From: Andi Kleen <ak@linux.intel.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Milind Chabbi <chabbi.milind@gmail.com>,
Jiri Olsa <jolsa@redhat.com>, Jiri Olsa <jolsa@kernel.org>,
Ingo Molnar <mingo@kernel.org>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
lkml <linux-kernel@vger.kernel.org>,
Namhyung Kim <namhyung@kernel.org>,
David Ahern <dsahern@gmail.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Hari Bathini <hbathini@linux.vnet.ibm.com>,
Jin Yao <yao.jin@linux.intel.com>,
Kan Liang <kan.liang@intel.com>,
Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>,
Oleg Nesterov <onestero@redhat.com>,
Will Deacon <will.deacon@arm.com>
Subject: Re: [PATCH 4/6] hw_breakpoint: Factor out __modify_user_hw_breakpoint function
Date: Mon, 27 Nov 2017 15:07:47 -0800 [thread overview]
Message-ID: <20171127230747.GC3070@tassilo.jf.intel.com> (raw)
In-Reply-To: <20171127220128.kzgywcu5ucudaeyl@hirez.programming.kicks-ass.net>
On Mon, Nov 27, 2017 at 11:01:28PM +0100, Peter Zijlstra wrote:
> On Mon, Nov 27, 2017 at 01:50:30PM -0800, Milind Chabbi wrote:
> > The possible checks is infinite
>
> struct perf_event_attr is very much a finite data type.
>
> Something as simple as:
>
> struct perf_event_attr tmp1 = new_attr, tmp2 = event->attr;
>
> tmp1.bp_type = tmp2.bp_type;
> tmp1.bp_addr = tmp2.bp_addr;
> tmp1.bp_len = tmp2.bp_len;
>
> if (memcmp(&tmp1, &tmp2, sizeof(tmp1)))
> return -EINVAL;
>
> would actually do the checks __modify_user_hw_breakpoint() needs to do.
It could fail with uninitialized padding.
-Andi
next prev parent reply other threads:[~2017-11-27 23:07 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-27 16:21 [PATCH 0/6] hw_breakpoint: Breakpoint modification fixes Jiri Olsa
2017-11-27 16:21 ` [PATCH 1/6] hw_breakpoint: Pass bp_type directly as find_slot_idx argument Jiri Olsa
2017-11-27 16:21 ` [PATCH 2/6] hw_breakpoint: Pass bp_type argument to __reserve_bp_slot|__release_bp_slot Jiri Olsa
2017-11-27 16:21 ` [PATCH 3/6] hw_breakpoint: Add modify_bp_slot function Jiri Olsa
2017-11-27 16:21 ` [PATCH 4/6] hw_breakpoint: Factor out __modify_user_hw_breakpoint function Jiri Olsa
2017-11-27 16:46 ` Peter Zijlstra
2017-11-27 17:09 ` Jiri Olsa
2017-11-27 17:12 ` Peter Zijlstra
2017-11-27 17:25 ` Jiri Olsa
2017-11-27 17:34 ` Peter Zijlstra
2017-11-27 21:20 ` Peter Zijlstra
2017-11-27 21:50 ` Milind Chabbi
2017-11-27 22:01 ` Peter Zijlstra
2017-11-27 22:16 ` Milind Chabbi
2017-11-27 22:25 ` Jiri Olsa
2017-11-27 22:41 ` Milind Chabbi
2017-11-27 23:07 ` Andi Kleen [this message]
2017-11-27 23:31 ` Milind Chabbi
2017-11-28 11:24 ` Jiri Olsa
2017-11-27 16:21 ` [PATCH 5/6] perf/core: fast breakpoint modification via _IOC_MODIFY_ATTRIBUTES Jiri Olsa
2017-11-27 16:21 ` [PATCH 6/6] perf tests: Add breakpoint accounting/modify test Jiri Olsa
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