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From: "tip-bot2 for Thomas Gleixner" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@kernel.org>, Andy Lutomirski <luto@kernel.org>,
	x86 <x86@kernel.org>, LKML <linux-kernel@vger.kernel.org>
Subject: [tip: x86/entry] x86/entry/64: Remove IRQ stack switching ASM
Date: Wed, 27 May 2020 08:11:46 -0000
Message-ID: <159056710606.17951.9824050639615238342.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20200521202120.021462159@linutronix.de>

The following commit has been merged into the x86/entry branch of tip:

Commit-ID:     300e5654198501a8cde5ad843ebad7dfbee147e4
Gitweb:        https://git.kernel.org/tip/300e5654198501a8cde5ad843ebad7dfbee147e4
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Thu, 21 May 2020 22:05:47 +02:00
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Tue, 26 May 2020 19:06:29 +02:00

x86/entry/64: Remove IRQ stack switching ASM

No more users.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20200521202120.021462159@linutronix.de
---
 arch/x86/entry/entry_64.S | 96 +--------------------------------------
 1 file changed, 96 deletions(-)

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 389f97f..29a8a83 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -370,102 +370,6 @@ SYM_CODE_END(ret_from_fork)
 #endif
 .endm
 
-/*
- * Enters the IRQ stack if we're not already using it.  NMI-safe.  Clobbers
- * flags and puts old RSP into old_rsp, and leaves all other GPRs alone.
- * Requires kernel GSBASE.
- *
- * The invariant is that, if irq_count != -1, then the IRQ stack is in use.
- */
-.macro ENTER_IRQ_STACK regs=1 old_rsp save_ret=0
-	DEBUG_ENTRY_ASSERT_IRQS_OFF
-
-	.if \save_ret
-	/*
-	 * If save_ret is set, the original stack contains one additional
-	 * entry -- the return address. Therefore, move the address one
-	 * entry below %rsp to \old_rsp.
-	 */
-	leaq	8(%rsp), \old_rsp
-	.else
-	movq	%rsp, \old_rsp
-	.endif
-
-	.if \regs
-	UNWIND_HINT_REGS base=\old_rsp
-	.endif
-
-	incl	PER_CPU_VAR(irq_count)
-	jnz	.Lirq_stack_push_old_rsp_\@
-
-	/*
-	 * Right now, if we just incremented irq_count to zero, we've
-	 * claimed the IRQ stack but we haven't switched to it yet.
-	 *
-	 * If anything is added that can interrupt us here without using IST,
-	 * it must be *extremely* careful to limit its stack usage.  This
-	 * could include kprobes and a hypothetical future IST-less #DB
-	 * handler.
-	 *
-	 * The OOPS unwinder relies on the word at the top of the IRQ
-	 * stack linking back to the previous RSP for the entire time we're
-	 * on the IRQ stack.  For this to work reliably, we need to write
-	 * it before we actually move ourselves to the IRQ stack.
-	 */
-
-	movq	\old_rsp, PER_CPU_VAR(irq_stack_backing_store + IRQ_STACK_SIZE - 8)
-	movq	PER_CPU_VAR(hardirq_stack_ptr), %rsp
-
-#ifdef CONFIG_DEBUG_ENTRY
-	/*
-	 * If the first movq above becomes wrong due to IRQ stack layout
-	 * changes, the only way we'll notice is if we try to unwind right
-	 * here.  Assert that we set up the stack right to catch this type
-	 * of bug quickly.
-	 */
-	cmpq	-8(%rsp), \old_rsp
-	je	.Lirq_stack_okay\@
-	ud2
-	.Lirq_stack_okay\@:
-#endif
-
-.Lirq_stack_push_old_rsp_\@:
-	pushq	\old_rsp
-
-	.if \regs
-	UNWIND_HINT_REGS indirect=1
-	.endif
-
-	.if \save_ret
-	/*
-	 * Push the return address to the stack. This return address can
-	 * be found at the "real" original RSP, which was offset by 8 at
-	 * the beginning of this macro.
-	 */
-	pushq	-8(\old_rsp)
-	.endif
-.endm
-
-/*
- * Undoes ENTER_IRQ_STACK.
- */
-.macro LEAVE_IRQ_STACK regs=1
-	DEBUG_ENTRY_ASSERT_IRQS_OFF
-	/* We need to be off the IRQ stack before decrementing irq_count. */
-	popq	%rsp
-
-	.if \regs
-	UNWIND_HINT_REGS
-	.endif
-
-	/*
-	 * As in ENTER_IRQ_STACK, irq_count == 0, we are still claiming
-	 * the irq stack but we're not on it.
-	 */
-
-	decl	PER_CPU_VAR(irq_count)
-.endm
-
 /**
  * idtentry_body - Macro to emit code calling the C function
  * @cfunc:		C function to be called

  reply index

Thread overview: 132+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-21 20:05 [patch V9 00/39] x86/entry: Rework leftovers (was part V) Thomas Gleixner
2020-05-21 20:05 ` [patch V9 01/39] nmi, tracing: Make hardware latency tracing noinstr safe Thomas Gleixner
2020-05-27  8:12   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 02/39] rcu: Abstract out rcu_irq_enter_check_tick() from rcu_nmi_enter() Thomas Gleixner
2020-05-21 21:03   ` Paul E. McKenney
2020-05-21 21:25     ` Thomas Gleixner
2020-05-26  8:14     ` Ingo Molnar
2020-05-26 15:34       ` Paul E. McKenney
2020-05-27  8:12   ` [tip: x86/entry] " tip-bot2 for Paul E. McKenney
2020-05-21 20:05 ` [patch V9 03/39] rcu: Provide rcu_irq_exit_check_preempt() Thomas Gleixner
2020-05-27  8:12   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 04/39] x86/entry: Provide idtentry_entry/exit_cond_rcu() Thomas Gleixner
2020-05-21 21:06   ` Paul E. McKenney
2020-05-26  8:23   ` Ingo Molnar
2020-05-26  8:58     ` Thomas Gleixner
2020-05-21 20:05 ` [patch V9 05/39] x86/entry: Provide idtentry_enter/exit_user() Thomas Gleixner
2020-05-27  8:12   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 06/39] x86/idtentry: Switch to conditional RCU handling Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 07/39] x86/entry: Cleanup idtentry_enter/exit() leftovers Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] x86/entry: Clean up " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 08/39] genirq: Provide irq_enter/exit_rcu() Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 09/39] genirq: Provide __irq_enter/exit_raw() Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 10/39] x86/entry: Provide helpers for execute on irqstack Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] x86/entry: Provide helpers for executing on the irqstack tip-bot2 for Thomas Gleixner
2020-06-05 17:18   ` [patch V9 10/39] x86/entry: Provide helpers for execute on irqstack Qian Cai
2020-06-05 17:36     ` Peter Zijlstra
2020-06-05 17:52       ` Qian Cai
2020-06-07 11:59         ` Thomas Gleixner
2020-06-07 18:27           ` Qian Cai
2020-06-08 16:01       ` Qian Cai
2020-06-08 22:20         ` Thomas Gleixner
2020-06-09  2:32           ` Qian Cai
2020-06-09 20:33             ` Thomas Gleixner
2020-06-09 20:50               ` Thomas Gleixner
2020-06-10 12:38                 ` Qian Cai
2020-06-10 19:38                   ` Thomas Gleixner
2020-06-13 13:55                     ` Qian Cai
2020-06-13 14:03                       ` Thomas Gleixner
2020-06-13 21:41                         ` Qian Cai
2020-06-14  8:59                           ` Thomas Gleixner
2020-05-21 20:05 ` [patch V9 11/39] x86/entry/64: Move do_softirq_own_stack() to C Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 12/39] x86/entry: Split out idtentry_exit_cond_resched() Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 13/39] x86/entry: Switch XEN/PV hypercall entry to IDTENTRY Thomas Gleixner
2020-05-22 18:32   ` [patch V9-1 " Thomas Gleixner
2020-05-26  7:44     ` Jürgen Groß
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 14/39] x86/entry/64: Simplify idtentry_body Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 15/39] x86/entry: Switch page fault exception to IDTENTRY_RAW Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 16/39] x86/entry: Remove the transition leftovers Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 17/39] x86/entry: Change exit path of xen_failsafe_callback Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 18/39] x86/entry/64: Remove error_exit Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] x86/entry/64: Remove error_exit() tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 19/39] x86/entry/32: Remove common_exception Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] x86/entry/32: Remove common_exception() tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 20/39] x86/irq: Use generic irq_regs implementation Thomas Gleixner
2020-05-26 18:39   ` damian
2020-05-28  9:50     ` Thomas Gleixner
2020-05-28 20:20       ` damian
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 21/39] x86/irq: Convey vector as argument and not in ptregs Thomas Gleixner
2020-05-22 19:34   ` Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-08-24 17:29   ` [patch V9 21/39] " Alexander Graf
2020-08-25 10:28     ` Thomas Gleixner
2020-08-25 23:17       ` Alexander Graf
2020-08-25 23:41         ` Andy Lutomirski
2020-08-26  0:04           ` Alexander Graf
2020-08-26  1:03             ` Brian Gerst
2020-08-26  0:55           ` Thomas Gleixner
2020-05-21 20:05 ` [patch V9 22/39] x86/irq: Rework handle_irq() for 64bit Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] x86/irq: Rework handle_irq() for 64-bit tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 23/39] x86/entry: Add IRQENTRY_IRQ macro Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 24/39] x86/entry: Use idtentry for interrupts Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 25/39] x86/entry: Provide IDTENTRY_SYSVEC Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 26/39] x86/entry: Convert APIC interrupts to IDTENTRY_SYSVEC Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 27/39] x86/entry: Convert SMP system vectors " Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 28/39] x86/entry: Convert various system vectors Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 29/39] x86/entry: Convert KVM vectors to IDTENTRY_SYSVEC* Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 30/39] x86/entry: Convert various hypervisor vectors to IDTENTRY_SYSVEC Thomas Gleixner
2020-05-26  9:29   ` Wei Liu
2020-05-27  1:46   ` Boqun Feng
2020-05-27  8:38     ` Wei Liu
2020-05-27 12:09       ` Wei Liu
2020-05-27 23:06         ` Boqun Feng
2020-05-27 12:30       ` Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 31/39] x86/entry: Convert XEN hypercall vector " Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 32/39] x86/entry: Convert reschedule interrupt to IDTENTRY_SYSVEC_SIMPLE Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 33/39] x86/entry: Remove the apic/BUILD interrupt leftovers Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 34/39] x86/entry/64: Remove IRQ stack switching ASM Thomas Gleixner
2020-05-27  8:11   ` tip-bot2 for Thomas Gleixner [this message]
2020-05-21 20:05 ` [patch V9 35/39] x86/entry: Make enter_from_user_mode() static Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 36/39] x86/entry/32: Remove redundant irq disable code Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 37/39] x86/entry/64: Remove TRACE_IRQS_*_DEBUG Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 38/39] x86/entry: Move paranoid irq tracing out of ASM code Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-21 20:05 ` [patch V9 39/39] x86/entry: Remove the TRACE_IRQS cruft Thomas Gleixner
2020-05-27  8:11   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-22  7:20 ` [patch V9 00/39] x86/entry: Rework leftovers (was part V) Andrew Cooper
2020-05-22 21:17   ` Peter Zijlstra
2020-06-03 19:18     ` Andrew Cooper
2020-06-04 13:25       ` Peter Zijlstra
2020-06-04 13:29         ` Paolo Bonzini
2020-06-04 13:35           ` Peter Zijlstra
2020-06-04 15:42             ` Andy Lutomirski
2020-06-04 15:55               ` Peter Zijlstra
2020-05-22 14:26 ` Boris Ostrovsky
2020-05-22 17:47   ` Thomas Gleixner
2020-05-22 18:08     ` Thomas Gleixner
2020-05-26  4:33 ` Andy Lutomirski

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