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From:   Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Date:   Thu, 1 Jun 2023 12:27:30 +0200
Message-ID: <CANiq72nf-MC36hHzv0ZpR+qUyaf3mhF+rfqpMcVbw0AheuRBpA@mail.gmail.com>
Subject: Re: [PATCH 2/2] powerpc/xmon: use KSYM_NAME_LEN in array size
To:     Michael Ellerman <mpe@ellerman.id.au>
Cc:     Maninder Singh <maninder1.s@samsung.com>, bcain@quicinc.com,
        npiggin@gmail.com, christophe.leroy@csgroup.eu,
        keescook@chromium.org, nathanl@linux.ibm.com, ustavoars@kernel.org,
        alex.gaynor@gmail.com, gary@garyguo.net, ojeda@kernel.org,
        pmladek@suse.com, wedsonaf@google.com,
        linux-hexagon@vger.kernel.org, linux-kernel@vger.kernel.org,
        linuxppc-dev@lists.ozlabs.org, Onkarnath <onkarnath.1@samsung.com>
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On Thu, Jun 1, 2023 at 4:02=E2=80=AFAM Michael Ellerman <mpe@ellerman.id.au=
> wrote:
>
> > Side-note: in `get_function_bounds()`, I see `kallsyms_lookup()` being
> > used, but the name seems discarded? Can
> > `kallsyms_lookup_size_offset()` be used instead, thus avoiding the
> > usage of the buffer there to begin with?
>
> A few lines below it uses the modname, and AFAICS there's no (easy) way
> to lookup the modname without also looking up the name.

Hmm... I think you are looking at the `xmon_print_symbol()` one? I was
referring to the `get_function_bounds()` one, where the `modname`
parameter is `NULL` (and the `name` contents are not used, only
whether it was found or not).

> > Side-note 2: in `scanhex()`, I see a loop `i<63` using `tmpstr` which
> > then is used to do a `kallsyms_lookup_name()`, so I guess symbols
> > larger than 64 couldn't be found. I have no idea about what are the
> > external constraints here, but perhaps it is possible to increase the
> > `line` buffer etc. to then allow for bigger symbols to be found.
>
> Yeah that looks wrong. I don't see any symbols that long in current
> kernels, but we should fix it.
>
> Thanks for looking.

My pleasure!

Cheers,
Miguel