diff options
Diffstat (limited to 'kernel/printk/internal.h')
| -rw-r--r-- | kernel/printk/internal.h | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h new file mode 100644 index 0000000000..7d4979d5c3 --- /dev/null +++ b/kernel/printk/internal.h @@ -0,0 +1,107 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * internal.h - printk internal definitions + */ +#include <linux/percpu.h> + +#if defined(CONFIG_PRINTK) && defined(CONFIG_SYSCTL) +void __init printk_sysctl_init(void); +int devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos); +#else +#define printk_sysctl_init() do { } while (0) +#endif + +#ifdef CONFIG_PRINTK + +#ifdef CONFIG_PRINTK_CALLER +#define PRINTK_PREFIX_MAX 48 +#else +#define PRINTK_PREFIX_MAX 32 +#endif + +/* + * the maximum size of a formatted record (i.e. with prefix added + * per line and dropped messages or in extended message format) + */ +#define PRINTK_MESSAGE_MAX 2048 + +/* the maximum size allowed to be reserved for a record */ +#define PRINTKRB_RECORD_MAX 1024 + +/* Flags for a single printk record. */ +enum printk_info_flags { + LOG_NEWLINE = 2, /* text ended with a newline */ + LOG_CONT = 8, /* text is a fragment of a continuation line */ +}; + +__printf(4, 0) +int vprintk_store(int facility, int level, + const struct dev_printk_info *dev_info, + 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); + +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) + +void defer_console_output(void); + +u16 printk_parse_prefix(const char *text, int *level, + enum printk_info_flags *flags); +#else + +#define PRINTK_PREFIX_MAX 0 +#define PRINTK_MESSAGE_MAX 0 +#define PRINTKRB_RECORD_MAX 0 + +/* + * In !PRINTK builds we still export 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) + +static inline bool printk_percpu_data_ready(void) { return false; } +#endif /* CONFIG_PRINTK */ + +/** + * struct printk_buffers - Buffers to read/format/output printk messages. + * @outbuf: After formatting, contains text to output. + * @scratchbuf: Used as temporary ringbuffer reading and string-print space. + */ +struct printk_buffers { + char outbuf[PRINTK_MESSAGE_MAX]; + char scratchbuf[PRINTKRB_RECORD_MAX]; +}; + +/** + * struct printk_message - Container for a prepared printk message. + * @pbufs: printk buffers used to prepare the message. + * @outbuf_len: The length of prepared text in @pbufs->outbuf to output. This + * does not count the terminator. A value of 0 means there is + * nothing to output and this record should be skipped. + * @seq: The sequence number of the record used for @pbufs->outbuf. + * @dropped: The number of dropped records from reading @seq. + */ +struct printk_message { + struct printk_buffers *pbufs; + unsigned int outbuf_len; + u64 seq; + unsigned long dropped; +}; + +bool other_cpu_in_panic(void); |