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/pm2fb.c | 1855 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1855 insertions(+) create mode 100644 drivers/video/fbdev/pm2fb.c (limited to 'drivers/video/fbdev/pm2fb.c') diff --git a/drivers/video/fbdev/pm2fb.c b/drivers/video/fbdev/pm2fb.c new file mode 100644 index 000000000..058075a34 --- /dev/null +++ b/drivers/video/fbdev/pm2fb.c @@ -0,0 +1,1855 @@ +/* + * Permedia2 framebuffer driver. + * + * 2.5/2.6 driver: + * Copyright (c) 2003 Jim Hague (jim.hague@acm.org) + * + * based on 2.4 driver: + * Copyright (c) 1998-2000 Ilario Nardinocchi (nardinoc@CS.UniBO.IT) + * Copyright (c) 1999 Jakub Jelinek (jakub@redhat.com) + * + * and additional input from James Simmon's port of Hannu Mallat's tdfx + * driver. + * + * I have a Creative Graphics Blaster Exxtreme card - pm2fb on x86. I + * have no access to other pm2fb implementations. Sparc (and thus + * hopefully other big-endian) devices now work, thanks to a lot of + * testing work by Ron Murray. I have no access to CVision hardware, + * and therefore for now I am omitting the CVision code. + * + * Multiple boards support has been on the TODO list for ages. + * Don't expect this to change. + * + * 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. + * + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include