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 --- arch/mips/cobalt/mtd.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) create mode 100644 arch/mips/cobalt/mtd.c (limited to 'arch/mips/cobalt/mtd.c') diff --git a/arch/mips/cobalt/mtd.c b/arch/mips/cobalt/mtd.c new file mode 100644 index 000000000..95f579d8c --- /dev/null +++ b/arch/mips/cobalt/mtd.c @@ -0,0 +1,47 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Registration of Cobalt MTD device. + * + * Copyright (C) 2006 Yoichi Yuasa + */ +#include +#include +#include +#include + +static struct mtd_partition cobalt_mtd_partitions[] = { + { + .name = "firmware", + .offset = 0x0, + .size = 0x80000, + }, +}; + +static struct physmap_flash_data cobalt_flash_data = { + .width = 1, + .nr_parts = 1, + .parts = cobalt_mtd_partitions, +}; + +static struct resource cobalt_mtd_resource = { + .start = 0x1fc00000, + .end = 0x1fc7ffff, + .flags = IORESOURCE_MEM, +}; + +static struct platform_device cobalt_mtd = { + .name = "physmap-flash", + .dev = { + .platform_data = &cobalt_flash_data, + }, + .num_resources = 1, + .resource = &cobalt_mtd_resource, +}; + +static int __init cobalt_mtd_init(void) +{ + platform_device_register(&cobalt_mtd); + + return 0; +} +device_initcall(cobalt_mtd_init); -- cgit v1.3.1