Loading...
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * internal.h - printk internal definitions
4 */
5#include <linux/percpu.h>
6
7#ifdef CONFIG_PRINTK
8
9#define PRINTK_SAFE_CONTEXT_MASK 0x3fffffff
10#define PRINTK_NMI_DIRECT_CONTEXT_MASK 0x40000000
11#define PRINTK_NMI_CONTEXT_MASK 0x80000000
12
13extern raw_spinlock_t logbuf_lock;
14
15__printf(5, 0)
16int vprintk_store(int facility, int level,
17 const char *dict, size_t dictlen,
18 const char *fmt, va_list args);
19
20__printf(1, 0) int vprintk_default(const char *fmt, va_list args);
21__printf(1, 0) int vprintk_deferred(const char *fmt, va_list args);
22__printf(1, 0) int vprintk_func(const char *fmt, va_list args);
23void __printk_safe_enter(void);
24void __printk_safe_exit(void);
25
26#define printk_safe_enter_irqsave(flags) \
27 do { \
28 local_irq_save(flags); \
29 __printk_safe_enter(); \
30 } while (0)
31
32#define printk_safe_exit_irqrestore(flags) \
33 do { \
34 __printk_safe_exit(); \
35 local_irq_restore(flags); \
36 } while (0)
37
38#define printk_safe_enter_irq() \
39 do { \
40 local_irq_disable(); \
41 __printk_safe_enter(); \
42 } while (0)
43
44#define printk_safe_exit_irq() \
45 do { \
46 __printk_safe_exit(); \
47 local_irq_enable(); \
48 } while (0)
49
50void defer_console_output(void);
51
52#else
53
54__printf(1, 0) int vprintk_func(const char *fmt, va_list args) { return 0; }
55
56/*
57 * In !PRINTK builds we still export logbuf_lock spin_lock, console_sem
58 * semaphore and some of console functions (console_unlock()/etc.), so
59 * printk-safe must preserve the existing local IRQ guarantees.
60 */
61#define printk_safe_enter_irqsave(flags) local_irq_save(flags)
62#define printk_safe_exit_irqrestore(flags) local_irq_restore(flags)
63
64#define printk_safe_enter_irq() local_irq_disable()
65#define printk_safe_exit_irq() local_irq_enable()
66
67#endif /* CONFIG_PRINTK */
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * internal.h - printk internal definitions
4 */
5#include <linux/percpu.h>
6#include <linux/console.h>
7#include "printk_ringbuffer.h"
8
9#if defined(CONFIG_PRINTK) && defined(CONFIG_SYSCTL)
10void __init printk_sysctl_init(void);
11int devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write,
12 void *buffer, size_t *lenp, loff_t *ppos);
13#else
14#define printk_sysctl_init() do { } while (0)
15#endif
16
17#define con_printk(lvl, con, fmt, ...) \
18 printk(lvl pr_fmt("%s%sconsole [%s%d] " fmt), \
19 (con->flags & CON_NBCON) ? "" : "legacy ", \
20 (con->flags & CON_BOOT) ? "boot" : "", \
21 con->name, con->index, ##__VA_ARGS__)
22
23#ifdef CONFIG_PRINTK
24
25#ifdef CONFIG_PRINTK_CALLER
26#define PRINTK_PREFIX_MAX 48
27#else
28#define PRINTK_PREFIX_MAX 32
29#endif
30
31/*
32 * the maximum size of a formatted record (i.e. with prefix added
33 * per line and dropped messages or in extended message format)
34 */
35#define PRINTK_MESSAGE_MAX 2048
36
37/* the maximum size allowed to be reserved for a record */
38#define PRINTKRB_RECORD_MAX 1024
39
40/* Flags for a single printk record. */
41enum printk_info_flags {
42 LOG_NEWLINE = 2, /* text ended with a newline */
43 LOG_CONT = 8, /* text is a fragment of a continuation line */
44};
45
46extern struct printk_ringbuffer *prb;
47
48__printf(4, 0)
49int vprintk_store(int facility, int level,
50 const struct dev_printk_info *dev_info,
51 const char *fmt, va_list args);
52
53__printf(1, 0) int vprintk_default(const char *fmt, va_list args);
54__printf(1, 0) int vprintk_deferred(const char *fmt, va_list args);
55
56bool printk_percpu_data_ready(void);
57
58#define printk_safe_enter_irqsave(flags) \
59 do { \
60 local_irq_save(flags); \
61 __printk_safe_enter(); \
62 } while (0)
63
64#define printk_safe_exit_irqrestore(flags) \
65 do { \
66 __printk_safe_exit(); \
67 local_irq_restore(flags); \
68 } while (0)
69
70void defer_console_output(void);
71
72u16 printk_parse_prefix(const char *text, int *level,
73 enum printk_info_flags *flags);
74
75u64 nbcon_seq_read(struct console *con);
76void nbcon_seq_force(struct console *con, u64 seq);
77bool nbcon_alloc(struct console *con);
78void nbcon_init(struct console *con);
79void nbcon_free(struct console *con);
80
81#else
82
83#define PRINTK_PREFIX_MAX 0
84#define PRINTK_MESSAGE_MAX 0
85#define PRINTKRB_RECORD_MAX 0
86
87/*
88 * In !PRINTK builds we still export console_sem
89 * semaphore and some of console functions (console_unlock()/etc.), so
90 * printk-safe must preserve the existing local IRQ guarantees.
91 */
92#define printk_safe_enter_irqsave(flags) local_irq_save(flags)
93#define printk_safe_exit_irqrestore(flags) local_irq_restore(flags)
94
95static inline bool printk_percpu_data_ready(void) { return false; }
96static inline u64 nbcon_seq_read(struct console *con) { return 0; }
97static inline void nbcon_seq_force(struct console *con, u64 seq) { }
98static inline bool nbcon_alloc(struct console *con) { return false; }
99static inline void nbcon_init(struct console *con) { }
100static inline void nbcon_free(struct console *con) { }
101
102#endif /* CONFIG_PRINTK */
103
104extern struct printk_buffers printk_shared_pbufs;
105
106/**
107 * struct printk_buffers - Buffers to read/format/output printk messages.
108 * @outbuf: After formatting, contains text to output.
109 * @scratchbuf: Used as temporary ringbuffer reading and string-print space.
110 */
111struct printk_buffers {
112 char outbuf[PRINTK_MESSAGE_MAX];
113 char scratchbuf[PRINTKRB_RECORD_MAX];
114};
115
116/**
117 * struct printk_message - Container for a prepared printk message.
118 * @pbufs: printk buffers used to prepare the message.
119 * @outbuf_len: The length of prepared text in @pbufs->outbuf to output. This
120 * does not count the terminator. A value of 0 means there is
121 * nothing to output and this record should be skipped.
122 * @seq: The sequence number of the record used for @pbufs->outbuf.
123 * @dropped: The number of dropped records from reading @seq.
124 */
125struct printk_message {
126 struct printk_buffers *pbufs;
127 unsigned int outbuf_len;
128 u64 seq;
129 unsigned long dropped;
130};
131
132bool other_cpu_in_panic(void);
133bool printk_get_next_message(struct printk_message *pmsg, u64 seq,
134 bool is_extended, bool may_supress);
135
136#ifdef CONFIG_PRINTK
137void console_prepend_dropped(struct printk_message *pmsg, unsigned long dropped);
138#endif