![James Morse](/assets/img/avatar_default.png)
sysrq_handle_reboot() re-enables interrupts while on the irq stack. The irq_stack implementation wrongly assumed this would only ever happen via the softirq path, allowing it to update irq_count late, in do_softirq_own_stack(). This means if an irq occurs in sysrq_handle_reboot(), during emergency_restart() the stack will be corrupted, as irq_count wasn't updated. Lose the optimisation, and instead of moving the adding/subtracting of irq_count into irq_stack_entry/irq_stack_exit, remove it, and compare sp_el0 (struct thread_info) with sp & ~(THREAD_SIZE - 1). This tells us if we are on a task stack, if so, we can safely switch to the irq stack. Finally, remove do_softirq_own_stack(), we don't need it anymore. Reported-by: Will Deacon <will.deacon@arm.com> Signed-off-by: James Morse <james.morse@arm.com> [will: use get_thread_info macro] Signed-off-by: Will Deacon <will.deacon@arm.com>
59 lines
1.7 KiB
C
59 lines
1.7 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/smp.h>
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#include <linux/init.h>
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#include <linux/irqchip.h>
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#include <linux/seq_file.h>
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unsigned long irq_err_count;
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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(unsigned long [IRQ_STACK_SIZE/sizeof(long)], irq_stack) __aligned(16);
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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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void (*handle_arch_irq)(struct pt_regs *) = NULL;
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void __init set_handle_irq(void (*handle_irq)(struct pt_regs *))
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{
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if (handle_arch_irq)
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return;
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handle_arch_irq = handle_irq;
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}
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void __init init_IRQ(void)
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{
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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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