linux/kernel/printk/internal.h
Petr Mladek 8c4e93c362 printk: Prepare for nested printk_nmi_enter()
There is plenty of space in the printk_context variable. Reserve one byte
there for the NMI context to be on the safe side.

It should never overflow. The BUG_ON(in_nmi() == NMI_MASK) in nmi_enter()
will trigger much earlier.

Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Link: https://lkml.kernel.org/r/20200505134100.681374113@linutronix.de
2020-05-19 15:51:16 +02:00

75 lines
2.0 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* internal.h - printk internal definitions
*/
#include <linux/percpu.h>
#ifdef CONFIG_PRINTK
#define PRINTK_SAFE_CONTEXT_MASK 0x007ffffff
#define PRINTK_NMI_DIRECT_CONTEXT_MASK 0x008000000
#define PRINTK_NMI_CONTEXT_MASK 0xff0000000
#define PRINTK_NMI_CONTEXT_OFFSET 0x010000000
extern raw_spinlock_t logbuf_lock;
__printf(5, 0)
int vprintk_store(int facility, int level,
const char *dict, size_t dictlen,
const char *fmt, va_list args);
__printf(1, 0) int vprintk_default(const char *fmt, va_list args);
__printf(1, 0) int vprintk_deferred(const char *fmt, va_list args);
__printf(1, 0) int vprintk_func(const char *fmt, va_list args);
void __printk_safe_enter(void);
void __printk_safe_exit(void);
void printk_safe_init(void);
bool printk_percpu_data_ready(void);
#define printk_safe_enter_irqsave(flags) \
do { \
local_irq_save(flags); \
__printk_safe_enter(); \
} while (0)
#define printk_safe_exit_irqrestore(flags) \
do { \
__printk_safe_exit(); \
local_irq_restore(flags); \
} while (0)
#define printk_safe_enter_irq() \
do { \
local_irq_disable(); \
__printk_safe_enter(); \
} while (0)
#define printk_safe_exit_irq() \
do { \
__printk_safe_exit(); \
local_irq_enable(); \
} while (0)
void defer_console_output(void);
#else
__printf(1, 0) int vprintk_func(const char *fmt, va_list args) { return 0; }
/*
* In !PRINTK builds we still export logbuf_lock spin_lock, console_sem
* semaphore and some of console functions (console_unlock()/etc.), so
* printk-safe must preserve the existing local IRQ guarantees.
*/
#define printk_safe_enter_irqsave(flags) local_irq_save(flags)
#define printk_safe_exit_irqrestore(flags) local_irq_restore(flags)
#define printk_safe_enter_irq() local_irq_disable()
#define printk_safe_exit_irq() local_irq_enable()
static inline void printk_safe_init(void) { }
static inline bool printk_percpu_data_ready(void) { return false; }
#endif /* CONFIG_PRINTK */