From 29e6b52efca13369e8ce35abeabbcb105554c0f0 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 26 Oct 2021 14:01:33 +0200 Subject: [PATCH] objtool: Classify symbols commit 1739c66eb7bd5f27f1b69a5a26e10e8327d1e136 upstream. In order to avoid calling str*cmp() on symbol names, over and over, do them all once upfront and store the result. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Borislav Petkov Acked-by: Josh Poimboeuf Tested-by: Alexei Starovoitov Link: https://lore.kernel.org/r/20211026120309.658539311@infradead.org [cascardo: no pv_target on struct symbol, because of missing db2b0c5d7b6f19b3c2cab08c531b65342eb5252b] Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Greg Kroah-Hartman --- tools/objtool/check.c | 34 ++++++++++++++++++++++------------ tools/objtool/include/objtool/elf.h | 7 +++++-- 2 files changed, 27 insertions(+), 14 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 8b3435a..236f34e 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -859,8 +859,7 @@ static void add_call_dest(struct objtool_file *file, struct instruction *insn, * so they need a little help, NOP out any KCOV calls from noinstr * text. */ - if (insn->sec->noinstr && - !strncmp(insn->call_dest->name, "__sanitizer_cov_", 16)) { + if (insn->sec->noinstr && insn->call_dest->kcov) { if (reloc) { reloc->type = R_NONE; elf_write_reloc(file->elf, reloc); @@ -884,7 +883,7 @@ static void add_call_dest(struct objtool_file *file, struct instruction *insn, } } - if (mcount && !strcmp(insn->call_dest->name, "__fentry__")) { + if (mcount && insn->call_dest->fentry) { if (sibling) WARN_FUNC("Tail call to __fentry__ !?!?", insn->sec, insn->offset); @@ -934,7 +933,7 @@ static int add_jump_destinations(struct objtool_file *file) } else if (reloc->sym->type == STT_SECTION) { dest_sec = reloc->sym->sec; dest_off = arch_dest_reloc_offset(reloc->addend); - } else if (arch_is_retpoline(reloc->sym)) { + } else if (reloc->sym->retpoline_thunk) { /* * Retpoline jumps are really dynamic jumps in * disguise, so convert them accordingly. @@ -1075,7 +1074,7 @@ static int add_call_destinations(struct objtool_file *file) add_call_dest(file, insn, dest, false); - } else if (arch_is_retpoline(reloc->sym)) { + } else if (reloc->sym->retpoline_thunk) { /* * Retpoline calls are really dynamic calls in * disguise, so convert them accordingly. @@ -1759,17 +1758,28 @@ static int read_intra_function_calls(struct objtool_file *file) return 0; } -static int read_static_call_tramps(struct objtool_file *file) +static int classify_symbols(struct objtool_file *file) { struct section *sec; struct symbol *func; for_each_sec(file, sec) { list_for_each_entry(func, &sec->symbol_list, list) { - if (func->bind == STB_GLOBAL && - !strncmp(func->name, STATIC_CALL_TRAMP_PREFIX_STR, + if (func->bind != STB_GLOBAL) + continue; + + if (!strncmp(func->name, STATIC_CALL_TRAMP_PREFIX_STR, strlen(STATIC_CALL_TRAMP_PREFIX_STR))) func->static_call_tramp = true; + + if (arch_is_retpoline(func)) + func->retpoline_thunk = true; + + if (!strcmp(func->name, "__fentry__")) + func->fentry = true; + + if (!strncmp(func->name, "__sanitizer_cov_", 16)) + func->kcov = true; } } @@ -1831,7 +1841,7 @@ static int decode_sections(struct objtool_file *file) /* * Must be before add_{jump_call}_destination. */ - ret = read_static_call_tramps(file); + ret = classify_symbols(file); if (ret) return ret; @@ -1889,9 +1899,9 @@ static int decode_sections(struct objtool_file *file) static bool is_fentry_call(struct instruction *insn) { - if (insn->type == INSN_CALL && insn->call_dest && - insn->call_dest->type == STT_NOTYPE && - !strcmp(insn->call_dest->name, "__fentry__")) + if (insn->type == INSN_CALL && + insn->call_dest && + insn->call_dest->fentry) return true; return false; diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index 4443652..d3915f5 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -54,8 +54,11 @@ struct symbol { unsigned long offset; unsigned int len; struct symbol *pfunc, *cfunc, *alias; - bool uaccess_safe; - bool static_call_tramp; + u8 uaccess_safe : 1; + u8 static_call_tramp : 1; + u8 retpoline_thunk : 1; + u8 fentry : 1; + u8 kcov : 1; }; struct reloc { -- 2.7.4