From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761451AbcALPbA (ORCPT ); Tue, 12 Jan 2016 10:31:00 -0500 Received: from mx1.redhat.com ([209.132.183.28]:52793 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752801AbcALPa6 (ORCPT ); Tue, 12 Jan 2016 10:30:58 -0500 Date: Tue, 12 Jan 2016 13:30:54 -0200 From: Arnaldo Carvalho de Melo To: Adrian Hunter 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 Subject: Re: [PATCH] perf tests: objdump output can contain multi byte chunks Message-ID: <20160112153054.GF21083@redhat.com> References: <07f0f7bcbda78deb423298708ef9b6a54d6b92bd.1452592712.git.jstancek@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <07f0f7bcbda78deb423298708ef9b6a54d6b92bd.1452592712.git.jstancek@redhat.com> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.20 (2009-12-10) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? 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