From: "tip-bot2 for Sean Christopherson" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Sean Christopherson <sean.j.christopherson@intel.com>,
Borislav Petkov <bp@suse.de>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [tip: x86/cleanups] x86/asm: Drop unused RDPID macro
Date: Thu, 26 Nov 2020 12:14:42 -0000 [thread overview]
Message-ID: <160639288228.3364.6749574723160205981.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20201027214532.1792-1-sean.j.christopherson@intel.com>
The following commit has been merged into the x86/cleanups branch of tip:
Commit-ID: 8539d3f06710a9e91b9968fa736549d7c6b44206
Gitweb: https://git.kernel.org/tip/8539d3f06710a9e91b9968fa736549d7c6b44206
Author: Sean Christopherson <sean.j.christopherson@intel.com>
AuthorDate: Tue, 27 Oct 2020 14:45:32 -07:00
Committer: Borislav Petkov <bp@suse.de>
CommitterDate: Thu, 26 Nov 2020 12:58:56 +01:00
x86/asm: Drop unused RDPID macro
Drop the GAS-compatible RDPID macro. RDPID is unsafe in the kernel
because KVM loads guest's TSC_AUX on VM-entry and may not restore the
host's value until the CPU returns to userspace.
See
6a3ea3e68b8a ("x86/entry/64: Do not use RDPID in paranoid entry to accomodate KVM")
for details.
It can always be resurrected from git history, if needed.
[ bp: Massage commit message. ]
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201027214532.1792-1-sean.j.christopherson@intel.com
---
arch/x86/include/asm/inst.h | 15 ---------------
1 file changed, 15 deletions(-)
diff --git a/arch/x86/include/asm/inst.h b/arch/x86/include/asm/inst.h
index bd7f024..438ccd4 100644
--- a/arch/x86/include/asm/inst.h
+++ b/arch/x86/include/asm/inst.h
@@ -143,21 +143,6 @@
.macro MODRM mod opd1 opd2
.byte \mod | (\opd1 & 7) | ((\opd2 & 7) << 3)
.endm
-
-.macro RDPID opd
- REG_TYPE rdpid_opd_type \opd
- .if rdpid_opd_type == REG_TYPE_R64
- R64_NUM rdpid_opd \opd
- .else
- R32_NUM rdpid_opd \opd
- .endif
- .byte 0xf3
- .if rdpid_opd > 7
- PFX_REX rdpid_opd 0
- .endif
- .byte 0x0f, 0xc7
- MODRM 0xc0 rdpid_opd 0x7
-.endm
#endif
#endif
prev parent reply other threads:[~2020-11-26 12:14 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-27 21:45 [PATCH] x86: Drop RDPID macro to discourage use of RDPID in the kernel Sean Christopherson
2020-10-28 8:54 ` Peter Zijlstra
2020-11-26 12:14 ` tip-bot2 for Sean Christopherson [this message]
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=160639288228.3364.6749574723160205981.tip-bot2@tip-bot2 \
--to=tip-bot2@linutronix.de \
--cc=bp@suse.de \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tip-commits@vger.kernel.org \
--cc=sean.j.christopherson@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).