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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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/* How much buffer is left on the trace_seq? */#define TRACE_SEQ_BUF_LEFT(s) seq_buf_buffer_left(&(s)->seq)
/* * trace_seq should work with being initialized with 0s. */static inline void __trace_seq_init(struct trace_seq *s){ if (unlikely(!s->seq.size)) trace_seq_init(s);}
/** * trace_print_seq - move the contents of trace_seq into a seq_file * @m: the seq_file descriptor that is the destination * @s: the trace_seq descriptor that is the source. * * Returns 0 on success and non zero on error. If it succeeds to * write to the seq_file it will reset the trace_seq, otherwise * it does not modify the trace_seq to let the caller try again. */int trace_print_seq(struct seq_file *m, struct trace_seq *s){ int ret;
__trace_seq_init(s);
ret = seq_buf_print_seq(m, &s->seq);
/* * Only reset this buffer if we successfully wrote to the * seq_file buffer. This lets the caller try again or * do something else with the contents. */ if (!ret) trace_seq_init(s);
return ret;}
/** * trace_seq_printf - sequence printing of trace information * @s: trace sequence descriptor * @fmt: printf format string * * The tracer may use either sequence operations or its own * copy to user routines. To simplify formatting of a trace * trace_seq_printf() is used to store strings into a special * buffer (@s). Then the output may be either used by * the sequencer or pulled into another buffer. */void trace_seq_printf(struct trace_seq *s, const char *fmt, ...){ unsigned int save_len = s->seq.len; va_list ap;
if (s->full) return;
__trace_seq_init(s);
va_start(ap, fmt); seq_buf_vprintf(&s->seq, fmt, ap); va_end(ap);
/* If we can't write it all, don't bother writing anything */ if (unlikely(seq_buf_has_overflowed(&s->seq))) { s->seq.len = save_len; s->full = 1; }}EXPORT_SYMBOL_GPL(trace_seq_printf);
/** * trace_seq_bitmask - write a bitmask array in its ASCII representation * @s: trace sequence descriptor * @maskp: points to an array of unsigned longs that represent a bitmask * @nmaskbits: The number of bits that are valid in @maskp * * Writes a ASCII representation of a bitmask string into @s. */void trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp, int nmaskbits){ unsigned int save_len = s->seq.len;
if (s->full) return;
__trace_seq_init(s);
seq_buf_printf(&s->seq, "%*pb", nmaskbits, maskp);
if (unlikely(seq_buf_has_overflowed(&s->seq))) { s->seq.len = save_len; s->full = 1; }}EXPORT_SYMBOL_GPL(trace_seq_bitmask);
/** * trace_seq_bitmask_list - write a bitmask array in its list representation * @s: trace sequence descriptor * @maskp: points to an array of unsigned longs that represent a bitmask * @nmaskbits: The number of bits that are valid in @maskp * * Writes a list representation (e.g., 0-3,5-7) of a bitmask string into @s. */void trace_seq_bitmask_list(struct trace_seq *s, const unsigned long *maskp, int nmaskbits){ unsigned int save_len = s->seq.len;
if (s->full) return;
__trace_seq_init(s);
seq_buf_printf(&s->seq, "%*pbl", nmaskbits, maskp);
if (unlikely(seq_buf_has_overflowed(&s->seq))) { s->seq.len = save_len; s->full = 1; }}EXPORT_SYMBOL_GPL(trace_seq_bitmask_list);
/** * trace_seq_vprintf - sequence printing of trace information * @s: trace sequence descriptor * @fmt: printf format string * @args: Arguments for the format string * * The tracer may use either sequence operations or its own * copy to user routines. To simplify formatting of a trace * trace_seq_printf is used to store strings into a special * buffer (@s). Then the output may be either used by * the sequencer or pulled into another buffer. */void trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args){ unsigned int save_len = s->seq.len;
if (s->full) return;
__trace_seq_init(s);
seq_buf_vprintf(&s->seq, fmt, args);
/* If we can't write it all, don't bother writing anything */ if (unlikely(seq_buf_has_overflowed(&s->seq))) { s->seq.len = save_len; s->full = 1; }}EXPORT_SYMBOL_GPL(trace_seq_vprintf);
/** * trace_seq_bprintf - Write the printf string from binary arguments * @s: trace sequence descriptor * @fmt: The format string for the @binary arguments * @binary: The binary arguments for @fmt. * * When recording in a fast path, a printf may be recorded with just * saving the format and the arguments as they were passed to the * function, instead of wasting cycles converting the arguments into * ASCII characters. Instead, the arguments are saved in a 32 bit * word array that is defined by the format string constraints. * * This function will take the format and the binary array and finish * the conversion into the ASCII string within the buffer. */void trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary){ unsigned int save_len = s->seq.len;
if (s->full) return;
__trace_seq_init(s);
seq_buf_bprintf(&s->seq, fmt, binary);
/* If we can't write it all, don't bother writing anything */ if (unlikely(seq_buf_has_overflowed(&s->seq))) { s->seq.len = save_len; s->full = 1; return; }}EXPORT_SYMBOL_GPL(trace_seq_bprintf);
/** * trace_seq_puts - trace sequence printing of simple string * @s: trace sequence descriptor * @str: simple string to record * * The tracer may use either the sequence operations or its own * copy to user routines. This function records a simple string * into a special buffer (@s) for later retrieval by a sequencer * or other mechanism. */void trace_seq_puts(struct trace_seq *s, const char *str){ unsigned int len = strlen(str);
if (s->full) return;
__trace_seq_init(s);
if (len > TRACE_SEQ_BUF_LEFT(s)) { s->full = 1; return; }
seq_buf_putmem(&s->seq, str, len);}EXPORT_SYMBOL_GPL(trace_seq_puts);
/** * trace_seq_putc - trace sequence printing of simple character * @s: trace sequence descriptor * @c: simple character to record * * The tracer may use either the sequence operations or its own * copy to user routines. This function records a simple character * into a special buffer (@s) for later retrieval by a sequencer * or other mechanism. */void trace_seq_putc(struct trace_seq *s, unsigned char c){ if (s->full) return;
__trace_seq_init(s);
if (TRACE_SEQ_BUF_LEFT(s) < 1) { s->full = 1; return; }
seq_buf_putc(&s->seq, c);}EXPORT_SYMBOL_GPL(trace_seq_putc);
/** * trace_seq_putmem - write raw data into the trace_seq buffer * @s: trace sequence descriptor * @mem: The raw memory to copy into the buffer * @len: The length of the raw memory to copy (in bytes) * * There may be cases where raw memory needs to be written into the * buffer and a strcpy() would not work. Using this function allows * for such cases. */void trace_seq_putmem(struct trace_seq *s, const void *mem, unsigned int len){ if (s->full) return;
__trace_seq_init(s);
if (len > TRACE_SEQ_BUF_LEFT(s)) { s->full = 1; return; }
seq_buf_putmem(&s->seq, mem, len);}EXPORT_SYMBOL_GPL(trace_seq_putmem);
/** * trace_seq_putmem_hex - write raw memory into the buffer in ASCII hex * @s: trace sequence descriptor * @mem: The raw memory to write its hex ASCII representation of * @len: The length of the raw memory to copy (in bytes) * * This is similar to trace_seq_putmem() except instead of just copying the * raw memory into the buffer it writes its ASCII representation of it * in hex characters. */void trace_seq_putmem_hex(struct trace_seq *s, const void *mem, unsigned int len){ unsigned int save_len = s->seq.len;
if (s->full) return;
__trace_seq_init(s);
/* Each byte is represented by two chars */ if (len * 2 > TRACE_SEQ_BUF_LEFT(s)) { s->full = 1; return; }
/* The added spaces can still cause an overflow */ seq_buf_putmem_hex(&s->seq, mem, len);
if (unlikely(seq_buf_has_overflowed(&s->seq))) { s->seq.len = save_len; s->full = 1; return; }}EXPORT_SYMBOL_GPL(trace_seq_putmem_hex);
/** * trace_seq_path - copy a path into the sequence buffer * @s: trace sequence descriptor * @path: path to write into the sequence buffer. * * Write a path name into the sequence buffer. * * Returns 1 if we successfully written all the contents to * the buffer. * Returns 0 if we the length to write is bigger than the * reserved buffer space. In this case, nothing gets written. */int trace_seq_path(struct trace_seq *s, const struct path *path){ unsigned int save_len = s->seq.len;
if (s->full) return 0;
__trace_seq_init(s);
if (TRACE_SEQ_BUF_LEFT(s) < 1) { s->full = 1; return 0; }
seq_buf_path(&s->seq, path, "\n");
if (unlikely(seq_buf_has_overflowed(&s->seq))) { s->seq.len = save_len; s->full = 1; return 0; }
return 1;}EXPORT_SYMBOL_GPL(trace_seq_path);
/** * trace_seq_to_user - copy the sequence buffer to user space * @s: trace sequence descriptor * @ubuf: The userspace memory location to copy to * @cnt: The amount to copy * * Copies the sequence buffer into the userspace memory pointed to * by @ubuf. It starts from the last read position (@s->readpos) * and writes up to @cnt characters or till it reaches the end of * the content in the buffer (@s->len), which ever comes first. * * On success, it returns a positive number of the number of bytes * it copied. * * On failure it returns -EBUSY if all of the content in the * sequence has been already read, which includes nothing in the * sequence (@s->len == @s->readpos). * * Returns -EFAULT if the copy to userspace fails. */int trace_seq_to_user(struct trace_seq *s, char __user *ubuf, int cnt){ int ret; __trace_seq_init(s); ret = seq_buf_to_user(&s->seq, ubuf, s->readpos, cnt); if (ret > 0) s->readpos += ret; return ret;}EXPORT_SYMBOL_GPL(trace_seq_to_user);
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){ unsigned int save_len = s->seq.len;
if (s->full) return 0;
__trace_seq_init(s);
if (TRACE_SEQ_BUF_LEFT(s) < 1) { s->full = 1; return 0; }
seq_buf_hex_dump(&(s->seq), prefix_str, prefix_type, rowsize, groupsize, buf, len, ascii);
if (unlikely(seq_buf_has_overflowed(&s->seq))) { s->seq.len = save_len; s->full = 1; return 0; }
return 1;}EXPORT_SYMBOL(trace_seq_hex_dump);
/* * trace_seq_acquire - acquire seq buffer with size len * @s: trace sequence descriptor * @len: size of buffer to be acquired * * acquire buffer with size of @len from trace_seq for output usage, * user can fill string into that buffer. * * Returns start address of acquired buffer. * * it allow multiple usage in one trace output function call. */char *trace_seq_acquire(struct trace_seq *s, unsigned int len){ char *ret = trace_seq_buffer_ptr(s);
if (!WARN_ON_ONCE(seq_buf_buffer_left(&s->seq) < len)) seq_buf_commit(&s->seq, len);
return ret;}EXPORT_SYMBOL(trace_seq_acquire);