From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756731AbdJLLyY (ORCPT ); Thu, 12 Oct 2017 07:54:24 -0400 Received: from mailout4.samsung.com ([203.254.224.34]:64384 "EHLO mailout4.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756251AbdJLLyV (ORCPT ); Thu, 12 Oct 2017 07:54:21 -0400 X-AuditID: b6c32a4b-56dff70000001095-dc-59df57eaf8a4 Mime-Version: 1.0 Subject: RE: [PATCH v2] stackdepot: ignore junk last entry in case of switch from user mode. Reply-To: v.narang@samsung.com From: Vaneet Narang To: Maninder Singh , "akpm@linux-foundation.org" , "dvyukov@google.com" , "chris@chris-wilson.co.uk" , "kasan-dev@googlegroups.com" , "mark.rutland@arm.com" CC: "linux-kernel@vger.kernel.org" , PANKAJ MISHRA , AMIT SAHRAWAT X-Priority: 3 X-Content-Kind-Code: NORMAL In-Reply-To: <1507725802-44574-1-git-send-email-maninder1.s@samsung.com> X-Drm-Type: Y,confirm X-EPLocale: en_US.EUC-KR X-EPWebmail-Msg-Type: personal X-Msg-Generator: Mail X-Msg-Type: PERSONAL X-Reply-Demand: N Illegal-Object: Syntax error in X-Sender: address found on vger.kernel.org: X-Sender: =?utf-8?B?U2Ftc3VuZyBFbGVjdHJvbmljcxtTUkktRGVsaGktUGw=?= ^-Extraneous program text X-Sender-IP: 107.109.224.164 X-Local-Sender: =?UTF-8?B?VmFuZWV0IE5hcmFuZxtTUkktRGVsaGktUGxhdGZvcm0gUy9XIDEgVGVh?= =?UTF-8?B?bRvsgrzshLHsoITsnpAbQ2hpZWYgRW5naW5lZXI=?= X-Global-Sender: =?UTF-8?B?VmFuZWV0IE5hcmFuZxtTUkktRGVsaGktUGxhdGZvcm0gUy9XIDEgVGVh?= =?UTF-8?B?bRtTYW1zdW5nIEVsZWN0cm9uaWNzG0NoaWVmIEVuZ2luZWVy?= X-Sender-Code: =?UTF-8?B?QzEwGxtDMTBJRDAySUQwMjgxMTU=?= Message-ID: <20171012111051epcms5p3117f59d0ec83cd2d62e36a0a2f73369f@epcms5p3> Date: Thu, 12 Oct 2017 11:10:51 +0000 X-CMS-MailID: 20171012111051epcms5p3117f59d0ec83cd2d62e36a0a2f73369f Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" X-Sendblock-Type: REQ_APPROVE X-MTR: 20171012111051epcms5p3117f59d0ec83cd2d62e36a0a2f73369f CMS-TYPE: 105P X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrEJsWRmVeSWpSXmKPExsWy7bCmhu6r8PuRBocXaVtc3J1qMWf9GjaL mw/PslpMeNjGbrHi2X0mi8u75rBZHJ7fxmKx9PpFJot7b7YyOXB6rJm3htFj5QctjwWbSj32 TDzJ5nFixm8Wj74tqxg9Pm+SC2CPSrXJSE1MSS1SSM1Lzk/JzEu3VfIOjneONzUzMNQ1tLQw V1LIS8xNtVVy8QnQdcvMAbpLSaEsMacUKBSQWFyspG9nU5RfWpKqkJFfXGKrFG1oaKRnaGCu Z2RkpGdiGmtlZApUkpCacbW5ouA6V8X82ReZGhg/cHQxcnJICJhIPGm/wNbFyMUhJLCbUeLu 851MXYwcHLwCghJ/dwiD1AgLxEl0HZvJAmILCchJHL+xmxEiriNxAug7kHI2AS2Jjy3hIGNE BHYySbT9n8UO4jALTGSUOPOokxViGa/EjPanLBC2tMT25VvBmjkFPCRWPo2GCItK/GmAKZGQ WL3wORuELScx7esaZpia98fmM0LYIhKt985CxQUlHvzcDRWvlZj2eBrUHBmJ71/7WUHukRDo ZpS4//YrC4QzhVFi0bx/UFXmEudPzgebxCvgK/Fg0zKwzSwCqhLPjl9mh6hxkXj39TbYBmYB eYntb+cwgzzALKApsX6XPkSJrMTUU+uYIGxbiQcNW9ghyvkken8/YYKFw455T5gmMKrMQgT1 LCRDZyEMXcDIvIpRMrWgODc9tdi0wDgvtVyvODG3uDQvXS85P3cTIzh9annvYNx0zucQowAH oxIP7wSNe5FCrIllxZW5hxglOJiVRHgNLO9HCvGmJFZWpRblxxeV5qQWH2I0BXpvIrOUaHI+ MLXnlcQbmlgamJiZmRsaGFiaKInzHttZGikkkJ5YkpqdmlqQWgTTx8TBKdXAaHyxQczBl+GB Lt8eodMeL4O7Arsl93X81XOfMP/AVMNW/TmBJSnKfQdqQmS3qtrwXF3VKvT3cu8nX4H8PTuP /1u7VzXj8bsdn4zvlzn8+5P5NnRB8Y6zqjsqTh5sXrHW72fGPMbNy0Mnpfn+V3iiFmIyW+PE 2SKlaSpupzfmWT67d7jJ7596gBJLcUaioRZzUXEiAMljzuO1AwAA DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20171011124443epcas5p23a0d74a4628baa3a1b424cb363fc5c81 X-RootMTR: 20171011124443epcas5p23a0d74a4628baa3a1b424cb363fc5c81 References: <1507725802-44574-1-git-send-email-maninder1.s@samsung.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Dmitry, >diff --git a/lib/stackdepot.c b/lib/stackdepot.c >index f87d138..a045748 100644 >--- a/lib/stackdepot.c >+++ b/lib/stackdepot.c >@@ -214,6 +214,13 @@ depot_stack_handle_t depot_save_stack(struct stack_trace *trace, > if (unlikely(trace->nr_entries == 0)) > goto fast_exit; > >+ /* >+ * Ignore last entry if it belongs to user space >+ * in case of switch from user mode. >+ */ >+ if (!kernel_text_address(trace->entries[trace->nr_entries - 1])) can we also add this check here:- if (!kernel_text_address(trace->entries[trace->nr_entries - 1]) || in_interrupt()) Because on further checking , last frame in case of svc to interrupt mode is some random core kernel / Kernel Module address like below:- irq_exit+0xe4/0x140 __handle_domain_irq+0x9c/0x130 gic_handle_irq+0x40/0x80 __irq_svc+0x44/0x7c hdmi_ocm_rx_get_scdc_sts+0x160/0x170 [sdp_hdmi] >> we need this frme?? This generates mismatch with existing entires and new entries get created and depot_index value keep on increasing slowly and reaches max value (STACK_ALLOC_SLABS_CAP) but after this change depot_index gets a stable value after some time. (Tested on ARM) >+ trace->nr_entries--; >+ > hash = hash_stack(trace->entries, trace->nr_entries); > bucket = &stack_table[hash & STACK_HASH_MASK]; > >-- >1.9.1 Regards, Vaneet Narang