Move the checksum functionality out of the main objtool command into a new "objtool klp checksum" subcommand.
This has the benefit of making the code (and the patch generation process itself) more modular. For bisectability, both "objtool --checksum" and "objtool klp checksum" work for now. The former will be removed after klp-build has been converted to use the new subcommand. Signed-off-by: Josh Poimboeuf <[email protected]> --- tools/objtool/Build | 2 +- tools/objtool/builtin-klp.c | 1 + tools/objtool/check.c | 209 +----------------- tools/objtool/include/objtool/check.h | 6 + tools/objtool/include/objtool/checksum.h | 4 + tools/objtool/include/objtool/klp.h | 1 + tools/objtool/klp-checksum.c | 257 +++++++++++++++++++++++ tools/objtool/klp-diff.c | 2 +- 8 files changed, 273 insertions(+), 209 deletions(-) create mode 100644 tools/objtool/klp-checksum.c diff --git a/tools/objtool/Build b/tools/objtool/Build index 600da051af12..93a37b0dfd31 100644 --- a/tools/objtool/Build +++ b/tools/objtool/Build @@ -12,7 +12,7 @@ objtool-$(BUILD_DISAS) += disas.o objtool-$(BUILD_DISAS) += trace.o objtool-$(BUILD_ORC) += orc_gen.o orc_dump.o -objtool-$(BUILD_KLP) += builtin-klp.o klp-diff.o klp-post-link.o +objtool-$(BUILD_KLP) += builtin-klp.o klp-checksum.o klp-diff.o klp-post-link.o objtool-y += libstring.o objtool-y += libctype.o diff --git a/tools/objtool/builtin-klp.c b/tools/objtool/builtin-klp.c index 56d5a5b92f72..58c3b9bda3eb 100644 --- a/tools/objtool/builtin-klp.c +++ b/tools/objtool/builtin-klp.c @@ -13,6 +13,7 @@ struct subcmd { }; static struct subcmd subcmds[] = { + { "checksum", "Generate per-function checksums", cmd_klp_checksum, }, { "diff", "Generate binary diff of two object files", cmd_klp_diff, }, { "post-link", "Finalize klp symbols/relocs after module linking", cmd_klp_post_link, }, }; diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 17cb9265973d..3e5d335d0e29 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -64,8 +64,8 @@ struct instruction *next_insn_same_sec(struct objtool_file *file, return insn; } -static struct instruction *next_insn_same_func(struct objtool_file *file, - struct instruction *insn) +struct instruction *next_insn_same_func(struct objtool_file *file, + struct instruction *insn) { struct instruction *next = next_insn_same_sec(file, insn); struct symbol *func = insn_func(insn); @@ -113,10 +113,6 @@ static struct instruction *prev_insn_same_sym(struct objtool_file *file, for_each_sec(file->elf, __sec) \ sec_for_each_insn(file, __sec, insn) -#define func_for_each_insn(file, func, insn) \ - for (insn = find_insn(file, func->sec, func->offset); \ - insn; \ - insn = next_insn_same_func(file, insn)) #define sym_for_each_insn(file, sym, insn) \ for (insn = find_insn(file, sym->sec, sym->offset); \ @@ -1023,56 +1019,6 @@ static int create_direct_call_sections(struct objtool_file *file) return 0; } -#ifdef BUILD_KLP -static int create_sym_checksum_section(struct objtool_file *file) -{ - struct section *sec; - struct symbol *sym; - unsigned int idx = 0; - struct sym_checksum *checksum; - size_t entsize = sizeof(struct sym_checksum); - - sec = find_section_by_name(file->elf, ".discard.sym_checksum"); - if (sec) { - if (!opts.dryrun) - WARN("file already has .discard.sym_checksum section, skipping"); - - return 0; - } - - for_each_sym(file->elf, sym) - if (sym->csum.checksum) - idx++; - - sec = elf_create_section_pair(file->elf, ".discard.sym_checksum", entsize, - idx, idx); - if (!sec) - return -1; - - idx = 0; - for_each_sym(file->elf, sym) { - if (!sym->csum.checksum) - continue; - - if (!elf_init_reloc(file->elf, sec->rsec, idx, idx * entsize, - sym, 0, R_TEXT64)) - return -1; - - checksum = (struct sym_checksum *)sec->data->d_buf + idx; - checksum->addr = 0; /* reloc */ - checksum->checksum = sym->csum.checksum; - - mark_sec_changed(file->elf, sec, true); - - idx++; - } - - return 0; -} -#else -static int create_sym_checksum_section(struct objtool_file *file) { return -EINVAL; } -#endif - /* * Warnings shouldn't be reported for ignored functions. */ @@ -3672,157 +3618,6 @@ static bool skip_alt_group(struct instruction *insn) return alt_insn->type == INSN_CLAC || alt_insn->type == INSN_STAC; } -#ifdef BUILD_KLP -static void enable_debug_checksum_cb(struct symbol *sym, void *d) -{ - bool *found = d; - - if (!is_func_sym(sym)) - return; - - sym->debug_checksum = 1; - *found = true; -} - -static int checksum_debug_init(struct objtool_file *file) -{ - char *dup, *s; - - if (!opts.debug_checksum) - return 0; - - dup = strdup(opts.debug_checksum); - if (!dup) { - ERROR_GLIBC("strdup"); - return -1; - } - - s = dup; - while (*s) { - bool found = false; - char *comma; - - comma = strchr(s, ','); - if (comma) - *comma = '\0'; - - iterate_sym_by_name(file->elf, s, enable_debug_checksum_cb, &found); - if (!found) - WARN("--debug-checksum: can't find '%s'", s); - - if (!comma) - break; - - s = comma + 1; - } - - free(dup); - return 0; -} - -static void checksum_update_insn(struct objtool_file *file, struct symbol *func, - struct instruction *insn) -{ - struct reloc *reloc = insn_reloc(file, insn); - struct alternative *alt; - unsigned long offset; - struct symbol *sym; - static bool in_alt; - - if (insn->fake) - return; - - checksum_update(func, insn, insn->sec->data->d_buf + insn->offset, insn->len); - - if (!reloc) { - struct symbol *call_dest = insn_call_dest(insn); - - if (call_dest) - checksum_update(func, insn, call_dest->demangled_name, - strlen(call_dest->demangled_name)); - goto alts; - } - - sym = reloc->sym; - offset = arch_insn_adjusted_addend(insn, reloc); - - if (is_string_sec(sym->sec)) { - char *str; - - str = sym->sec->data->d_buf + sym->offset + offset; - checksum_update(func, insn, str, strlen(str)); - goto alts; - } - - if (is_sec_sym(sym)) { - sym = find_symbol_containing(reloc->sym->sec, offset); - if (!sym) - goto alts; - - offset -= sym->offset; - } - - checksum_update(func, insn, sym->demangled_name, strlen(sym->demangled_name)); - checksum_update(func, insn, &offset, sizeof(offset)); - -alts: - for (alt = insn->alts; alt; alt = alt->next) { - struct alt_group *alt_group = alt->insn->alt_group; - - /* Prevent __ex_table recursion, e.g. LOAD_SEGMENT() */ - if (in_alt) - break; - in_alt = true; - - checksum_update(func, insn, &alt->type, sizeof(alt->type)); - - if (alt_group && alt_group->orig_group) { - struct instruction *alt_insn; - - checksum_update(func, insn, &alt_group->feature, sizeof(alt_group->feature)); - - for (alt_insn = alt->insn; alt_insn; alt_insn = next_insn_same_sec(file, alt_insn)) { - checksum_update_insn(file, func, alt_insn); - if (!alt_group->last_insn || alt_insn == alt_group->last_insn) - break; - } - } else { - checksum_update_insn(file, func, alt->insn); - } - - in_alt = false; - } -} - -static int calculate_checksums(struct objtool_file *file) -{ - struct instruction *insn; - struct symbol *func; - - if (checksum_debug_init(file)) - return -1; - - for_each_sym(file->elf, func) { - /* - * Skip cold subfunctions and aliases: they share the - * parent's checksum via func_for_each_insn() which - * follows func->cfunc into the cold subfunction. - */ - if (!is_func_sym(func) || is_cold_func(func) || - is_alias_sym(func) || !func->len) - continue; - - checksum_init(func); - - func_for_each_insn(file, func, insn) - checksum_update_insn(file, func, insn); - - checksum_finish(func); - } - return 0; -} -#endif /* BUILD_KLP */ - static int validate_branch(struct objtool_file *file, struct symbol *func, struct instruction *insn, struct insn_state state); static int do_validate_branch(struct objtool_file *file, struct symbol *func, diff --git a/tools/objtool/include/objtool/check.h b/tools/objtool/include/objtool/check.h index 6489e52ea2f2..eea64728d39b 100644 --- a/tools/objtool/include/objtool/check.h +++ b/tools/objtool/include/objtool/check.h @@ -144,6 +144,12 @@ struct instruction *find_insn(struct objtool_file *file, struct section *sec, unsigned long offset); struct instruction *next_insn_same_sec(struct objtool_file *file, struct instruction *insn); +struct instruction *next_insn_same_func(struct objtool_file *file, struct instruction *insn); + +#define func_for_each_insn(file, func, insn) \ + for (insn = find_insn(file, func->sec, func->offset); \ + insn; \ + insn = next_insn_same_func(file, insn)) #define sec_for_each_insn(file, _sec, insn) \ for (insn = find_insn(file, _sec, 0); \ diff --git a/tools/objtool/include/objtool/checksum.h b/tools/objtool/include/objtool/checksum.h index 3f25df90305d..be4eb7dfe6f2 100644 --- a/tools/objtool/include/objtool/checksum.h +++ b/tools/objtool/include/objtool/checksum.h @@ -31,9 +31,13 @@ static inline void checksum_finish(struct symbol *func) } } +int calculate_checksums(struct objtool_file *file); +int create_sym_checksum_section(struct objtool_file *file); + #else /* !BUILD_KLP */ static inline int calculate_checksums(struct objtool_file *file) { return -ENOSYS; } +static inline int create_sym_checksum_section(struct objtool_file *file) { return -EINVAL; } #endif /* !BUILD_KLP */ diff --git a/tools/objtool/include/objtool/klp.h b/tools/objtool/include/objtool/klp.h index e32e5e8bc631..6f60cf05db86 100644 --- a/tools/objtool/include/objtool/klp.h +++ b/tools/objtool/include/objtool/klp.h @@ -29,6 +29,7 @@ struct klp_reloc { u32 type; }; +int cmd_klp_checksum(int argc, const char **argv); int cmd_klp_diff(int argc, const char **argv); int cmd_klp_post_link(int argc, const char **argv); diff --git a/tools/objtool/klp-checksum.c b/tools/objtool/klp-checksum.c new file mode 100644 index 000000000000..4edd29028bff --- /dev/null +++ b/tools/objtool/klp-checksum.c @@ -0,0 +1,257 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +#include <string.h> +#include <subcmd/parse-options.h> + +#include <objtool/arch.h> +#include <objtool/builtin.h> +#include <objtool/check.h> +#include <objtool/elf.h> +#include <objtool/klp.h> +#include <objtool/objtool.h> +#include <objtool/warn.h> +#include <objtool/checksum.h> + +static void enable_debug_checksum_cb(struct symbol *sym, void *d) +{ + bool *found = d; + + if (!is_func_sym(sym)) + return; + + sym->debug_checksum = 1; + *found = true; +} + +static int checksum_debug_init(struct objtool_file *file) +{ + char *dup, *s; + + if (!opts.debug_checksum) + return 0; + + dup = strdup(opts.debug_checksum); + if (!dup) { + ERROR_GLIBC("strdup"); + return -1; + } + + s = dup; + while (*s) { + bool found = false; + char *comma; + + comma = strchr(s, ','); + if (comma) + *comma = '\0'; + + iterate_sym_by_name(file->elf, s, enable_debug_checksum_cb, &found); + if (!found) + WARN("--debug-checksum: can't find '%s'", s); + + if (!comma) + break; + + s = comma + 1; + } + + free(dup); + return 0; +} + +static void checksum_update_insn(struct objtool_file *file, struct symbol *func, + struct instruction *insn) +{ + struct reloc *reloc = insn_reloc(file, insn); + struct alternative *alt; + unsigned long offset; + struct symbol *sym; + static bool in_alt; + + if (insn->fake) + return; + + checksum_update(func, insn, insn->sec->data->d_buf + insn->offset, insn->len); + + if (!reloc) { + struct symbol *call_dest = insn_call_dest(insn); + + if (call_dest) + checksum_update(func, insn, call_dest->demangled_name, + strlen(call_dest->demangled_name)); + goto alts; + } + + sym = reloc->sym; + offset = arch_insn_adjusted_addend(insn, reloc); + + if (is_string_sec(sym->sec)) { + char *str; + + str = sym->sec->data->d_buf + sym->offset + offset; + checksum_update(func, insn, str, strlen(str)); + goto alts; + } + + if (is_sec_sym(sym)) { + sym = find_symbol_containing(reloc->sym->sec, offset); + if (!sym) + goto alts; + + offset -= sym->offset; + } + + checksum_update(func, insn, sym->demangled_name, strlen(sym->demangled_name)); + checksum_update(func, insn, &offset, sizeof(offset)); + +alts: + for (alt = insn->alts; alt; alt = alt->next) { + struct alt_group *alt_group = alt->insn->alt_group; + + /* Prevent __ex_table recursion, e.g. LOAD_SEGMENT() */ + if (in_alt) + break; + in_alt = true; + + checksum_update(func, insn, &alt->type, sizeof(alt->type)); + + if (alt_group && alt_group->orig_group) { + struct instruction *alt_insn; + + checksum_update(func, insn, &alt_group->feature, sizeof(alt_group->feature)); + + for (alt_insn = alt->insn; alt_insn; alt_insn = next_insn_same_sec(file, alt_insn)) { + checksum_update_insn(file, func, alt_insn); + if (!alt_group->last_insn || alt_insn == alt_group->last_insn) + break; + } + } else { + checksum_update_insn(file, func, alt->insn); + } + + in_alt = false; + } +} + +int calculate_checksums(struct objtool_file *file) +{ + struct instruction *insn; + struct symbol *func; + + if (checksum_debug_init(file)) + return -1; + + for_each_sym(file->elf, func) { + /* + * Skip cold subfunctions and aliases: they share the + * parent's checksum via func_for_each_insn() which + * follows func->cfunc into the cold subfunction. + */ + if (!is_func_sym(func) || is_cold_func(func) || + is_alias_sym(func) || !func->len) + continue; + + checksum_init(func); + + func_for_each_insn(file, func, insn) + checksum_update_insn(file, func, insn); + + checksum_finish(func); + } + return 0; +} + +int create_sym_checksum_section(struct objtool_file *file) +{ + struct section *sec; + struct symbol *sym; + unsigned int idx = 0; + struct sym_checksum *checksum; + size_t entsize = sizeof(struct sym_checksum); + + sec = find_section_by_name(file->elf, ".discard.sym_checksum"); + if (sec) { + if (!opts.dryrun) + WARN("file already has .discard.sym_checksum section, skipping"); + + return 0; + } + + for_each_sym(file->elf, sym) + if (sym->csum.checksum) + idx++; + + sec = elf_create_section_pair(file->elf, ".discard.sym_checksum", entsize, + idx, idx); + if (!sec) + return -1; + + idx = 0; + for_each_sym(file->elf, sym) { + if (!sym->csum.checksum) + continue; + + if (!elf_init_reloc(file->elf, sec->rsec, idx, idx * entsize, + sym, 0, R_TEXT64)) + return -1; + + checksum = (struct sym_checksum *)sec->data->d_buf + idx; + checksum->addr = 0; /* reloc */ + checksum->checksum = sym->csum.checksum; + + mark_sec_changed(file->elf, sec, true); + + idx++; + } + + return 0; +} + +static const char * const klp_checksum_usage[] = { + "objtool klp checksum [<options>] file.o", + NULL, +}; + +int cmd_klp_checksum(int argc, const char **argv) +{ + struct objtool_file *file; + int ret; + + const struct option options[] = { + OPT_STRING(0, "debug-checksum", &opts.debug_checksum, "funcs", "enable checksum debug output"), + OPT_BOOLEAN(0, "dry-run", &opts.dryrun, "don't write modifications"), + OPT_END(), + }; + + argc = parse_options(argc, argv, options, klp_checksum_usage, 0); + if (argc != 1) + usage_with_options(klp_checksum_usage, options); + + opts.checksum = true; + + objname = argv[0]; + + file = objtool_open_read(objname); + if (!file) + return 1; + + ret = decode_file(file); + if (ret) + goto out; + + ret = calculate_checksums(file); + if (ret) + goto out; + + ret = create_sym_checksum_section(file); + +out: + free_insns(file); + + if (ret) + return ret; + + if (!opts.dryrun && file->elf->changed && elf_write(file->elf)) + return 1; + + return elf_close(file->elf); +} diff --git a/tools/objtool/klp-diff.c b/tools/objtool/klp-diff.c index 266f0d2ba4fe..c903aa65d4b6 100644 --- a/tools/objtool/klp-diff.c +++ b/tools/objtool/klp-diff.c @@ -171,7 +171,7 @@ static int read_sym_checksums(struct elf *elf) sec = find_section_by_name(elf, ".discard.sym_checksum"); if (!sec) { - ERROR("'%s' missing .discard.sym_checksum section, file not processed by 'objtool --checksum'?", + ERROR("'%s' missing .discard.sym_checksum section, file not processed by 'objtool klp checksum'?", elf->name); return -1; } -- 2.53.0
