Re: [PATCH v2 00/20] objtool: vmlinux.o and CLANG LTO support

From: Sedat Dilek <sedat.dilek@gmail.com>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
	Peter Zijlstra <peterz@infradead.org>,
	Sami Tolvanen <samitolvanen@google.com>,
	Kees Cook <keescook@chromium.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Clang-Built-Linux ML <clang-built-linux@googlegroups.com>,
	Miroslav Benes <mbenes@suse.cz>
Subject: Re: [PATCH v2 00/20] objtool: vmlinux.o and CLANG LTO support
Date: Thu, 21 Jan 2021 23:38:54 +0100	[thread overview]
Message-ID: <CA+icZUU6QBeahDWpgYPjkf_OmRC+4T4SAnCg=iObNq9+CGT6jA@mail.gmail.com> (raw)
In-Reply-To: <cover.1611263461.git.jpoimboe@redhat.com>

On Thu, Jan 21, 2021 at 10:29 PM Josh Poimboeuf <jpoimboe@redhat.com> wrote:
>
> v2:
> - fix commit description for why xen hypervisor page contents don't
>   matter [Juergen]
> - annotate indirect jumps as safe instead of converting them to
>   retpolines [Andrew, Juergen]
> - drop patch 1 - fake jumps no longer exist
> - add acks
>
> Based on tip/objtool/core.
>
>
> Add support for proper vmlinux.o validation, which will be needed for
> Sami's upcoming x86 LTO set.  (And vmlinux validation is the future for
> objtool anyway, for other reasons.)
>
> This isn't 100% done -- most notably, crypto still needs to be supported
> -- but I think this gets us most of the way there.
>
> This can also be found at
>
>   git://git.kernel.org/pub/scm/linux/kernel/git/jpoimboe/linux.git objtool-vmlinux
>

Should this be s/objtool-vmlinux/objtool-vmlinux-v2 ?

- Sedat -

> And for more testing it can be combined with Sami's x86 LTO patches:
>
>   https://github.com/samitolvanen/linux clang-lto
>
>
> Josh Poimboeuf (20):
>   objtool: Fix error handling for STD/CLD warnings
>   objtool: Fix retpoline detection in asm code
>   objtool: Fix ".cold" section suffix check for newer versions of GCC
>   objtool: Support retpoline jump detection for vmlinux.o
>   x86/ftrace: Add UNWIND_HINT_FUNC annotation for ftrace_stub
>   objtool: Assume only ELF functions do sibling calls
>   objtool: Add asm version of STACK_FRAME_NON_STANDARD
>   objtool: Combine UNWIND_HINT_RET_OFFSET and UNWIND_HINT_FUNC
>   objtool: Add xen_start_kernel() to noreturn list
>   objtool: Move unsuffixed symbol conversion to a helper function
>   objtool: Add CONFIG_CFI_CLANG support
>   x86/xen: Support objtool validation in xen-asm.S
>   x86/xen: Support objtool vmlinux.o validation in xen-head.S
>   x86/xen/pvh: Annotate indirect branch as safe
>   x86/ftrace: Support objtool vmlinux.o validation in ftrace_64.S
>   x86/acpi: Annotate indirect branch as safe
>   x86/acpi: Support objtool validation in wakeup_64.S
>   x86/power: Annotate indirect branches as safe
>   x86/power: Move restore_registers() to top of the file
>   x86/power: Support objtool validation in hibernate_asm_64.S
>
>  arch/x86/include/asm/unwind_hints.h   |  13 +---
>  arch/x86/kernel/acpi/Makefile         |   1 -
>  arch/x86/kernel/acpi/wakeup_64.S      |   4 +
>  arch/x86/kernel/ftrace_64.S           |   8 +-
>  arch/x86/lib/retpoline.S              |   2 +-
>  arch/x86/platform/pvh/head.S          |   2 +
>  arch/x86/power/Makefile               |   1 -
>  arch/x86/power/hibernate_asm_64.S     | 103 +++++++++++++-------------
>  arch/x86/xen/Makefile                 |   1 -
>  arch/x86/xen/xen-asm.S                |  29 +++++---
>  arch/x86/xen/xen-head.S               |   5 +-
>  include/linux/objtool.h               |  13 +++-
>  tools/include/linux/objtool.h         |  13 +++-
>  tools/objtool/arch/x86/decode.c       |   4 +-
>  tools/objtool/arch/x86/special.c      |   2 +-
>  tools/objtool/check.c                 |  89 ++++++++++++----------
>  tools/objtool/elf.c                   |  88 ++++++++++++++++------
>  tools/objtool/include/objtool/check.h |  12 ++-
>  tools/objtool/include/objtool/elf.h   |   2 +-
>  19 files changed, 240 insertions(+), 152 deletions(-)
>
> --
> 2.29.2
>