linux-kernel - Re: [PATCH v2 12/39] x86/ibt,ftrace: Search for __fentry_

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:   Wed, 02 Mar 2022 00:27:51 +0530
From:   "Naveen N. Rao" <naveen.n.rao@...ux.vnet.ibm.com>
To:     Masami Hiramatsu <mhiramat@...nel.org>,
        Steven Rostedt <rostedt@...dmis.org>
Cc:     alexei.starovoitov@...il.com, alyssa.milburn@...el.com,
        andrew.cooper3@...rix.com, hjl.tools@...il.com,
        joao@...rdrivepizza.com, jpoimboe@...hat.com,
        keescook@...omium.org, linux-kernel@...r.kernel.org,
        mark.rutland@....com, mbenes@...e.cz, ndesaulniers@...gle.com,
        Peter Zijlstra <peterz@...radead.org>, samitolvanen@...gle.com,
        x86@...nel.org
Subject: Re: [PATCH v2 12/39] x86/ibt,ftrace: Search for __fentry__ location

Steven Rostedt wrote:
> On Fri, 25 Feb 2022 19:20:08 +0900
> Masami Hiramatsu <mhiramat@...nel.org> wrote:
> 
>> > No. It only acts like ftrace_location_range(sym, sym_end) if the passed
>> > in argument is the ip of the function (kallsyms returns offset = 0)  
>> 
>> Got it. So now ftrace_location() will return the ftrace address
>> when the ip == func or ip == mcount-call.

Won't this cause issues with ftrace_set_filter_ip() and others? If the 
passed-in ip points to func+0 when the actual ftrace location is at some 
offset, the ftrace location check in ftrace_match_addr() will now pass, 
resulting in adding func+0 to the hash. Should we also update 
ftrace_match_addr() to use the ip returned by ftrace_location()?


- Naveen