Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 457FAC05027 for ; Thu, 2 Feb 2023 07:42:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231868AbjBBHmd (ORCPT ); Thu, 2 Feb 2023 02:42:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37524 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231751AbjBBHm3 (ORCPT ); Thu, 2 Feb 2023 02:42:29 -0500 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id C66AD751BE; Wed, 1 Feb 2023 23:42:27 -0800 (PST) Received: from x64host.home (unknown [47.187.213.40]) by linux.microsoft.com (Postfix) with ESMTPSA id AA81E20B74F8; Wed, 1 Feb 2023 23:42:26 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com AA81E20B74F8 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1675323747; bh=Dvi0sg7fNuFFbBH2nQXmc7LKL1McUIEsYXR3ernuKUg=; h=From:To:Subject:Date:In-Reply-To:References:From; b=l+zQFcwZXVAVxrTLIKvrKvC5DKsTieLcvIIOOTnUFliWxXaOMEkHTL0uh8OoX+eRF sYk7GrU4mZiOu51Q7on0MD7dozaRld9DmufEc16kdV/4nTDLBRok9zdjCQmjsWBIWx kdwO1HwVANVeHSVImlg/sim8QNdBCHYtd34/lGcc= From: madvenka@linux.microsoft.com To: jpoimboe@redhat.com, peterz@infradead.org, chenzhongjin@huawei.com, mark.rutland@arm.com, broonie@kernel.org, nobuta.keiya@fujitsu.com, sjitindarsingh@gmail.com, catalin.marinas@arm.com, will@kernel.org, jamorris@linux.microsoft.com, linux-arm-kernel@lists.infradead.org, live-patching@vger.kernel.org, linux-kernel@vger.kernel.org, madvenka@linux.microsoft.com Subject: [RFC PATCH v3 02/22] objtool: Reorganize instruction-related code Date: Thu, 2 Feb 2023 01:40:16 -0600 Message-Id: <20230202074036.507249-3-madvenka@linux.microsoft.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230202074036.507249-1-madvenka@linux.microsoft.com> References: <0337266cf19f4c98388e3f6d09f590d9de258dc7> <20230202074036.507249-1-madvenka@linux.microsoft.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Madhavan T. Venkataraman" check.c implements static stack validation. But the instruction-related code that it contains can be shared with other types of validation. E.g., dynamic FP validation. Move the instruction-related code to its own files - insn.h and insn.c. Signed-off-by: Madhavan T. Venkataraman --- tools/objtool/Build | 1 + tools/objtool/check.c | 201 -------------------------- tools/objtool/include/objtool/check.h | 77 +--------- tools/objtool/include/objtool/insn.h | 125 ++++++++++++++++ tools/objtool/insn.c | 186 ++++++++++++++++++++++++ 5 files changed, 313 insertions(+), 277 deletions(-) create mode 100644 tools/objtool/include/objtool/insn.h create mode 100644 tools/objtool/insn.c diff --git a/tools/objtool/Build b/tools/objtool/Build index 21db9d79c69f..1149048e6b3e 100644 --- a/tools/objtool/Build +++ b/tools/objtool/Build @@ -6,6 +6,7 @@ objtool-y += check.o objtool-y += special.o objtool-y += builtin-check.o objtool-y += cfi.o +objtool-y += insn.o objtool-y += elf.o objtool-y += objtool.o diff --git a/tools/objtool/check.c b/tools/objtool/check.c index e6a2afa08748..d208086a8a18 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -28,86 +28,6 @@ struct alternative { bool skip_orig; }; -struct instruction *find_insn(struct objtool_file *file, - struct section *sec, unsigned long offset) -{ - struct instruction *insn; - - hash_for_each_possible(file->insn_hash, insn, hash, sec_offset_hash(sec, offset)) { - if (insn->sec == sec && insn->offset == offset) - return insn; - } - - return NULL; -} - -static struct instruction *next_insn_same_sec(struct objtool_file *file, - struct instruction *insn) -{ - struct instruction *next = list_next_entry(insn, list); - - if (!next || &next->list == &file->insn_list || next->sec != insn->sec) - return NULL; - - return next; -} - -static struct instruction *next_insn_same_func(struct objtool_file *file, - struct instruction *insn) -{ - struct instruction *next = list_next_entry(insn, list); - struct symbol *func = insn->func; - - if (!func) - return NULL; - - if (&next->list != &file->insn_list && next->func == func) - return next; - - /* Check if we're already in the subfunction: */ - if (func == func->cfunc) - return NULL; - - /* Move to the subfunction: */ - return find_insn(file, func->cfunc->sec, func->cfunc->offset); -} - -static struct instruction *prev_insn_same_sym(struct objtool_file *file, - struct instruction *insn) -{ - struct instruction *prev = list_prev_entry(insn, list); - - if (&prev->list != &file->insn_list && prev->func == insn->func) - return prev; - - return NULL; -} - -#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); \ - insn && &insn->list != &file->insn_list && \ - insn->sec == sym->sec && \ - insn->offset < sym->offset + sym->len; \ - insn = list_next_entry(insn, list)) - -#define sym_for_each_insn_continue_reverse(file, sym, insn) \ - for (insn = list_prev_entry(insn, list); \ - &insn->list != &file->insn_list && \ - insn->sec == sym->sec && insn->offset >= sym->offset; \ - insn = list_prev_entry(insn, list)) - -#define sec_for_each_insn_from(file, insn) \ - for (; insn; insn = next_insn_same_sec(file, insn)) - -#define sec_for_each_insn_continue(file, insn) \ - for (insn = next_insn_same_sec(file, insn); insn; \ - insn = next_insn_same_sec(file, insn)) - static bool is_jump_table_jump(struct instruction *insn) { struct alt_group *alt_group = insn->alt_group; @@ -249,21 +169,6 @@ static bool dead_end_function(struct objtool_file *file, struct symbol *func) return __dead_end_function(file, func, 0); } -static void init_insn_state(struct objtool_file *file, struct insn_state *state, - struct section *sec) -{ - memset(state, 0, sizeof(*state)); - init_cfi_state(&state->cfi); - - /* - * We need the full vmlinux for noinstr validation, otherwise we can - * not correctly determine insn->call_dest->sec (external symbols do - * not have a section). - */ - if (opts.link && opts.noinstr && sec) - state->noinstr = sec->noinstr; -} - static unsigned long nr_insns; static unsigned long nr_insns_visited; @@ -439,19 +344,6 @@ static int init_pv_ops(struct objtool_file *file) return 0; } -static struct instruction *find_last_insn(struct objtool_file *file, - struct section *sec) -{ - struct instruction *insn = NULL; - unsigned int offset; - unsigned int end = (sec->sh.sh_size > 10) ? sec->sh.sh_size - 10 : 0; - - for (offset = sec->sh.sh_size - 1; offset >= end && !insn; offset--) - insn = find_insn(file, sec, offset); - - return insn; -} - /* * Mark "ud2" instructions and manually annotated dead ends. */ @@ -1072,28 +964,6 @@ __weak bool arch_is_rethunk(struct symbol *sym) return false; } -#define NEGATIVE_RELOC ((void *)-1L) - -static struct reloc *insn_reloc(struct objtool_file *file, struct instruction *insn) -{ - if (insn->reloc == NEGATIVE_RELOC) - return NULL; - - if (!insn->reloc) { - if (!file) - return NULL; - - insn->reloc = find_reloc_by_dest_range(file->elf, insn->sec, - insn->offset, insn->len); - if (!insn->reloc) { - insn->reloc = NEGATIVE_RELOC; - return NULL; - } - } - - return insn->reloc; -} - static void remove_insn_ops(struct instruction *insn) { struct stack_op *op, *tmp; @@ -1252,27 +1122,6 @@ static void add_return_call(struct objtool_file *file, struct instruction *insn, list_add_tail(&insn->call_node, &file->return_thunk_list); } -static bool same_function(struct instruction *insn1, struct instruction *insn2) -{ - return insn1->func->pfunc == insn2->func->pfunc; -} - -static bool is_first_func_insn(struct objtool_file *file, struct instruction *insn) -{ - if (insn->offset == insn->func->offset) - return true; - - if (opts.ibt) { - struct instruction *prev = prev_insn_same_sym(file, insn); - - if (prev && prev->type == INSN_ENDBR && - insn->offset == insn->func->offset + prev->len) - return true; - } - - return false; -} - /* * Find the destination instructions for all jumps. */ @@ -2987,56 +2836,6 @@ static int handle_insn_ops(struct instruction *insn, return 0; } -static bool insn_cfi_match(struct instruction *insn, struct cfi_state *cfi2) -{ - struct cfi_state *cfi1 = insn->cfi; - int i; - - if (!cfi1) { - WARN("CFI missing"); - return false; - } - - if (memcmp(&cfi1->cfa, &cfi2->cfa, sizeof(cfi1->cfa))) { - - WARN_FUNC("stack state mismatch: cfa1=%d%+d cfa2=%d%+d", - insn->sec, insn->offset, - cfi1->cfa.base, cfi1->cfa.offset, - cfi2->cfa.base, cfi2->cfa.offset); - - } else if (memcmp(&cfi1->regs, &cfi2->regs, sizeof(cfi1->regs))) { - for (i = 0; i < CFI_NUM_REGS; i++) { - if (!memcmp(&cfi1->regs[i], &cfi2->regs[i], - sizeof(struct cfi_reg))) - continue; - - WARN_FUNC("stack state mismatch: reg1[%d]=%d%+d reg2[%d]=%d%+d", - insn->sec, insn->offset, - i, cfi1->regs[i].base, cfi1->regs[i].offset, - i, cfi2->regs[i].base, cfi2->regs[i].offset); - break; - } - - } else if (cfi1->type != cfi2->type) { - - WARN_FUNC("stack state mismatch: type1=%d type2=%d", - insn->sec, insn->offset, cfi1->type, cfi2->type); - - } else if (cfi1->drap != cfi2->drap || - (cfi1->drap && cfi1->drap_reg != cfi2->drap_reg) || - (cfi1->drap && cfi1->drap_offset != cfi2->drap_offset)) { - - WARN_FUNC("stack state mismatch: drap1=%d(%d,%d) drap2=%d(%d,%d)", - insn->sec, insn->offset, - cfi1->drap, cfi1->drap_reg, cfi1->drap_offset, - cfi2->drap, cfi2->drap_reg, cfi2->drap_offset); - - } else - return true; - - return false; -} - static inline bool func_uaccess_safe(struct symbol *func) { if (func) diff --git a/tools/objtool/include/objtool/check.h b/tools/objtool/include/objtool/check.h index 036129cebeee..a093f5cb100a 100644 --- a/tools/objtool/include/objtool/check.h +++ b/tools/objtool/include/objtool/check.h @@ -7,17 +7,7 @@ #define _CHECK_H #include -#include -#include - -struct insn_state { - struct cfi_state cfi; - unsigned int uaccess_stack; - bool uaccess; - bool df; - bool noinstr; - s8 instr; -}; +#include struct alt_group { /* @@ -36,74 +26,9 @@ struct alt_group { struct cfi_state **cfi; }; -struct instruction { - struct list_head list; - struct hlist_node hash; - struct list_head call_node; - struct section *sec; - unsigned long offset; - unsigned int len; - enum insn_type type; - unsigned long immediate; - - u16 dead_end : 1, - ignore : 1, - ignore_alts : 1, - hint : 1, - save : 1, - restore : 1, - retpoline_safe : 1, - noendbr : 1, - entry : 1; - /* 7 bit hole */ - - s8 instr; - u8 visited; - - struct alt_group *alt_group; - struct symbol *call_dest; - struct instruction *jump_dest; - struct instruction *first_jump_src; - struct reloc *jump_table; - struct reloc *reloc; - struct list_head alts; - struct symbol *func; - struct list_head stack_ops; - struct cfi_state *cfi; -}; - #define VISITED_BRANCH 0x01 #define VISITED_BRANCH_UACCESS 0x02 #define VISITED_BRANCH_MASK 0x03 #define VISITED_ENTRY 0x04 -static inline bool is_static_jump(struct instruction *insn) -{ - return insn->type == INSN_JUMP_CONDITIONAL || - insn->type == INSN_JUMP_UNCONDITIONAL; -} - -static inline bool is_dynamic_jump(struct instruction *insn) -{ - return insn->type == INSN_JUMP_DYNAMIC || - insn->type == INSN_JUMP_DYNAMIC_CONDITIONAL; -} - -static inline bool is_jump(struct instruction *insn) -{ - return is_static_jump(insn) || is_dynamic_jump(insn); -} - -struct instruction *find_insn(struct objtool_file *file, - struct section *sec, unsigned long offset); - -#define for_each_insn(file, insn) \ - list_for_each_entry(insn, &file->insn_list, list) - -#define sec_for_each_insn(file, sec, insn) \ - for (insn = find_insn(file, sec, 0); \ - insn && &insn->list != &file->insn_list && \ - insn->sec == sec; \ - insn = list_next_entry(insn, list)) - #endif /* _CHECK_H */ diff --git a/tools/objtool/include/objtool/insn.h b/tools/objtool/include/objtool/insn.h new file mode 100644 index 000000000000..b40756a38994 --- /dev/null +++ b/tools/objtool/include/objtool/insn.h @@ -0,0 +1,125 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C) 2017 Josh Poimboeuf + */ + +#ifndef _INSN_H +#define _INSN_H + +#include +#include + +struct insn_state { + struct cfi_state cfi; + unsigned int uaccess_stack; + bool uaccess; + bool df; + bool noinstr; + s8 instr; +}; + +struct instruction { + struct list_head list; + struct hlist_node hash; + struct list_head call_node; + struct section *sec; + unsigned long offset; + unsigned int len; + enum insn_type type; + unsigned long immediate; + + u16 dead_end : 1, + ignore : 1, + ignore_alts : 1, + hint : 1, + save : 1, + restore : 1, + retpoline_safe : 1, + noendbr : 1, + entry : 1; + /* 7 bit hole */ + + s8 instr; + u8 visited; + + struct alt_group *alt_group; + struct symbol *call_dest; + struct instruction *jump_dest; + struct instruction *first_jump_src; + struct reloc *jump_table; + struct reloc *reloc; + struct list_head alts; + struct symbol *func; + struct list_head stack_ops; + struct cfi_state *cfi; +}; + +static inline bool is_static_jump(struct instruction *insn) +{ + return insn->type == INSN_JUMP_CONDITIONAL || + insn->type == INSN_JUMP_UNCONDITIONAL; +} + +static inline bool is_dynamic_jump(struct instruction *insn) +{ + return insn->type == INSN_JUMP_DYNAMIC || + insn->type == INSN_JUMP_DYNAMIC_CONDITIONAL; +} + +static inline bool is_jump(struct instruction *insn) +{ + return is_static_jump(insn) || is_dynamic_jump(insn); +} + +void init_insn_state(struct objtool_file *file, struct insn_state *state, + struct section *sec); +struct instruction *find_insn(struct objtool_file *file, + struct section *sec, unsigned long offset); +struct instruction *find_last_insn(struct objtool_file *file, + struct section *sec); +struct instruction *prev_insn_same_sym(struct objtool_file *file, + struct instruction *insn); +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); +struct reloc *insn_reloc(struct objtool_file *file, struct instruction *insn); +bool insn_cfi_match(struct instruction *insn, struct cfi_state *cfi2); +bool same_function(struct instruction *insn1, struct instruction *insn2); +bool is_first_func_insn(struct objtool_file *file, struct instruction *insn); + +#define for_each_insn(file, insn) \ + list_for_each_entry(insn, &file->insn_list, list) + +#define sec_for_each_insn(file, sec, insn) \ + for (insn = find_insn(file, sec, 0); \ + insn && &insn->list != &file->insn_list && \ + insn->sec == sec; \ + insn = list_next_entry(insn, list)) + +#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); \ + insn && &insn->list != &file->insn_list && \ + insn->sec == sym->sec && \ + insn->offset < sym->offset + sym->len; \ + insn = list_next_entry(insn, list)) + +#define sym_for_each_insn_continue_reverse(file, sym, insn) \ + for (insn = list_prev_entry(insn, list); \ + &insn->list != &file->insn_list && \ + insn->sec == sym->sec && insn->offset >= sym->offset; \ + insn = list_prev_entry(insn, list)) + +#define sec_for_each_insn_from(file, insn) \ + for (; insn; insn = next_insn_same_sec(file, insn)) + +#define sec_for_each_insn_continue(file, insn) \ + for (insn = next_insn_same_sec(file, insn); insn; \ + insn = next_insn_same_sec(file, insn)) + +#endif /* _INSN_H */ diff --git a/tools/objtool/insn.c b/tools/objtool/insn.c new file mode 100644 index 000000000000..e570b46ad39e --- /dev/null +++ b/tools/objtool/insn.c @@ -0,0 +1,186 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2015-2017 Josh Poimboeuf + */ + +#include + +#include +#include +#include + +struct instruction *find_insn(struct objtool_file *file, + struct section *sec, unsigned long offset) +{ + struct instruction *insn; + + hash_for_each_possible(file->insn_hash, insn, hash, sec_offset_hash(sec, offset)) { + if (insn->sec == sec && insn->offset == offset) + return insn; + } + + return NULL; +} + +struct instruction *next_insn_same_sec(struct objtool_file *file, + struct instruction *insn) +{ + struct instruction *next = list_next_entry(insn, list); + + if (!next || &next->list == &file->insn_list || next->sec != insn->sec) + return NULL; + + return next; +} + +struct instruction *next_insn_same_func(struct objtool_file *file, + struct instruction *insn) +{ + struct instruction *next = list_next_entry(insn, list); + struct symbol *func = insn->func; + + if (!func) + return NULL; + + if (&next->list != &file->insn_list && next->func == func) + return next; + + /* Check if we're already in the subfunction: */ + if (func == func->cfunc) + return NULL; + + /* Move to the subfunction: */ + return find_insn(file, func->cfunc->sec, func->cfunc->offset); +} + +struct instruction *prev_insn_same_sym(struct objtool_file *file, + struct instruction *insn) +{ + struct instruction *prev = list_prev_entry(insn, list); + + if (&prev->list != &file->insn_list && prev->func == insn->func) + return prev; + + return NULL; +} + +void init_insn_state(struct objtool_file *file, struct insn_state *state, + struct section *sec) +{ + memset(state, 0, sizeof(*state)); + init_cfi_state(&state->cfi); + + /* + * We need the full vmlinux for noinstr validation, otherwise we can + * not correctly determine insn->call_dest->sec (external symbols do + * not have a section). + */ + if (opts.link && opts.noinstr && sec) + state->noinstr = sec->noinstr; +} + +struct instruction *find_last_insn(struct objtool_file *file, + struct section *sec) +{ + struct instruction *insn = NULL; + unsigned int offset; + unsigned int end = (sec->sh.sh_size > 10) ? sec->sh.sh_size - 10 : 0; + + for (offset = sec->sh.sh_size - 1; offset >= end && !insn; offset--) + insn = find_insn(file, sec, offset); + + return insn; +} + +#define NEGATIVE_RELOC ((void *)-1L) + +struct reloc *insn_reloc(struct objtool_file *file, struct instruction *insn) +{ + if (insn->reloc == NEGATIVE_RELOC) + return NULL; + + if (!insn->reloc) { + if (!file) + return NULL; + + insn->reloc = find_reloc_by_dest_range(file->elf, insn->sec, + insn->offset, insn->len); + if (!insn->reloc) { + insn->reloc = NEGATIVE_RELOC; + return NULL; + } + } + + return insn->reloc; +} + +bool same_function(struct instruction *insn1, struct instruction *insn2) +{ + return insn1->func->pfunc == insn2->func->pfunc; +} + +bool is_first_func_insn(struct objtool_file *file, struct instruction *insn) +{ + if (insn->offset == insn->func->offset) + return true; + + if (opts.ibt) { + struct instruction *prev = prev_insn_same_sym(file, insn); + + if (prev && prev->type == INSN_ENDBR && + insn->offset == insn->func->offset + prev->len) + return true; + } + + return false; +} + +bool insn_cfi_match(struct instruction *insn, struct cfi_state *cfi2) +{ + struct cfi_state *cfi1 = insn->cfi; + int i; + + if (!cfi1) { + WARN("CFI missing"); + return false; + } + + if (memcmp(&cfi1->cfa, &cfi2->cfa, sizeof(cfi1->cfa))) { + + WARN_FUNC("stack state mismatch: cfa1=%d%+d cfa2=%d%+d", + insn->sec, insn->offset, + cfi1->cfa.base, cfi1->cfa.offset, + cfi2->cfa.base, cfi2->cfa.offset); + + } else if (memcmp(&cfi1->regs, &cfi2->regs, sizeof(cfi1->regs))) { + for (i = 0; i < CFI_NUM_REGS; i++) { + if (!memcmp(&cfi1->regs[i], &cfi2->regs[i], + sizeof(struct cfi_reg))) + continue; + + WARN_FUNC("stack state mismatch: reg1[%d]=%d%+d reg2[%d]=%d%+d", + insn->sec, insn->offset, + i, cfi1->regs[i].base, cfi1->regs[i].offset, + i, cfi2->regs[i].base, cfi2->regs[i].offset); + break; + } + + } else if (cfi1->type != cfi2->type) { + + WARN_FUNC("stack state mismatch: type1=%d type2=%d", + insn->sec, insn->offset, cfi1->type, cfi2->type); + + } else if (cfi1->drap != cfi2->drap || + (cfi1->drap && cfi1->drap_reg != cfi2->drap_reg) || + (cfi1->drap && cfi1->drap_offset != cfi2->drap_offset)) { + + WARN_FUNC("stack state mismatch: drap1=%d(%d,%d) drap2=%d(%d,%d)", + insn->sec, insn->offset, + cfi1->drap, cfi1->drap_reg, cfi1->drap_offset, + cfi2->drap, cfi2->drap_reg, cfi2->drap_offset); + + } else + return true; + + return false; +} -- 2.25.1