From: Josh Poimboeuf <jpoimboe@kernel.org>
To: Sami Tolvanen <samitolvanen@google.com>
Cc: linux-kernel@vger.kernel.org, Kees Cook <keescook@chromium.org>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
x86@kernel.org, Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Joao Moreira <joao@overdrivepizza.com>,
Sedat Dilek <sedat.dilek@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
linux-hardening@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, llvm@lists.linux.dev
Subject: Re: [RFC PATCH v3 15/20] objtool: Disable CFI warnings
Date: Mon, 13 Jun 2022 09:10:43 -0700 [thread overview]
Message-ID: <20220613161043.4wiqservfyxeme4f@treble> (raw)
In-Reply-To: <20220610233513.1798771-16-samitolvanen@google.com>
On Fri, Jun 10, 2022 at 04:35:08PM -0700, Sami Tolvanen wrote:
> The __cfi_ preambles contain int3 padding and a mov instruction that
> embeds the KCFI type identifier in the following format:
>
> ; type preamble
> __cfi_function:
> int3
> int3
> mov <id>, %eax
> int3
> int3
> function:
> ...
>
> While the preamble symbols are STT_FUNC and contain valid
> instructions, they are never executed and always fall through. Skip
> the warning for them.
>
> .kcfi_traps sections point to CFI traps in text sections. Also skip
> the warning about them referencing !ENDBR instructions.
>
> Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
--
Josh
next prev parent reply other threads:[~2022-06-13 18:59 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-10 23:34 [RFC PATCH v3 00/20] KCFI support Sami Tolvanen
2022-06-10 23:34 ` [RFC PATCH v3 01/20] treewide: Filter out CC_FLAGS_CFI Sami Tolvanen
2022-06-10 23:34 ` [RFC PATCH v3 02/20] scripts/kallsyms: Ignore __kcfi_typeid_ Sami Tolvanen
2022-06-10 23:34 ` [RFC PATCH v3 03/20] cfi: Remove CONFIG_CFI_CLANG_SHADOW Sami Tolvanen
2022-06-10 23:34 ` [RFC PATCH v3 04/20] cfi: Drop __CFI_ADDRESSABLE Sami Tolvanen
2022-06-10 23:34 ` [RFC PATCH v3 05/20] cfi: Switch to -fsanitize=kcfi Sami Tolvanen
2022-06-10 23:34 ` [RFC PATCH v3 06/20] cfi: Add type helper macros Sami Tolvanen
2022-06-10 23:35 ` [RFC PATCH v3 07/20] lkdtm: Emit an indirect call for CFI tests Sami Tolvanen
2022-06-10 23:43 ` Nick Desaulniers
2022-06-11 6:01 ` Kees Cook
2022-06-10 23:35 ` [RFC PATCH v3 08/20] arm64: Add types to indirect called assembly functions Sami Tolvanen
2022-06-10 23:35 ` [RFC PATCH v3 09/20] arm64: Add CFI error handling Sami Tolvanen
2022-06-10 23:35 ` [RFC PATCH v3 10/20] arm64: Drop unneeded __nocfi attributes Sami Tolvanen
2022-06-10 23:35 ` [RFC PATCH v3 11/20] init: Drop __nocfi from __init Sami Tolvanen
2022-06-10 23:35 ` [RFC PATCH v3 12/20] treewide: Drop function_nocfi Sami Tolvanen
2022-06-10 23:35 ` [RFC PATCH v3 13/20] treewide: Drop WARN_ON_FUNCTION_MISMATCH Sami Tolvanen
2022-06-10 23:35 ` [RFC PATCH v3 14/20] treewide: Drop __cficanonical Sami Tolvanen
2022-06-10 23:35 ` [RFC PATCH v3 15/20] objtool: Disable CFI warnings Sami Tolvanen
2022-06-13 16:10 ` Josh Poimboeuf [this message]
2022-06-10 23:35 ` [RFC PATCH v3 16/20] kallsyms: Drop CONFIG_CFI_CLANG workarounds Sami Tolvanen
2022-06-10 23:40 ` Nick Desaulniers
2022-06-13 19:19 ` Bill Wendling
2022-06-10 23:35 ` [RFC PATCH v3 17/20] x86/tools/relocs: Ignore __kcfi_typeid_ relocations Sami Tolvanen
2022-06-10 23:35 ` [RFC PATCH v3 18/20] x86: Add types to indirectly called assembly functions Sami Tolvanen
2022-06-10 23:35 ` [RFC PATCH v3 19/20] x86/purgatory: Disable CFI Sami Tolvanen
2022-06-10 23:35 ` [RFC PATCH v3 20/20] x86: Add support for CONFIG_CFI_CLANG Sami Tolvanen
2022-07-23 11:21 ` Peter Zijlstra
2022-07-26 0:09 ` Sami Tolvanen
2022-06-13 17:04 ` [RFC PATCH v3 00/20] KCFI support Kees Cook
2022-07-18 21:46 ` Peter Zijlstra
2022-07-19 13:36 ` Will Deacon
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