From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, T_DKIMWL_WL_MED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 20678C43142 for ; Mon, 25 Jun 2018 22:42:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C36852622D for ; Mon, 25 Jun 2018 22:42:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="oBXDkDZ2" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C36852622D Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755754AbeFYWm4 (ORCPT ); Mon, 25 Jun 2018 18:42:56 -0400 Received: from mail-yw0-f202.google.com ([209.85.161.202]:37668 "EHLO mail-yw0-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754079AbeFYWmx (ORCPT ); Mon, 25 Jun 2018 18:42:53 -0400 Received: by mail-yw0-f202.google.com with SMTP id p11-v6so2698312ywm.4 for ; Mon, 25 Jun 2018 15:42:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:date:in-reply-to:message-id:references:subject:from:to :cc; bh=R2r79+X0b/ELpXa2zgTHCygaB4cb8B9XjtpsN6oi2vE=; b=oBXDkDZ2moMDG/e0KqKyw2G9lofsExkCswfJhgNE8feHvIqmuPEgj+FRjvC6VX38lF /G/H6WRRFYVY6RWa+wMzrRpTnPGSnnbaFURbKLQn+K02QK1CpTaecd7tr09MVj/glhk7 LLKSUo64fYvVWGgbPCdsZ4YHgjd3IxHngjStY+hJ0+ZsEpmrIFA0c3BDRxjnOLysFACs O8Rz/CAtrrOJo4Ie6117mnzdQarvkcYKfip/pGjdrvoJJh928ew4m0cNrsf57Z/BMaet 20yfJRhps6V6IPmz9n7R32nv8b3WsG0IXj0Qu7vhtTootIaK3QFZnaHaleUfdgG2VwRu KigA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:date:in-reply-to:message-id :references:subject:from:to:cc; bh=R2r79+X0b/ELpXa2zgTHCygaB4cb8B9XjtpsN6oi2vE=; b=fhJJcDbIJ1EUL7boSlIkeq2/dldzL1jmVku/M4nGBubJFpbet8oq+PowHbe4glMZGR epiapnICWqRVZtUfiU1GWF5Fw9OSX8joFxc2Cq8upC91v+to8mqLSi2lqiz/A+y/gSFz cvXkC4H5VJCUgop5uOA6whNWa7LN1S3KOpAUx9u8xBsRtKF7IxT3wLWnqOBBI8pRmRze zqcX9BQvubFIqHoM5DJYS1TfdMRwcyfz6qbuDLBnpRg5FdtApXQT4iFt+c6OaxOpXp5S wwAqZ+YVBgkP6R3K7QmKum9vZ/RZhp27RnmEvYMKrJMLCLb+3+yUBM94e6DCc/2utd1t OncQ== X-Gm-Message-State: APt69E0ZI/Z8CoAGmCWPmivU9Rbh7ZqJ6lXQUb3xNtNaUdHaODT4Ir+o 2jLVpHlXnByNxgpKxs0qsipT4V5uVsAUXg== X-Google-Smtp-Source: ADUXVKJt2WPZGwuCOhBK2mS9NR98cUP/hV1PBdPmLq1Wx2OOXovNBg/gEYfH4sw+Q5ejyaq7okbJGp6Ewo8JFw== MIME-Version: 1.0 X-Received: by 2002:a81:9a93:: with SMTP id r141-v6mr3821092ywg.159.1529966572456; Mon, 25 Jun 2018 15:42:52 -0700 (PDT) Date: Mon, 25 Jun 2018 15:39:14 -0700 In-Reply-To: <20180625224014.134829-1-thgarnie@google.com> Message-Id: <20180625224014.134829-27-thgarnie@google.com> References: <20180625224014.134829-1-thgarnie@google.com> X-Mailer: git-send-email 2.18.0.rc2.346.g013aa6912e-goog Subject: [PATCH v5 26/27] x86/relocs: Add option to generate 64-bit relocations From: Thomas Garnier To: kernel-hardening@lists.openwall.com Cc: Thomas Garnier , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, "H.J. Lu" , Philippe Ombredanne , Kate Stewart , Greg Kroah-Hartman , linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The x86 relocation tool generates a list of 32-bit signed integers. There was no need to use 64-bit integers because all addresses where above the 2G top of the memory. This change add a large-reloc option to generate 64-bit unsigned integers. It can be used when the kernel plan to go below the top 2G and 32-bit integers are not enough. Signed-off-by: Thomas Garnier --- arch/x86/tools/relocs.c | 60 +++++++++++++++++++++++++++------- arch/x86/tools/relocs.h | 4 +-- arch/x86/tools/relocs_common.c | 15 ++++++--- 3 files changed, 60 insertions(+), 19 deletions(-) diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c index 29283ad3950f..a29cccceaac6 100644 --- a/arch/x86/tools/relocs.c +++ b/arch/x86/tools/relocs.c @@ -13,8 +13,14 @@ static Elf_Ehdr ehdr; +#if ELF_BITS == 64 +typedef uint64_t rel_off_t; +#else +typedef uint32_t rel_off_t; +#endif + struct relocs { - uint32_t *offset; + rel_off_t *offset; unsigned long count; unsigned long size; }; @@ -685,7 +691,7 @@ static void print_absolute_relocs(void) printf("\n"); } -static void add_reloc(struct relocs *r, uint32_t offset) +static void add_reloc(struct relocs *r, rel_off_t offset) { if (r->count == r->size) { unsigned long newsize = r->size + 50000; @@ -1061,26 +1067,48 @@ static void sort_relocs(struct relocs *r) qsort(r->offset, r->count, sizeof(r->offset[0]), cmp_relocs); } -static int write32(uint32_t v, FILE *f) +static int write32(rel_off_t rel, FILE *f) { - unsigned char buf[4]; + unsigned char buf[sizeof(uint32_t)]; + uint32_t v = (uint32_t)rel; put_unaligned_le32(v, buf); - return fwrite(buf, 1, 4, f) == 4 ? 0 : -1; + return fwrite(buf, 1, sizeof(buf), f) == sizeof(buf) ? 0 : -1; } -static int write32_as_text(uint32_t v, FILE *f) +static int write32_as_text(rel_off_t rel, FILE *f) { + uint32_t v = (uint32_t)rel; return fprintf(f, "\t.long 0x%08"PRIx32"\n", v) > 0 ? 0 : -1; } -static void emit_relocs(int as_text, int use_real_mode) +static int write64(rel_off_t rel, FILE *f) +{ + unsigned char buf[sizeof(uint64_t)]; + uint64_t v = (uint64_t)rel; + + put_unaligned_le64(v, buf); + return fwrite(buf, 1, sizeof(buf), f) == sizeof(buf) ? 0 : -1; +} + +static int write64_as_text(rel_off_t rel, FILE *f) +{ + uint64_t v = (uint64_t)rel; + return fprintf(f, "\t.quad 0x%016"PRIx64"\n", v) > 0 ? 0 : -1; +} + +static void emit_relocs(int as_text, int use_real_mode, int use_large_reloc) { int i; - int (*write_reloc)(uint32_t, FILE *) = write32; + int (*write_reloc)(rel_off_t, FILE *); int (*do_reloc)(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, const char *symname); + if (use_large_reloc) + write_reloc = write64; + else + write_reloc = write32; + #if ELF_BITS == 64 if (!use_real_mode) do_reloc = do_reloc64; @@ -1091,6 +1119,9 @@ static void emit_relocs(int as_text, int use_real_mode) do_reloc = do_reloc32; else do_reloc = do_reloc_real; + + /* Large relocations only for 64-bit */ + use_large_reloc = 0; #endif /* Collect up the relocations */ @@ -1114,8 +1145,13 @@ static void emit_relocs(int as_text, int use_real_mode) * gas will like. */ printf(".section \".data.reloc\",\"a\"\n"); - printf(".balign 4\n"); - write_reloc = write32_as_text; + if (use_large_reloc) { + printf(".balign 8\n"); + write_reloc = write64_as_text; + } else { + printf(".balign 4\n"); + write_reloc = write32_as_text; + } } if (use_real_mode) { @@ -1183,7 +1219,7 @@ static void print_reloc_info(void) void process(FILE *fp, int use_real_mode, int as_text, int show_absolute_syms, int show_absolute_relocs, - int show_reloc_info) + int show_reloc_info, int use_large_reloc) { regex_init(use_real_mode); read_ehdr(fp); @@ -1206,5 +1242,5 @@ void process(FILE *fp, int use_real_mode, int as_text, print_reloc_info(); return; } - emit_relocs(as_text, use_real_mode); + emit_relocs(as_text, use_real_mode, use_large_reloc); } diff --git a/arch/x86/tools/relocs.h b/arch/x86/tools/relocs.h index 43c83c0fd22c..3d401da59df7 100644 --- a/arch/x86/tools/relocs.h +++ b/arch/x86/tools/relocs.h @@ -31,8 +31,8 @@ enum symtype { void process_32(FILE *fp, int use_real_mode, int as_text, int show_absolute_syms, int show_absolute_relocs, - int show_reloc_info); + int show_reloc_info, int use_large_reloc); void process_64(FILE *fp, int use_real_mode, int as_text, int show_absolute_syms, int show_absolute_relocs, - int show_reloc_info); + int show_reloc_info, int use_large_reloc); #endif /* RELOCS_H */ diff --git a/arch/x86/tools/relocs_common.c b/arch/x86/tools/relocs_common.c index 6634352a20bc..11f49adf1c06 100644 --- a/arch/x86/tools/relocs_common.c +++ b/arch/x86/tools/relocs_common.c @@ -12,14 +12,14 @@ void die(char *fmt, ...) static void usage(void) { - die("relocs [--abs-syms|--abs-relocs|--reloc-info|--text|--realmode]" \ - " vmlinux\n"); + die("relocs [--abs-syms|--abs-relocs|--reloc-info|--text|--realmode|" \ + "--large-reloc] vmlinux\n"); } int main(int argc, char **argv) { int show_absolute_syms, show_absolute_relocs, show_reloc_info; - int as_text, use_real_mode; + int as_text, use_real_mode, use_large_reloc; const char *fname; FILE *fp; int i; @@ -30,6 +30,7 @@ int main(int argc, char **argv) show_reloc_info = 0; as_text = 0; use_real_mode = 0; + use_large_reloc = 0; fname = NULL; for (i = 1; i < argc; i++) { char *arg = argv[i]; @@ -54,6 +55,10 @@ int main(int argc, char **argv) use_real_mode = 1; continue; } + if (strcmp(arg, "--large-reloc") == 0) { + use_large_reloc = 1; + continue; + } } else if (!fname) { fname = arg; @@ -75,11 +80,11 @@ int main(int argc, char **argv) if (e_ident[EI_CLASS] == ELFCLASS64) process_64(fp, use_real_mode, as_text, show_absolute_syms, show_absolute_relocs, - show_reloc_info); + show_reloc_info, use_large_reloc); else process_32(fp, use_real_mode, as_text, show_absolute_syms, show_absolute_relocs, - show_reloc_info); + show_reloc_info, use_large_reloc); fclose(fp); return 0; } -- 2.18.0.rc2.346.g013aa6912e-goog