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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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df835e7083
On x86, stacks go top to bottom, but the stack overflow check uses it the other way round, which is just confusing. Clean it up and sanitize the warning string a bit. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Nicolai Stange <nstange@suse.de> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190414160143.961241397@linutronix.de
89 lines
2.3 KiB
C
89 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
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*
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* This file contains the lowest level x86_64-specific interrupt
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* entry and irq statistics code. All the remaining irq logic is
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* done by the generic kernel/irq/ code and in the
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* x86_64-specific irq controller code. (e.g. i8259.c and
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* io_apic.c.)
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*/
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#include <linux/kernel_stat.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/seq_file.h>
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#include <linux/delay.h>
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#include <linux/ftrace.h>
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#include <linux/uaccess.h>
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#include <linux/smp.h>
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#include <linux/sched/task_stack.h>
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#include <asm/io_apic.h>
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#include <asm/apic.h>
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int sysctl_panic_on_stackoverflow;
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/*
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* Probabilistic stack overflow check:
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*
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* Regular device interrupts can enter on the following stacks:
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*
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* - User stack
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*
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* - Kernel task stack
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*
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* - Interrupt stack if a device driver reenables interrupts
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* which should only happen in really old drivers.
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*
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* - Debug IST stack
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*
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* All other contexts are invalid.
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*/
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static inline void stack_overflow_check(struct pt_regs *regs)
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{
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#ifdef CONFIG_DEBUG_STACKOVERFLOW
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#define STACK_MARGIN 128
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struct orig_ist *oist;
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u64 irq_stack_top, irq_stack_bottom;
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u64 estack_top, estack_bottom;
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u64 curbase = (u64)task_stack_page(current);
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if (user_mode(regs))
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return;
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if (regs->sp >= curbase + sizeof(struct pt_regs) + STACK_MARGIN &&
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regs->sp <= curbase + THREAD_SIZE)
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return;
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irq_stack_top = (u64)__this_cpu_read(irq_stack_ptr);
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irq_stack_bottom = irq_stack_top - IRQ_STACK_SIZE + STACK_MARGIN;
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if (regs->sp >= irq_stack_bottom && regs->sp <= irq_stack_top)
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return;
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oist = this_cpu_ptr(&orig_ist);
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estack_top = (u64)oist->ist[DEBUG_STACK];
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estack_bottom = estack_top - DEBUG_STKSZ + STACK_MARGIN;
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if (regs->sp >= estack_bottom && regs->sp <= estack_top)
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return;
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WARN_ONCE(1, "do_IRQ(): %s has overflown the kernel stack (cur:%Lx,sp:%lx, irq stack:%Lx-%Lx, exception stack: %Lx-%Lx, ip:%pF)\n",
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current->comm, curbase, regs->sp,
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irq_stack_bottom, irq_stack_top,
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estack_bottom, estack_top, (void *)regs->ip);
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if (sysctl_panic_on_stackoverflow)
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panic("low stack detected by irq handler - check messages\n");
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#endif
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}
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bool handle_irq(struct irq_desc *desc, struct pt_regs *regs)
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{
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stack_overflow_check(regs);
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if (IS_ERR_OR_NULL(desc))
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return false;
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generic_handle_irq_desc(desc);
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return true;
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}
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