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Date:   Wed, 21 Jul 2021 11:19:01 -0400
From:   Sasha Levin <sashal@kernel.org>
To:     Steven Rostedt <rostedt@goodmis.org>
Cc:     Pavel Machek <pavel@denx.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        David Wysochanski <dwysocha@redhat.com>,
        Chuck Lever <chuck.lever@oracle.com>,
        "J. Bruce Fields" <bfields@redhat.com>
Subject: Re: [PATCH 5.10 147/243] NFSD: Fix TP_printk() format specifier in
 nfsd_clid_class
Message-ID: <YPg65XyiPf+A/2yi@sashalap>
References: <20210719144940.904087935@linuxfoundation.org>
 <20210719144945.657682587@linuxfoundation.org>
 <20210720214847.GB704@amd>
 <20210721100413.227fd0cb@oasis.local.home>
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On Wed, Jul 21, 2021 at 10:04:13AM -0400, Steven Rostedt wrote:
>On Tue, 20 Jul 2021 23:48:47 +0200
>Pavel Machek <pavel@denx.de> wrote:
>
>> Hi!
>>
>> > [ Upstream commit a948b1142cae66785521a389cab2cce74069b547 ]
>> >
>> > Since commit 9a6944fee68e ("tracing: Add a verifier to check string
>> > pointers for trace events"), which was merged in v5.13-rc1,
>> > TP_printk() no longer tacitly supports the "%.*s" format specifier.
>> >
>> > These are low value tracepoints, so just remove them.
>>
>> So I understand we want this for mainline, but AFAICT 5.10 does not
>> have 9a6944fee68e ("tracing: Add a verifier to check string pointers
>> for trace events") commit, so this does not fix any bug and removal of
>> tracepoints can be surprising.
>>
>
>Thanks for pointing this out. I get so many stable patches, I don't
>have time to look at all of them.
>
>Greg, I don't think this should be backported. The verifier code had a
>bug in it that broke the '%.*s' formats. This patch removed the good
>code because of the broken code.
>
>See eb01f5353bdaa ("tracing: Handle %.*s in trace_check_vprintf()")

Uh, yes, I'll drop it. Thanks for catching this!

-- 
Thanks,
Sasha