From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751933AbaHTIU5 (ORCPT ); Wed, 20 Aug 2014 04:20:57 -0400 Received: from terminus.zytor.com ([198.137.202.10]:46982 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751423AbaHTIUx (ORCPT ); Wed, 20 Aug 2014 04:20:53 -0400 Date: Wed, 20 Aug 2014 01:18:37 -0700 From: tip-bot for Pawel Moll Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, peterz@infradead.org, drew.richardson@arm.com, acme@kernel.org, jolsa@redhat.com, pawel.moll@arm.com, tglx@linutronix.de Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, peterz@infradead.org, drew.richardson@arm.com, acme@kernel.org, jolsa@redhat.com, pawel.moll@arm.com, tglx@linutronix.de In-Reply-To: <1402671812-9078-1-git-send-email-pawel.moll@arm.com> References: <1402671812-9078-1-git-send-email-pawel.moll@arm.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] perf: Handle compat ioctl Git-Commit-ID: b3f207855f57b9c8f43a547a801340bb5cbc59e5 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: b3f207855f57b9c8f43a547a801340bb5cbc59e5 Gitweb: http://git.kernel.org/tip/b3f207855f57b9c8f43a547a801340bb5cbc59e5 Author: Pawel Moll AuthorDate: Fri, 13 Jun 2014 16:03:32 +0100 Committer: Ingo Molnar CommitDate: Wed, 20 Aug 2014 09:42:13 +0200 perf: Handle compat ioctl When running a 32-bit userspace on a 64-bit kernel (eg. i386 application on x86_64 kernel or 32-bit arm userspace on arm64 kernel) some of the perf ioctls must be treated with special care, as they have a pointer size encoded in the command. For example, PERF_EVENT_IOC_ID in 32-bit world will be encoded as 0x80042407, but 64-bit kernel will expect 0x80082407. In result the ioctl will fail returning -ENOTTY. This patch solves the problem by adding code fixing up the size as compat_ioctl file operation. Reported-by: Drew Richardson Signed-off-by: Pawel Moll Signed-off-by: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Link: http://lkml.kernel.org/r/1402671812-9078-1-git-send-email-pawel.moll@arm.com Signed-off-by: Ingo Molnar --- kernel/events/core.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 1cf24b3..f9c1ed0 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -41,6 +41,7 @@ #include #include #include +#include #include "internal.h" @@ -3717,6 +3718,26 @@ static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) return 0; } +#ifdef CONFIG_COMPAT +static long perf_compat_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + switch (_IOC_NR(cmd)) { + case _IOC_NR(PERF_EVENT_IOC_SET_FILTER): + case _IOC_NR(PERF_EVENT_IOC_ID): + /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */ + if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) { + cmd &= ~IOCSIZE_MASK; + cmd |= sizeof(void *) << IOCSIZE_SHIFT; + } + break; + } + return perf_ioctl(file, cmd, arg); +} +#else +# define perf_compat_ioctl NULL +#endif + int perf_event_task_enable(void) { struct perf_event *event; @@ -4222,7 +4243,7 @@ static const struct file_operations perf_fops = { .read = perf_read, .poll = perf_poll, .unlocked_ioctl = perf_ioctl, - .compat_ioctl = perf_ioctl, + .compat_ioctl = perf_compat_ioctl, .mmap = perf_mmap, .fasync = perf_fasync, };