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Date:   Wed, 7 Apr 2021 14:21:21 -0700
From:   Andrew Morton <akpm@linux-foundation.org>
To:     Nick Desaulniers <ndesaulniers@google.com>
Cc:     Peter Oberparleiter <oberpar@linux.ibm.com>,
        Nathan Chancellor <nathan@kernel.org>,
        linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com,
        Fangrui Song <maskray@google.com>,
        Prasad Sodagudi <psodagud@quicinc.com>, stable@vger.kernel.org
Subject: Re: [PATCH 1/2] gcov: re-fix clang-11+ support
Message-Id: <20210407142121.677e971e9e5dc85643441811@linux-foundation.org>
In-Reply-To: <20210407185456.41943-2-ndesaulniers@google.com>
References: <20210407185456.41943-1-ndesaulniers@google.com>
        <20210407185456.41943-2-ndesaulniers@google.com>
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On Wed,  7 Apr 2021 11:54:55 -0700 Nick Desaulniers <ndesaulniers@google.com> wrote:

> LLVM changed the expected function signature for
> llvm_gcda_emit_function() in the clang-11 release.  Users of clang-11 or
> newer may have noticed their kernels producing invalid coverage
> information:
> 
> $ llvm-cov gcov -a -c -u -f -b <input>.gcda -- gcno=<input>.gcno
> 1 <func>: checksum mismatch, \
>   (<lineno chksum A>, <cfg chksum B>) != (<lineno chksum A>, <cfg chksum C>)
> 2 Invalid .gcda File!
> ...
> 
> Fix up the function signatures so calling this function interprets its
> parameters correctly and computes the correct cfg checksum. In
> particular, in clang-11, the additional checksum is no longer optional.

Which tree is this against?  I'm seeing quite a lot of rejects against
Linus's current.