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From:   Michael Ellerman <mpe@ellerman.id.au>
To:     Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
        Maninder Singh <maninder1.s@samsung.com>
Cc:     bcain@quicinc.com, npiggin@gmail.com, christophe.leroy@csgroup.eu,
        keescook@chromium.org, nathanl@linux.ibm.com, ustavoars@kernel.org,
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        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>
Subject: Re: [PATCH 2/2] powerpc/xmon: use KSYM_NAME_LEN in array size
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Date:   Thu, 01 Jun 2023 12:02:16 +1000
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Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> writes:
> On Mon, May 29, 2023 at 1:14=E2=80=AFPM Maninder Singh <maninder1.s@samsu=
ng.com> wrote:
>>
>> +static char tmpstr[KSYM_NAME_LEN];
>
> Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
>
> 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.

> 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.

cheers