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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319/* SPDX-License-Identifier: GPL-2.0 */#ifndef _LINUX_SEQ_BUF_H#define _LINUX_SEQ_BUF_H
#include <linux/bug.h>#include <linux/minmax.h>#include <linux/seq_file.h>#include <linux/string.h>#include <linux/types.h>
/* * Trace sequences are used to allow a function to call several other functions * to create a string of data to use. */
/** * struct seq_buf - seq buffer structure * @buffer: pointer to the buffer * @size: size of the buffer * @len: the amount of data inside the buffer */struct seq_buf { char *buffer; size_t size; size_t len;};
#define DECLARE_SEQ_BUF(NAME, SIZE) \ struct seq_buf NAME = { \ .buffer = (char[SIZE]) { 0 }, \ .size = SIZE, \ }
/** * seq_buf_clear - reset the seq_buf to be read / appended from the beginning * @s: the seq_buf handle */static inline void seq_buf_clear(struct seq_buf *s){ s->len = 0; if (s->size) s->buffer[0] = '\0';}
/** * seq_buf_init - initialize a seq_buf * @s: the seq_buf handle * @buf: pointer to the buffer * @size: total size of @buf * * The contents of the buffer are ignored. */static inline voidseq_buf_init(struct seq_buf *s, char *buf, unsigned int size){ s->buffer = buf; s->size = size; seq_buf_clear(s);}
/* * seq_buf have a buffer that might overflow. When this happens * len is set to be greater than size. */static inline boolseq_buf_has_overflowed(struct seq_buf *s){ return s->len > s->size;}
/* * Mark @s as overflowed, which discards the length of what it holds. The * bytes up to its last one are the string from then on, as that is where * seq_buf_str() terminates it, so clear whatever was not written: a writer * sets len to how much it filled, and anything past that was never adopted. */static inline voidseq_buf_set_overflow(struct seq_buf *s){ if (s->len < s->size) memset(s->buffer + s->len, 0, s->size - s->len);
s->len = s->size + 1;}
/** * seq_buf_init_append - initialize a seq_buf over a buffer that may * already hold NUL-terminated content * @s: the seq_buf handle * @buf: pointer to the (possibly non-empty) buffer * @size: total size of @buf * * Unlike seq_buf_init(), which always starts @buf at len=0, this * preserves whatever NUL-terminated content @buf already holds and * positions @s to append after it. Useful for converting code that used * to append to an existing buffer with strlcat()/scnprintf() and friends. * * If @buf holds no NUL within @size, @s starts out overflowed, as * strlcat() treats such a buffer as already truncated. */static inline voidseq_buf_init_append(struct seq_buf *s, char *buf, unsigned int size){ s->buffer = buf; s->size = size; s->len = strnlen(buf, size); if (s->len == size) seq_buf_set_overflow(s);}
/* * How much buffer is left on the seq_buf? */static inline unsigned intseq_buf_buffer_left(struct seq_buf *s){ if (seq_buf_has_overflowed(s)) return 0;
return s->size - s->len;}
/* How much buffer was written? */static inline unsigned int seq_buf_used(struct seq_buf *s){ return min(s->len, s->size);}
/* * NUL-terminate the buffer in @s: directly after the data when there is * room for it, otherwise in the last byte of the buffer. @s->size must not * be zero. * * Returns: the offset of the NUL. */static inline size_t __seq_buf_terminate(struct seq_buf *s){ size_t end;
if (seq_buf_buffer_left(s)) end = s->len; else end = s->size - 1;
s->buffer[end] = 0;
return end;}
/** * seq_buf_str - get NUL-terminated C string from seq_buf * @s: the seq_buf handle * * This makes sure that the buffer in @s is NUL-terminated and * safe to read as a string. * * Note, if this is called when the buffer has overflowed, then * the last byte of the buffer is zeroed, and the len will still * point passed it. The same happens when the buffer is exactly * full: the NUL takes the place of the last byte written, which is * lost, though seq_buf_used() still counts it. * * A zero-sized seq_buf has nowhere to put a NUL, so the empty string * is returned instead of writing to @s->buffer. Any other seq_buf * returns @s->buffer, even when it holds an empty string, so callers * always get their own buffer back. * * After this function is called, s->buffer is safe to use * in string operations. * * Returns: @s->buf after making sure it is terminated. */static inline const char *seq_buf_str(struct seq_buf *s){ if (s->size == 0) return "";
__seq_buf_terminate(s);
return s->buffer;}
/** * seq_buf_strlen - get the length of the NUL-terminated C string in seq_buf * @s: the seq_buf handle * * This makes sure that the buffer in @s is NUL-terminated, exactly as * seq_buf_str() does, and returns the length of the resulting string * without walking it. Unlike seq_buf_used(), this does not count the byte * given up to the NUL when the buffer is full or has overflowed. When the * buffer is exactly full, that byte is the last one written, and calling * either function loses it. * * A zero-sized seq_buf holds no string, so 0 is returned without writing * to @s->buffer, matching what seq_buf_str() returns for one. * * After this function is called, s->buffer is safe to use * in string operations. * * Returns: the offset of the NUL that terminates @s->buffer. That is the * length of the string unless an earlier NUL is in the way, either one the * data written to @s carried itself, or one seq_buf_set_overflow() left * behind when it cleared what no writer had claimed. */static inline size_t seq_buf_strlen(struct seq_buf *s){ if (s->size == 0) return 0;
return __seq_buf_terminate(s);}
/** * seq_buf_terminate - NUL-terminate the string in a seq_buf * @s: the seq_buf handle * * Terminate @s->buffer exactly as seq_buf_str() and seq_buf_strlen() do, * for callers that want neither the pointer nor the length and only need * the buffer to be safe to read as a C string. A zero-sized seq_buf has * nowhere to put a NUL and is left untouched. * * Nothing is returned on purpose: a caller that wants the length should * use seq_buf_strlen(), which says so. * * After this function is called, s->buffer is safe to use * in string operations. */static inline void seq_buf_terminate(struct seq_buf *s){ if (s->size == 0) return;
__seq_buf_terminate(s);}
/** * seq_buf_get_buf - get buffer to write arbitrary data to * @s: the seq_buf handle * @bufp: the beginning of the buffer is stored here * * Returns: the number of bytes available in the buffer, or zero if * there's no space. */static inline size_t seq_buf_get_buf(struct seq_buf *s, char **bufp){ WARN_ON(s->len > s->size + 1);
if (s->len < s->size) { *bufp = s->buffer + s->len; return s->size - s->len; }
*bufp = NULL; return 0;}
/** * seq_buf_commit - commit data to the buffer * @s: the seq_buf handle * @num: the number of bytes to commit * * Commit @num bytes of data written to a buffer previously acquired * by seq_buf_get_buf(). To signal an error condition, or that the data * didn't fit in the available space, pass a negative @num value. */static inline void seq_buf_commit(struct seq_buf *s, int num){ if (num < 0) { seq_buf_set_overflow(s); } else { /* num must be negative on overflow */ BUG_ON(s->len + num > s->size); s->len += num; }}
/** * seq_buf_pop - pop off the last written character * @s: the seq_buf handle * * Removes the last written character to the seq_buf @s. * * Returns the last character, or -1 if @s is empty or has overflowed. */static inline int seq_buf_pop(struct seq_buf *s){ if (!s->len || seq_buf_has_overflowed(s)) return -1;
s->len--; return (unsigned int)s->buffer[s->len];}
extern __printf(2, 3)int seq_buf_printf(struct seq_buf *s, const char *fmt, ...);extern __printf(2, 0)int seq_buf_vprintf(struct seq_buf *s, const char *fmt, va_list args);extern int seq_buf_print_seq(struct seq_file *m, struct seq_buf *s);extern int seq_buf_to_user(struct seq_buf *s, char __user *ubuf, size_t start, int cnt);extern int seq_buf_puts(struct seq_buf *s, const char *str);extern int seq_buf_putc(struct seq_buf *s, unsigned char c);extern int seq_buf_putmem(struct seq_buf *s, const void *mem, unsigned int len);extern int seq_buf_putmem_hex(struct seq_buf *s, const void *mem, unsigned int len);extern int seq_buf_path(struct seq_buf *s, const struct path *path, const char *esc);extern int seq_buf_hex_dump(struct seq_buf *s, const char *prefix_str, int prefix_type, int rowsize, int groupsize, const void *buf, size_t len, bool ascii);
#ifdef CONFIG_BINARY_PRINTF__printf(2, 0)int seq_buf_bprintf(struct seq_buf *s, const char *fmt, const u32 *binary);#endif
void seq_buf_do_printk(struct seq_buf *s, const char *lvl);
#endif /* _LINUX_SEQ_BUF_H */