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, 20 insertions, 0 deletions

diff --git a/tools/firewire/Makefile b/tools/firewire/Makefile
new file mode 100644
index 000000000..67b6e9fca
--- /dev/null
+++ b/tools/firewire/Makefile
@@ -0,0 +1,20 @@
+# SPDX-License-Identifier: GPL-2.0
+prefix = /usr
+nosy-dump-version = 0.4
+
+CC = gcc
+
+all : nosy-dump
+
+nosy-dump : CFLAGS = -Wall -O2 -g
+nosy-dump : CPPFLAGS = -DVERSION=\"$(nosy-dump-version)\" -I../../drivers/firewire
+nosy-dump : LDFLAGS = -g
+nosy-dump : LDLIBS = -lpopt
+
+nosy-dump : nosy-dump.o decode-fcp.o
+
+clean :
+	rm -rf *.o nosy-dump
+
+install :
+	install nosy-dump $(prefix)/bin/nosy-dump