Messages in this thread | | | Date | Thu, 1 Apr 2021 16:53:04 -0400 | From | Steven Rostedt <> | Subject | Re: [GIT PULL] ftrace: Check if pages were allocated before calling free_pages() |
| |
On Thu, 1 Apr 2021 13:18:59 -0700 Linus Torvalds <torvalds@linux-foundation.org> wrote:
> On Thu, Apr 1, 2021 at 1:07 PM Steven Rostedt <rostedt@goodmis.org> wrote: > > > > On Wed, 31 Mar 2021 11:03:21 -0700 > > Linus Torvalds <torvalds@linux-foundation.org> wrote: > > > > > @@ -6231,7 +6231,8 @@ static int ftrace_process_locs(struct module *mod, > > > if (!addr) > > > continue; > > > > > > - if (pg->index == pg->size) { > > > + end_offset = (pg->index+1) * sizeof(pg->records[0]); > > > + if (end_offset < PAGE_SIZE << pg->order) { > > > > I believe that needs to be: > > > > if (end_offset >= PAGE_SIZE << pg->order) { >
[..]
> which will be > > end_offset = (3+1) * 1024; > > ie 4096. That just means that the struct fill fill things _up_to_ the > end of the page. > > So only when the end_offset is strictly larger than the page would it > have overflowed the allocation.
Ah, I forgot about the "+1" you added to the pg->index, which would make it equivalent to replacing:
if (pg->index + 1 > pg->size) {
Will update and add your SOB.
Thanks,
-- Steve
| |