From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752928AbcFTJZZ (ORCPT ); Mon, 20 Jun 2016 05:25:25 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:5863 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751577AbcFTJZP (ORCPT ); Mon, 20 Jun 2016 05:25:15 -0400 X-IBM-Helo: d28dlp02.in.ibm.com X-IBM-MailFrom: maddy@linux.vnet.ibm.com X-IBM-RcptTo: linux-kernel@vger.kernel.org From: Madhavan Srinivasan To: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Cc: Madhavan Srinivasan , Yury Norov , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Alexander Shishkin , Jiri Olsa , Adrian Hunter , Kan Liang , Wang Nan , Michael Ellerman Subject: [PATCH v2] tools/perf: Fix the mask in regs_dump__printf and Date: Mon, 20 Jun 2016 14:14:01 +0530 X-Mailer: git-send-email 1.9.1 X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16062008-0004-0000-0000-000002A83FD4 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16062008-0005-0000-0000-00000D89F378 Message-Id: <1466412241-27502-1-git-send-email-maddy@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-06-20_06:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1606200103 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When decoding the perf_regs mask in regs_dump__printf(), we loop through the mask using find_first_bit and find_next_bit functions. "mask" is of type "u64", but sent as a "unsigned long *" to lib functions along with sizeof(). While the exisitng code works fine in most of the case, the logic is broken when using a 32bit perf on a 64bit kernel (Big Endian). We end up reading the wrong word of the u64 first in the lib functions. Proposed fix is to swap the words of the u64 to handle this case. This is not endianess swap. Suggested-by: Yury Norov Cc: Yury Norov Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Adrian Hunter Cc: Kan Liang Cc: Wang Nan Cc: Michael Ellerman Signed-off-by: Madhavan Srinivasan --- Changelog v1: 1)updated commit message and patch subject 2)Add the fix to print_sample_iregs() in builtin-script.c tools/perf/builtin-script.c | 7 ++++++- tools/perf/util/session.c | 7 ++++++- 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c index e3ce2f34d3ad..76d5006ebcc3 100644 --- a/tools/perf/builtin-script.c +++ b/tools/perf/builtin-script.c @@ -412,11 +412,16 @@ static void print_sample_iregs(struct perf_sample *sample, struct regs_dump *regs = &sample->intr_regs; uint64_t mask = attr->sample_regs_intr; unsigned i = 0, r; + unsigned long _mask[sizeof(mask)/sizeof(unsigned long)]; if (!regs) return; - for_each_set_bit(r, (unsigned long *) &mask, sizeof(mask) * 8) { + _mask[0] = mask & ULONG_MAX; + if (sizeof(mask) > sizeof(unsigned long)) + _mask[1] = mask >> 32; + + for_each_set_bit(r, _mask, sizeof(mask) * 8) { u64 val = regs->regs[i++]; printf("%5s:0x%"PRIx64" ", perf_reg_name(r), val); } diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 5214974e841a..2eaa42a4832a 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -940,8 +940,13 @@ static void branch_stack__printf(struct perf_sample *sample) static void regs_dump__printf(u64 mask, u64 *regs) { unsigned rid, i = 0; + unsigned long _mask[sizeof(mask)/sizeof(unsigned long)]; - for_each_set_bit(rid, (unsigned long *) &mask, sizeof(mask) * 8) { + _mask[0] = mask & ULONG_MAX; + if (sizeof(mask) > sizeof(unsigned long)) + _mask[1] = mask >> 32; + + for_each_set_bit(rid, _mask, sizeof(mask) * 8) { u64 val = regs[i++]; printf(".... %-5s 0x%" PRIx64 "\n", -- 1.9.1