linux-kernel - [patch V4 part 2 02/18] x86/entry/32: Move non entry code into .text section

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Date:   Tue, 05 May 2020 15:41:14 +0200
From:   Thomas Gleixner <tglx@...utronix.de>
To:     LKML <linux-kernel@...r.kernel.org>
Cc:     x86@...nel.org, "Paul E. McKenney" <paulmck@...nel.org>,
        Andy Lutomirski <luto@...nel.org>,
        Alexandre Chartre <alexandre.chartre@...cle.com>,
        Frederic Weisbecker <frederic@...nel.org>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Sean Christopherson <sean.j.christopherson@...el.com>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Petr Mladek <pmladek@...e.com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Joel Fernandes <joel@...lfernandes.org>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        Juergen Gross <jgross@...e.com>,
        Brian Gerst <brgerst@...il.com>,
        Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
        Josh Poimboeuf <jpoimboe@...hat.com>,
        Will Deacon <will@...nel.org>
Subject: [patch V4 part 2 02/18] x86/entry/32: Move non entry code into .text section

All ASM code which is not part of the entry functionality can move out into
the .text section. No reason to keep it in the non-instrumentable entry
section.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
 arch/x86/entry/entry_32.S |   11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -729,7 +729,8 @@
 /*
  * %eax: prev task
  * %edx: next task
- */
+*/
+.pushsection .text, "ax"
 SYM_CODE_START(__switch_to_asm)
 	/*
 	 * Save callee-saved registers
@@ -776,6 +777,7 @@ SYM_CODE_START(__switch_to_asm)
 
 	jmp	__switch_to
 SYM_CODE_END(__switch_to_asm)
+.popsection
 
 /*
  * The unwinder expects the last frame on the stack to always be at the same
@@ -784,6 +786,7 @@ SYM_CODE_END(__switch_to_asm)
  * asmlinkage function so its argument has to be pushed on the stack.  This
  * wrapper creates a proper "end of stack" frame header before the call.
  */
+.pushsection .text, "ax"
 SYM_FUNC_START(schedule_tail_wrapper)
 	FRAME_BEGIN
 
@@ -794,6 +797,8 @@ SYM_FUNC_START(schedule_tail_wrapper)
 	FRAME_END
 	ret
 SYM_FUNC_END(schedule_tail_wrapper)
+.popsection
+
 /*
  * A newly forked process directly context switches into this address.
  *
@@ -801,6 +806,7 @@ SYM_FUNC_END(schedule_tail_wrapper)
  * ebx: kernel thread func (NULL for user thread)
  * edi: kernel thread arg
  */
+.pushsection .text, "ax"
 SYM_CODE_START(ret_from_fork)
 	call	schedule_tail_wrapper
 
@@ -825,6 +831,7 @@ SYM_CODE_START(ret_from_fork)
 	movl	$0, PT_EAX(%esp)
 	jmp	2b
 SYM_CODE_END(ret_from_fork)
+.popsection
 
 /*
  * Return to user mode is not as complex as all this looks,
@@ -1693,6 +1700,7 @@ SYM_CODE_START(general_protection)
 	jmp	common_exception
 SYM_CODE_END(general_protection)
 
+.pushsection .text, "ax"
 SYM_CODE_START(rewind_stack_do_exit)
 	/* Prevent any naive code from trying to unwind to our caller. */
 	xorl	%ebp, %ebp
@@ -1703,3 +1711,4 @@ SYM_CODE_START(rewind_stack_do_exit)
 	call	do_exit
 1:	jmp 1b
 SYM_CODE_END(rewind_stack_do_exit)
+.popsection