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/stifb.c | 1531 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1531 insertions(+) create mode 100644 drivers/video/fbdev/stifb.c (limited to 'drivers/video/fbdev/stifb.c') diff --git a/drivers/video/fbdev/stifb.c b/drivers/video/fbdev/stifb.c new file mode 100644 index 000000000..8e5bac275 --- /dev/null +++ b/drivers/video/fbdev/stifb.c @@ -0,0 +1,1531 @@ +/* + * linux/drivers/video/stifb.c - + * Low level Frame buffer driver for HP workstations with + * STI (standard text interface) video firmware. + * + * Copyright (C) 2001-2006 Helge Deller + * Portions Copyright (C) 2001 Thomas Bogendoerfer + * + * Based on: + * - linux/drivers/video/artistfb.c -- Artist frame buffer driver + * Copyright (C) 2000 Philipp Rumpf + * - based on skeletonfb, which was + * Created 28 Dec 1997 by Geert Uytterhoeven + * - HP Xhp cfb-based X11 window driver for XFree86 + * (c)Copyright 1992 Hewlett-Packard Co. + * + * + * The following graphics display devices (NGLE family) are supported by this driver: + * + * HPA4070A known as "HCRX", a 1280x1024 color device with 8 planes + * HPA4071A known as "HCRX24", a 1280x1024 color device with 24 planes, + * optionally available with a hardware accelerator as HPA4071A_Z + * HPA1659A known as "CRX", a 1280x1024 color device with 8 planes + * HPA1439A known as "CRX24", a 1280x1024 color device with 24 planes, + * optionally available with a hardware accelerator. + * HPA1924A known as "GRX", a 1280x1024 grayscale device with 8 planes + * HPA2269A known as "Dual CRX", a 1280x1024 color device with 8 planes, + * implements support for two displays on a single graphics card. + * HP710C internal graphics support optionally available on the HP9000s710 SPU, + * supports 1280x1024 color displays with 8 planes. + * HP710G same as HP710C, 1280x1024 grayscale only + * HP710L same as HP710C, 1024x768 color only + * HP712 internal graphics support on HP9000s712 SPU, supports 640x480, + * 1024x768 or 1280x1024 color displays on 8 planes (Artist) + * + * 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. + */ + +/* TODO: + * - 1bpp mode is completely untested + * - add support for h/w acceleration + * - add hardware cursor + * - automatically disable double buffering (e.g. on RDI precisionbook laptop) + */ + + +/* on supported graphic devices you may: + * #define FALLBACK_TO_1BPP to fall back to 1 bpp, or + * #undef FALLBACK_TO_1BPP to reject support for unsupported cards */ +#undef FALLBACK_TO_1BPP + +#undef DEBUG_STIFB_REGS /* debug sti register accesses */ + + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include /* for HP-UX compatibility */ +#include + +#include