linux/arch/x86/kernel/irq_64.c
Andy Lutomirski 4f3789e792 x86/irq/64: Print the offending IP in the stack overflow warning
In case something goes wrong with unwind (not unlikely in case of
overflow), print the offending IP where we detected the overflow.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.231677119@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-17 13:59:53 +01:00

80 lines
2.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
*
* This file contains the lowest level x86_64-specific interrupt
* entry and irq statistics code. All the remaining irq logic is
* done by the generic kernel/irq/ code and in the
* x86_64-specific irq controller code. (e.g. i8259.c and
* io_apic.c.)
*/
#include <linux/kernel_stat.h>
#include <linux/interrupt.h>
#include <linux/seq_file.h>
#include <linux/delay.h>
#include <linux/ftrace.h>
#include <linux/uaccess.h>
#include <linux/smp.h>
#include <linux/sched/task_stack.h>
#include <asm/io_apic.h>
#include <asm/apic.h>
int sysctl_panic_on_stackoverflow;
/*
* Probabilistic stack overflow check:
*
* Only check the stack in process context, because everything else
* runs on the big interrupt stacks. Checking reliably is too expensive,
* so we just check from interrupts.
*/
static inline void stack_overflow_check(struct pt_regs *regs)
{
#ifdef CONFIG_DEBUG_STACKOVERFLOW
#define STACK_TOP_MARGIN 128
struct orig_ist *oist;
u64 irq_stack_top, irq_stack_bottom;
u64 estack_top, estack_bottom;
u64 curbase = (u64)task_stack_page(current);
if (user_mode(regs))
return;
if (regs->sp >= curbase + sizeof(struct pt_regs) + STACK_TOP_MARGIN &&
regs->sp <= curbase + THREAD_SIZE)
return;
irq_stack_top = (u64)this_cpu_ptr(irq_stack_union.irq_stack) +
STACK_TOP_MARGIN;
irq_stack_bottom = (u64)__this_cpu_read(irq_stack_ptr);
if (regs->sp >= irq_stack_top && regs->sp <= irq_stack_bottom)
return;
oist = this_cpu_ptr(&orig_ist);
estack_top = (u64)oist->ist[0] - EXCEPTION_STKSZ + STACK_TOP_MARGIN;
estack_bottom = (u64)oist->ist[N_EXCEPTION_STACKS - 1];
if (regs->sp >= estack_top && regs->sp <= estack_bottom)
return;
WARN_ONCE(1, "do_IRQ(): %s has overflown the kernel stack (cur:%Lx,sp:%lx,irq stk top-bottom:%Lx-%Lx,exception stk top-bottom:%Lx-%Lx,ip:%pF)\n",
current->comm, curbase, regs->sp,
irq_stack_top, irq_stack_bottom,
estack_top, estack_bottom, (void *)regs->ip);
if (sysctl_panic_on_stackoverflow)
panic("low stack detected by irq handler - check messages\n");
#endif
}
bool handle_irq(struct irq_desc *desc, struct pt_regs *regs)
{
stack_overflow_check(regs);
if (IS_ERR_OR_NULL(desc))
return false;
generic_handle_irq_desc(desc);
return true;
}