From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 07DFE274FDE; Thu, 26 Jun 2025 23:56:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750982199; cv=none; b=tDNOHeajLTzyu86sAQcqpO+8hqQYQJ7WGXn7/z+kkwMllhlrStSmPSeDgyJJ4GRt7neZyB5hV3xI/57VewMN6sKo1TG/GV0NLEEBhQu2Q7XOuGTUnqaGUHlxtdbudjIAShNjyEvGtxIYK/4MnTr5TihL+ccUrtimuRWhInAWoNY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750982199; c=relaxed/simple; bh=YFjpIuy+cdDolJGfH6auTZuPlPXQPBgN7+Za6i/GtdM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=r+iXsbOyNmc/664v5TsgWXFVS1xrGTg+Ucf0Tbvw2fEZiY6Mv4dOPrx+BV6xVqe0kYo6Ilit2KVuTVt+fl6f8qvwYzbJChyscnZUTUhkqWWkhiofz2NuegwNZHuqotB0Y5uqSZIrOPxIg4qPpJH+7D1zPoN/2uS7FsYnHR8WtdM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TrXyQqOO; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="TrXyQqOO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4C6F8C4CEEF; Thu, 26 Jun 2025 23:56:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750982198; bh=YFjpIuy+cdDolJGfH6auTZuPlPXQPBgN7+Za6i/GtdM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TrXyQqOO59nfM6h2xq56JzN3TKWesc1RMqwiFby6lPGv+xEgRtFJhWeQeyvjSgCl6 rYZdXjbmmxy77vdhhw9iM+OWD0gVADz7abQkr5Yc/JBKD+rkfhK/3KRXmEHkg8hlQ+ 4Jnq3aqOBOLnt2EV7E2ZsvTUw+MVrJUsTGfBl66838zDMtZTMzp77dgcjX0VZfQh8p J29RhSh1roNXeW4oMC8PWUqcnpmALObQ6+ijhBf8/2jioqj+cTDqOnIZKMzFvPfDQt Wk4tJoyPG/EBHgnXhdaKFTHdU8C4n23a9xyrdRBR5AFuvKM/hmE8pNZQaziKTwSrNo Yz2IYd3AB59xw== From: Josh Poimboeuf To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, Petr Mladek , Miroslav Benes , Joe Lawrence , live-patching@vger.kernel.org, Song Liu , laokz , Jiri Kosina , Marcos Paulo de Souza , Weinan Liu , Fazla Mehrab , Chen Zhongjin , Puranjay Mohan , Dylan Hatch Subject: [PATCH v3 39/64] objtool: Add elf_create_data() Date: Thu, 26 Jun 2025 16:55:26 -0700 Message-ID: X-Mailer: git-send-email 2.49.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: live-patching@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit In preparation for the objtool klp diff subcommand, refactor elf_add_string() by adding a new elf_add_data() helper which allows the adding of arbitrary data to a section. Make both interfaces public so they can be used by the upcoming klp diff code. Signed-off-by: Josh Poimboeuf --- tools/objtool/elf.c | 66 ++++++++++++++++++++--------- tools/objtool/include/objtool/elf.h | 10 +++-- 2 files changed, 54 insertions(+), 22 deletions(-) diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 4f56ea426683..535bdcf077d0 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -18,10 +18,11 @@ #include #include #include - #include #include +#define ALIGN_UP(x, align_to) (((x) + ((align_to)-1)) & ~((align_to)-1)) + static inline u32 str_hash(const char *str) { return jhash(str, strlen(str), 0); @@ -760,8 +761,6 @@ static int elf_update_symbol(struct elf *elf, struct section *symtab, return 0; } -static int elf_add_string(struct elf *elf, struct section *strtab, const char *str); - struct symbol *elf_create_symbol(struct elf *elf, const char *name, struct section *sec, unsigned int bind, unsigned int type, unsigned long offset, @@ -1097,11 +1096,9 @@ struct elf *elf_open_read(const char *name, int flags) return NULL; } -static int elf_add_string(struct elf *elf, struct section *strtab, const char *str) +unsigned int elf_add_string(struct elf *elf, struct section *strtab, const char *str) { - Elf_Data *data; - Elf_Scn *s; - int len; + unsigned int offset; if (!strtab) strtab = find_section_by_name(elf, ".strtab"); @@ -1110,28 +1107,59 @@ static int elf_add_string(struct elf *elf, struct section *strtab, const char *s return -1; } - s = elf_getscn(elf->elf, strtab->idx); + if (!strtab->sh.sh_addralign) { + ERROR("'%s': invalid sh_addralign", strtab->name); + return -1; + } + + offset = ALIGN_UP(strtab->sh.sh_size, strtab->sh.sh_addralign); + + if (!elf_add_data(elf, strtab, str, strlen(str) + 1)) + return -1; + + return offset; +} + +void *elf_add_data(struct elf *elf, struct section *sec, const void *data, size_t size) +{ + unsigned long offset; + Elf_Scn *s; + + if (!sec->sh.sh_addralign) { + ERROR("'%s': invalid sh_addralign", sec->name); + return NULL; + } + + s = elf_getscn(elf->elf, sec->idx); if (!s) { ERROR_ELF("elf_getscn"); - return -1; + return NULL; } - data = elf_newdata(s); - if (!data) { + sec->data = elf_newdata(s); + if (!sec->data) { ERROR_ELF("elf_newdata"); - return -1; + return NULL; } - data->d_buf = strdup(str); - data->d_size = strlen(str) + 1; - data->d_align = 1; + sec->data->d_buf = calloc(1, size); + if (!sec->data->d_buf) { + ERROR_GLIBC("calloc"); + return NULL; + } - len = strtab->sh.sh_size; - strtab->sh.sh_size += data->d_size; + if (data) + memcpy(sec->data->d_buf, data, size); - mark_sec_changed(elf, strtab, true); + sec->data->d_size = size; + sec->data->d_align = 1; - return len; + offset = ALIGN_UP(sec->sh.sh_size, sec->sh.sh_addralign); + sec->sh.sh_size = offset + size; + + mark_sec_changed(elf, sec, true); + + return sec->data->d_buf; } struct section *elf_create_section(struct elf *elf, const char *name, diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index b366516b119d..fc00f86bedba 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -134,6 +134,10 @@ struct symbol *elf_create_section_symbol(struct elf *elf, struct section *sec); struct symbol *elf_create_prefix_symbol(struct elf *elf, struct symbol *orig, size_t size); +void *elf_add_data(struct elf *elf, struct section *sec, const void *data, + size_t size); + +unsigned int elf_add_string(struct elf *elf, struct section *strtab, const char *str); struct reloc *elf_init_reloc_text_sym(struct elf *elf, struct section *sec, unsigned long offset, @@ -147,9 +151,9 @@ struct reloc *elf_init_reloc_data_sym(struct elf *elf, struct section *sec, struct symbol *sym, s64 addend); -int elf_write_insn(struct elf *elf, struct section *sec, - unsigned long offset, unsigned int len, - const char *insn); +int elf_write_insn(struct elf *elf, struct section *sec, unsigned long offset, + unsigned int len, const char *insn); + int elf_write(struct elf *elf); void elf_close(struct elf *elf); -- 2.49.0