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/bamboo.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 arch/powerpc/boot/bamboo.c (limited to 'arch/powerpc/boot/bamboo.c') diff --git a/arch/powerpc/boot/bamboo.c b/arch/powerpc/boot/bamboo.c new file mode 100644 index 000000000..dcdfa586a --- /dev/null +++ b/arch/powerpc/boot/bamboo.c @@ -0,0 +1,45 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright IBM Corporation, 2007 + * Josh Boyer + * + * Based on ebony wrapper: + * Copyright 2007 David Gibson, IBM Corporation. + * + * Clocking code based on code by: + * Stefan Roese + */ +#include +#include +#include "types.h" +#include "elf.h" +#include "string.h" +#include "stdio.h" +#include "page.h" +#include "ops.h" +#include "dcr.h" +#include "4xx.h" +#include "44x.h" + +static u8 *bamboo_mac0, *bamboo_mac1; + +static void bamboo_fixups(void) +{ + unsigned long sysclk = 33333333; + + ibm440ep_fixup_clocks(sysclk, 11059200, 25000000); + ibm4xx_sdram_fixup_memsize(); + ibm4xx_quiesce_eth((u32 *)0xef600e00, (u32 *)0xef600f00); + dt_fixup_mac_address_by_alias("ethernet0", bamboo_mac0); + dt_fixup_mac_address_by_alias("ethernet1", bamboo_mac1); +} + +void bamboo_init(void *mac0, void *mac1) +{ + platform_ops.fixups = bamboo_fixups; + platform_ops.exit = ibm44x_dbcr_reset; + bamboo_mac0 = mac0; + bamboo_mac1 = mac1; + fdt_init(_dtb_start); + serial_console_init(); +} -- cgit v1.3.1