diff options
Diffstat (limited to 'include/linux/trace_seq.h')
| -rw-r--r-- | include/linux/trace_seq.h | 154 |
1 files changed, 115 insertions, 39 deletions
diff --git a/include/linux/trace_seq.h b/include/linux/trace_seq.h index a32d86ec8bf2..4a0b8c172d27 100644 --- a/include/linux/trace_seq.h +++ b/include/linux/trace_seq.h @@ -1,28 +1,96 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_TRACE_SEQ_H #define _LINUX_TRACE_SEQ_H -#include <linux/fs.h> +#include <linux/seq_buf.h> #include <asm/page.h> /* * Trace sequences are used to allow a function to call several other functions - * to create a string of data to use (up to a max of PAGE_SIZE). + * to create a string of data to use. + * + * Have the trace seq to be 8K which is typically PAGE_SIZE * 2 on + * most architectures. The TRACE_SEQ_BUFFER_SIZE (which is + * TRACE_SEQ_SIZE minus the other fields of trace_seq), is the + * max size the output of a trace event may be. */ +#define TRACE_SEQ_SIZE 8192 +#define TRACE_SEQ_BUFFER_SIZE (TRACE_SEQ_SIZE - \ + (sizeof(struct seq_buf) + sizeof(size_t) + sizeof(int))) + struct trace_seq { - unsigned char buffer[PAGE_SIZE]; - unsigned int len; - unsigned int readpos; + struct seq_buf seq; + size_t readpos; int full; + char buffer[TRACE_SEQ_BUFFER_SIZE]; }; static inline void trace_seq_init(struct trace_seq *s) { - s->len = 0; - s->readpos = 0; + seq_buf_init(&s->seq, s->buffer, TRACE_SEQ_BUFFER_SIZE); s->full = 0; + s->readpos = 0; +} + +/** + * trace_seq_used - amount of actual data written to buffer + * @s: trace sequence descriptor + * + * Returns the amount of data written to the buffer. + * + * IMPORTANT! + * + * Use this instead of @s->seq.len if you need to pass the amount + * of data from the buffer to another buffer (userspace, or what not). + * The @s->seq.len on overflow is bigger than the buffer size and + * using it can cause access to undefined memory. + */ +static inline int trace_seq_used(struct trace_seq *s) +{ + return seq_buf_used(&s->seq); +} + +/** + * trace_seq_buffer_ptr - return pointer to next location in buffer + * @s: trace sequence descriptor + * + * Returns the pointer to the buffer where the next write to + * the buffer will happen. This is useful to save the location + * that is about to be written to and then return the result + * of that write. + */ +static inline char * +trace_seq_buffer_ptr(struct trace_seq *s) +{ + return s->buffer + seq_buf_used(&s->seq); +} + +/** + * trace_seq_has_overflowed - return true if the trace_seq took too much + * @s: trace sequence descriptor + * + * Returns true if too much data was added to the trace_seq and it is + * now full and will not take anymore. + */ +static inline bool trace_seq_has_overflowed(struct trace_seq *s) +{ + return s->full || seq_buf_has_overflowed(&s->seq); +} + +/** + * trace_seq_pop - pop off the last written character + * @s: trace sequence descriptor + * + * Removes the last written character to the trace_seq @s. + * + * Returns the last character or -1 if it is empty. + */ +static inline int trace_seq_pop(struct trace_seq *s) +{ + return seq_buf_pop(&s->seq); } /* @@ -30,68 +98,76 @@ trace_seq_init(struct trace_seq *s) */ #ifdef CONFIG_TRACING extern __printf(2, 3) -int trace_seq_printf(struct trace_seq *s, const char *fmt, ...); +void trace_seq_printf(struct trace_seq *s, const char *fmt, ...); extern __printf(2, 0) -int trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args); -extern int -trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary); +void trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args); +extern __printf(2, 0) +void trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary); extern int trace_print_seq(struct seq_file *m, struct trace_seq *s); -extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, - size_t cnt); -extern int trace_seq_puts(struct trace_seq *s, const char *str); -extern int trace_seq_putc(struct trace_seq *s, unsigned char c); -extern int trace_seq_putmem(struct trace_seq *s, const void *mem, size_t len); -extern int trace_seq_putmem_hex(struct trace_seq *s, const void *mem, - size_t len); -extern void *trace_seq_reserve(struct trace_seq *s, size_t len); +extern int trace_seq_to_user(struct trace_seq *s, char __user *ubuf, + int cnt); +extern void trace_seq_puts(struct trace_seq *s, const char *str); +extern void trace_seq_putc(struct trace_seq *s, unsigned char c); +extern void trace_seq_putmem(struct trace_seq *s, const void *mem, unsigned int len); +extern void trace_seq_putmem_hex(struct trace_seq *s, const void *mem, + unsigned int len); extern int trace_seq_path(struct trace_seq *s, const struct path *path); +extern void trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp, + int nmaskbits); + +extern int trace_seq_hex_dump(struct trace_seq *s, const char *prefix_str, + int prefix_type, int rowsize, int groupsize, + const void *buf, size_t len, bool ascii); +char *trace_seq_acquire(struct trace_seq *s, unsigned int len); + #else /* CONFIG_TRACING */ -static inline int trace_seq_printf(struct trace_seq *s, const char *fmt, ...) +static inline __printf(2, 3) +void trace_seq_printf(struct trace_seq *s, const char *fmt, ...) { - return 0; } -static inline int -trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary) +static inline __printf(2, 0) +void trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary) { - return 0; } -static inline int trace_print_seq(struct seq_file *m, struct trace_seq *s) +static inline void +trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp, + int nmaskbits) { - return 0; } -static inline ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, - size_t cnt) + +static inline int trace_print_seq(struct seq_file *m, struct trace_seq *s) { return 0; } -static inline int trace_seq_puts(struct trace_seq *s, const char *str) +static inline int trace_seq_to_user(struct trace_seq *s, char __user *ubuf, + int cnt) { return 0; } -static inline int trace_seq_putc(struct trace_seq *s, unsigned char c) +static inline void trace_seq_puts(struct trace_seq *s, const char *str) { - return 0; } -static inline int -trace_seq_putmem(struct trace_seq *s, const void *mem, size_t len) +static inline void trace_seq_putc(struct trace_seq *s, unsigned char c) { - return 0; } -static inline int trace_seq_putmem_hex(struct trace_seq *s, const void *mem, - size_t len) +static inline void +trace_seq_putmem(struct trace_seq *s, const void *mem, unsigned int len) { - return 0; } -static inline void *trace_seq_reserve(struct trace_seq *s, size_t len) +static inline void trace_seq_putmem_hex(struct trace_seq *s, const void *mem, + unsigned int len) { - return NULL; } static inline int trace_seq_path(struct trace_seq *s, const struct path *path) { return 0; } +static inline char *trace_seq_acquire(struct trace_seq *s, unsigned int len) +{ + return NULL; +} #endif /* CONFIG_TRACING */ #endif /* _LINUX_TRACE_SEQ_H */ |