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| author | Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2026-09-04 10:43:19 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-09-04 07:58:36 -0700 |
| commit | 6668ed271eaefaa63e686bdfbedaeb7b8e492722 (patch) | |
| tree | 58e8288fead484f6755ad0815fc74c3742663761 /arch/arm/mm/proc-syms.c | |
| download | linux-stable-6668ed271eaefaa63e686bdfbedaeb7b8e492722.tar.gz linux-stable-6668ed271eaefaa63e686bdfbedaeb7b8e492722.zip | |
selftests/bpf: Reject graph kptr use after RCU unlockgrafted
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 <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'arch/arm/mm/proc-syms.c')
| -rw-r--r-- | arch/arm/mm/proc-syms.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/arch/arm/mm/proc-syms.c b/arch/arm/mm/proc-syms.c new file mode 100644 index 000000000..e21249548 --- /dev/null +++ b/arch/arm/mm/proc-syms.c @@ -0,0 +1,50 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/arch/arm/mm/proc-syms.c + * + * Copyright (C) 2000-2002 Russell King + */ +#include <linux/module.h> +#include <linux/mm.h> + +#include <asm/cacheflush.h> +#include <asm/proc-fns.h> +#include <asm/tlbflush.h> +#include <asm/page.h> + +#ifndef MULTI_CPU +EXPORT_SYMBOL(cpu_dcache_clean_area); +#ifdef CONFIG_MMU +EXPORT_SYMBOL(cpu_set_pte_ext); +#endif +#else +EXPORT_SYMBOL(processor); +#endif + +#ifndef MULTI_CACHE +EXPORT_SYMBOL(__cpuc_flush_kern_all); +EXPORT_SYMBOL(__cpuc_flush_user_all); +EXPORT_SYMBOL(__cpuc_flush_user_range); +EXPORT_SYMBOL(__cpuc_coherent_kern_range); +EXPORT_SYMBOL(__cpuc_flush_dcache_area); +#else +EXPORT_SYMBOL(cpu_cache); +#endif + +#ifdef CONFIG_MMU +#ifndef MULTI_USER +EXPORT_SYMBOL(__cpu_clear_user_highpage); +EXPORT_SYMBOL(__cpu_copy_user_highpage); +#else +EXPORT_SYMBOL(cpu_user); +#endif +#endif + +/* + * No module should need to touch the TLB (and currently + * no modules do. We export this for "loadkernel" support + * (booting a new kernel from within a running kernel.) + */ +#ifdef MULTI_TLB +EXPORT_SYMBOL(cpu_tlb); +#endif |