From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (bilbo.ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3ysJcJ5YqQzDqkv for ; Thu, 7 Dec 2017 00:00:00 +1100 (AEDT) In-Reply-To: <20171130083322.31206-1-ravi.bangoria@linux.vnet.ibm.com> To: Ravi Bangoria From: Michael Ellerman Cc: maddy@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, Ravi Bangoria , paulus@samba.org, kan.liang@intel.com, tglx@linutronix.de, sukadev@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org Subject: Re: powerpc/perf: Fix oops when grouping different pmu events Message-Id: <3ysJcJ3ygHz9sRV@ozlabs.org> Date: Wed, 6 Dec 2017 23:59:59 +1100 (AEDT) List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, 2017-11-30 at 08:33:22 UTC, Ravi Bangoria wrote: > When user tries to group imc (In-Memory Collections) event with > normal event, (sometime) kernel crashes with following log: > > Faulting instruction address: 0x00000000 > [link register ] c00000000010ce88 power_check_constraints+0x128/0x980 > ... > c00000000010e238 power_pmu_event_init+0x268/0x6f0 > c0000000002dc60c perf_try_init_event+0xdc/0x1a0 > c0000000002dce88 perf_event_alloc+0x7b8/0xac0 > c0000000002e92e0 SyS_perf_event_open+0x530/0xda0 > c00000000000b004 system_call+0x38/0xe0 > > 'event_base' field of 'struct hw_perf_event' is used as flags for > normal hw events and used as memory address for imc events. While > grouping these two types of events, collect_events() tries to > interpret imc 'event_base' as a flag, which causes a corruption > resulting in a crash. > > Consider only those events which belongs to 'perf_hw_context' in > collect_events(). > > Signed-off-by: Ravi Bangoria > Reviewed-By: Madhavan Srinivasan Applied to powerpc fixes, thanks. https://git.kernel.org/powerpc/c/5aa04b3eb6fca63d2e9827be656dca cheers