commit 8927806ad017c29f34a94a7f2d687c606132f736 Author: Joe Damato Date: Mon Sep 7 01:38:11 2009 -0700 Add new option '-g' '--no-plt' which disables setting breakpoints on PLTs. This is useful if the normal ltrace output is too overwhelming. diff --git a/elf.c b/elf.c index aeff211..795c062 100644 --- a/elf.c +++ b/elf.c @@ -468,95 +468,100 @@ read_elf(Process *proc) { proc->e_machine = lte->ehdr.e_machine; for (i = 0; i < library_num; ++i) do_init_elf(<e[i + 1], library[i]); + + if (!options.no_plt) { #ifdef __mips__ - // MIPS doesn't use the PLT and the GOT entries get changed - // on startup. - proc->need_to_reinitialize_breakpoints = 1; - for(i=lte->mips_gotsym; idynsym_count;i++){ - GElf_Sym sym; - const char *name; - GElf_Addr addr = arch_plt_sym_val(lte, i, 0); - if (gelf_getsym(lte->dynsym, i, &sym) == NULL){ - error(EXIT_FAILURE, 0, - "Couldn't get relocation from \"%s\"", - proc->filename); - } - name=lte->dynstr+sym.st_name; - if(ELF64_ST_TYPE(sym.st_info) != STT_FUNC){ - debug(2,"sym %s not a function",name); - continue; + // MIPS doesn't use the PLT and the GOT entries get changed + // on startup. + proc->need_to_reinitialize_breakpoints = 1; + for(i=lte->mips_gotsym; idynsym_count;i++){ + GElf_Sym sym; + const char *name; + GElf_Addr addr = arch_plt_sym_val(lte, i, 0); + if (gelf_getsym(lte->dynsym, i, &sym) == NULL){ + error(EXIT_FAILURE, 0, + "Couldn't get relocation from \"%s\"", + proc->filename); + } + name=lte->dynstr+sym.st_name; + if(ELF64_ST_TYPE(sym.st_info) != STT_FUNC){ + debug(2,"sym %s not a function",name); + continue; + } + add_library_symbol(addr, name, &library_symbols, 0, + ELF64_ST_BIND(sym.st_info) != 0); + if (!lib_tail) + lib_tail = &(library_symbols->next); } - add_library_symbol(addr, name, &library_symbols, 0, - ELF64_ST_BIND(sym.st_info) != 0); - if (!lib_tail) - lib_tail = &(library_symbols->next); - } #else - for (i = 0; i < lte->relplt_count; ++i) { - GElf_Rel rel; - GElf_Rela rela; - GElf_Sym sym; - GElf_Addr addr; - void *ret; - const char *name; + for (i = 0; i < lte->relplt_count; ++i) { + GElf_Rel rel; + GElf_Rela rela; + GElf_Sym sym; + GElf_Addr addr; + void *ret; + const char *name; + + if (lte->relplt->d_type == ELF_T_REL) { + ret = gelf_getrel(lte->relplt, i, &rel); + rela.r_offset = rel.r_offset; + rela.r_info = rel.r_info; + rela.r_addend = 0; + } else + ret = gelf_getrela(lte->relplt, i, &rela); - if (lte->relplt->d_type == ELF_T_REL) { - ret = gelf_getrel(lte->relplt, i, &rel); - rela.r_offset = rel.r_offset; - rela.r_info = rel.r_info; - rela.r_addend = 0; - } else - ret = gelf_getrela(lte->relplt, i, &rela); - - if (ret == NULL - || ELF64_R_SYM(rela.r_info) >= lte->dynsym_count - || gelf_getsym(lte->dynsym, ELF64_R_SYM(rela.r_info), - &sym) == NULL) - error(EXIT_FAILURE, 0, - "Couldn't get relocation from \"%s\"", - proc->filename); + if (ret == NULL + || ELF64_R_SYM(rela.r_info) >= lte->dynsym_count + || gelf_getsym(lte->dynsym, ELF64_R_SYM(rela.r_info), + &sym) == NULL) + error(EXIT_FAILURE, 0, + "Couldn't get relocation from \"%s\"", + proc->filename); #ifdef PLT_REINITALISATION_BP - if (!sym.st_value && PLTs_initialized_by_here) - proc->need_to_reinitialize_breakpoints = 1; + if (!sym.st_value && PLTs_initialized_by_here) + proc->need_to_reinitialize_breakpoints = 1; #endif - name = lte->dynstr + sym.st_name; - if (in_load_libraries(name, lte)) { - addr = arch_plt_sym_val(lte, i, &rela); - add_library_symbol(addr, name, &library_symbols, - (PLTS_ARE_EXECUTABLE(lte) - ? LS_TOPLT_EXEC : LS_TOPLT_POINT), - ELF64_ST_BIND(sym.st_info) == STB_WEAK); - if (!lib_tail) - lib_tail = &(library_symbols->next); + name = lte->dynstr + sym.st_name; + if (in_load_libraries(name, lte)) { + addr = arch_plt_sym_val(lte, i, &rela); + add_library_symbol(addr, name, &library_symbols, + (PLTS_ARE_EXECUTABLE(lte) + ? LS_TOPLT_EXEC : LS_TOPLT_POINT), + ELF64_ST_BIND(sym.st_info) == STB_WEAK); + if (!lib_tail) + lib_tail = &(library_symbols->next); + } } - } #endif // !__mips__ #ifdef PLT_REINITALISATION_BP - struct opt_x_t *main_cheat; - - if (proc->need_to_reinitialize_breakpoints) { - /* Add "PLTs_initialized_by_here" to opt_x list, if not - already there. */ - main_cheat = (struct opt_x_t *)malloc(sizeof(struct opt_x_t)); - if (main_cheat == NULL) - error(EXIT_FAILURE, 0, "Couldn't allocate memory"); - main_cheat->next = opt_x; - main_cheat->found = 0; - main_cheat->name = PLTs_initialized_by_here; - - for (xptr = opt_x; xptr; xptr = xptr->next) - if (strcmp(xptr->name, PLTs_initialized_by_here) == 0 - && main_cheat) { - free(main_cheat); - main_cheat = NULL; - break; - } - if (main_cheat) - opt_x = main_cheat; - } + struct opt_x_t *main_cheat; + + if (proc->need_to_reinitialize_breakpoints) { + /* Add "PLTs_initialized_by_here" to opt_x list, if not + already there. */ + main_cheat = (struct opt_x_t *)malloc(sizeof(struct opt_x_t)); + if (main_cheat == NULL) + error(EXIT_FAILURE, 0, "Couldn't allocate memory"); + main_cheat->next = opt_x; + main_cheat->found = 0; + main_cheat->name = PLTs_initialized_by_here; + + for (xptr = opt_x; xptr; xptr = xptr->next) + if (strcmp(xptr->name, PLTs_initialized_by_here) == 0 + && main_cheat) { + free(main_cheat); + main_cheat = NULL; + break; + } + if (main_cheat) + opt_x = main_cheat; + } #endif + } else { + lib_tail = &library_symbols; + } for (i = 0; i < lte->symtab_count; ++i) { GElf_Sym sym; diff --git a/options.c b/options.c index aef73b1..f2290b8 100644 --- a/options.c +++ b/options.c @@ -98,6 +98,7 @@ usage(void) { " -T show the time spent inside each call.\n" " -u USERNAME run command with the userid, groupid of username.\n" " -V, --version output version information and exit.\n" + " -g, --no-plt disable breakpoints on PLT entries.\n" " -x NAME treat the global NAME like a library subroutine.\n" #ifdef PLT_REINITALISATION_BP " -X NAME same as -x; and PLT's will be initialized by here.\n" @@ -179,6 +180,7 @@ char ** process_options(int argc, char **argv) { progname = argv[0]; options.output = stderr; + options.no_plt = 0; guess_cols(); @@ -198,9 +200,10 @@ process_options(int argc, char **argv) { {"library", 1, 0, 'l'}, {"output", 1, 0, 'o'}, {"version", 0, 0, 'V'}, + {"no-plt", 0, 0, 'g'}, {0, 0, 0, 0} }; - c = getopt_long(argc, argv, "+cfhiLrStTV" + c = getopt_long(argc, argv, "+cfhiLrStTVg" # ifdef USE_DEMANGLE "C" # endif @@ -351,6 +354,9 @@ process_options(int argc, char **argv) { "This is free software; see the GNU General Public Licence\n" "version 2 or later for copying conditions. There is NO warranty.\n"); exit(0); + case 'g': + options.no_plt = 1; + break; case 'X': #ifdef PLT_REINITALISATION_BP PLTs_initialized_by_here = optarg; diff --git a/options.h b/options.h index db253c5..b74b495 100644 --- a/options.h +++ b/options.h @@ -14,6 +14,7 @@ struct options_t { int arraylen; /* default maximum # of array elements printed */ int strlen; /* default maximum # of bytes printed in strings */ int follow; /* trace child processes */ + int no_plt; /* set bps on PLT entries */ }; extern struct options_t options;