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/ralink/prom.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 arch/mips/ralink/prom.c (limited to 'arch/mips/ralink/prom.c') diff --git a/arch/mips/ralink/prom.c b/arch/mips/ralink/prom.c new file mode 100644 index 000000000..c3b968618 --- /dev/null +++ b/arch/mips/ralink/prom.c @@ -0,0 +1,65 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * + * Copyright (C) 2009 Gabor Juhos + * Copyright (C) 2010 Joonas Lahtinen + * Copyright (C) 2013 John Crispin + */ + +#include + +#include +#include + +#include + +#include "common.h" + +struct ralink_soc_info soc_info; + +enum ralink_soc_type ralink_soc; +EXPORT_SYMBOL_GPL(ralink_soc); + +const char *get_system_type(void) +{ + return soc_info.sys_type; +} + +static __init void prom_init_cmdline(void) +{ + int argc; + char **argv; + int i; + + pr_debug("prom: fw_arg0=%08x fw_arg1=%08x fw_arg2=%08x fw_arg3=%08x\n", + (unsigned int)fw_arg0, (unsigned int)fw_arg1, + (unsigned int)fw_arg2, (unsigned int)fw_arg3); + + argc = fw_arg0; + argv = (char **) KSEG1ADDR(fw_arg1); + + if (!argv) { + pr_debug("argv=%p is invalid, skipping\n", + argv); + return; + } + + for (i = 0; i < argc; i++) { + char *p = (char *) KSEG1ADDR(argv[i]); + + if (CPHYSADDR(p) && *p) { + pr_debug("argv[%d]: %s\n", i, p); + strlcat(arcs_cmdline, " ", sizeof(arcs_cmdline)); + strlcat(arcs_cmdline, p, sizeof(arcs_cmdline)); + } + } +} + +void __init prom_init(void) +{ + prom_soc_init(&soc_info); + + pr_info("SoC Type: %s\n", get_system_type()); + + prom_init_cmdline(); +} -- cgit v1.3.1