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| author | Nuoqi Gui <gnq25@mails.tsinghua.edu.cn> | 2026-09-04 12:41:55 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-09-04 12:24:25 -0700 |
| commit | 2b97956af60810cd382b86b9ce9aea421b889861 (patch) | |
| tree | 7d9b0d8a91f77e63deff23976f68555a4895346a /tools/arch/sh/include | |
| download | linux-stable-2b97956af60810cd382b86b9ce9aea421b889861.tar.gz linux-stable-2b97956af60810cd382b86b9ce9aea421b889861.zip | |
selftests/bpf: Test rhtab kptr cancellation semanticsgrafted
Resizable hash-map updates and deletions must not perform full special-field
destruction in their caller context. In particular, a referenced kptr must
remain attached to the allocation until the memory allocator destructor can
release it safely.
Add separate coverage for both affected paths. The update test stores a task
kptr, replaces the ordinary value bytes with BPF_EXIST, and verifies that the
kptr survived. The delete test removes an element and exchanges its kptr
through the still-valid map-value pointer before the allocation is reclaimed.
Both cases observe a NULL kptr when rhtab uses bpf_obj_free_fields(). They
recover and release the reference after rhtab switches to cancellation
semantics.
Signed-off-by: Nuoqi Gui <gnq25@mails.tsinghua.edu.cn>
[ kkd: Split update and delete coverage and rewrote the commit log ]
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904104203.345917-5-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/arch/sh/include')
| -rw-r--r-- | tools/arch/sh/include/asm/barrier.h | 33 | ||||
| -rw-r--r-- | tools/arch/sh/include/uapi/asm/mman.h | 7 |
2 files changed, 40 insertions, 0 deletions
diff --git a/tools/arch/sh/include/asm/barrier.h b/tools/arch/sh/include/asm/barrier.h new file mode 100644 index 000000000..7eaea27cd --- /dev/null +++ b/tools/arch/sh/include/asm/barrier.h @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copied from the kernel sources: + * + * Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima + * Copyright (C) 2002 Paul Mundt + */ +#ifndef __TOOLS_LINUX_ASM_SH_BARRIER_H +#define __TOOLS_LINUX_ASM_SH_BARRIER_H + +/* + * A brief note on ctrl_barrier(), the control register write barrier. + * + * Legacy SH cores typically require a sequence of 8 nops after + * modification of a control register in order for the changes to take + * effect. On newer cores (like the sh4a and sh5) this is accomplished + * with icbi. + * + * Also note that on sh4a in the icbi case we can forego a synco for the + * write barrier, as it's not necessary for control registers. + * + * Historically we have only done this type of barrier for the MMUCR, but + * it's also necessary for the CCR, so we make it generic here instead. + */ +#if defined(__SH4A__) +#define mb() __asm__ __volatile__ ("synco": : :"memory") +#define rmb() mb() +#define wmb() mb() +#endif + +#include <asm-generic/barrier.h> + +#endif /* __TOOLS_LINUX_ASM_SH_BARRIER_H */ diff --git a/tools/arch/sh/include/uapi/asm/mman.h b/tools/arch/sh/include/uapi/asm/mman.h new file mode 100644 index 000000000..88c0e2930 --- /dev/null +++ b/tools/arch/sh/include/uapi/asm/mman.h @@ -0,0 +1,7 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef TOOLS_ARCH_SH_UAPI_ASM_MMAN_FIX_H +#define TOOLS_ARCH_SH_UAPI_ASM_MMAN_FIX_H +#include <uapi/asm-generic/mman.h> +/* MAP_32BIT is undefined on sh, fix it for perf */ +#define MAP_32BIT 0 +#endif |