linux-kernel - Re: [PATCH v2 0/7] perf trace pagefaults

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: <20140620161859.GN15620@stfomichev-desktop.yandex.net>
Date:	Fri, 20 Jun 2014 20:18:59 +0400
From:	Stanislav Fomichev <stfomichev@...dex-team.ru>
To:	Arnaldo Carvalho de Melo <acme@...nel.org>
Cc:	a.p.zijlstra@...llo.nl, paulus@...ba.org, mingo@...hat.com,
	dsahern@...il.com, jolsa@...hat.com,
	xiaoguangrong@...ux.vnet.ibm.com, yangds.fnst@...fujitsu.com,
	adrian.hunter@...el.com, namhyung@...nel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 0/7] perf trace pagefaults

> Hey, haven't you seen the vfs_getname probe? Idea is to hook on where
> the relevant copy_from_user is done and insert that into the ring
> buffer, as we already do for mapping fd -> pathname.
I saw it but didn't actually try because it needs all the debugging
stuff enabled and in place.

> I.e. no need for actual tracepoints from day one, just wannabe
> tracepoints using whatever probe inserting gizmo the kprobes_tracer used
> by 'perf probe' now thinks its best to use.
But we then need to predefine many probes for decoding to work in the form of
func:offset, and then play catch-up with all the kernel changes.
Or I miss something important here?

> For now try:
> 
>   perf probe 'vfs_getname=getname_flags:65 pathname=result->name:string'
>   trace
> 
> And look at how it manages to decode fds.
I will try, but does 65 still work after c4ad8f98bef77c7356aa6a9ad9188a6acc6b849d? :-)
--
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/