From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, "Paul E. McKenney" <paulmck@kernel.org>,
Andy Lutomirski <luto@kernel.org>,
Alexandre Chartre <alexandre.chartre@oracle.com>,
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>,
Tom Lendacky <thomas.lendacky@amd.com>,
Wei Liu <wei.liu@kernel.org>,
Michael Kelley <mikelley@microsoft.com>,
Jason Chen CJ <jason.cj.chen@intel.com>,
Zhao Yakui <yakui.zhao@intel.com>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>
Subject: [patch V5 33/38] x86/entry/64: Remove IRQ stack switching ASM
Date: Tue, 12 May 2020 23:01:32 +0200 [thread overview]
Message-ID: <20200512213812.782687559@linutronix.de> (raw)
In-Reply-To: 20200512210059.056244513@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/entry/entry_64.S | 96 ----------------------------------------------
1 file changed, 96 deletions(-)
--- 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
next prev parent reply other threads:[~2020-05-12 22:25 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-12 21:00 [patch V5 00/38] x86/entry: Entry/exception code rework - the leftovers Thomas Gleixner
2020-05-12 21:01 ` [patch V5 01/38] x86/kvm/svm: Use uninstrumented wrmsrl() to restore GS Thomas Gleixner
2020-05-13 7:11 ` Jürgen Groß
2020-05-12 21:01 ` [patch V5 02/38] x86/entry/64: Use native swapgs in asm_native_load_gs_index() Thomas Gleixner
2020-05-13 2:02 ` Steven Rostedt
2020-05-13 6:34 ` Thomas Gleixner
2020-05-13 7:12 ` Jürgen Groß
2020-05-19 19:58 ` [tip: x86/entry] x86/entry/64: Use native swapgs in asm_load_gs_index() tip-bot2 for Thomas Gleixner
2020-05-12 21:01 ` [patch V5 03/38] nmi, tracing: Provide nmi_enter/exit_notrace() Thomas Gleixner
2020-05-15 1:32 ` Steven Rostedt
2020-05-15 1:35 ` Steven Rostedt
2020-05-15 1:37 ` Steven Rostedt
2020-05-12 21:01 ` [patch V5 04/38] x86: Make hardware latency tracing explicit Thomas Gleixner
2020-05-15 1:43 ` Steven Rostedt
2020-05-15 15:08 ` Thomas Gleixner
2020-05-12 21:01 ` [patch V5 05/38] genirq: Provide irq_enter/exit_rcu() Thomas Gleixner
2020-05-12 21:01 ` [patch V5 06/38] x86/entry: Provide helpers for execute on irqstack Thomas Gleixner
2020-05-13 21:43 ` Josh Poimboeuf
2020-05-12 21:01 ` [patch V5 07/38] x86/entry/64: Move do_softirq_own_stack() to C Thomas Gleixner
2020-05-12 21:01 ` [patch V5 08/38] x86/entry: Split idtentry_enter/exit() Thomas Gleixner
2020-05-12 21:01 ` [patch V5 09/38] x86/entry: Switch XEN/PV hypercall entry to IDTENTRY Thomas Gleixner
2020-05-14 16:24 ` Boris Ostrovsky
2020-05-12 21:01 ` [patch V5 10/38] x86/entry/64: Simplify idtentry_body Thomas Gleixner
2020-05-12 21:01 ` [patch V5 11/38] rcu: Provide __rcu_is_watching() Thomas Gleixner
2020-05-19 19:52 ` [tip: core/rcu] " tip-bot2 for Thomas Gleixner
2020-05-12 21:01 ` [patch V5 12/38] x86/entry: Provide idtentry_entry/exit_cond_rcu() Thomas Gleixner
2020-05-12 21:01 ` [patch V5 13/38] x86/entry: Switch page fault exception to IDTENTRY_RAW Thomas Gleixner
2020-05-12 21:01 ` [patch V5 14/38] x86/entry: Remove the transition leftovers Thomas Gleixner
2020-05-12 21:01 ` [patch V5 15/38] x86/entry: Change exit path of xen_failsafe_callback Thomas Gleixner
2020-05-12 21:01 ` [patch V5 16/38] x86/entry/64: Remove error_exit Thomas Gleixner
2020-05-12 21:01 ` [patch V5 17/38] x86/entry/32: Remove common_exception Thomas Gleixner
2020-05-12 21:01 ` [patch V5 18/38] x86/irq: Use generic irq_regs implementation Thomas Gleixner
2020-05-12 21:01 ` [patch V5 19/38] x86/irq: Convey vector as argument and not in ptregs Thomas Gleixner
2020-05-12 21:01 ` [patch V5 20/38] x86/irq/64: Provide handle_irq() Thomas Gleixner
2020-05-12 21:01 ` [patch V5 21/38] x86/entry: Add IRQENTRY_IRQ macro Thomas Gleixner
2020-05-12 21:01 ` [patch V5 22/38] x86/entry: Use idtentry for interrupts Thomas Gleixner
2020-05-12 21:01 ` [patch V5 23/38] genirq: Provde __irq_enter/exit_raw() Thomas Gleixner
2020-05-12 21:01 ` [patch V5 24/38] x86/entry: Provide IDTENTRY_SYSVEC Thomas Gleixner
2020-05-15 0:16 ` Boris Ostrovsky
2020-05-15 8:52 ` Thomas Gleixner
2020-05-12 21:01 ` [patch V5 25/38] x86/entry: Convert APIC interrupts to IDTENTRY_SYSVEC Thomas Gleixner
2020-05-12 21:01 ` [patch V5 26/38] x86/entry: Convert SMP system vectors " Thomas Gleixner
2020-05-12 21:01 ` [patch V5 27/38] x86/entry: Convert various system vectors Thomas Gleixner
2020-05-12 21:01 ` [patch V5 28/38] x86/entry: Convert KVM vectors to IDTENTRY_SYSVEC Thomas Gleixner
2020-05-12 21:01 ` [patch V5 29/38] x86/entry: Convert various hypervisor " Thomas Gleixner
2020-05-12 21:01 ` [patch V5 30/38] x86/entry: Convert XEN hypercall vector " Thomas Gleixner
2020-05-12 21:01 ` [patch V5 31/38] x86/entry: Convert reschedule interrupt to IDTENTRY_SYSVEC_SIMPLE Thomas Gleixner
2020-05-12 21:01 ` [patch V5 32/38] x86/entry: Remove the apic/BUILD interrupt leftovers Thomas Gleixner
2020-05-12 21:01 ` Thomas Gleixner [this message]
2020-05-12 21:01 ` [patch V5 34/38] x86/entry: Make enter_from_user_mode() static Thomas Gleixner
2020-05-12 21:01 ` [patch V5 35/38] x86/entry/32: Remove redundant irq disable code Thomas Gleixner
2020-05-12 21:01 ` [patch V5 36/38] x86/entry/64: Remove TRACE_IRQS_*_DEBUG Thomas Gleixner
2020-05-12 21:01 ` [patch V5 37/38] x86/entry: Move paranoid irq tracing out of ASM code Thomas Gleixner
2020-05-12 21:01 ` [patch V5 38/38] x86/entry: Remove the TRACE_IRQS cruft Thomas Gleixner
2020-05-14 16:35 ` [patch V5 00/38] x86/entry: Entry/exception code rework - the leftovers Paul E. McKenney
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