From: Lai Jiangshan <jiangshanlai@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: x86@kernel.org, Borislav Petkov <bp@alien8.de>,
Peter Zijlstra <peterz@infradead.org>,
Lai Jiangshan <jiangshan.ljs@antgroup.com>,
Andy Lutomirski <luto@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>
Subject: [PATCH V3 4/7] x86/entry: move PUSH_AND_CLEAR_REGS out of error_entry
Date: Tue, 15 Mar 2022 15:39:46 +0800 [thread overview]
Message-ID: <20220315073949.7541-5-jiangshanlai@gmail.com> (raw)
In-Reply-To: <20220315073949.7541-1-jiangshanlai@gmail.com>
From: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Moving PUSH_AND_CLEAR_REGS out of error_entry doesn't change any
functionality.
It makes error_entry() do not fiddle with the stack.
It will enlarge the size:
size arch/x86/entry/entry_64.o.before:
text data bss dec hex filename
17916 384 0 18300 477c arch/x86/entry/entry_64.o
size --format=SysV arch/x86/entry/entry_64.o.before:
.entry.text 5528 0
.orc_unwind 6456 0
.orc_unwind_ip 4304 0
size arch/x86/entry/entry_64.o.after:
text data bss dec hex filename
26868 384 0 27252 6a74 arch/x86/entry/entry_64.o
size --format=SysV arch/x86/entry/entry_64.o.after:
.entry.text 8200 0
.orc_unwind 10224 0
.orc_unwind_ip 6816 0
But .entry.text in x86_64 is 2M aligned, enlarging it to 8.2k doesn't
enlarge the final text size.
The tables .orc_unwind[_ip] are enlarged due to it adds many pushes.
It is prepared for not calling error_entry() from XENPV in later patch
and for future converting the whole error_entry into C code.
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
---
arch/x86/entry/entry_64.S | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 7768cdd0c7ed..903da9119e7a 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -325,6 +325,9 @@ SYM_CODE_END(ret_from_fork)
*/
.macro idtentry_body cfunc has_error_code:req
+ PUSH_AND_CLEAR_REGS
+ ENCODE_FRAME_POINTER
+
call error_entry
movq %rax, %rsp /* switch stack settled by sync_regs() */
ENCODE_FRAME_POINTER
@@ -1002,8 +1005,6 @@ SYM_CODE_END(paranoid_exit)
SYM_CODE_START_LOCAL(error_entry)
UNWIND_HINT_FUNC
cld
- PUSH_AND_CLEAR_REGS save_ret=1
- ENCODE_FRAME_POINTER 8
testb $3, CS+8(%rsp)
jz .Lerror_kernelspace
--
2.19.1.6.gb485710b
next prev parent reply other threads:[~2022-03-15 7:39 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-15 7:39 [PATCH V3 0/7] x86/entry: Clean up entry code Lai Jiangshan
2022-03-15 7:39 ` [PATCH V3 1/7] x86/entry: Use idtentry macro for entry_INT80_compat Lai Jiangshan
2022-03-16 13:48 ` Peter Zijlstra
2022-03-15 7:39 ` [PATCH V3 2/7] x86/traps: Move pt_regs only in fixup_bad_iret() Lai Jiangshan
2022-03-15 7:39 ` [PATCH V3 3/7] x86/entry: Switch the stack after error_entry() returns Lai Jiangshan
2022-03-16 2:37 ` Josh Poimboeuf
2022-03-16 3:02 ` Lai Jiangshan
2022-03-16 15:05 ` Peter Zijlstra
2022-03-16 16:43 ` Lai Jiangshan
2022-03-18 11:12 ` Peter Zijlstra
2022-03-15 7:39 ` Lai Jiangshan [this message]
2022-03-16 15:07 ` [PATCH V3 4/7] x86/entry: move PUSH_AND_CLEAR_REGS out of error_entry Peter Zijlstra
2022-03-16 16:18 ` Lai Jiangshan
2022-03-15 7:39 ` [PATCH V3 5/7] x86/entry: Move cld to the start of idtentry Lai Jiangshan
2022-03-15 7:39 ` [PATCH V3 6/7] x86/entry: Don't call error_entry for XENPV Lai Jiangshan
2022-03-16 2:59 ` Josh Poimboeuf
2022-03-16 15:09 ` Peter Zijlstra
2022-03-16 16:48 ` Lai Jiangshan
2022-03-15 7:39 ` [PATCH V3 7/7] x86/entry: Convert SWAPGS to swapgs and remove the definition of SWAPGS Lai Jiangshan
2022-03-16 15:12 ` [PATCH V3 0/7] x86/entry: Clean up entry code Peter Zijlstra
2022-03-16 15:13 ` Peter Zijlstra
2022-03-17 12:58 ` Lai Jiangshan
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=20220315073949.7541-5-jiangshanlai@gmail.com \
--to=jiangshanlai@gmail.com \
--cc=bp@alien8.de \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=jiangshan.ljs@antgroup.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--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).