From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751947AbbEDG1J (ORCPT ); Mon, 4 May 2015 02:27:09 -0400 Received: from ozlabs.org ([103.22.144.67]:40091 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751084AbbEDG1D (ORCPT ); Mon, 4 May 2015 02:27:03 -0400 From: Michael Ellerman To: Cc: a.p.zijlstra@chello.nl, mingo@kernel.org, Paul Mackerras , , acme@ghostprotocols.net, Andrew Morton , Anton Blanchard , sukadev@linux.vnet.ibm.com Subject: [PATCH] perf_event: Don't allow vmalloc backed perf on powerpc Date: Mon, 4 May 2015 16:26:39 +1000 Message-Id: <1430720799-18426-1-git-send-email-mpe@ellerman.id.au> X-Mailer: git-send-email 2.1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On powerpc the perf event interrupt is not masked when interrupts are disabled, allowing it to function as an NMI. This causes problems if perf is using vmalloc. If we take a page fault on the vmalloc region the fault handler will fail the page fault because it detects we are coming in from an NMI (see do_hash_page()). We don't actually need or want vmalloc backed perf so just disable it on powerpc. Signed-off-by: Michael Ellerman --- init/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/init/Kconfig b/init/Kconfig index dc24dec60232..81050e4d9941 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1637,7 +1637,7 @@ config PERF_EVENTS config DEBUG_PERF_USE_VMALLOC default n bool "Debug: use vmalloc to back perf mmap() buffers" - depends on PERF_EVENTS && DEBUG_KERNEL + depends on PERF_EVENTS && DEBUG_KERNEL && !PPC select PERF_USE_VMALLOC help Use vmalloc memory to back perf mmap() buffers. -- 2.1.0