From: Borislav Petkov <bp@alien8.de>
To: Yu-cheng Yu <yu-cheng.yu@intel.com>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
"H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Tony Luck <tony.luck@intel.com>,
Andy Lutomirski <luto@kernel.org>,
Rik van Riel <riel@surriel.com>,
"Ravi V. Shankar" <ravi.v.shankar@intel.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Fenghua Yu <fenghua.yu@intel.com>,
Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH v3 06/10] x86/fpu/xstate: Update sanitize_restored_xstate() for supervisor xstates
Date: Thu, 7 May 2020 15:11:42 +0200 [thread overview]
Message-ID: <20200507131142.GA23026@zn.tnic> (raw)
In-Reply-To: <20200328164307.17497-7-yu-cheng.yu@intel.com>
On Sat, Mar 28, 2020 at 09:43:03AM -0700, Yu-cheng Yu wrote:
> The function sanitize_restored_xstate() sanitizes user xstates of an XSAVE
> buffer by setting the buffer's header->xfeatures to the input 'xfeatures',
It doesn't set them to the input xfeatures. I see a "&=" there.
> effectively resetting features not in 'xfeatures' back to the init state.
>
> When supervisor xstates are introduced, it is necessary to make sure only
> user xstates are sanitized. Ensure supervisor bits in header->xfeatures
> stay set and supervisor states are not modified.
>
> To make names clear, also:
>
> - Rename the function to sanitize_restored_user_xstate().
> - Rename input parameter 'xfeatures' to 'xfeatures_from_user'.
> - In __fpu__restore_sig(), rename 'xfeatures' to 'user_xfeatures'.
>
> v3:
> - Change xfeatures_user to user_xfeatures.
>
> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
> ---
> arch/x86/kernel/fpu/signal.c | 37 +++++++++++++++++++++++-------------
> 1 file changed, 24 insertions(+), 13 deletions(-)
>
> diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c
> index cd6eafba12da..d09d72334a12 100644
> --- a/arch/x86/kernel/fpu/signal.c
> +++ b/arch/x86/kernel/fpu/signal.c
> @@ -211,9 +211,9 @@ int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size)
> }
>
> static inline void
> -sanitize_restored_xstate(union fpregs_state *state,
> - struct user_i387_ia32_struct *ia32_env,
> - u64 xfeatures, int fx_only)
> +sanitize_restored_user_xstate(union fpregs_state *state,
> + struct user_i387_ia32_struct *ia32_env,
> + u64 xfeatures_from_user, int fx_only)
Name those user_xfeatures too.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2020-05-07 13:11 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-28 16:42 [PATCH v3 00/10] Support XSAVES supervisor states Yu-cheng Yu
2020-03-28 16:42 ` [PATCH v3 01/10] x86/fpu/xstate: Rename validate_xstate_header() to validate_user_xstate_header() Yu-cheng Yu
2020-04-28 17:11 ` Borislav Petkov
2020-04-28 17:15 ` Yu-cheng Yu
2020-03-28 16:42 ` [PATCH v3 02/10] x86/fpu/xstate: Define new macros for supervisor and user xstates Yu-cheng Yu
2020-03-28 16:43 ` [PATCH v3 03/10] x86/fpu/xstate: Separate user and supervisor xfeatures mask Yu-cheng Yu
2020-03-28 16:43 ` [PATCH v3 04/10] x86/fpu/xstate: Introduce XSAVES supervisor states Yu-cheng Yu
2020-03-28 16:43 ` [PATCH v3 05/10] x86/fpu/xstate: Define new functions for clearing fpregs and xstates Yu-cheng Yu
2020-04-29 9:27 ` Borislav Petkov
2020-04-29 16:09 ` Yu-cheng Yu
2020-04-29 16:06 ` Yu-cheng Yu
2020-04-29 16:39 ` Borislav Petkov
2020-04-29 17:02 ` Yu-cheng Yu
2020-04-29 17:32 ` Borislav Petkov
2020-04-29 17:42 ` Yu-cheng Yu
2020-04-29 19:10 ` Yu-cheng Yu
2020-03-28 16:43 ` [PATCH v3 06/10] x86/fpu/xstate: Update sanitize_restored_xstate() for supervisor xstates Yu-cheng Yu
2020-05-07 13:11 ` Borislav Petkov [this message]
2020-05-07 15:55 ` Yu-cheng Yu
2020-03-28 16:43 ` [PATCH v3 07/10] x86/fpu/xstate: Update copy_kernel_to_xregs_err() for XSAVES supervisor states Yu-cheng Yu
2020-05-07 13:28 ` Borislav Petkov
2020-05-07 15:58 ` Yu-cheng Yu
2020-03-28 16:43 ` [PATCH v3 08/10] x86/fpu: Introduce copy_supervisor_to_kernel() Yu-cheng Yu
2020-03-28 16:43 ` [PATCH v3 09/10] x86/fpu/xstate: Preserve supervisor states for slow path of __fpu__restore_sig() Yu-cheng Yu
2020-05-10 8:46 ` Borislav Petkov
2020-05-11 20:16 ` Yu-cheng Yu
2020-03-28 16:43 ` [PATCH v3 10/10] x86/fpu/xstate: Restore supervisor states for signal return Yu-cheng Yu
2020-05-10 8:49 ` Borislav Petkov
2020-05-11 20:20 ` Yu-cheng Yu
2020-05-11 20:27 ` [PATCH v3 00/10] Support XSAVES supervisor states Borislav Petkov
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