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/powerpc/boot/redboot-8xx.c | 55 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) create mode 100644 arch/powerpc/boot/redboot-8xx.c (limited to 'arch/powerpc/boot/redboot-8xx.c') diff --git a/arch/powerpc/boot/redboot-8xx.c b/arch/powerpc/boot/redboot-8xx.c new file mode 100644 index 000000000..d7006eeaf --- /dev/null +++ b/arch/powerpc/boot/redboot-8xx.c @@ -0,0 +1,55 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * RedBoot firmware support + * + * Author: Scott Wood + * + * Copyright (c) 2007 Freescale Semiconductor, Inc. + */ + +#include "ops.h" +#include "stdio.h" +#include "redboot.h" +#include "fsl-soc.h" +#include "io.h" + +static bd_t bd; +BSS_STACK(4096); + +#define MHZ(x) ((x + 500000) / 1000000) + +static void platform_fixups(void) +{ + void *node; + + dt_fixup_memory(bd.bi_memstart, bd.bi_memsize); + dt_fixup_mac_addresses(bd.bi_enetaddr); + dt_fixup_cpu_clocks(bd.bi_intfreq, bd.bi_busfreq / 16, bd.bi_busfreq); + + node = finddevice("/soc/cpm/brg"); + if (node) { + printf("BRG clock-frequency <- 0x%x (%dMHz)\r\n", + bd.bi_busfreq, MHZ(bd.bi_busfreq)); + setprop(node, "clock-frequency", &bd.bi_busfreq, 4); + } +} + +void platform_init(unsigned long r3, unsigned long r4, unsigned long r5, + unsigned long r6, unsigned long r7) +{ + memcpy(&bd, (char *)r3, sizeof(bd)); + + if (bd.bi_tag != 0x42444944) + return; + + simple_alloc_init(_end, + bd.bi_memstart + bd.bi_memsize - (unsigned long)_end, + 32, 64); + + fdt_init(_dtb_start); + serial_console_init(); + platform_ops.fixups = platform_fixups; + + loader_info.cmdline = (char *)bd.bi_cmdline; + loader_info.cmdline_len = strlen((char *)bd.bi_cmdline); +} -- cgit v1.3.1