linux-kernel - Re: [PATCH 9/9] tools lib traceevent: Honor operator priority

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 13 Apr 2015 10:41:41 -0300
From:	Arnaldo Carvalho de Melo <acme@...nel.org>
To:	Namhyung Kim <namhyung@...nel.org>
Cc:	Ingo Molnar <mingo@...nel.org>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Jiri Olsa <jolsa@...hat.com>,
	LKML <linux-kernel@...r.kernel.org>,
	David Ahern <dsahern@...il.com>,
	Minchan Kim <minchan@...nel.org>,
	Joonsoo Kim <js1304@...il.com>, linux-mm@...ck.org,
	Steven Rostedt <rostedt@...dmis.org>
Subject: Re: [PATCH 9/9] tools lib traceevent: Honor operator priority

Em Mon, Apr 06, 2015 at 02:36:16PM +0900, Namhyung Kim escreveu:
> Currently it ignores operator priority and just sets processed args as a
> right operand.  But it could result in priority inversion in case that
> the right operand is also a operator arg and its priority is lower.
> 
> For example, following print format is from new kmem events.
> 
>   "page=%p", REC->pfn != -1UL ? (((struct page *)(0xffffea0000000000UL)) + (REC->pfn)) : ((void *)0)
> 
> But this was treated as below:
> 
>   REC->pfn != ((null - 1UL) ? ((struct page *)0xffffea0000000000UL + REC->pfn) : (void *) 0)
> 
> In this case, the right arg was '?' operator which has lower priority.
> But it just sets the whole arg so making the output confusing - page was
> always 0 or 1 since that's the result of logical operation.
> 
> With this patch, it can handle it properly like following:
> 
>   ((REC->pfn != (null - 1UL)) ? ((struct page *)0xffffea0000000000UL + REC->pfn) : (void *) 0)

And this one already went upstream.

- Arnaldo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/