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 --- tools/arch/arc/include/uapi/asm/mman.h | 7 +++++ tools/arch/arc/include/uapi/asm/unistd.h | 51 ++++++++++++++++++++++++++++++++ 2 files changed, 58 insertions(+) create mode 100644 tools/arch/arc/include/uapi/asm/mman.h create mode 100644 tools/arch/arc/include/uapi/asm/unistd.h (limited to 'tools/arch/arc/include') diff --git a/tools/arch/arc/include/uapi/asm/mman.h b/tools/arch/arc/include/uapi/asm/mman.h new file mode 100644 index 000000000..81f0f9bf0 --- /dev/null +++ b/tools/arch/arc/include/uapi/asm/mman.h @@ -0,0 +1,7 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef TOOLS_ARCH_ARC_UAPI_ASM_MMAN_FIX_H +#define TOOLS_ARCH_ARC_UAPI_ASM_MMAN_FIX_H +#include +/* MAP_32BIT is undefined on arc, fix it for perf */ +#define MAP_32BIT 0 +#endif diff --git a/tools/arch/arc/include/uapi/asm/unistd.h b/tools/arch/arc/include/uapi/asm/unistd.h new file mode 100644 index 000000000..5eafa1115 --- /dev/null +++ b/tools/arch/arc/include/uapi/asm/unistd.h @@ -0,0 +1,51 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +/* + * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +/******** no-legacy-syscalls-ABI *******/ + +/* + * Non-typical guard macro to enable inclusion twice in ARCH sys.c + * That is how the Generic syscall wrapper generator works + */ +#if !defined(_UAPI_ASM_ARC_UNISTD_H) || defined(__SYSCALL) +#define _UAPI_ASM_ARC_UNISTD_H + +#define __ARCH_WANT_RENAMEAT +#define __ARCH_WANT_STAT64 +#define __ARCH_WANT_SET_GET_RLIMIT +#define __ARCH_WANT_SYS_EXECVE +#define __ARCH_WANT_SYS_CLONE +#define __ARCH_WANT_SYS_VFORK +#define __ARCH_WANT_SYS_FORK +#define __ARCH_WANT_TIME32_SYSCALLS + +#define sys_mmap2 sys_mmap_pgoff + +#include + +#define NR_syscalls __NR_syscalls + +/* Generic syscall (fs/filesystems.c - lost in asm-generic/unistd.h */ +#define __NR_sysfs (__NR_arch_specific_syscall + 3) + +/* ARC specific syscall */ +#define __NR_cacheflush (__NR_arch_specific_syscall + 0) +#define __NR_arc_settls (__NR_arch_specific_syscall + 1) +#define __NR_arc_gettls (__NR_arch_specific_syscall + 2) +#define __NR_arc_usr_cmpxchg (__NR_arch_specific_syscall + 4) + +__SYSCALL(__NR_cacheflush, sys_cacheflush) +__SYSCALL(__NR_arc_settls, sys_arc_settls) +__SYSCALL(__NR_arc_gettls, sys_arc_gettls) +__SYSCALL(__NR_arc_usr_cmpxchg, sys_arc_usr_cmpxchg) +__SYSCALL(__NR_sysfs, sys_sysfs) + +#undef __SYSCALL + +#endif -- cgit v1.3.1