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, 31 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/Kconfig b/arch/powerpc/sysdev/Kconfig
new file mode 100644
index 000000000..18ff2c4a8
--- /dev/null
+++ b/arch/powerpc/sysdev/Kconfig
@@ -0,0 +1,31 @@
+# SPDX-License-Identifier: GPL-2.0
+# For a description of the syntax of this configuration file,
+# see Documentation/kbuild/kconfig-language.rst.
+#
+
+config PPC4xx_PCI_EXPRESS
+	bool
+	depends on PCI && 44x
+
+config PPC4xx_HSTA_MSI
+	bool
+	depends on PCI_MSI
+	depends on PCI && 44x
+
+config PPC_MSI_BITMAP
+	bool
+	depends on PCI_MSI
+	default y if MPIC
+	default y if FSL_PCI
+	default y if PPC_POWERNV
+
+source "arch/powerpc/sysdev/xics/Kconfig"
+source "arch/powerpc/sysdev/xive/Kconfig"
+
+config GE_FPGA
+	bool
+
+config FSL_CORENET_RCPM
+	bool
+	help
+	  This option enables support for RCPM (Run Control/Power Management).