From: Andy Lutomirski <luto@amacapital.net>
To: Jiri Olsa <jolsa@redhat.com>
Cc: acme@redhat.com, a.p.zijlstra@chello.nl, mingo@elte.hu,
paulus@samba.org, cjashfor@linux.vnet.ibm.com,
fweisbec@gmail.com, eranian@google.com, gorcunov@openvz.org,
tzanussi@gmail.com, mhiramat@redhat.com, robert.richter@amd.com,
fche@redhat.com, linux-kernel@vger.kernel.org,
masami.hiramatsu.pt@hitachi.com, drepper@gmail.com,
asharma@fb.com, benjamin.redelings@nescent.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 03/17] perf, x86: Add copy_from_user_nmi_nochk for best effort copy
Date: Thu, 02 Aug 2012 11:47:30 -0700 [thread overview]
Message-ID: <501ACB42.6060201@amacapital.net> (raw)
In-Reply-To: <1342959280-5361-4-git-send-email-jolsa@redhat.com>
On 07/22/2012 05:14 AM, Jiri Olsa wrote:
> Adding copy_from_user_nmi_nochk that provides the best effort
> copy regardless the requesting size crossing the task boundary.
>
> This is going to be useful for stack dump we need in post
> DWARF CFI based unwind, where we have predefined size of
> the user stack to dump, and we need to store the most of
> the requested dump size, regardless this size is crossing
> the task boundary.
Huh? This is a TASK_SIZE check, which makes sure that the request
doesn't cross into kernel land. Otherwise userspace could presumably
read kernel memory by setting bogus values of sp.
--Andy
next prev parent reply other threads:[~2012-08-02 18:47 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-22 12:14 [PATCHv7 00/17] perf: Add backtrace post dwarf unwind Jiri Olsa
2012-07-22 12:14 ` [PATCH 01/17] perf: Unified API to record selective sets of arch registers Jiri Olsa
2012-07-25 16:12 ` Frederic Weisbecker
2012-07-26 17:51 ` Arnaldo Carvalho de Melo
2012-07-29 22:45 ` Paul Mackerras
2012-07-22 12:14 ` [PATCH 02/17] perf: Add ability to attach user level registers dump to sample Jiri Olsa
2012-07-25 16:13 ` Frederic Weisbecker
2012-07-25 17:00 ` Arnaldo Carvalho de Melo
2012-07-25 17:39 ` Stephane Eranian
2012-07-25 18:27 ` Jiri Olsa
2012-07-26 17:42 ` Stephane Eranian
2012-07-26 17:58 ` Jiri Olsa
2012-07-22 12:14 ` [PATCH 03/17] perf, x86: Add copy_from_user_nmi_nochk for best effort copy Jiri Olsa
2012-07-25 16:11 ` Frederic Weisbecker
2012-07-25 17:16 ` Jiri Olsa
2012-07-25 17:25 ` Frederic Weisbecker
2012-07-25 17:30 ` Jiri Olsa
2012-07-25 17:35 ` Frederic Weisbecker
2012-08-02 18:47 ` Andy Lutomirski [this message]
2012-08-03 11:12 ` Jiri Olsa
2012-07-22 12:14 ` [PATCH 04/17] perf: Factor __output_copy to be usable with specific copy function Jiri Olsa
2012-07-22 12:14 ` [PATCH 05/17] perf: Add perf_output_skip function to skip bytes in sample Jiri Olsa
2012-07-22 12:14 ` [PATCH 06/17] perf: Add ability to attach user stack dump to sample Jiri Olsa
2012-07-25 16:36 ` Frederic Weisbecker
2012-07-25 17:03 ` Jiri Olsa
2012-07-22 12:14 ` [PATCH 07/17] perf: Add attribute to filter out callchains Jiri Olsa
2012-07-22 12:14 ` [PATCH 08/17] perf, tool: Adding PERF_ATTR_SIZE_VER2 to the header swap check Jiri Olsa
2012-07-22 12:14 ` [PATCH 09/17] perf, tool: Factor DSO symtab types to generic binary types Jiri Olsa
2012-07-25 19:24 ` [tip:perf/core] perf symbols: " tip-bot for Jiri Olsa
2012-07-22 12:14 ` [PATCH 10/17] perf, tool: Add interface to read DSO image data Jiri Olsa
2012-07-25 19:25 ` [tip:perf/core] perf symbols: " tip-bot for Jiri Olsa
2012-07-22 12:14 ` [PATCH 11/17] perf, tool: Add interface to arch registers sets Jiri Olsa
2012-07-22 12:14 ` [PATCH 12/17] perf, tool: Add libunwind dependency for dwarf cfi unwinding Jiri Olsa
2012-07-22 12:14 ` [PATCH 13/17] perf, tool: Support user regs and stack in sample parsing Jiri Olsa
2012-07-22 12:14 ` [PATCH 14/17] perf, tool: Support for dwarf cfi unwinding on post processing Jiri Olsa
2012-07-25 17:05 ` Frederic Weisbecker
2012-07-25 17:16 ` Arnaldo Carvalho de Melo
2012-07-25 17:21 ` Frederic Weisbecker
2012-07-22 12:14 ` [PATCH 15/17] perf, tool: Support for dwarf mode callchain on perf record Jiri Olsa
2012-07-22 12:14 ` [PATCH 16/17] perf, tool: Add dso data caching Jiri Olsa
2012-07-25 17:11 ` Frederic Weisbecker
2012-07-25 19:26 ` [tip:perf/core] perf symbols: " tip-bot for Jiri Olsa
2012-07-22 12:14 ` [PATCH 17/17] perf, tool: Add dso data caching tests Jiri Olsa
2012-07-25 19:28 ` [tip:perf/core] perf test: " tip-bot for Jiri Olsa
2012-07-25 17:15 ` [PATCHv7 00/17] perf: Add backtrace post dwarf unwind Frederic Weisbecker
2012-07-25 17:19 ` Ingo Molnar
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