linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Yu-cheng Yu <yu-cheng.yu@intel.com>
To: 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>, Borislav Petkov <bp@alien8.de>,
	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>
Cc: Yu-cheng Yu <yu-cheng.yu@intel.com>
Subject: [PATCH v3 07/10] x86/fpu/xstate: Update copy_kernel_to_xregs_err() for XSAVES supervisor states
Date: Sat, 28 Mar 2020 09:43:04 -0700	[thread overview]
Message-ID: <20200328164307.17497-8-yu-cheng.yu@intel.com> (raw)
In-Reply-To: <20200328164307.17497-1-yu-cheng.yu@intel.com>

The function copy_kernel_to_xregs_err() uses XRSTOR, which can work with
standard or compacted format without supervisor xstates.  However, when
supervisor xstates are present, XRSTORS must be used.  Fix it by using
XRSTORS when XSAVES is enabled.

I also considered if there were additional cases where XRSTOR might be
mistakenly called instead of XRSTORS.  There are only three XRSTOR sites
in kernel:

1. copy_kernel_to_xregs_booting(), already switches between XRSTOR and
   XRSTORS based on X86_FEATURE_XSAVES.
2. copy_user_to_xregs(), which *needs* XRSTOR because it is copying from
   userspace and must never copy supervisor state with XRSTORS.
3. copy_kernel_to_xregs_err() mistakenly used XRSTOR only.  Fixed in
   this patch.

Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
---
 arch/x86/include/asm/fpu/internal.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h
index a42fcb4b690d..42159f45bf9c 100644
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -400,7 +400,10 @@ static inline int copy_kernel_to_xregs_err(struct xregs_state *xstate, u64 mask)
 	u32 hmask = mask >> 32;
 	int err;
 
-	XSTATE_OP(XRSTOR, xstate, lmask, hmask, err);
+	if (static_cpu_has(X86_FEATURE_XSAVES))
+		XSTATE_OP(XRSTORS, xstate, lmask, hmask, err);
+	else
+		XSTATE_OP(XRSTOR, xstate, lmask, hmask, err);
 
 	return err;
 }
-- 
2.21.0


  parent reply	other threads:[~2020-03-28 16:44 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
2020-05-07 15:55   ` Yu-cheng Yu
2020-03-28 16:43 ` Yu-cheng Yu [this message]
2020-05-07 13:28   ` [PATCH v3 07/10] x86/fpu/xstate: Update copy_kernel_to_xregs_err() for XSAVES supervisor states 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

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=20200328164307.17497-8-yu-cheng.yu@intel.com \
    --to=yu-cheng.yu@intel.com \
    --cc=bigeasy@linutronix.de \
    --cc=bp@alien8.de \
    --cc=dave.hansen@linux.intel.com \
    --cc=fenghua.yu@intel.com \
    --cc=hpa@zytor.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luto@kernel.org \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    --cc=ravi.v.shankar@intel.com \
    --cc=riel@surriel.com \
    --cc=tglx@linutronix.de \
    --cc=tony.luck@intel.com \
    --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;
as well as URLs for NNTP newsgroup(s).