /* is SHT_REL or SHT_RELA */		 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);		succeed_file();	}	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 && is_mcounted_section_name(txtname))			totrelsz += _w(shdrp->sh_size);	}	return totrelsz;}  /* Overall supervision for Elf32 ET_REL file. */static void

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