linux-kernel - Re: [PATCH 03/22] tools lib traceevent: Add traceevent_host

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, 25 Nov 2013 16:24:52 +0900
From:	Namhyung Kim <namhyung@...nel.org>
To:	Steven Rostedt <rostedt@...dmis.org>
Cc:	Jiri Olsa <jolsa@...hat.com>, linux-kernel@...r.kernel.org,
	Corey Ashford <cjashfor@...ux.vnet.ibm.com>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Ingo Molnar <mingo@...e.hu>, Paul Mackerras <paulus@...ba.org>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Arnaldo Carvalho de Melo <acme@...hat.com>,
	David Ahern <dsahern@...il.com>
Subject: Re: [PATCH 03/22] tools lib traceevent: Add traceevent_host_bigendian function

Hi Steve,

On Sat, 23 Nov 2013 03:27:08 -0500, Steven Rostedt wrote:
> On Fri, 22 Nov 2013 23:22:52 +0900
> Namhyung Kim <namhyung@...nel.org> wrote:
>
>> 2013-11-21 (목), 12:01 +0100, Jiri Olsa:
>> > Adding traceevent_host_bigendian function to get host
>> > endianity. It's used in following patches.
>> 
>> [SNIP]
>> > +static inline int traceevent_host_bigendian(void)
>> > +{
>> > +	unsigned char str[] = { 0x1, 0x2, 0x3, 0x4 };
>> > +	unsigned int *ptr;
>> > +
>> > +	ptr = (unsigned int *)str;
>> > +	return *ptr == 0x01020304;
>> 
>> Is it safe for every architecture supported - especially ones that
>> require stricter alignment?  I know many architectures/compilers align
>> stack but not sure doing this is safe for all architecture.
>
> Would you prefer this (I tested it on both a big and little endian)
>
> {
> 	unsigned char str[] = { 0x1, 0x2, 0x3, 0x4 };
> 	unsigned int val;
>
> 	memcpy(&val, str, 4);
> 	return val == 0x01020304;
> }

Yeah, looks good to me.

Thanks,
Namhyung
--
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/