linux-kernel - [PATCH RFC v2 16/28] ARM: entry: Drop argument to asm

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Message-Id: <20241029-arm-generic-entry-v2-16-573519abef38@linaro.org>
Date: Tue, 29 Oct 2024 11:52:56 +0100
From: Linus Walleij <linus.walleij@...aro.org>
To: Oleg Nesterov <oleg@...hat.com>, Russell King <linux@...linux.org.uk>, 
 Kees Cook <kees@...nel.org>, Andy Lutomirski <luto@...capital.net>, 
 Will Drewry <wad@...omium.org>, Frederic Weisbecker <frederic@...nel.org>, 
 "Paul E. McKenney" <paulmck@...nel.org>, 
 Jinjie Ruan <ruanjinjie@...wei.com>, Arnd Bergmann <arnd@...db.de>, 
 Ard Biesheuvel <ardb@...nel.org>, Al Viro <viro@...iv.linux.org.uk>
Cc: linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org, 
 Linus Walleij <linus.walleij@...aro.org>
Subject: [PATCH RFC v2 16/28] ARM: entry: Drop argument to asm_irqentry
 macros

asm_irqentry_enter_from_user_mode and asm_irqentry_exit_to_user_mode
have a "save" argument that will save and restore registers before
the call to the C function.

Now all invocations set this argument to 0 so drop the surplus
code.

Signed-off-by: Linus Walleij <linus.walleij@...aro.org>
---
 arch/arm/kernel/entry-armv.S   |  8 ++++----
 arch/arm/kernel/entry-common.S |  2 +-
 arch/arm/kernel/entry-header.S | 18 ++----------------
 3 files changed, 7 insertions(+), 21 deletions(-)

diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 0328860475e1..09ce1be1f677 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -421,7 +421,7 @@ ENDPROC(__fiq_abt)
 	.align	5
 __dabt_usr:
 	usr_entry uaccess=0
-	asm_irqentry_enter_from_user_mode save = 0
+	asm_irqentry_enter_from_user_mode
 	kuser_cmpxchg_check
 	mov	r2, sp
 	dabt_helper
@@ -432,7 +432,7 @@ ENDPROC(__dabt_usr)
 	.align	5
 __irq_usr:
 	usr_entry
-	asm_irqentry_enter_from_user_mode save = 0
+	asm_irqentry_enter_from_user_mode
 	kuser_cmpxchg_check
 	irq_handler from_user=1
 	get_thread_info tsk
@@ -446,7 +446,7 @@ ENDPROC(__irq_usr)
 	.align	5
 __und_usr:
 	usr_entry uaccess=0
-	asm_irqentry_enter_from_user_mode save = 0
+	asm_irqentry_enter_from_user_mode
 
 	@ IRQs must be enabled before attempting to read the instruction from
 	@ user space since that could cause a page/translation fault if the
@@ -471,7 +471,7 @@ ENDPROC(__und_usr)
 	.align	5
 __pabt_usr:
 	usr_entry
-	asm_irqentry_enter_from_user_mode save = 0
+	asm_irqentry_enter_from_user_mode
 	mov	r2, sp				@ regs
 	pabt_helper
  UNWIND(.fnend		)
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 14b2495cae3c..df564388905e 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -109,7 +109,7 @@ ENTRY(ret_to_user_from_irq)
 	movs	r1, r1, lsl #16
 	bne	slow_work_pending
 no_work_pending:
-	asm_irqentry_exit_to_user_mode save = 0
+	asm_irqentry_exit_to_user_mode
 
 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
 	bl	stackleak_erase_on_task_stack
diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index fb5bb019199b..50c0b55adc74 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -365,28 +365,14 @@ ALT_UP_B(.L1_\@)
  * Context tracking and other mode transitions. Used to instrument transitions
  * between user and kernel mode.
 */
-	.macro asm_irqentry_enter_from_user_mode, save = 1
-	.if	\save
-	stmdb   sp!, {r0-r3, ip, lr}
+	.macro asm_irqentry_enter_from_user_mode
 	mov	r0, sp				@ regs
 	bl	irqentry_enter_from_user_mode
-	ldmia	sp!, {r0-r3, ip, lr}
-	.else
-	mov	r0, sp				@ regs
-	bl	irqentry_enter_from_user_mode
-	.endif
 	.endm
 
-	.macro asm_irqentry_exit_to_user_mode, save = 1
-	.if	\save
-	stmdb   sp!, {r0-r3, ip, lr}
+	.macro asm_irqentry_exit_to_user_mode
 	mov	r0, sp				@ regs
 	bl	irqentry_exit_to_user_mode
-	ldmia	sp!, {r0-r3, ip, lr}
-	.else
-	mov	r0, sp				@ regs
-	bl	irqentry_exit_to_user_mode
-	.endif
 	.endm
 
 /*

-- 
2.46.2