linux-kernel - Re: [PATCH 13/15] perf_counter: provide generic callchain bits

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]

Message-Id: <1238658096.8530.5480.camel@twins>
Date:	Thu, 02 Apr 2009 09:41:36 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	Corey Ashford <cjashfor@...ux.vnet.ibm.com>
Cc:	Paul Mackerras <paulus@...ba.org>, Ingo Molnar <mingo@...e.hu>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 13/15] perf_counter: provide generic callchain bits

On Thu, 2009-04-02 at 08:43 +0200, Peter Zijlstra wrote:
> On Wed, 2009-04-01 at 16:25 -0700, Corey Ashford wrote:
> 
> > > struct callchain_event {
> > > 	u64 nr
> > > 	u64 ips[nr]
> > > };
> > 
> > Looking at the current version of perf_counter.h in the -tip tree, this 
> > struct definition is not visible to userspace (it's in the #ifdef KERNEL 
> > section).
> 
> Correct. Its been on my todo list to write a meta-struct definition
> along with the perf_event_type enum that details the data layout of the
> various types, but not include any actual structure other than the
> header in the userspace bits.
> 
> Also, related to a comment Paul made on callchain markers, I wanted to
> change it so that we have ip markers in the chain that separate the
> kernel and user bits.
> 
> I was thinking of ending the kernel trace with -1ULL and ending the user
> chain with 0ULL. Presumably we need one more to end hypervisor chains in
> case anybody manages to generate those ;-).
> 
> This chain however will not change the struct, it will merely add 2
> extra entries.

Hmm, another idea:

struct perf_callchain_entry {
  __u32 total, hv, kernel, user;
  __u64 ips[total];
};


--
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/