| /* SPDX-License-Identifier: GPL-2.0 */ |
| #ifndef _LINUX_TRACE_SEQ_H |
| #define _LINUX_TRACE_SEQ_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). |
| */ |
| |
| struct trace_seq { |
| char buffer[PAGE_SIZE]; |
| struct seq_buf seq; |
| int full; |
| }; |
| |
| static inline void |
| trace_seq_init(struct trace_seq *s) |
| { |
| seq_buf_init(&s->seq, s->buffer, PAGE_SIZE); |
| s->full = 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); |
| } |
| |
| /* |
| * Currently only defined when tracing is enabled. |
| */ |
| #ifdef CONFIG_TRACING |
| extern __printf(2, 3) |
| void trace_seq_printf(struct trace_seq *s, const char *fmt, ...); |
| extern __printf(2, 0) |
| void trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args); |
| extern 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 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); |
| |
| #else /* CONFIG_TRACING */ |
| static inline void trace_seq_printf(struct trace_seq *s, const char *fmt, ...) |
| { |
| } |
| static inline void |
| trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary) |
| { |
| } |
| |
| static inline void |
| trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp, |
| int nmaskbits) |
| { |
| } |
| |
| static inline int trace_print_seq(struct seq_file *m, struct trace_seq *s) |
| { |
| return 0; |
| } |
| static inline int trace_seq_to_user(struct trace_seq *s, char __user *ubuf, |
| int cnt) |
| { |
| return 0; |
| } |
| static inline void trace_seq_puts(struct trace_seq *s, const char *str) |
| { |
| } |
| static inline void trace_seq_putc(struct trace_seq *s, unsigned char c) |
| { |
| } |
| static inline void |
| trace_seq_putmem(struct trace_seq *s, const void *mem, unsigned int len) |
| { |
| } |
| static inline void trace_seq_putmem_hex(struct trace_seq *s, const void *mem, |
| unsigned int len) |
| { |
| } |
| static inline int trace_seq_path(struct trace_seq *s, const struct path *path) |
| { |
| return 0; |
| } |
| #endif /* CONFIG_TRACING */ |
| |
| #endif /* _LINUX_TRACE_SEQ_H */ |