From patchwork Tue Feb 18 14:24:28 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andi Kleen X-Patchwork-Id: 3671181 Return-Path: X-Original-To: patchwork-linux-kbuild@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 513739F39B for ; Tue, 18 Feb 2014 14:26:46 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 40DBC201F7 for ; Tue, 18 Feb 2014 14:26:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2CF5F201D3 for ; Tue, 18 Feb 2014 14:26:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755766AbaBROZ0 (ORCPT ); Tue, 18 Feb 2014 09:25:26 -0500 Received: from mga11.intel.com ([192.55.52.93]:38928 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755084AbaBROZY (ORCPT ); Tue, 18 Feb 2014 09:25:24 -0500 Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga102.fm.intel.com with ESMTP; 18 Feb 2014 06:25:12 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,502,1389772800"; d="scan'208";a="483434542" Received: from laut.jf.intel.com (HELO localhost) ([10.23.232.94]) by fmsmga002.fm.intel.com with ESMTP; 18 Feb 2014 06:25:12 -0800 Received: by localhost (Postfix, from userid 1000) id E8F2F124ACD; Tue, 18 Feb 2014 15:24:32 +0100 (CET) From: Andi Kleen To: linux-kernel@vger.kernel.org Cc: sam@ravnborg.org, x86@kernel.org, linux-kbuild@vger.kernel.org, Andi Kleen Subject: [PATCH 4/6] kbuild: Support padding in kallsyms tables v2 Date: Tue, 18 Feb 2014 15:24:28 +0100 Message-Id: <1392733470-8228-5-git-send-email-andi@firstfloor.org> X-Mailer: git-send-email 1.8.5.2 In-Reply-To: <1392733470-8228-1-git-send-email-andi@firstfloor.org> References: <1392733470-8228-1-git-send-email-andi@firstfloor.org> Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Andi Kleen Add support for padding the variable length tables in kallsyms. This adds a new --pad=XXX option to kallsyms to specify the table lengths, and another option --pad-file=X to write the table lengths to a file. Then when a table is shorter than the padding add the necessary padding at the end. This allows to replace an existing symbol table later with a different one that may differ slightly. Add 5% slack for now in case the prediction is too small (can happen with LTO) v2: Fix build error, found by Markus Trippelsdorf. Signed-off-by: Andi Kleen --- scripts/kallsyms.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 90 insertions(+), 3 deletions(-) diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c index d79027e..293c9eb 100644 --- a/scripts/kallsyms.c +++ b/scripts/kallsyms.c @@ -23,6 +23,13 @@ #include #include +/* + * The ratio to increase the padding, by how much the final kallsyms + * can be larger. This is for symbols that are not visible before + * final linking. + */ +#define PAD_RATIO 20 /* 1/x = ~5% */ + #ifndef ARRAY_SIZE #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0])) #endif @@ -41,6 +48,14 @@ struct text_range { unsigned long long start, end; }; +enum pads { + PAD_OFF, + PAD_NAMES, + PAD_MARKERS, + PAD_TOKTAB, + NUM_PAD +}; + static unsigned long long _text; static struct text_range text_ranges[] = { { "_stext", "_etext" }, @@ -69,6 +84,7 @@ static void usage(void) fprintf(stderr, "Usage: kallsyms [--all-symbols] " "[--symbol-prefix=] " "[--page-offset=] " + "[--pad=A,B,C] [--pad-file=name] " "< in.map > out.S\n"); exit(1); } @@ -303,7 +319,14 @@ static int expand_symbol(unsigned char *data, int len, char *result) return total; } -static void write_src(void) +static void bad_padding(char *msg, int diff) +{ + fprintf(stderr, "kallsyms: %s padding too short: %d missing\n", + msg, diff); + exit(EXIT_FAILURE); +} + +static void write_src(int *pad, int *opad) { unsigned int i, k, off; unsigned int best_idx[256]; @@ -335,6 +358,16 @@ static void write_src(void) for (i = 0; i < table_cnt; i++) { printf("\tPTR\t%#llx\n", table[i].addr - _text); } + if (pad) { + if (i > pad[PAD_OFF]) + bad_padding("address pointers", i - pad[PAD_OFF]); + for (; i < pad[PAD_OFF]; i++) + printf("\tPTR\t0\n"); + } else { + for (i = 0; i < table_cnt / PAD_RATIO; i++) + printf("\tPTR\t0\n"); + opad[PAD_OFF] = table_cnt + table_cnt/PAD_RATIO; + } printf("\n"); output_label("kallsyms_num_syms"); @@ -363,11 +396,31 @@ static void write_src(void) off += table[i].len + 1; } + if (pad) { + if (off > pad[PAD_NAMES]) + bad_padding("name table", off - pad[PAD_NAMES]); + if (off < pad[PAD_NAMES]) + printf("\t.fill %d,1,0\n", pad[PAD_NAMES] - off); + } else { + printf("\t.fill %d,1,0\n", off/PAD_RATIO); + off += off/PAD_RATIO; + opad[PAD_NAMES] = off; + } printf("\n"); output_label("kallsyms_markers"); for (i = 0; i < ((table_cnt + 255) >> 8); i++) printf("\tPTR\t%d\n", markers[i]); + if (pad) { + if (i > pad[PAD_MARKERS]) + bad_padding("markers", i - pad[PAD_MARKERS]); + for (; i < pad[PAD_MARKERS]; i++) + printf("\tPTR\t0\n"); + } else { + for (k = 0; k < i/PAD_RATIO; k++) + printf("\tPTR\t0\n"); + opad[PAD_MARKERS] = i + i/PAD_RATIO; + } printf("\n"); free(markers); @@ -380,6 +433,16 @@ static void write_src(void) printf("\t.asciz\t\"%s\"\n", buf); off += strlen(buf) + 1; } + if (pad) { + if (off > pad[PAD_TOKTAB]) + bad_padding("token table", off - pad[PAD_TOKTAB]); + if (off < pad[PAD_TOKTAB]) + printf("\t.fill %d,1,0\n", pad[PAD_TOKTAB] - off); + } else { + printf("\t.fill %d,1,0\n", off/PAD_RATIO); + off += off/PAD_RATIO; + opad[PAD_TOKTAB] = off; + } printf("\n"); output_label("kallsyms_token_index"); @@ -647,6 +710,10 @@ static void sort_symbols(void) int main(int argc, char **argv) { + int inpad[NUM_PAD], opad[NUM_PAD]; + int *inpadp = NULL; + FILE *opadf = NULL; + if (argc >= 2) { int i; for (i = 1; i < argc; i++) { @@ -661,6 +728,22 @@ int main(int argc, char **argv) } else if (strncmp(argv[i], "--page-offset=", 14) == 0) { const char *p = &argv[i][14]; kernel_start_addr = strtoull(p, NULL, 16); + } else if (strncmp(argv[i], "--pad=", 6) == 0) { + inpadp = inpad; + if (sscanf(argv[i] + 6, "%d,%d,%d,%d", + inpad + 0, + inpad + 1, + inpad + 2, + inpad + 3) != NUM_PAD) { + fprintf(stderr, "Bad pad list\n"); + exit(EXIT_FAILURE); + } + } else if (strncmp(argv[i], "--pad-file=", 11) == 0) { + opadf = fopen(argv[i] + 11, "w"); + if (!opadf) { + fprintf(stderr, "Cannot open %s", argv[i]+11); + exit(EXIT_FAILURE); + } } else usage(); } @@ -670,7 +753,11 @@ int main(int argc, char **argv) read_map(stdin); sort_symbols(); optimize_token_table(); - write_src(); - + write_src(inpadp, opad); + if (opadf) { + fprintf(opadf, "--pad=%d,%d,%d,%d\n", + opad[0], opad[1], opad[2], opad[3]); + fclose(opadf); + } return 0; }