From: Kees Cook <keescook@chromium.org>
To: Borislav Petkov <bp@alien8.de>
Cc: X86 ML <x86@kernel.org>, LKML <linux-kernel@vger.kernel.org>,
Lai Jiangshan <jiangshanlai@gmail.com>
Subject: Re: [PATCH v2 3/6] x86/cpu: Remove CONFIG_X86_SMAP and "nosmap"
Date: Mon, 7 Feb 2022 14:07:27 -0800 [thread overview]
Message-ID: <202202071405.FB72C07@keescook> (raw)
In-Reply-To: <20220127115626.14179-4-bp@alien8.de>
On Thu, Jan 27, 2022 at 12:56:23PM +0100, Borislav Petkov wrote:
> From: Borislav Petkov <bp@suse.de>
>
> Those were added as part of the SMAP enablement but SMAP is currently
> an integral part of kernel proper and there's no need to disable it
> anymore.
>
> Rip out that functionality.
>
> If still needed - clearcpuid=smap.
>
> Signed-off-by: Borislav Petkov <bp@suse.de>
> Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>
> ---
> .../admin-guide/kernel-parameters.txt | 2 +-
> Documentation/x86/cpuinfo.rst | 5 ++--
> arch/x86/Kconfig | 11 ---------
> arch/x86/include/asm/disabled-features.h | 8 +------
> arch/x86/include/asm/smap.h | 24 -------------------
> arch/x86/kernel/cpu/common.c | 15 +-----------
> scripts/Makefile.build | 1 -
> scripts/link-vmlinux.sh | 3 ---
> .../arch/x86/include/asm/disabled-features.h | 8 +------
> 9 files changed, 6 insertions(+), 71 deletions(-)
> [...]
> diff --git a/scripts/Makefile.build b/scripts/Makefile.build
> index a4b89b757287..9b37902607ed 100644
> --- a/scripts/Makefile.build
> +++ b/scripts/Makefile.build
> @@ -233,7 +233,6 @@ objtool_args = \
> $(if $(CONFIG_FRAME_POINTER),, --no-fp) \
> $(if $(CONFIG_GCOV_KERNEL)$(CONFIG_LTO_CLANG), --no-unreachable)\
> $(if $(CONFIG_RETPOLINE), --retpoline) \
> - $(if $(CONFIG_X86_SMAP), --uaccess) \
> $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \
> $(if $(CONFIG_SLS), --sls)
>
> diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
> index 666f7bbc13eb..8547aaa1a630 100755
> --- a/scripts/link-vmlinux.sh
> +++ b/scripts/link-vmlinux.sh
> @@ -140,9 +140,6 @@ objtool_link()
> if is_enabled CONFIG_RETPOLINE; then
> objtoolopt="${objtoolopt} --retpoline"
> fi
> - if is_enabled CONFIG_X86_SMAP; then
> - objtoolopt="${objtoolopt} --uaccess"
> - fi
> if is_enabled CONFIG_SLS; then
> objtoolopt="${objtoolopt} --sls"
> fi
I was expecting to see --uaccess unconditionally added to objtool
arguments. I think that needs to happen?
--
Kees Cook
next prev parent reply other threads:[~2022-02-07 22:07 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-27 11:56 [PATCH v2 0/6] x86/cpu: Do some janitorial work Borislav Petkov
2022-01-27 11:56 ` [PATCH v2 1/6] x86/cpu: Allow feature bit names from /proc/cpuinfo in clearcpuid= Borislav Petkov
2022-02-07 22:04 ` Kees Cook
2022-02-08 11:54 ` Borislav Petkov
2022-04-04 18:22 ` [tip: x86/cpu] " tip-bot2 for Borislav Petkov
2022-01-27 11:56 ` [PATCH v2 2/6] x86/cpu: Remove "nosep" Borislav Petkov
2022-02-07 21:58 ` Kees Cook
2022-04-04 18:22 ` [tip: x86/cpu] " tip-bot2 for Borislav Petkov
2022-01-27 11:56 ` [PATCH v2 3/6] x86/cpu: Remove CONFIG_X86_SMAP and "nosmap" Borislav Petkov
2022-02-07 22:07 ` Kees Cook [this message]
2022-02-08 15:06 ` Borislav Petkov
2022-02-08 21:01 ` Borislav Petkov
2022-02-09 2:56 ` Kees Cook
2022-02-09 11:53 ` Borislav Petkov
2022-04-04 18:22 ` [tip: x86/cpu] " tip-bot2 for Borislav Petkov
2022-01-27 11:56 ` [PATCH v2 4/6] x86/cpu: Remove "nosmep" Borislav Petkov
2022-02-07 22:07 ` Kees Cook
2022-04-04 18:22 ` [tip: x86/cpu] " tip-bot2 for Borislav Petkov
2022-01-27 11:56 ` [PATCH v2 5/6] x86/cpu: Remove "noexec" Borislav Petkov
2022-02-07 22:25 ` Kees Cook
2022-02-08 17:40 ` Sean Christopherson
2022-02-08 19:56 ` Borislav Petkov
2022-04-04 18:22 ` [tip: x86/cpu] " tip-bot2 for Borislav Petkov
2022-01-27 11:56 ` [PATCH v2 6/6] x86/cpu: Remove "noclflush" Borislav Petkov
2022-02-07 22:08 ` Kees Cook
2022-04-04 18:22 ` [tip: x86/cpu] " tip-bot2 for Borislav Petkov
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