Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755352Ab3GCCbD (ORCPT ); Tue, 2 Jul 2013 22:31:03 -0400 Received: from mailxx.hitachi.co.jp ([133.145.228.50]:34171 "EHLO mailxx.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754075Ab3GCCaG (ORCPT ); Tue, 2 Jul 2013 22:30:06 -0400 X-AuditID: 85900ec0-d1ac5b900000151e-7b-51d388d901b4 X-Mailbox-Line: From nobody Wed Jul 3 10:46:16 2013 From: Hidehiro Kawai Subject: [RFC PATCH 4/5] msghash: Add userland msghash tool To: linux-kernel@vger.kernel.org Cc: yrl.pp-manager.tt@hitachi.com, akpm@linux-foundation.org, gregkh@linuxfoundation.org, kay@vrfy.org, davem@davemloft.net, Hidehiro Kawai , Andrew Morton , Greg Kroah-Hartman , Kay Sievers , "David S. Miller" Date: Wed, 03 Jul 2013 10:46:16 +0900 Message-ID: <20130703014616.18745.85336.stgit@localhost.localdomain> In-Reply-To: <20130703014616.18745.34699.stgit@localhost.localdomain> References: <20130703014616.18745.34699.stgit@localhost.localdomain> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 13610 Lines: 457 This patch adds scripts/msghash/msghash. msghash scans a kmsg_meta table between __start___kmsg_meta to __stop___kmsg_meta in the target object file (vmlinux), computes a hash value for each message format string, then replaces the format string with the hash value. Valid flags are also set to entries in the kmsg_meta table. When computing the hash value, prefixed loglevel characters are ignored. Even if configured with CONFIG_KMSG_HASH=y, without running msghash, no hash values are output via /dev/kmsg. So msghash is executed during the build process, just after generating vmlinux. msghash also generate a Hash-and-message catalog named ".msglist". Each line in the .msglist file is output in the form of: @:, .msglist file is useful to match /dev/kmsg messages with messages you concern. Here is the example of .msglist: ... b6be0058@init/main.c:180,"Parameter %s is obsolete, ignored" 72dfe336@init/main.c:403,"Malformed early option '%s'" 85788d36@init/do_mounts.c:573,"Waiting for root device %s..." ... Currently, only vmlinux is supported. msghash can't update the kmsg_meta tables of kernel modules. Signed-off-by: Hidehiro Kawai Cc: Andrew Morton Cc: Greg Kroah-Hartman Cc: Kay Sievers Cc: "David S. Miller" --- .gitignore | 1 Makefile | 7 + lib/Kconfig.debug | 5 + scripts/Makefile | 1 scripts/link-vmlinux.sh | 5 + scripts/msghash/.gitignore | 1 scripts/msghash/Makefile | 7 + scripts/msghash/msghash.c | 241 ++++++++++++++++++++++++++++++++++++++++++++ scripts/msghash/msghash.sh | 45 ++++++++ 9 files changed, 312 insertions(+), 1 deletions(-) create mode 100644 scripts/msghash/.gitignore create mode 100644 scripts/msghash/Makefile create mode 100644 scripts/msghash/msghash.c create mode 100755 scripts/msghash/msghash.sh diff --git a/.gitignore b/.gitignore index 3b8b9b3..3bb5735 100644 --- a/.gitignore +++ b/.gitignore @@ -32,6 +32,7 @@ modules.builtin *.lzo *.patch *.gcno +*.msglist # # Top-level generic files diff --git a/Makefile b/Makefile index e5e3ba0..2693d7d 100644 --- a/Makefile +++ b/Makefile @@ -766,6 +766,10 @@ vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_INIT) $(KBUILD_VMLINUX_MAIN) cmd_link-vmlinux = $(CONFIG_SHELL) $< $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux) quiet_cmd_link-vmlinux = LINK $@ +# Remove old .msglist + cmd_rm-msglist = echo rm -f $@.msglist +quiet_cmd_rm-msglist = CLEAN $@.msglist + # Include targets which we want to # execute if the rest of the kernel build went well. vmlinux: scripts/link-vmlinux.sh $(vmlinux-deps) FORCE @@ -1273,7 +1277,8 @@ clean: $(clean-dirs) -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \ -o -name '*.symtypes' -o -name 'modules.order' \ -o -name modules.builtin -o -name '.tmp_*.o.*' \ - -o -name '*.gcno' \) -type f -print | xargs rm -f + -o -name '*.gcno' -o -name '*.msglist' \) -type f -print |\ + xargs rm -f # Generate tags for editors # --------------------------------------------------------------------------- diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 9302ece..bd05088 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -11,6 +11,11 @@ config PRINTK_TIME to /dev/kmsg. This flag just specifies if the timestamp should be included, not that the timestamp is recorded. + Hash values are calculated during the build process and + put into a table in object files. Hash-and-message catalogs + named .msglist are also generated for convenience + in message handling in userland. + The behavior is also controlled by the kernel command line parameter printk.time=1. See Documentation/kernel-parameters.txt diff --git a/scripts/Makefile b/scripts/Makefile index 01e7adb..7568e35 100644 --- a/scripts/Makefile +++ b/scripts/Makefile @@ -37,6 +37,7 @@ subdir-$(CONFIG_MODVERSIONS) += genksyms subdir-y += mod subdir-$(CONFIG_SECURITY_SELINUX) += selinux subdir-$(CONFIG_DTC) += dtc +subdir-$(CONFIG_KMSG_HASH) += msghash # Let clean descend into subdirs subdir- += basic kconfig package selinux diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index 0149949..575c2bb 100644 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -228,5 +228,10 @@ if [ -n "${CONFIG_KALLSYMS}" ]; then fi fi +if [ -n "${CONFIG_KMSG_HASH}" ]; then + rm -f vmlinux.msglist + ${srctree}/scripts/msghash/msghash.sh vmlinux || exit 1 +fi + # We made a new kernel - delete old version file rm -f .old_version diff --git a/scripts/msghash/.gitignore b/scripts/msghash/.gitignore new file mode 100644 index 0000000..8bcfa1d --- /dev/null +++ b/scripts/msghash/.gitignore @@ -0,0 +1 @@ +msghash diff --git a/scripts/msghash/Makefile b/scripts/msghash/Makefile new file mode 100644 index 0000000..add1e14 --- /dev/null +++ b/scripts/msghash/Makefile @@ -0,0 +1,7 @@ +hostprogs-y := msghash + +HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include + +always := $(hostprogs-y) +clean-files := $(hostprogs-y) + diff --git a/scripts/msghash/msghash.c b/scripts/msghash/msghash.c new file mode 100644 index 0000000..832fdb9 --- /dev/null +++ b/scripts/msghash/msghash.c @@ -0,0 +1,241 @@ +/* + * msghash.c: calculate hash values of printk messages and update the + * kmsg_meta table in the target object file. + * + * Copyright 2013 Hidehiro Kawai + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +typedef u_int8_t u8; +typedef u_int16_t u16; +typedef u_int32_t u32; +typedef u_int64_t u64; + +#include +#include + +#define KERN_SOH_ASCII '\001' +static inline char *printk_skip_level(char *buffer) +{ + if (buffer[0] == KERN_SOH_ASCII && buffer[1]) { + switch (buffer[1]) { + case '0' ... '7': + case 'd': /* KERN_DEFAULT */ + return buffer + 2; + } + } + return buffer; +} + +static unsigned long rodata_addr; +static unsigned long rodata_off; +static FILE *outfp; +struct msghash_stat { + int updated; /* number of entries updated successfully */ + int skipped; /* skipped entries because of having a valid hash */ + int invalid; /* entries whoes format string is not constant */ +} st; + +static inline unsigned long addr_to_offset(unsigned long addr) +{ + return addr - rodata_addr + rodata_off; +} + +static void usage(void) +{ + fprintf(stderr, + "Usage: msghash [-o ] \n" + " \n"); +} + +/* + * Update the hash value of a given kmsg_meta object and write out + * a Hash-and-message line to the specified file. + */ +static void update_and_print_hash(char *buf, struct kmsg_meta *meta) +{ + static char fmtbuf[4096]; + u_int32_t hash; + char *str; + int len; + int i, j, c; + + if (meta->flags & KMSG_FLAGS_HASH_VALID) { + st.skipped++; + return; + } + + /* Non-constant format case, skip it. */ + if (!meta->u.format) { + st.invalid++; + return; + } + + str = buf + addr_to_offset((unsigned long)meta->u.format); + str = printk_skip_level(str); + len = strlen(str); + hash = jhash(str, len, 0); + meta->u.format = 0; + meta->u.hash = hash; + meta->flags |= KMSG_FLAGS_HASH_VALID; + + /* + * We output the kmsg metadata info only if the hash value + * has just been updated because a pointer to the format string + * is overwritten with a hash value. + */ + if (outfp) { + /* Don't printout a newline at the tail. */ + if (str[len - 1] == '\n') + len--; + + /* Escape special codes same as reading /dev/kmsg */ + for (i = 0, j = 0; i < len; i++) { + c = str[i]; + + if (c < ' ' || c >= 127 || c == '\\') + j += sprintf(fmtbuf + j, "\\x%02x", c); + else + fmtbuf[j++] = c; + } + fmtbuf[j] = 0; + fprintf(outfp, "%08x@%s:%d,\"%s\"\n", meta->u.hash, + buf + addr_to_offset((unsigned long)meta->filename), + meta->lineno, fmtbuf); + } + + st.updated++; +} + +/* + * Calculate hash values of printk message formats and replace it with + * the hash values. This means we modify kmsg_meta table in .rodata + * section of the target file (vmlinux). + */ +static void walk_kmsg_meta(char *buf, unsigned long start, unsigned long end) +{ + char *p; + + for (p = buf + start; p < buf + end; p += sizeof(struct kmsg_meta)) + update_and_print_hash(buf, (struct kmsg_meta *)p); +} + +static char *do_mmap_objfile(const char *filename, size_t *len) +{ + int fd; + struct stat sb; + char *buf; + + fd = open(filename, O_RDWR | O_APPEND); + if (fd < 0) { + perror("msghash: open"); + return NULL; + } + + if (fstat(fd, &sb) < 0) { + perror("msghash: fstat"); + return NULL; + } + + buf = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); + if (buf == MAP_FAILED) { + perror("msghash: mmap"); + return NULL; + } + *len = sb.st_size; + + return buf; +} + +int main(int argc, char *argv[]) +{ + unsigned long start_meta, stop_meta, start, end; + char *outfile = NULL; + char *buf; + size_t len; + int total; + int c; + int ret; + + while ((c = getopt(argc, argv, "o:")) >= 0) { + switch (c) { + case 'o': + outfile = optarg; + break; + default: + usage(); + return 1; + } + } + + if (argc - optind < 5) { + usage(); + return 1; + } + + start_meta = strtoul(argv[optind + 1], NULL, 0); + stop_meta = strtoul(argv[optind + 2], NULL, 0); + rodata_addr = strtoul(argv[optind + 3], NULL, 0); + rodata_off = strtoul(argv[optind + 4], NULL, 0); + + /* Do some sanity checks. */ + if (!start_meta || !stop_meta || start_meta > stop_meta) { + fprintf(stderr, "msghash: Invalid arguments\n"); + fprintf(stderr, " start_meta: 0x%08lx\n", start_meta); + fprintf(stderr, " stop_meta: 0x%08lx\n", stop_meta); + fprintf(stderr, " rodata_addr: 0x%08lx\n", rodata_addr); + fprintf(stderr, " rodata_off: 0x%08lx\n", rodata_off); + return 1; + } + + if (start_meta == stop_meta) { + /* There is nothing to do. */ + return 0; + } + + buf = do_mmap_objfile(argv[optind], &len); + if (!buf) + return 1; + outfp = fopen(outfile, "w"); + if (outfp < 0) { + perror("msghash: fopen output file"); + return 1; + } + + start = addr_to_offset(start_meta); + end = addr_to_offset(stop_meta); + + walk_kmsg_meta(buf, start, end); + ret = msync(buf, len, MS_SYNC); + if (ret < 0) { + perror("msghash: msync"); + return 1; + } + + total = st.updated + st.skipped + st.invalid; + printf("msghash: %d/%d entries updated, %d skipped, %d invalid\n", + st.updated, total, st.skipped, st.invalid); + + return 0; +} diff --git a/scripts/msghash/msghash.sh b/scripts/msghash/msghash.sh new file mode 100755 index 0000000..a0b749f7 --- /dev/null +++ b/scripts/msghash/msghash.sh @@ -0,0 +1,45 @@ +#!/bin/sh +# +# msghash.sh -- calculate hash values of printk messages and update +# the kmsg_meta table in a given object file. +# A Message-and-hash catalog named