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Subject: Re: [PATCH 5/7] printk: Make %pS and friends print module build ID
From:   Stephen Boyd <swboyd@chromium.org>
Cc:     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>,
        Steven Rostedt <rostedt@goodmis.org>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        linux-doc@vger.kernel.org
To:     Matthew Wilcox <willy@infradead.org>
Date:   Thu, 04 Mar 2021 11:15:41 -0800
Message-ID: <161488534185.1478170.10285681551102444519@swboyd.mtv.corp.google.com>
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Quoting Matthew Wilcox (2021-03-04 09:00:52)
> On Mon, Mar 01, 2021 at 09:47:47AM -0800, Stephen Boyd wrote:
> > Example:
> >=20
> >  WARNING: CPU: 4 PID: 3255 at drivers/misc/lkdtm/bugs.c:83 lkdtm_WARNIN=
G+0x28/0x30 [lkdtm] (ed5019fdf5e53be37cb1ba7899292d7e143b259e)
>=20
> Would the first 12 characters instead of all 40 make it more palatable
> without reducing its utility?

I can't seem to request debuginfo from debuginfod without the full 40
characters. It's not a git sha1 hash.=20

> And I feel it should be within the [], so maybe this:
>=20
> WARNING: CPU: 4 PID: 3255 at drivers/misc/lkdtm/bugs.c:83 lkdtm_WARNING+0=
x28/0x30 [lkdtm ed5019fdf5e5]
>=20

Sure I could put the hex numbers inside the brackets. I suspect changing
%pS or updating the "Modules linked in:" line isn't going to be
palatable. I've decided to introduce another printk format %pT to print
the stacktrace and then updated the architecture code on arm64 and x86
to see how it goes. Other architecures can be updated if this is
acceptable. I'll send out a patch series in a little bit that also
updates the decode_stacktrace.sh script to parse this.