On Fri, 20 Oct 2023 05:59:36 +0800
kernel test robot <[email protected]> wrote:
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> 323) /**
> 9dbbc3b9d09d6d lib/seq_buf.c Zhen Lei 2021-07-07
> 324 * seq_buf_to_user - copy the sequence buffer to user space
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> 325) * @s: seq_buf descriptor
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> 326) * @ubuf: The userspace memory location to copy to
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> 327) * @cnt: The amount to copy
When you resend, I guess you should add the @start as well.
-- Steve
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> 328) *
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> 329) * Copies the sequence buffer into the userspace memory pointed to
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> 330) * by @ubuf. It starts from the last read position (@s->readpos)
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> 331) * and writes up to @cnt characters or till it reaches the end of
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> 332) * the content in the buffer (@s->len), which ever comes first.
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> 333) *
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> 334) * On success, it returns a positive number of the number of bytes
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> 335) * it copied.
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> 336) *
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> 337) * On failure it returns -EBUSY if all of the content in the
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> 338) * sequence has been already read, which includes nothing in the
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> 339) * sequence (@s->len == @s->readpos).
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> 340) *
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> 341) * Returns -EFAULT if the copy to userspace fails.
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> 342) */
> 9377093a882be0 lib/seq_buf.c Matthew Wilcox (Oracle 2023-10-19
> 343) int seq_buf_to_user(struct seq_buf *s, char __user *ubuf, size_t start,
> int cnt)
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> @344) {
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> 345) int len;
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> 346) int ret;
> 3a161d99c43ce7 kernel/trace/seq_buf.c Steven Rostedt (Red Hat 2014-06-25
> 347)
