From: Peter Zijlstra <peterz@infradead.org>
To: Sami Tolvanen <samitolvanen@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Kees Cook <keescook@chromium.org>,
Josh Poimboeuf <jpoimboe@redhat.com>, X86 ML <x86@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
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 <linux-arm-kernel@lists.infradead.org>,
llvm@lists.linux.dev
Subject: Re: [PATCH v4 00/21] KCFI support
Date: Fri, 2 Sep 2022 09:51:41 +0200 [thread overview]
Message-ID: <YxG2DUEBnIpAMKF2@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <CABCJKucP5nXGiCTTCEPUGYo5Z9A9qaQkJ6_kXTOfw-o-=TYH0g@mail.gmail.com>
On Thu, Sep 01, 2022 at 05:33:29PM -0700, Sami Tolvanen wrote:
> > I do see a few new objtool warnings as well:
> >
> > vmlinux.o: warning: objtool: apply_relocate_add+0x34: relocation to !ENDBR: memcpy+0x0
> > vmlinux.o: warning: objtool: ___ksymtab+__memcpy+0x0: data relocation to !ENDBR: memcpy+0x0
> > vmlinux.o: warning: objtool: ___ksymtab+memcpy+0x0: data relocation to !ENDBR: memcpy+0x0
>
> That's interesting. I can only reproduce this warning with
> allmodconfig+LTO, even though the relocation exists in all builds (the
> code makes an indirect call to memcpy) and memcpy (aliased to
> __memcpy) doesn't start with endbr. I'll have to take a closer look at
> why this warning only appears with LTO.
From just looking at the patches I'd say patch #19 breaks it. IIRC you
forgot to make the SYM_TYPED_FUNC things emit ENDBR.
Look at how x86/asm/linkage.h is overriding SYM_FUNC_START*().
You might have the same bug vs ARM64 BTI, they do the same thing.
next prev parent reply other threads:[~2022-09-02 7:52 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-30 23:31 [PATCH v4 00/21] KCFI support Sami Tolvanen
2022-08-30 23:31 ` [PATCH v4 01/21] treewide: Filter out CC_FLAGS_CFI Sami Tolvanen
2022-08-30 23:31 ` [PATCH v4 02/21] scripts/kallsyms: Ignore __kcfi_typeid_ Sami Tolvanen
2022-08-30 23:31 ` [PATCH v4 03/21] cfi: Remove CONFIG_CFI_CLANG_SHADOW Sami Tolvanen
2022-08-30 23:31 ` [PATCH v4 04/21] cfi: Drop __CFI_ADDRESSABLE Sami Tolvanen
2022-08-30 23:31 ` [PATCH v4 05/21] cfi: Switch to -fsanitize=kcfi Sami Tolvanen
2022-08-30 23:31 ` [PATCH v4 06/21] cfi: Add type helper macros Sami Tolvanen
2022-08-30 23:31 ` [PATCH v4 07/21] lkdtm: Emit an indirect call for CFI tests Sami Tolvanen
2022-08-30 23:31 ` [PATCH v4 08/21] psci: Fix the function type for psci_initcall_t Sami Tolvanen
2022-08-31 18:22 ` Kees Cook
2022-08-30 23:31 ` [PATCH v4 09/21] arm64: Add types to indirect called assembly functions Sami Tolvanen
2022-08-30 23:31 ` [PATCH v4 10/21] arm64: Add CFI error handling Sami Tolvanen
2022-08-30 23:31 ` [PATCH v4 11/21] arm64: Drop unneeded __nocfi attributes Sami Tolvanen
2022-08-30 23:31 ` [PATCH v4 12/21] init: Drop __nocfi from __init Sami Tolvanen
2022-08-30 23:31 ` [PATCH v4 13/21] treewide: Drop function_nocfi Sami Tolvanen
2022-08-30 23:31 ` [PATCH v4 14/21] treewide: Drop WARN_ON_FUNCTION_MISMATCH Sami Tolvanen
2022-08-30 23:31 ` [PATCH v4 15/21] treewide: Drop __cficanonical Sami Tolvanen
2022-08-30 23:31 ` [PATCH v4 16/21] objtool: Disable CFI warnings Sami Tolvanen
2022-08-31 18:23 ` Kees Cook
2022-08-30 23:31 ` [PATCH v4 17/21] kallsyms: Drop CONFIG_CFI_CLANG workarounds Sami Tolvanen
2022-08-31 18:23 ` Kees Cook
2022-08-30 23:31 ` [PATCH v4 18/21] x86/tools/relocs: Ignore __kcfi_typeid_ relocations Sami Tolvanen
2022-08-30 23:31 ` [PATCH v4 19/21] x86: Add types to indirectly called assembly functions Sami Tolvanen
2022-08-30 23:31 ` [PATCH v4 20/21] x86/purgatory: Disable CFI Sami Tolvanen
2022-08-30 23:31 ` [PATCH v4 21/21] x86: Add support for CONFIG_CFI_CLANG Sami Tolvanen
2022-08-31 18:28 ` Kees Cook
2022-08-31 22:04 ` [PATCH v4 00/21] KCFI support Kees Cook
2022-09-01 21:19 ` Nathan Chancellor
2022-09-02 0:33 ` Sami Tolvanen
2022-09-02 7:51 ` Peter Zijlstra [this message]
2022-09-02 15:39 ` Sami Tolvanen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YxG2DUEBnIpAMKF2@hirez.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=catalin.marinas@arm.com \
--cc=joao@overdrivepizza.com \
--cc=jpoimboe@redhat.com \
--cc=keescook@chromium.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-hardening@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=llvm@lists.linux.dev \
--cc=mark.rutland@arm.com \
--cc=nathan@kernel.org \
--cc=ndesaulniers@google.com \
--cc=rostedt@goodmis.org \
--cc=samitolvanen@google.com \
--cc=sedat.dilek@gmail.com \
--cc=will@kernel.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox