On Wed, 2019-02-13 at 13:03 +0000, Rantala, Tommi T. (Nokia - FI/Espoo) wrote: > On Mon, 2019-02-11 at 15:19 +0100, Greg Kroah-Hartman wrote: > > 4.14-stable review patch. If anyone has any objections, please let > > me know. > > > > ------------------ > > > > From: Mark Rutland <mark.rutl...@arm.com> > > > > commit 9dff0aa95a324e262ffb03f425d00e4751f3294e upstream. > > > > The perf tool uses /proc/sys/kernel/perf_event_mlock_kb to > > determine > > how > > large its ringbuffer mmap should be. This can be configured to > > arbitrary > > values, which can be larger than the maximum possible allocation > > from > > kmalloc. > > > > When this is configured to a suitably large value (e.g. thanks to > > the > > perf fuzzer), attempting to use perf record triggers a > > WARN_ON_ONCE() > > in > > __alloc_pages_nodemask(): > > > > WARNING: CPU: 2 PID: 5666 at mm/page_alloc.c:4511 > > __alloc_pages_nodemask+0x3f8/0xbc8 > > > > Let's avoid this by checking that the requested allocation is > > possible > > before calling kzalloc. > > Hi, > > Perf tool is broken for me in 4.14.99 (running in x86_64 VM), > bisection > points to this patch.
... and I see there's a fix available: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?id=528871b456026e6127d95b1b2bd8e3a003dc1614 -Tommi > > > > Reported-by: Julien Thierry <julien.thie...@arm.com> > > Signed-off-by: Mark Rutland <mark.rutl...@arm.com> > > Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> > > Reviewed-by: Julien Thierry <julien.thie...@arm.com> > > Cc: Alexander Shishkin <alexander.shish...@linux.intel.com> > > Cc: Arnaldo Carvalho de Melo <a...@redhat.com> > > Cc: Jiri Olsa <jo...@redhat.com> > > Cc: Linus Torvalds <torva...@linux-foundation.org> > > Cc: Namhyung Kim <namhy...@kernel.org> > > Cc: Peter Zijlstra <pet...@infradead.org> > > Cc: Thomas Gleixner <t...@linutronix.de> > > Cc: <sta...@vger.kernel.org> > > Link: > > https://lkml.kernel.org/r/20190110142745.25495-1-mark.rutl...@arm.com > > Signed-off-by: Ingo Molnar <mi...@kernel.org> > > Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> > > > > --- > > kernel/events/ring_buffer.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > --- a/kernel/events/ring_buffer.c > > +++ b/kernel/events/ring_buffer.c > > @@ -719,6 +719,9 @@ struct ring_buffer *rb_alloc(int nr_page > > size = sizeof(struct ring_buffer); > > size += nr_pages * sizeof(void *); > > > > + if (order_base_2(size) >= MAX_ORDER) > > + goto fail; > > + > > rb = kzalloc(size, GFP_KERNEL); > > if (!rb) > > goto fail; > > > >
