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Date:   Thu, 4 Mar 2021 17:19:40 +0000
From:   Matthew Wilcox <willy@infradead.org>
To:     Steven Rostedt <rostedt@goodmis.org>
Cc:     Stephen Boyd <swboyd@chromium.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-kernel@vger.kernel.org, Jiri Olsa <jolsa@kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Jessica Yu <jeyu@kernel.org>,
        Evan Green <evgreen@chromium.org>,
        Hsin-Yi Wang <hsinyi@chromium.org>,
        Petr Mladek <pmladek@suse.com>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        linux-doc@vger.kernel.org
Subject: Re: [PATCH 5/7] printk: Make %pS and friends print module build ID
Message-ID: <20210304171940.GL2723601@casper.infradead.org>
References: <20210301174749.1269154-1-swboyd@chromium.org>
 <20210301174749.1269154-6-swboyd@chromium.org>
 <20210301214319.7e54c66f@oasis.local.home>
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On Mon, Mar 01, 2021 at 09:43:19PM -0500, Steven Rostedt wrote:
> On Mon,  1 Mar 2021 09:47:47 -0800
> Stephen Boyd <swboyd@chromium.org> wrote:
> 
> > The %pS printk format (among some others) is used to print kernel
> > addresses symbolically. When the kernel prints an address inside of a
> > module, the kernel prints the addresses' symbol name along with the
> > module's name that contains the address. Let's make kernel stacktraces
> > easier to identify on KALLSYMS builds by including the build ID of a
> > module when we print the address.
> 
> Please no!
> 
> This kills the output of tracing with offset, and can possibly break
> scripts. I don't want to look at traces like this!
> 
>           <idle>-0       [004] ..s1   353.842577: ipv4_conntrack_in+0x0/0x10 [nf_conntrack] (3b39eb771b2566331887f671c741f90bfba0b051) <-nf_hook_slow+0x40/0xb0

Would it make sense to only print the build-id if it differs from the
build-id of the kernel which has loaded it?