From 2b97956af60810cd382b86b9ce9aea421b889861 Mon Sep 17 00:00:00 2001 From: Nuoqi Gui Date: Fri, 4 Sep 2026 12:41:55 +0200 Subject: selftests/bpf: Test rhtab kptr cancellation semantics 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 [ kkd: Split update and delete coverage and rewrote the commit log ] Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904104203.345917-5-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- drivers/base/hypervisor.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 drivers/base/hypervisor.c (limited to 'drivers/base/hypervisor.c') diff --git a/drivers/base/hypervisor.c b/drivers/base/hypervisor.c new file mode 100644 index 000000000..1ce59b4b5 --- /dev/null +++ b/drivers/base/hypervisor.c @@ -0,0 +1,24 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * hypervisor.c - /sys/hypervisor subsystem. + * + * Copyright (C) IBM Corp. 2006 + * Copyright (C) 2007 Greg Kroah-Hartman + * Copyright (C) 2007 Novell Inc. + */ + +#include +#include +#include +#include "base.h" + +struct kobject *hypervisor_kobj; +EXPORT_SYMBOL_GPL(hypervisor_kobj); + +int __init hypervisor_init(void) +{ + hypervisor_kobj = kobject_create_and_add("hypervisor", NULL); + if (!hypervisor_kobj) + return -ENOMEM; + return 0; +} -- cgit v1.3.1