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/microblaze/lib/libgcc.h | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 arch/microblaze/lib/libgcc.h (limited to 'arch/microblaze/lib/libgcc.h') diff --git a/arch/microblaze/lib/libgcc.h b/arch/microblaze/lib/libgcc.h new file mode 100644 index 000000000..a909366c2 --- /dev/null +++ b/arch/microblaze/lib/libgcc.h @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_LIBGCC_H +#define __ASM_LIBGCC_H + +#include + +typedef int word_type __attribute__ ((mode (__word__))); + +#ifdef __BIG_ENDIAN +struct DWstruct { + int high, low; +}; +#elif defined(__LITTLE_ENDIAN) +struct DWstruct { + int low, high; +}; +#else +#error I feel sick. +#endif + +typedef union { + struct DWstruct s; + long long ll; +} DWunion; + +extern long long __ashldi3(long long u, word_type b); +extern long long __ashrdi3(long long u, word_type b); +extern word_type __cmpdi2(long long a, long long b); +extern long long __lshrdi3(long long u, word_type b); +extern long long __muldi3(long long u, long long v); +extern word_type __ucmpdi2(unsigned long long a, unsigned long long b); + +#endif /* __ASM_LIBGCC_H */ -- cgit v1.3.1