On Wed, 7 Jan 2026 11:41:33 -0500
Steven Rostedt <[email protected]> wrote:
> > @@ -4888,6 +4888,9 @@ static int tracing_open(struct inode *inode, struct
> > file *file)
> > int cpu = tracing_get_cpu(inode);
> > struct array_buffer *trace_buf = &tr->array_buffer;
> >
> > + if (trace_array_is_readonly(tr))
> > + return -EPERM;
>
> So this fails if someone opens a file in RDONLY mode?
>
> Why?
This is for `trace` file and this block is to erase the buffer.
-----
/* If this file was open for write, then erase contents */
if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
int cpu = tracing_get_cpu(inode);
struct array_buffer *trace_buf = &tr->array_buffer;
if (trace_array_is_readonly(tr))
return -EPERM;
-----
Thus, if user opens it RDONLY mode to read the buffer, we don't care
because it is readonly (readable).
Thank you,
--
Masami Hiramatsu (Google) <[email protected]>
