linux/arch/x86/include/asm/nmi.h
Thomas Gleixner a7fed5c043 x86/nmi: Make register_nmi_handler() more robust
register_nmi_handler() has no sanity check whether a handler has been
registered already. Such an unintended double-add leads to list corruption
and hard to diagnose problems during the next NMI handling.

Init the list head in the static NMI action struct and check it for being
empty in register_nmi_handler().

  [ bp: Fixups. ]

Reported-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/lkml/20220511234332.3654455-1-seanjc@google.com
2022-05-17 09:25:25 +02:00

67 lines
1.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_NMI_H
#define _ASM_X86_NMI_H
#include <linux/irq_work.h>
#include <linux/pm.h>
#include <asm/irq.h>
#include <asm/io.h>
#ifdef CONFIG_X86_LOCAL_APIC
extern int reserve_perfctr_nmi(unsigned int);
extern void release_perfctr_nmi(unsigned int);
extern int reserve_evntsel_nmi(unsigned int);
extern void release_evntsel_nmi(unsigned int);
struct ctl_table;
extern int proc_nmi_enabled(struct ctl_table *, int ,
void __user *, size_t *, loff_t *);
extern int unknown_nmi_panic;
#endif /* CONFIG_X86_LOCAL_APIC */
#define NMI_FLAG_FIRST 1
enum {
NMI_LOCAL=0,
NMI_UNKNOWN,
NMI_SERR,
NMI_IO_CHECK,
NMI_MAX
};
#define NMI_DONE 0
#define NMI_HANDLED 1
typedef int (*nmi_handler_t)(unsigned int, struct pt_regs *);
struct nmiaction {
struct list_head list;
nmi_handler_t handler;
u64 max_duration;
unsigned long flags;
const char *name;
};
#define register_nmi_handler(t, fn, fg, n, init...) \
({ \
static struct nmiaction init fn##_na = { \
.list = LIST_HEAD_INIT(fn##_na.list), \
.handler = (fn), \
.name = (n), \
.flags = (fg), \
}; \
__register_nmi_handler((t), &fn##_na); \
})
int __register_nmi_handler(unsigned int, struct nmiaction *);
void unregister_nmi_handler(unsigned int, const char *);
void stop_nmi(void);
void restart_nmi(void);
void local_touch_nmi(void);
#endif /* _ASM_X86_NMI_H */