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/m68k/mm/init.c | 118 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 118 insertions(+) create mode 100644 arch/m68k/mm/init.c (limited to 'arch/m68k/mm/init.c') diff --git a/arch/m68k/mm/init.c b/arch/m68k/mm/init.c new file mode 100644 index 000000000..3b88c0dd1 --- /dev/null +++ b/arch/m68k/mm/init.c @@ -0,0 +1,118 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/arch/m68k/mm/init.c + * + * Copyright (C) 1995 Hamish Macdonald + * + * Contains common initialization routines, specific init code moved + * to motorola.c and sun3mmu.c + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#ifdef CONFIG_ATARI +#include +#endif +#include +#include + +void __init arch_zone_limits_init(unsigned long *max_zone_pfns) +{ + max_zone_pfns[ZONE_DMA] = PFN_DOWN(memblock_end_of_DRAM()); +} + +#ifdef CONFIG_MMU + +int m68k_virt_to_node_shift; + +void __init m68k_setup_node(int node) +{ + node_set_online(node); +} + +#else /* CONFIG_MMU */ + +/* + * paging_init() continues the virtual memory environment setup which + * was begun by the code in arch/head.S. + * The parameters are pointers to where to stick the starting and ending + * addresses of available kernel virtual memory. + */ +void __init paging_init(void) +{ + /* + * Make sure start_mem is page aligned, otherwise bootmem and + * page_alloc get different views of the world. + */ + unsigned long end_mem = memory_end & PAGE_MASK; + + high_memory = (void *) end_mem; +} + +#endif /* CONFIG_MMU */ + +void free_initmem(void) +{ +#ifndef CONFIG_MMU_SUN3 + free_initmem_default(-1); +#endif /* CONFIG_MMU_SUN3 */ +} + +#if defined(CONFIG_MMU) && !defined(CONFIG_COLDFIRE) +#define VECTORS &vectors[0] +#else +#define VECTORS _ramvec +#endif + +static inline void init_pointer_tables(void) +{ +#if defined(CONFIG_MMU) && !defined(CONFIG_SUN3) && !defined(CONFIG_COLDFIRE) + int i, j; + + /* insert pointer tables allocated so far into the tablelist */ + init_pointer_table(kernel_pg_dir, TABLE_PGD); + for (i = 0; i < PTRS_PER_PGD; i++) { + pud_t *pud = (pud_t *)&kernel_pg_dir[i]; + pmd_t *pmd_dir; + + if (!pud_present(*pud)) + continue; + + pmd_dir = (pmd_t *)pgd_page_vaddr(kernel_pg_dir[i]); + init_pointer_table(pmd_dir, TABLE_PMD); + + for (j = 0; j < PTRS_PER_PMD; j++) { + pmd_t *pmd = &pmd_dir[j]; + pte_t *pte_dir; + + if (!pmd_present(*pmd)) + continue; + + pte_dir = (pte_t *)pmd_page_vaddr(*pmd); + init_pointer_table(pte_dir, TABLE_PTE); + } + } +#endif +} + +void __init mem_init(void) +{ + init_pointer_tables(); +} -- cgit v1.3.1