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From: Lai Jiangshan <jiangshanlai@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: Lai Jiangshan <laijs@linux.alibaba.com>,
	Andy Lutomirski <luto@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>
Subject: [PATCH V2 14/41] x86/entry: move PUSH_AND_CLEAR_REGS out of error_entry
Date: Sun, 26 Sep 2021 23:08:11 +0800	[thread overview]
Message-ID: <20210926150838.197719-15-jiangshanlai@gmail.com> (raw)
In-Reply-To: <20210926150838.197719-1-jiangshanlai@gmail.com>

From: Lai Jiangshan <laijs@linux.alibaba.com>

Moving PUSH_AND_CLEAR_REGS out of error_entry doesn't change any
functionality.  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 converting the whole error_entry into C code.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.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 dd453a8e7317..757e7155670e 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -322,6 +322,9 @@ 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
@@ -967,8 +970,6 @@ 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


  parent reply	other threads:[~2021-09-26 15:10 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-26 15:07 [PATCH V2 00/41] x86/entry/64: Convert a bunch of ASM entry code into C code Lai Jiangshan
2021-09-26 15:07 ` [PATCH V2 01/41] x86/entry: Fix swapgs fence Lai Jiangshan
2021-09-26 20:43   ` Thomas Gleixner
2021-09-27  1:10     ` Lai Jiangshan
2021-09-27  3:27       ` Lai Jiangshan
2021-09-27  7:50         ` Thomas Gleixner
2021-09-26 15:07 ` [PATCH V2 02/41] x86/traps: Remove stack-protector from traps.c Lai Jiangshan
2021-09-27 10:19   ` Borislav Petkov
2021-09-27 10:49     ` Lai Jiangshan
2021-09-27 11:01       ` Borislav Petkov
2021-09-27 14:38         ` Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 03/41] compiler_types.h: Add __noinstr_section() for noinstr Lai Jiangshan
2021-09-27 18:09   ` Kees Cook
2021-09-26 15:08 ` [PATCH V2 04/41] x86/entry: Introduce __entry_text for entry code written in C Lai Jiangshan
2021-09-30 11:49   ` Borislav Petkov
2021-09-26 15:08 ` [PATCH V2 05/41] x86/entry: Move PTI_USER_* to arch/x86/include/asm/processor-flags.h Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 06/41] x86: Mark __native_read_cr3() & native_write_cr3() as __always_inline Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 07/41] x86/traps: Move the declaration of native_irq_return_iret into proto.h Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 08/41] x86/entry: Add arch/x86/entry/entry64.c for C entry code Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 09/41] x86/entry: Expose the address of .Lgs_change to entry64.c Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 10/41] x86/entry: Add C verion of SWITCH_TO_KERNEL_CR3 as switch_to_kernel_cr3() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 11/41] x86/entry: Add C user_entry_swapgs_and_fence() and kernel_entry_fence_no_swapgs() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 12/41] x86/traps: Move pt_regs only in fixup_bad_iret() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 13/41] x86/entry: Switch the stack after error_entry() returns Lai Jiangshan
2021-09-26 15:08 ` Lai Jiangshan [this message]
2021-09-26 15:08 ` [PATCH V2 15/41] objtool: Allow .entry.text function using CLD instruction Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 16/41] x86/entry: Implement the whole error_entry() as C code Lai Jiangshan
2021-09-28 21:34   ` Brian Gerst
2021-09-29  8:45     ` Peter Zijlstra
2021-09-26 15:08 ` [PATCH V2 17/41] x86/entry: Make paranoid_exit() callable Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 18/41] x86/entry: Call paranoid_exit() in asm_exc_nmi() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 19/41] x86/entry: move PUSH_AND_CLEAR_REGS out of paranoid_entry Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 20/41] x86/entry: Add the C version ist_switch_to_kernel_cr3() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 21/41] x86/entry: Add the C version ist_restore_cr3() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 22/41] x86/entry: Add the C version get_percpu_base() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 23/41] x86/entry: Add the C version ist_switch_to_kernel_gsbase() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 24/41] x86/entry: Implement the C version ist_paranoid_entry() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 25/41] x86/entry: Implement the C version ist_paranoid_exit() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 26/41] x86/entry: Add a C macro to define the function body for IST in .entry.text Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 27/41] x86/mce: Remove stack protector from mce/core.c Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 28/41] x86/debug, mce: Use C entry code Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 29/41] x86/idtentry.h: Move the definitions *IDTENTRY_{MCE|DEBUG}* up Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 30/41] x86/nmi: Use DEFINE_IDTENTRY_NMI for nmi Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 31/41] x86/nmi: Remove stack protector from nmi.c Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 32/41] x86/nmi: Use C entry code Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 33/41] x86/entry: Add a C macro to define the function body for IST in .entry.text with an error code Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 34/41] x86/doublefault: Use C entry code Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 35/41] x86/sev: Add and use ist_vc_switch_off_ist() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 36/41] x86/sev: Remove stack protector from sev.c Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 37/41] x86/sev: Use C entry code Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 38/41] x86/entry: Remove ASM function paranoid_entry() and paranoid_exit() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 39/41] x86/entry: Remove the unused ASM macros Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 40/41] x86/entry: Remove save_ret from PUSH_AND_CLEAR_REGS Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 41/41] x86/syscall/64: Move the checking for sysret to C code Lai Jiangshan

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