From: Alexandre Chartre <alexandre.chartre@oracle.com>
To: Thomas Gleixner <tglx@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, "Paul E. McKenney" <paulmck@kernel.org>,
Andy Lutomirski <luto@kernel.org>,
Frederic Weisbecker <frederic@kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <sean.j.christopherson@intel.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
Petr Mladek <pmladek@suse.com>,
Steven Rostedt <rostedt@goodmis.org>,
Joel Fernandes <joel@joelfernandes.org>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Juergen Gross <jgross@suse.com>, Brian Gerst <brgerst@gmail.com>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Will Deacon <will@kernel.org>
Subject: Re: [patch V4 part 2 02/18] x86/entry/32: Move non entry code into .text section
Date: Thu, 7 May 2020 15:15:27 +0200 [thread overview]
Message-ID: <6e8a7549-9c0a-f863-fc7d-fcbfcb642bc4@oracle.com> (raw)
In-Reply-To: <20200505134340.320164650@linutronix.de>
On 5/5/20 3:41 PM, Thomas Gleixner wrote:
> 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@linutronix.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
> - */
> +*/
Misaligned comment end, this line shouldn't change.
alex.
> +.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
>
next prev parent reply other threads:[~2020-05-07 13:17 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-05 13:41 [patch V4 part 2 00/18] x86/entry: Entry/exception code rework, syscall and KVM changes Thomas Gleixner
2020-05-05 13:41 ` [patch V4 part 2 01/18] x86/entry/64: Move non entry code into .text section Thomas Gleixner
2020-05-06 15:51 ` Peter Zijlstra
2020-05-08 1:31 ` Steven Rostedt
2020-05-08 23:53 ` Andy Lutomirski
2020-05-10 13:39 ` Thomas Gleixner
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:41 ` [patch V4 part 2 02/18] x86/entry/32: " Thomas Gleixner
2020-05-07 13:15 ` Alexandre Chartre [this message]
2020-05-07 14:14 ` Thomas Gleixner
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:41 ` [patch V4 part 2 03/18] x86/entry: Mark enter_from_user_mode() noinstr Thomas Gleixner
2020-05-08 8:21 ` Masami Hiramatsu
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:41 ` [patch V4 part 2 04/18] x86/entry/common: Protect against instrumentation Thomas Gleixner
2020-05-07 13:39 ` Alexandre Chartre
2020-05-07 14:13 ` Thomas Gleixner
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:41 ` [patch V4 part 2 05/18] x86/entry: Move irq tracing on syscall entry to C-code Thomas Gleixner
2020-05-07 13:55 ` Alexandre Chartre
2020-05-07 14:10 ` Thomas Gleixner
2020-05-07 15:03 ` Thomas Gleixner
2020-05-07 17:06 ` Thomas Gleixner
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:41 ` [patch V4 part 2 06/18] x86/entry: Move irq flags tracing to prepare_exit_to_usermode() Thomas Gleixner
2020-05-08 23:57 ` Andy Lutomirski
2020-05-09 10:16 ` Thomas Gleixner
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:41 ` [patch V4 part 2 07/18] context_tracking: Ensure that the critical path cannot be instrumented Thomas Gleixner
2020-05-08 8:23 ` Masami Hiramatsu
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:41 ` [patch V4 part 2 08/18] lib/smp_processor_id: Move it into noinstr section Thomas Gleixner
2020-05-19 19:58 ` [tip: x86/entry] x86/speculation/mds: Mark mds_user_clear_cpu_buffers() __always_inline tip-bot2 for Thomas Gleixner
2020-05-19 19:58 ` [tip: x86/entry] lib/smp_processor_id: Move it into noinstr section tip-bot2 for Thomas Gleixner
2020-05-05 13:41 ` [patch V4 part 2 09/18] x86/speculation/mds: Mark mds_user_clear_cpu_buffers() __always_inline Thomas Gleixner
2020-05-05 13:41 ` [patch V4 part 2 10/18] x86/entry/64: Check IF in __preempt_enable_notrace() thunk Thomas Gleixner
2020-05-07 14:15 ` Alexandre Chartre
2020-05-09 0:10 ` Andy Lutomirski
2020-05-09 10:25 ` Thomas Gleixner
2020-05-10 18:47 ` Thomas Gleixner
2020-05-11 18:27 ` Thomas Gleixner
2020-05-12 1:48 ` Steven Rostedt
2020-05-12 1:51 ` Steven Rostedt
2020-05-12 8:14 ` Thomas Gleixner
2020-05-05 13:41 ` [patch V4 part 2 11/18] x86/entry/64: Mark ___preempt_schedule_notrace() thunk noinstr Thomas Gleixner
2020-05-05 13:41 ` [patch V4 part 2 12/18] x86,objtool: Make entry_64_compat.S objtool clean Thomas Gleixner
2020-05-09 0:11 ` Andy Lutomirski
2020-05-09 10:06 ` Thomas Gleixner
2020-05-19 19:58 ` [tip: x86/entry] x86/entry: " tip-bot2 for Peter Zijlstra
2020-05-05 13:41 ` [patch V4 part 2 13/18] x86/kvm: Move context tracking where it belongs Thomas Gleixner
2020-05-06 7:42 ` Paolo Bonzini
2020-05-09 0:14 ` Andy Lutomirski
2020-05-09 10:12 ` Thomas Gleixner
2020-05-05 13:41 ` [patch V4 part 2 14/18] x86/kvm/vmx: Add hardirq tracing to guest enter/exit Thomas Gleixner
2020-05-06 7:55 ` Paolo Bonzini
2020-05-05 13:41 ` [patch V4 part 2 15/18] x86/kvm/svm: Handle hardirqs proper on " Thomas Gleixner
2020-05-06 8:15 ` Paolo Bonzini
2020-05-06 8:48 ` Thomas Gleixner
2020-05-06 9:21 ` Paolo Bonzini
2020-05-07 14:44 ` [patch V5 " Thomas Gleixner
2020-05-08 13:45 ` Paolo Bonzini
2020-05-08 14:01 ` Thomas Gleixner
2020-05-05 13:41 ` [patch V4 part 2 16/18] context_tracking: Make guest_enter/exit() .noinstr ready Thomas Gleixner
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:41 ` [patch V4 part 2 17/18] x86/kvm/vmx: Move guest enter/exit into .noinstr.text Thomas Gleixner
2020-05-06 8:17 ` Paolo Bonzini
2020-05-05 13:41 ` [patch V4 part 2 18/18] x86/kvm/svm: " Thomas Gleixner
2020-05-06 8:17 ` Paolo Bonzini
2020-05-07 14:47 ` Alexandre Chartre
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