Messages in this thread | | | Date | Wed, 9 Jun 2021 18:36:53 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH 1/2] tracing: Simplify the max length test when using the filtering temp buffer |
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On Wed, 9 Jun 2021 15:21:52 -0700 Linus Torvalds <torvalds@linux-foundation.org> wrote:
> On Wed, Jun 9, 2021 at 3:05 PM Steven Rostedt <rostedt@goodmis.org> wrote: > > > > val = this_cpu_inc_return(trace_buffered_event_cnt); > > - if ((len < (PAGE_SIZE - sizeof(*entry) - sizeof(entry->array[0]))) && val == 1) { > > + if (val == 1 && unlikely(len < max_len)) { > > unlikely? No.
Bah, that was suppose to be "likely()" :-p
> > Also, I still think that "len < max_len" should actually be "len <= > max_len". It should be ok to use the whole page, no?
Sure, I was still being paranoid. ;-)
> > Unless there is some *other* overflow issue, and "len" doesn't contain > a terminating NUL character or something like that. >
No, this is kind of like an internal "malloc", where the caller is passing in the length via "len" of what it needs.
-- Steve
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