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/arm/mach-davinci/common.c | 100 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 100 insertions(+) create mode 100644 arch/arm/mach-davinci/common.c (limited to 'arch/arm/mach-davinci/common.c') diff --git a/arch/arm/mach-davinci/common.c b/arch/arm/mach-davinci/common.c new file mode 100644 index 000000000..7bc701868 --- /dev/null +++ b/arch/arm/mach-davinci/common.c @@ -0,0 +1,100 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Code commons to all DaVinci SoCs. + * + * Author: Mark A. Greer + * + * 2009 (c) MontaVista Software, Inc. + */ +#include +#include +#include +#include +#include +#include + +#include +#include + +#include "common.h" +#include "cputype.h" + +struct davinci_soc_info davinci_soc_info; +EXPORT_SYMBOL(davinci_soc_info); + +static int __init davinci_init_id(struct davinci_soc_info *soc_info) +{ + int i; + struct davinci_id *dip; + u8 variant; + u16 part_no; + void __iomem *base; + + base = ioremap(soc_info->jtag_id_reg, SZ_4K); + if (!base) { + pr_err("Unable to map JTAG ID register\n"); + return -ENOMEM; + } + + soc_info->jtag_id = __raw_readl(base); + iounmap(base); + + variant = (soc_info->jtag_id & 0xf0000000) >> 28; + part_no = (soc_info->jtag_id & 0x0ffff000) >> 12; + + for (i = 0, dip = soc_info->ids; i < soc_info->ids_num; + i++, dip++) + /* Don't care about the manufacturer right now */ + if ((dip->part_no == part_no) && (dip->variant == variant)) { + soc_info->cpu_id = dip->cpu_id; + pr_info("DaVinci %s variant 0x%x\n", dip->name, + dip->variant); + return 0; + } + + pr_err("Unknown DaVinci JTAG ID 0x%x\n", soc_info->jtag_id); + return -EINVAL; +} + +void __init davinci_common_init(const struct davinci_soc_info *soc_info) +{ + int ret; + + if (!soc_info) { + ret = -EINVAL; + goto err; + } + + memcpy(&davinci_soc_info, soc_info, sizeof(struct davinci_soc_info)); + + if (davinci_soc_info.io_desc && (davinci_soc_info.io_desc_num > 0)) + iotable_init(davinci_soc_info.io_desc, + davinci_soc_info.io_desc_num); + + /* + * Normally devicemaps_init() would flush caches and tlb after + * mdesc->map_io(), but we must also do it here because of the CPU + * revision check below. + */ + local_flush_tlb_all(); + flush_cache_all(); + + /* + * We want to check CPU revision early for cpu_is_xxxx() macros. + * IO space mapping must be initialized before we can do that. + */ + ret = davinci_init_id(&davinci_soc_info); + if (ret < 0) + goto err; + + + return; + +err: + panic("davinci_common_init: SoC Initialization failed\n"); +} + +void __init davinci_init_late(void) +{ + davinci_cpufreq_init(); +} -- cgit v1.3.1