bpf: mark a NULL kfunc argument precisegrafted

check_kfunc_arg() allows bpf_register_is_null() for nullable arguments
w/o marking the underlying scalar register precise. Hence a checkpoint
created on such a path would prune against arbitrary scalar value.

Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 23 insertions, 0 deletions

diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug
new file mode 100644
index 000000000..265c44610
--- /dev/null
+++ b/arch/arm64/Kconfig.debug
@@ -0,0 +1,23 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+config PID_IN_CONTEXTIDR
+	bool "Write the current PID to the CONTEXTIDR register"
+	help
+	  Enabling this option causes the kernel to write the current PID to
+	  the CONTEXTIDR register, at the expense of some additional
+	  instructions during context switch. Say Y here only if you are
+	  planning to use hardware trace tools with this kernel.
+
+config DEBUG_EFI
+	depends on EFI && DEBUG_INFO
+	bool "UEFI debugging"
+	help
+	  Enable this option to include EFI specific debugging features into
+	  the kernel that are only useful when using a debug build of the
+	  UEFI firmware
+
+config ARM64_RELOC_TEST
+	depends on m
+	tristate "Relocation testing module"
+
+source "drivers/hwtracing/coresight/Kconfig"