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>

1 files changed, 22 insertions, 0 deletions

diff --git a/drivers/cdx/controller/Kconfig b/drivers/cdx/controller/Kconfig
new file mode 100644
index 000000000..a480b62cb
--- /dev/null
+++ b/drivers/cdx/controller/Kconfig
@@ -0,0 +1,22 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# CDX controller configuration
+#
+# Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
+#
+
+if CDX_BUS
+
+config CDX_CONTROLLER
+	tristate "CDX bus controller"
+	depends on HAS_DMA
+	select REMOTEPROC
+	select RPMSG
+	help
+	  CDX controller drives the CDX bus. It interacts with
+	  firmware to get the hardware devices and registers with
+	  the CDX bus. Say Y to enable the CDX hardware driver.
+
+	  If unsure, say N.
+
+endif