Re: [PATCHv2 3/3] tracing - buf iterator support for set_graph_function set_ftrace_filter set_ftrace_notrace

Steven Rostedt
2009-09-10T20:43:33Z

On Sat, 2009-09-05 at 03:13 +0200, jolsa@redhat.com wrote:
> Updated 'set_graph_function', 'set_ftrace_filter', 'set_ftrace_notrace' write methods
> to use the 'trace_get_user' function.
>
> Removed FTRACE_ITER_CONT flag, since it's not needed after this change.
>
> Fixed minor in set_graph_function display - g_show function.
>

This patch seems fine as long as it gets updated with the same comments
of the other patches.

-- Steve

> wbr,
> jirka
>
> Signed-off-by: Jiri Olsa <jolsa@redhat.com>
>
> ---
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index 8c804e2..04bffba 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -1323,11 +1323,10 @@ static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
>
> enum {
> FTRACE_ITER_FILTER = (1 << 0),
> - FTRACE_ITER_CONT = (1 << 1),
> - FTRACE_ITER_NOTRACE = (1 << 2),
> - FTRACE_ITER_FAILURES = (1 << 3),
> - FTRACE_ITER_PRINTALL = (1 << 4),
> - FTRACE_ITER_HASH = (1 << 5),
> + FTRACE_ITER_NOTRACE = (1 << 1),
> + FTRACE_ITER_FAILURES = (1 << 2),
> + FTRACE_ITER_PRINTALL = (1 << 3),
> + FTRACE_ITER_HASH = (1 << 4),
> };
>
> #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
> @@ -1337,8 +1336,7 @@ struct ftrace_iterator {
> int hidx;
> int idx;
> unsigned flags;
> - unsigned char buffer[FTRACE_BUFF_MAX+1];
> - unsigned buffer_idx;
> + struct trace_biter biter;
> };
>
> static void *
> @@ -1604,6 +1602,11 @@ ftrace_regex_open(struct inode *inode, struct file *file, int enable)
> if (!iter)
> return -ENOMEM;
>
> + if (trace_biter_alloc(&iter->biter, FTRACE_BUFF_MAX)) {
> + kfree(iter);
> + return -ENOMEM;
> + }
> +
> mutex_lock(&ftrace_regex_lock);
> if ((file->f_mode & FMODE_WRITE) &&
> (file->f_flags & O_TRUNC))
> @@ -2196,9 +2199,8 @@ ftrace_regex_write(struct file *file, const char __user *ubuf,
> size_t cnt, loff_t *ppos, int enable)
> {
> struct ftrace_iterator *iter;
> - char ch;
> - size_t read = 0;
> - ssize_t ret;
> + struct trace_biter *biter;
> + ssize_t ret, read;
>
> if (!cnt || cnt < 0)
> return 0;
> @@ -2211,72 +2213,23 @@ ftrace_regex_write(struct file *file, const char __user *ubuf,
> } else
> iter = file->private_data;
>
> - if (!*ppos) {
> - iter->flags &= ~FTRACE_ITER_CONT;
> - iter->buffer_idx = 0;
> - }
> -
> - ret = get_user(ch, ubuf++);
> - if (ret)
> - goto out;
> - read++;
> - cnt--;
> + biter = &iter->biter;
> + read = trace_get_user(biter, ubuf, cnt, ppos);
>
> - /*
> - * If the parser haven't finished with the last write,
> - * continue reading the user input without skipping spaces.
> - */
> - if (!(iter->flags & FTRACE_ITER_CONT)) {
> - /* skip white space */
> - while (cnt && isspace(ch)) {
> - ret = get_user(ch, ubuf++);
> - if (ret)
> - goto out;
> - read++;
> - cnt--;
> - }
> -
> - /* only spaces were written */
> - if (isspace(ch)) {
> - *ppos += read;
> - ret = read;
> - goto out;
> - }
> -
> - iter->buffer_idx = 0;
> - }
> -
> - while (cnt && !isspace(ch)) {
> - if (iter->buffer_idx < FTRACE_BUFF_MAX)
> - iter->buffer[iter->buffer_idx++] = ch;
> - else {
> - ret = -EINVAL;
> - goto out;
> - }
> - ret = get_user(ch, ubuf++);
> + if (TRACE_BITER_LOADED(biter) &&
> + !TRACE_BITER_CONT(biter)) {
> + ret = ftrace_process_regex(biter->buffer,
> + biter->idx, enable);
> if (ret)
> goto out;
> - read++;
> - cnt--;
> - }
>
> - if (isspace(ch)) {
> - iter->buffer[iter->buffer_idx] = 0;
> - ret = ftrace_process_regex(iter->buffer,
> - iter->buffer_idx, enable);
> - if (ret)
> - goto out;
> - iter->buffer_idx = 0;
> - } else {
> - iter->flags |= FTRACE_ITER_CONT;
> - iter->buffer[iter->buffer_idx++] = ch;
> + TRACE_BITER_CLEAR(biter);
> }
>
> - *ppos += read;
> ret = read;
> - out:
> - mutex_unlock(&ftrace_regex_lock);
>
> + mutex_unlock(&ftrace_regex_lock);
> +out:
> return ret;
> }
>
> @@ -2381,6 +2334,7 @@ ftrace_regex_release(struct inode *inode, struct file *file, int enable)
> {
> struct seq_file *m = (struct seq_file *)file->private_data;
> struct ftrace_iterator *iter;
> + struct trace_biter *biter;
>
> mutex_lock(&ftrace_regex_lock);
> if (file->f_mode & FMODE_READ) {
> @@ -2390,9 +2344,10 @@ ftrace_regex_release(struct inode *inode, struct file *file, int enable)
> } else
> iter = file->private_data;
>
> - if (iter->buffer_idx) {
> - iter->buffer[iter->buffer_idx] = 0;
> - ftrace_match_records(iter->buffer, iter->buffer_idx, enable);
> + biter = &iter->biter;
> + if (TRACE_BITER_LOADED(biter)) {
> + biter->buffer[biter->idx] = 0;
> + ftrace_match_records(biter->buffer, biter->idx, enable);
> }
>
> mutex_lock(&ftrace_lock);
> @@ -2400,7 +2355,9 @@ ftrace_regex_release(struct inode *inode, struct file *file, int enable)
> ftrace_run_update_code(FTRACE_ENABLE_CALLS);
> mutex_unlock(&ftrace_lock);
>
> + trace_biter_free(biter);
> kfree(iter);
> +
> mutex_unlock(&ftrace_regex_lock);
> return 0;
> }
> @@ -2499,7 +2456,7 @@ static int g_show(struct seq_file *m, void *v)
> return 0;
> }
>
> - seq_printf(m, "%pf\n", v);
> + seq_printf(m, "%p\n", (void*) *ptr);
>
> return 0;
> }
> @@ -2602,12 +2559,10 @@ static ssize_t
> ftrace_graph_write(struct file *file, const char __user *ubuf,
> size_t cnt, loff_t *ppos)
> {
> - unsigned char buffer[FTRACE_BUFF_MAX+1];
> + struct trace_biter biter;
> unsigned long *array;
> size_t read = 0;
> ssize_t ret;
> - int index = 0;
> - char ch;
>
> if (!cnt || cnt < 0)
> return 0;
> @@ -2625,51 +2580,27 @@ ftrace_graph_write(struct file *file, const char __user *ubuf,
> } else
> array = file->private_data;
>
> - ret = get_user(ch, ubuf++);
> - if (ret)
> + if (trace_biter_alloc(&biter, FTRACE_BUFF_MAX)) {
> + ret = -ENOMEM;
> goto out;
> - read++;
> - cnt--;
> -
> - /* skip white space */
> - while (cnt && isspace(ch)) {
> - ret = get_user(ch, ubuf++);
> - if (ret)
> - goto out;
> - read++;
> - cnt--;
> }
>
> - if (isspace(ch)) {
> - *ppos += read;
> - ret = read;
> - goto out;
> - }
> + read = trace_get_user(&biter, ubuf, cnt, ppos);
> +
> + if (TRACE_BITER_LOADED((&biter))) {
> + biter.buffer[biter.idx] = 0;
> +
> + /* we allow only one expression at a time */
> + ret = ftrace_set_func(array, &ftrace_graph_count,
> + biter.buffer);
>
> - while (cnt && !isspace(ch)) {
> - if (index < FTRACE_BUFF_MAX)
> - buffer[index++] = ch;
> - else {
> - ret = -EINVAL;
> - goto out;
> - }
> - ret = get_user(ch, ubuf++);
> if (ret)
> goto out;
> - read++;
> - cnt--;
> }
> - buffer[index] = 0;
> -
> - /* we allow only one expression at a time */
> - ret = ftrace_set_func(array, &ftrace_graph_count, buffer);
> - if (ret)
> - goto out;
> -
> - file->f_pos += read;
>
> ret = read;
> out:
> + trace_biter_free(&biter);
> mutex_unlock(&graph_lock);
>
> return ret;