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/rt3883.c | 110 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 110 insertions(+) create mode 100644 arch/mips/ralink/rt3883.c (limited to 'arch/mips/ralink/rt3883.c') diff --git a/arch/mips/ralink/rt3883.c b/arch/mips/ralink/rt3883.c new file mode 100644 index 000000000..98aee412f --- /dev/null +++ b/arch/mips/ralink/rt3883.c @@ -0,0 +1,110 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * + * Parts of this file are based on Ralink's 2.6.21 BSP + * + * Copyright (C) 2008 Imre Kaloz + * Copyright (C) 2008-2011 Gabor Juhos + * Copyright (C) 2013 John Crispin + */ + +#include +#include +#include +#include + +#include +#include +#include + +#include "common.h" + +static struct ralink_soc_info *soc_info_ptr; + +static unsigned int __init rt3883_get_soc_name0(void) +{ + return __raw_readl(RT3883_SYSC_BASE + RT3883_SYSC_REG_CHIPID0_3); +} + +static unsigned int __init rt3883_get_soc_name1(void) +{ + return __raw_readl(RT3883_SYSC_BASE + RT3883_SYSC_REG_CHIPID4_7); +} + +static bool __init rt3883_soc_valid(void) +{ + if (rt3883_get_soc_name0() == RT3883_CHIP_NAME0 && + rt3883_get_soc_name1() == RT3883_CHIP_NAME1) + return true; + else + return false; +} + +static const char __init *rt3883_get_soc_name(void) +{ + if (rt3883_soc_valid()) + return "RT3883"; + else + return "invalid"; +} + +static unsigned int __init rt3883_get_soc_id(void) +{ + return __raw_readl(RT3883_SYSC_BASE + RT3883_SYSC_REG_REVID); +} + +static unsigned int __init rt3883_get_soc_ver(void) +{ + return (rt3883_get_soc_id() >> RT3883_REVID_VER_ID_SHIFT) & RT3883_REVID_VER_ID_MASK; +} + +static unsigned int __init rt3883_get_soc_rev(void) +{ + return (rt3883_get_soc_id() & RT3883_REVID_ECO_ID_MASK); +} + +static int __init rt3883_soc_dev_init(void) +{ + struct soc_device *soc_dev; + struct soc_device_attribute *soc_dev_attr; + + soc_dev_attr = kzalloc_obj(*soc_dev_attr); + if (!soc_dev_attr) + return -ENOMEM; + + soc_dev_attr->family = "Ralink"; + soc_dev_attr->soc_id = rt3883_get_soc_name(); + + soc_dev_attr->data = soc_info_ptr; + + soc_dev = soc_device_register(soc_dev_attr); + if (IS_ERR(soc_dev)) { + kfree(soc_dev_attr); + return PTR_ERR(soc_dev); + } + + return 0; +} +device_initcall(rt3883_soc_dev_init); + +void __init prom_soc_init(struct ralink_soc_info *soc_info) +{ + if (rt3883_soc_valid()) + soc_info->compatible = "ralink,rt3883-soc"; + else + panic("rt3883: unknown SoC, n0:%08x n1:%08x", + rt3883_get_soc_name0(), rt3883_get_soc_name1()); + + snprintf(soc_info->sys_type, RAMIPS_SYS_TYPE_LEN, + "Ralink %s ver:%u eco:%u", + rt3883_get_soc_name(), + rt3883_get_soc_ver(), + rt3883_get_soc_rev()); + + soc_info->mem_base = RT3883_SDRAM_BASE; + soc_info->mem_size_min = RT3883_MEM_SIZE_MIN; + soc_info->mem_size_max = RT3883_MEM_SIZE_MAX; + + ralink_soc = RT3883_SOC; + soc_info_ptr = soc_info; +} -- cgit v1.3.1