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/generic/board-realtek.c | 79 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) create mode 100644 arch/mips/generic/board-realtek.c (limited to 'arch/mips/generic/board-realtek.c') diff --git a/arch/mips/generic/board-realtek.c b/arch/mips/generic/board-realtek.c new file mode 100644 index 000000000..9cce6103d --- /dev/null +++ b/arch/mips/generic/board-realtek.c @@ -0,0 +1,79 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2024 Allied Telesis + */ + +#include +#include +#include +#include + +#include +#include + +static __init int realtek_add_initrd(void *fdt) +{ + int node, err; + u32 start, size; + + node = fdt_path_offset(fdt, "/chosen"); + if (node < 0) { + pr_err("/chosen node not found\n"); + return -ENOENT; + } + + start = fw_getenvl("initrd_start"); + size = fw_getenvl("initrd_size"); + + if (start == 0 && size == 0) + return 0; + + pr_info("Adding initrd info from environment\n"); + + err = fdt_setprop_u32(fdt, node, "linux,initrd-start", start); + if (err) { + pr_err("unable to set initrd-start: %d\n", err); + return err; + } + + err = fdt_setprop_u32(fdt, node, "linux,initrd-end", start + size); + if (err) { + pr_err("unable to set initrd-end: %d\n", err); + return err; + } + + return 0; +} + +static const struct mips_fdt_fixup realtek_fdt_fixups[] __initconst = { + { realtek_add_initrd, "add initrd" }, + {}, +}; + +static __init const void *realtek_fixup_fdt(const void *fdt, const void *match_data) +{ + static unsigned char fdt_buf[16 << 10] __initdata; + int err; + + if (fdt_check_header(fdt)) + panic("Corrupt DT"); + + fw_init_cmdline(); + + err = apply_mips_fdt_fixups(fdt_buf, sizeof(fdt_buf), fdt, realtek_fdt_fixups); + if (err) + panic("Unable to fixup FDT: %d", err); + + return fdt_buf; + +} + +static const struct of_device_id realtek_of_match[] __initconst = { + { .compatible = "realtek,rtl9302-soc" }, + {} +}; + +MIPS_MACHINE(realtek) = { + .matches = realtek_of_match, + .fixup_fdt = realtek_fixup_fdt, +}; -- cgit v1.3.1