From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- drivers/video/fbdev/metronomefb.c | 728 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 728 insertions(+) create mode 100644 drivers/video/fbdev/metronomefb.c (limited to 'drivers/video/fbdev/metronomefb.c') diff --git a/drivers/video/fbdev/metronomefb.c b/drivers/video/fbdev/metronomefb.c new file mode 100644 index 000000000..83c614963 --- /dev/null +++ b/drivers/video/fbdev/metronomefb.c @@ -0,0 +1,728 @@ +/* + * linux/drivers/video/metronomefb.c -- FB driver for Metronome controller + * + * Copyright (C) 2008, Jaya Kumar + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of this archive for + * more details. + * + * Layout is based on skeletonfb.c by James Simmons and Geert Uytterhoeven. + * + * This work was made possible by help and equipment support from E-Ink + * Corporation. https://www.eink.com/ + * + * This driver is written to be used with the Metronome display controller. + * It is intended to be architecture independent. A board specific driver + * must be used to perform all the physical IO interactions. An example + * is provided as am200epd.c + * + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include