17ce302f31
In the presence of any form of instrumentation, nmi_enter() should be
done before calling any traceable code and any instrumentation code.
Currently, nmi_enter() is done in handle_domain_nmi(), which is much
too late as instrumentation code might get called before. Move the
nmi_enter/exit() calls to the arch IRQ vector handler.
On arm64, it is not possible to know if the IRQ vector handler was
called because of an NMI before acknowledging the interrupt. However, It
is possible to know whether normal interrupts could be taken in the
interrupted context (i.e. if taking an NMI in that context could
introduce a potential race condition).
When interrupting a context with IRQs disabled, call nmi_enter() as soon
as possible. In contexts with IRQs enabled, defer this to the interrupt
controller, which is in a better position to know if an interrupt taken
is an NMI.
Fixes: bc3c03ccb4 ("arm64: Enable the support of pseudo-NMIs")
Cc: <stable@vger.kernel.org> # 5.1.x-
Cc: Will Deacon <will.deacon@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
96 lines
2.4 KiB
C
96 lines
2.4 KiB
C
/*
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* Based on arch/arm/kernel/irq.c
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*
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* Copyright (C) 1992 Linus Torvalds
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* Modifications for ARM processor Copyright (C) 1995-2000 Russell King.
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* Support for Dynamic Tick Timer Copyright (C) 2004-2005 Nokia Corporation.
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* Dynamic Tick Timer written by Tony Lindgren <tony@atomide.com> and
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* Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>.
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* Copyright (C) 2012 ARM Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/kernel_stat.h>
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#include <linux/irq.h>
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#include <linux/memory.h>
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#include <linux/smp.h>
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#include <linux/init.h>
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#include <linux/irqchip.h>
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#include <linux/kprobes.h>
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#include <linux/seq_file.h>
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#include <linux/vmalloc.h>
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#include <asm/daifflags.h>
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#include <asm/vmap_stack.h>
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unsigned long irq_err_count;
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/* Only access this in an NMI enter/exit */
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DEFINE_PER_CPU(struct nmi_ctx, nmi_contexts);
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DEFINE_PER_CPU(unsigned long *, irq_stack_ptr);
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int arch_show_interrupts(struct seq_file *p, int prec)
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{
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show_ipi_list(p, prec);
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seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
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return 0;
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}
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#ifdef CONFIG_VMAP_STACK
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static void init_irq_stacks(void)
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{
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int cpu;
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unsigned long *p;
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for_each_possible_cpu(cpu) {
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p = arch_alloc_vmap_stack(IRQ_STACK_SIZE, cpu_to_node(cpu));
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per_cpu(irq_stack_ptr, cpu) = p;
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}
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}
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#else
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/* irq stack only needs to be 16 byte aligned - not IRQ_STACK_SIZE aligned. */
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DEFINE_PER_CPU_ALIGNED(unsigned long [IRQ_STACK_SIZE/sizeof(long)], irq_stack);
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static void init_irq_stacks(void)
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{
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int cpu;
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for_each_possible_cpu(cpu)
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per_cpu(irq_stack_ptr, cpu) = per_cpu(irq_stack, cpu);
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}
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#endif
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void __init init_IRQ(void)
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{
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init_irq_stacks();
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irqchip_init();
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if (!handle_arch_irq)
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panic("No interrupt controller found.");
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}
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/*
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* Stubs to make nmi_enter/exit() code callable from ASM
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*/
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asmlinkage void notrace asm_nmi_enter(void)
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{
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nmi_enter();
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}
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NOKPROBE_SYMBOL(asm_nmi_enter);
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asmlinkage void notrace asm_nmi_exit(void)
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{
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nmi_exit();
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}
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NOKPROBE_SYMBOL(asm_nmi_exit);
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