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/clk/meson/parm.h | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 drivers/clk/meson/parm.h (limited to 'drivers/clk/meson/parm.h') diff --git a/drivers/clk/meson/parm.h b/drivers/clk/meson/parm.h new file mode 100644 index 000000000..3c9ef1b50 --- /dev/null +++ b/drivers/clk/meson/parm.h @@ -0,0 +1,46 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (c) 2015 Endless Mobile, Inc. + * Author: Carlo Caione + */ + +#ifndef __MESON_PARM_H +#define __MESON_PARM_H + +#include +#include + +#define PMASK(width) GENMASK(width - 1, 0) +#define SETPMASK(width, shift) GENMASK(shift + width - 1, shift) +#define CLRPMASK(width, shift) (~SETPMASK(width, shift)) + +#define PARM_GET(width, shift, reg) \ + (((reg) & SETPMASK(width, shift)) >> (shift)) +#define PARM_SET(width, shift, reg, val) \ + (((reg) & CLRPMASK(width, shift)) | ((val) << (shift))) + +#define MESON_PARM_APPLICABLE(p) (!!((p)->width)) + +struct parm { + u16 reg_off; + u8 shift; + u8 width; +}; + +static inline unsigned int meson_parm_read(struct regmap *map, struct parm *p) +{ + unsigned int val; + + regmap_read(map, p->reg_off, &val); + return PARM_GET(p->width, p->shift, val); +} + +static inline void meson_parm_write(struct regmap *map, struct parm *p, + unsigned int val) +{ + regmap_update_bits(map, p->reg_off, SETPMASK(p->width, p->shift), + val << p->shift); +} + +#endif /* __MESON_PARM_H */ + -- cgit v1.3.1