Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Kees Cook <keescook@chromium.org>
To:     x86@kernel.org, Sami Tolvanen <samitolvanen@google.com>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Nathan Chancellor <nathan@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>
Cc:     Kees Cook <keescook@chromium.org>,
        clang-built-linux@googlegroups.com,
        Anthony Ruhier <aruhier@mailbox.org>,
        linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH] x86: Fix location of '-plugin-opt=' flags
Date:   Fri, 21 May 2021 10:59:10 -0700
Message-Id: <162161994470.2028902.331062863146834934.b4-ty@chromium.org>
In-Reply-To: <20210518190106.60935-1-nathan@kernel.org>
References: <20210518190106.60935-1-nathan@kernel.org>
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 8bit
Precedence: bulk

On Tue, 18 May 2021 12:01:06 -0700, Nathan Chancellor wrote:
> Commit b33fff07e3e3 ("x86, build: allow LTO to be selected") added a
> couple of '-plugin-opt=' flags to KBUILD_LDFLAGS because the code model
> and stack alignment are not stored in LLVM bitcode. However, these flags
> were added to KBUILD_LDFLAGS prior to the emulation flag assignment,
> which uses ':=', so they were overwritten and never added to $(LD)
> invocations. The absence of these flags caused misalignment issues in
> the AMDGPU driver when compiling with CONFIG_LTO_CLANG, resulting in
> general protection faults.
> 
> [...]

(I've slightly adjusted the title.)

Applied to for-next/clang/features, thanks!

[1/1] x86: lto: Fix location of '-plugin-opt=' flags
      https://git.kernel.org/kees/c/5d6c8592ee5f

-- 
Kees Cook