From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755171AbcAMIZb (ORCPT ); Wed, 13 Jan 2016 03:25:31 -0500 Received: from mga09.intel.com ([134.134.136.24]:29054 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750752AbcAMIZ3 (ORCPT ); Wed, 13 Jan 2016 03:25:29 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.22,288,1449561600"; d="scan'208";a="889495284" Subject: Re: [PATCH] perf tests: objdump output can contain multi byte chunks To: Arnaldo Carvalho de Melo References: <07f0f7bcbda78deb423298708ef9b6a54d6b92bd.1452592712.git.jstancek@redhat.com> <20160112153054.GF21083@redhat.com> Cc: Jan Stancek , linux-kernel@vger.kernel.org, xiakaixu@huawei.com, cjashfor@linux.vnet.ibm.com, dsahern@gmail.com, fweisbec@gmail.com, jolsa@kernel.org, acme@kernel.org, namhyung@kernel.org, paulus@samba.org, a.p.zijlstra@chello.nl From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Message-ID: <5696092C.30100@intel.com> Date: Wed, 13 Jan 2016 10:22:04 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <20160112153054.GF21083@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/01/16 17:30, Arnaldo Carvalho de Melo wrote: > Em Tue, Jan 12, 2016 at 11:07:44AM +0100, Jan Stancek escreveu: >> objdump's raw insn output can vary across architectures on number of >> bytes per chunk (bpc) displayed and their endian. >> >> code-reading test relied on reading objdump output as 1 bpc. Kaixu Xia >> reported test failure on ARM64, where objdump displays 4 bpc: >> 70c48: f90027bf str xzr, [x29,#72] >> 70c4c: 91224000 add x0, x0, #0x890 >> 70c50: f90023a0 str x0, [x29,#64] >> >> This patch adds support to read raw insn output for any bpc length. >> In case of 2+ bpc it also guesses objdump's display endian. > > Adrian, from a quick read of the patch and problem/solution description, > I think this is ok and Kaixu reports it solves the problem on ARM64, can > I have your reviewed-by/Acked-by? Acked-by: Adrian Hunter > > Thanks, > > - Arnaldo > >> Signed-off-by: Jan Stancek >> Reported-and-tested-by: Kaixu Xia >> Cc: Arnaldo Carvalho de Melo >> Cc: Adrian Hunter >> Cc: Corey Ashford >> Cc: David Ahern >> Cc: Frederic Weisbecker >> Cc: Jiri Olsa >> Cc: Namhyung Kim >> Cc: Paul Mackerras >> Cc: Peter Zijlstra >> --- >> tools/perf/tests/code-reading.c | 100 ++++++++++++++++++++++++++++------------ >> 1 file changed, 71 insertions(+), 29 deletions(-) >> >> diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c >> index a767a6400c5c..0108cb22d1a2 100644 >> --- a/tools/perf/tests/code-reading.c >> +++ b/tools/perf/tests/code-reading.c >> @@ -33,44 +33,86 @@ static unsigned int hex(char c) >> return c - 'A' + 10; >> } >> >> -static size_t read_objdump_line(const char *line, size_t line_len, void *buf, >> - size_t len) >> +static size_t read_objdump_chunk(const char **line, unsigned char **buf, >> + size_t *buf_len) >> +{ >> + size_t bytes_read = 0; >> + unsigned char *chunk_start = *buf; >> + >> + /* Read bytes */ >> + while (*buf_len > 0) { >> + char c1, c2; >> + >> + /* Get 2 hex digits */ >> + c1 = *(*line)++; >> + if (!isxdigit(c1)) >> + break; >> + c2 = *(*line)++; >> + if (!isxdigit(c2)) >> + break; >> + >> + /* Store byte and advance buf */ >> + **buf = (hex(c1) << 4) | hex(c2); >> + (*buf)++; >> + (*buf_len)--; >> + bytes_read++; >> + >> + /* End of chunk? */ >> + if (isspace(**line)) >> + break; >> + } >> + >> + /* >> + * objdump will display raw insn as LE if code endian >> + * is LE and bytes_per_chunk > 1. In that case reverse >> + * the chunk we just read. >> + * >> + * see disassemble_bytes() at binutils/objdump.c for details >> + * how objdump chooses display endian) >> + */ >> + if (bytes_read > 1 && !bigendian()) { >> + unsigned char *chunk_end = chunk_start + bytes_read - 1; >> + unsigned char tmp; >> + >> + while (chunk_start < chunk_end) { >> + tmp = *chunk_start; >> + *chunk_start = *chunk_end; >> + *chunk_end = tmp; >> + chunk_start++; >> + chunk_end--; >> + } >> + } >> + >> + return bytes_read; >> +} >> + >> +static size_t read_objdump_line(const char *line, unsigned char *buf, >> + size_t buf_len) >> { >> const char *p; >> - size_t i, j = 0; >> + size_t ret, bytes_read = 0; >> >> /* Skip to a colon */ >> p = strchr(line, ':'); >> if (!p) >> return 0; >> - i = p + 1 - line; >> + p++; >> >> - /* Read bytes */ >> - while (j < len) { >> - char c1, c2; >> - >> - /* Skip spaces */ >> - for (; i < line_len; i++) { >> - if (!isspace(line[i])) >> - break; >> - } >> - /* Get 2 hex digits */ >> - if (i >= line_len || !isxdigit(line[i])) >> - break; >> - c1 = line[i++]; >> - if (i >= line_len || !isxdigit(line[i])) >> - break; >> - c2 = line[i++]; >> - /* Followed by a space */ >> - if (i < line_len && line[i] && !isspace(line[i])) >> + /* Skip initial spaces */ >> + while (*p) { >> + if (!isspace(*p)) >> break; >> - /* Store byte */ >> - *(unsigned char *)buf = (hex(c1) << 4) | hex(c2); >> - buf += 1; >> - j++; >> + p++; >> } >> + >> + do { >> + ret = read_objdump_chunk(&p, &buf, &buf_len); >> + bytes_read += ret; >> + p++; >> + } while (ret > 0); >> + >> /* return number of successfully read bytes */ >> - return j; >> + return bytes_read; >> } >> >> static int read_objdump_output(FILE *f, void *buf, size_t *len, u64 start_addr) >> @@ -95,7 +137,7 @@ static int read_objdump_output(FILE *f, void *buf, size_t *len, u64 start_addr) >> } >> >> /* read objdump data into temporary buffer */ >> - read_bytes = read_objdump_line(line, ret, tmp, sizeof(tmp)); >> + read_bytes = read_objdump_line(line, tmp, sizeof(tmp)); >> if (!read_bytes) >> continue; >> >> @@ -152,7 +194,7 @@ static int read_via_objdump(const char *filename, u64 addr, void *buf, >> >> ret = read_objdump_output(f, buf, &len, addr); >> if (len) { >> - pr_debug("objdump read too few bytes\n"); >> + pr_debug("objdump read too few bytes: %lu\n", len); >> if (!ret) >> ret = len; >> } >> -- >> 1.8.3.1 >