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Date:   Wed, 14 Sep 2022 01:12:05 +0100
From:   Josh Poimboeuf <jpoimboe@kernel.org>
To:     Indu Bhagat <indu.bhagat@oracle.com>
Cc:     linux-toolchains@vger.kernel.org,
        Peter Zijlstra <peterz@infradead.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        linux-kernel@vger.kernel.org, "Jose E. Marchesi" <jemarch@gnu.org>,
        Miroslav Benes <mbenes@suse.cz>,
        Mark Rutland <mark.rutland@arm.com>,
        Will Deacon <will@kernel.org>, x86@kernel.org,
        linux-arm-kernel@lists.infradead.org,
        live-patching@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
        Ard Biesheuvel <ardb@kernel.org>,
        Chen Zhongjin <chenzhongjin@huawei.com>,
        Sathvika Vasireddy <sv@linux.ibm.com>,
        Christophe Leroy <christophe.leroy@csgroup.eu>,
        Mark Brown <broonie@kernel.org>
Subject: Re: [RFC] Objtool toolchain proposal:
 -fannotate-{jump-table,noreturn}
Message-ID: <20220914001205.ygvmwya5wcawcodj@treble>
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 <9f01a8b9-9ec6-6759-ba14-ee529a5b973a@oracle.com>
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On Tue, Sep 13, 2022 at 03:51:44PM -0700, Indu Bhagat wrote:
> Curious to know what all features of objtool rely on the need to reverse
> engineer the control flow graph. Is it a larger set or it is only for ORC
> generation ?

Objtool features which rely on the CFG:

- Frame pointer rule validation (when using
  CONFIG_UNWINDER_FRAME_POINTER)

- ORC metadata generation

- Intel SMAP rule validation - ensures EFLAGS #AC is only set during
  usercopy

- "noinstr" rule validation - ensures no instrumentation/tracing
  functions are called in certain critical sections

-- 
Josh