From: David Ahern <dsahern@gmail.com>
To: Andi Kleen <andi@firstfloor.org>, Jun Wang <junwang123@gmail.com>
Cc: linux-perf-users@vger.kernel.org
Subject: Re: access function parameters with DWARF-less perf probing
Date: Thu, 24 Apr 2014 08:12:34 -0600 [thread overview]
Message-ID: <53591BD2.6080001@gmail.com> (raw)
In-Reply-To: <87iopzb8vw.fsf@tassilo.jf.intel.com>
On 4/23/14, 11:21 PM, Andi Kleen wrote:
> Jun Wang <junwang123@gmail.com> writes:
>
>> Hi Everyone,
>>
>> With systemTap, in the absence of debugging information (DWARF), one
>> can access function parameters using (positional) numbers. Can the
>> same be done with `perf`?
>> Why? I'm trying to capture variables in a kernel function but I don't
>> have an good perf with DWARF support and there is are significant
>> challenges to build one due to the relatively old distro.
>
> You can specify the registers according to the ABI.
> di = 1. arg, si = 2nd arg etc.
http://en.wikipedia.org/wiki/X86_calling_conventions#List_of_x86_calling_conventions
next prev parent reply other threads:[~2014-04-24 14:12 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-22 17:31 access function parameters with DWARF-less perf probing Jun Wang
2014-04-24 5:21 ` Andi Kleen
2014-04-24 14:12 ` David Ahern [this message]
2014-04-30 18:47 ` Jun Wang
2014-04-29 15:48 ` Milian Wolff
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