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/sni/eisa.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 arch/mips/sni/eisa.c (limited to 'arch/mips/sni/eisa.c') diff --git a/arch/mips/sni/eisa.c b/arch/mips/sni/eisa.c new file mode 100644 index 000000000..483a43d07 --- /dev/null +++ b/arch/mips/sni/eisa.c @@ -0,0 +1,49 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Virtual EISA root driver. + * Acts as a placeholder if we don't have a proper EISA bridge. + * + * (C) 2003 Marc Zyngier + * modified for SNI usage by Thomas Bogendoerfer + */ + +#include +#include +#include +#include + +/* The default EISA device parent (virtual root device). + * Now use a platform device, since that's the obvious choice. */ + +static struct platform_device eisa_root_dev = { + .name = "eisa", + .id = 0, +}; + +static struct eisa_root_device eisa_bus_root = { + .dev = &eisa_root_dev.dev, + .bus_base_addr = 0, + .res = &ioport_resource, + .slots = EISA_MAX_SLOTS, + .dma_mask = 0xffffffff, + .force_probe = 1, +}; + +int __init sni_eisa_root_init(void) +{ + int r; + + r = platform_device_register(&eisa_root_dev); + if (!r) + return r; + + dev_set_drvdata(&eisa_root_dev.dev, &eisa_bus_root); + + if (eisa_root_register(&eisa_bus_root)) { + /* A real bridge may have been registered before + * us. So quietly unregister. */ + platform_device_unregister(&eisa_root_dev); + return -1; + } + return 0; +} -- cgit v1.3.1