From nobody Fri Apr 19 23:28:16 2024 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 1F468C433FE for ; Tue, 24 May 2022 00:16:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231383AbiEXAQw (ORCPT ); Mon, 23 May 2022 20:16:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58164 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229453AbiEXAQu (ORCPT ); Mon, 23 May 2022 20:16:50 -0400 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 7B8B36BFE2; Mon, 23 May 2022 17:16:48 -0700 (PDT) Received: from x64host.home (unknown [47.189.24.195]) by linux.microsoft.com (Postfix) with ESMTPSA id 69AFD20B6C7C; Mon, 23 May 2022 17:16:47 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 69AFD20B6C7C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1653351408; bh=/tONLk1QXRDCTsXJLk+T4mjehc+6vK0E7p5YrpSTPtk=; h=From:To:Subject:Date:In-Reply-To:References:From; b=NtS0Q9D8QbZiGnNIvmshLwN+aeWRo/Unp38H0DrQs7OH58PS0FtYYPCjwFgHliFnp YRh9KMzz+qaWjpyB6+aDgGoXPMC9H1DdzQIfj8RDD9Tdf8DZvEY7DMmj49rpiWPT6E M9R40O6YRiI6c3DNueI5Lnw/B3tngTedfG2cNVhg= 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 v2 01/20] objtool: Reorganize CFI code Date: Mon, 23 May 2022 19:16:18 -0500 Message-Id: <20220524001637.1707472-2-madvenka@linux.microsoft.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220524001637.1707472-1-madvenka@linux.microsoft.com> References: <20220524001637.1707472-1-madvenka@linux.microsoft.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "Madhavan T. Venkataraman" check.c implements static stack validation. But the CFI code that it contains can be shared with other types of validation. E.g., dynamic FP validation. Move the CFI code to its own files - cfi.h and cfi.c. Signed-off-by: Madhavan T. Venkataraman --- tools/objtool/Build | 2 + tools/objtool/cfi.c | 108 ++++++++++++++++++++++++++++ tools/objtool/check.c | 96 ------------------------- tools/objtool/include/objtool/cfi.h | 12 ++++ 4 files changed, 122 insertions(+), 96 deletions(-) create mode 100644 tools/objtool/cfi.c diff --git a/tools/objtool/Build b/tools/objtool/Build index b7222d5cc7bc..695cfee5cfde 100644 --- a/tools/objtool/Build +++ b/tools/objtool/Build @@ -3,8 +3,10 @@ objtool-y +=3D arch/$(SRCARCH)/ objtool-y +=3D weak.o =20 objtool-$(SUBCMD_CHECK) +=3D check.o +objtool-$(SUBCMD_CHECK) +=3D cfi.o objtool-$(SUBCMD_CHECK) +=3D special.o objtool-$(SUBCMD_ORC) +=3D check.o +objtool-$(SUBCMD_ORC) +=3D cfi.o objtool-$(SUBCMD_ORC) +=3D orc_gen.o objtool-$(SUBCMD_ORC) +=3D orc_dump.o =20 diff --git a/tools/objtool/cfi.c b/tools/objtool/cfi.c new file mode 100644 index 000000000000..d5de6df59d72 --- /dev/null +++ b/tools/objtool/cfi.c @@ -0,0 +1,108 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2015-2017 Josh Poimboeuf + */ + +#include +#include + +#include +#include +#include + +unsigned long nr_cfi, nr_cfi_reused, nr_cfi_cache; + +struct cfi_init_state initial_func_cfi; +struct cfi_state init_cfi; +struct cfi_state func_cfi; + +void init_cfi_state(struct cfi_state *cfi) +{ + int i; + + for (i =3D 0; i < CFI_NUM_REGS; i++) { + cfi->regs[i].base =3D CFI_UNDEFINED; + cfi->vals[i].base =3D CFI_UNDEFINED; + } + cfi->cfa.base =3D CFI_UNDEFINED; + cfi->drap_reg =3D CFI_UNDEFINED; + cfi->drap_offset =3D -1; +} + +static struct cfi_state *cfi_alloc(void) +{ + struct cfi_state *cfi =3D calloc(sizeof(struct cfi_state), 1); + + if (!cfi) { + WARN("calloc failed"); + exit(1); + } + nr_cfi++; + return cfi; +} + +static int cfi_bits; +static struct hlist_head *cfi_hash; + +bool cficmp(struct cfi_state *cfi1, struct cfi_state *cfi2) +{ + return memcmp((void *)cfi1 + sizeof(cfi1->hash), + (void *)cfi2 + sizeof(cfi2->hash), + sizeof(struct cfi_state) - sizeof(struct hlist_node)); +} + +static inline u32 cfi_key(struct cfi_state *cfi) +{ + return jhash((void *)cfi + sizeof(cfi->hash), + sizeof(*cfi) - sizeof(cfi->hash), 0); +} + +struct cfi_state *cfi_hash_find_or_add(struct cfi_state *cfi) +{ + struct hlist_head *head =3D &cfi_hash[hash_min(cfi_key(cfi), cfi_bits)]; + struct cfi_state *obj; + + hlist_for_each_entry(obj, head, hash) { + if (!cficmp(cfi, obj)) { + nr_cfi_cache++; + return obj; + } + } + + obj =3D cfi_alloc(); + *obj =3D *cfi; + hlist_add_head(&obj->hash, head); + + return obj; +} + +void cfi_hash_add(struct cfi_state *cfi) +{ + struct hlist_head *head =3D &cfi_hash[hash_min(cfi_key(cfi), cfi_bits)]; + + hlist_add_head(&cfi->hash, head); +} + +void *cfi_hash_alloc(unsigned long size) +{ + cfi_bits =3D max(10, ilog2(size)); + cfi_hash =3D mmap(NULL, sizeof(struct hlist_head) << cfi_bits, + PROT_READ|PROT_WRITE, + MAP_PRIVATE|MAP_ANON, -1, 0); + if (cfi_hash =3D=3D (void *)-1L) { + WARN("mmap fail cfi_hash"); + cfi_hash =3D NULL; + } else if (stats) { + printf("cfi_bits: %d\n", cfi_bits); + } + + return cfi_hash; +} + +void set_func_state(struct cfi_state *state) +{ + state->cfa =3D initial_func_cfi.cfa; + memcpy(&state->regs, &initial_func_cfi.regs, + CFI_NUM_REGS * sizeof(struct cfi_reg)); + state->stack_size =3D initial_func_cfi.cfa.offset; +} diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 6de5085e3e5a..12acc9d329de 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -27,12 +27,6 @@ struct alternative { bool skip_orig; }; =20 -static unsigned long nr_cfi, nr_cfi_reused, nr_cfi_cache; - -static struct cfi_init_state initial_func_cfi; -static struct cfi_state init_cfi; -static struct cfi_state func_cfi; - struct instruction *find_insn(struct objtool_file *file, struct section *sec, unsigned long offset) { @@ -249,19 +243,6 @@ static bool dead_end_function(struct objtool_file *fil= e, struct symbol *func) return __dead_end_function(file, func, 0); } =20 -static void init_cfi_state(struct cfi_state *cfi) -{ - int i; - - for (i =3D 0; i < CFI_NUM_REGS; i++) { - cfi->regs[i].base =3D CFI_UNDEFINED; - cfi->vals[i].base =3D CFI_UNDEFINED; - } - cfi->cfa.base =3D CFI_UNDEFINED; - cfi->drap_reg =3D CFI_UNDEFINED; - cfi->drap_offset =3D -1; -} - static void init_insn_state(struct insn_state *state, struct section *sec) { memset(state, 0, sizeof(*state)); @@ -276,75 +257,6 @@ static void init_insn_state(struct insn_state *state, = struct section *sec) state->noinstr =3D sec->noinstr; } =20 -static struct cfi_state *cfi_alloc(void) -{ - struct cfi_state *cfi =3D calloc(sizeof(struct cfi_state), 1); - if (!cfi) { - WARN("calloc failed"); - exit(1); - } - nr_cfi++; - return cfi; -} - -static int cfi_bits; -static struct hlist_head *cfi_hash; - -static inline bool cficmp(struct cfi_state *cfi1, struct cfi_state *cfi2) -{ - return memcmp((void *)cfi1 + sizeof(cfi1->hash), - (void *)cfi2 + sizeof(cfi2->hash), - sizeof(struct cfi_state) - sizeof(struct hlist_node)); -} - -static inline u32 cfi_key(struct cfi_state *cfi) -{ - return jhash((void *)cfi + sizeof(cfi->hash), - sizeof(*cfi) - sizeof(cfi->hash), 0); -} - -static struct cfi_state *cfi_hash_find_or_add(struct cfi_state *cfi) -{ - struct hlist_head *head =3D &cfi_hash[hash_min(cfi_key(cfi), cfi_bits)]; - struct cfi_state *obj; - - hlist_for_each_entry(obj, head, hash) { - if (!cficmp(cfi, obj)) { - nr_cfi_cache++; - return obj; - } - } - - obj =3D cfi_alloc(); - *obj =3D *cfi; - hlist_add_head(&obj->hash, head); - - return obj; -} - -static void cfi_hash_add(struct cfi_state *cfi) -{ - struct hlist_head *head =3D &cfi_hash[hash_min(cfi_key(cfi), cfi_bits)]; - - hlist_add_head(&cfi->hash, head); -} - -static void *cfi_hash_alloc(unsigned long size) -{ - cfi_bits =3D max(10, ilog2(size)); - cfi_hash =3D mmap(NULL, sizeof(struct hlist_head) << cfi_bits, - PROT_READ|PROT_WRITE, - MAP_PRIVATE|MAP_ANON, -1, 0); - if (cfi_hash =3D=3D (void *)-1L) { - WARN("mmap fail cfi_hash"); - cfi_hash =3D NULL; - } else if (stats) { - printf("cfi_bits: %d\n", cfi_bits); - } - - return cfi_hash; -} - static unsigned long nr_insns; static unsigned long nr_insns_visited; =20 @@ -1866,14 +1778,6 @@ static int add_jump_table_alts(struct objtool_file *= file) return 0; } =20 -static void set_func_state(struct cfi_state *state) -{ - state->cfa =3D initial_func_cfi.cfa; - memcpy(&state->regs, &initial_func_cfi.regs, - CFI_NUM_REGS * sizeof(struct cfi_reg)); - state->stack_size =3D initial_func_cfi.cfa.offset; -} - static int read_unwind_hints(struct objtool_file *file) { struct cfi_state cfi =3D init_cfi; diff --git a/tools/objtool/include/objtool/cfi.h b/tools/objtool/include/ob= jtool/cfi.h index f11d1ac1dadf..7d54f1058655 100644 --- a/tools/objtool/include/objtool/cfi.h +++ b/tools/objtool/include/objtool/cfi.h @@ -37,4 +37,16 @@ struct cfi_state { bool end; }; =20 +void init_cfi_state(struct cfi_state *cfi); +struct cfi_state *cfi_hash_find_or_add(struct cfi_state *cfi); +void cfi_hash_add(struct cfi_state *cfi); +void *cfi_hash_alloc(unsigned long size); +bool cficmp(struct cfi_state *cfi1, struct cfi_state *cfi2); +void set_func_state(struct cfi_state *state); + +extern unsigned long nr_cfi, nr_cfi_reused, nr_cfi_cache; +extern struct cfi_init_state initial_func_cfi; +extern struct cfi_state init_cfi; +extern struct cfi_state func_cfi; + #endif /* _OBJTOOL_CFI_H */ --=20 2.25.1