objtool: Validate disassembler headers in libopcodes probegrafted

commit 3f2de814c059 ("objtool: Fix libopcodes linking with static libraries")
tested for libopcodes availability by linking a test snippet with a forward
declaration of disassemble_init_for_target().

However, testing symbol linkage with an extern declaration only verifies
the presence of the library (.so/.a) and bypasses checking for development
headers (binutils-dev). On systems where libopcodes is present without
development headers installed, the probe succeeds, enabling BUILD_DISAS.
Subsequent compilation of objtool then fails:

  fatal error: 'bfd.h' file not found
    113 | #include <bfd.h>

Additionally, the probe invokes $(HOSTCC) without $(HOSTCFLAGS), ignoring
any sysroot or include flags specified for the host compiler.

Fix this by including <bfd.h> and <dis-asm.h> directly in the test snippet,
passing $(HOSTCFLAGS) so host compiler options are respected, and defining
PACKAGE="objtool" to satisfy the configuration check in <bfd.h>.

Fixes: 3f2de814c059 ("objtool: Fix libopcodes linking with static libraries")
Fixes: 436326bc525d ("objtool: fix build failure due to missing libopcodes check")
Reported-by: Alice Ryhl <aliceryhl@google.com>
Assisted-by: Antigravity:Gemini-Next
Signed-off-by: Ulises Mendez Martinez <umendez@google.com>
Link: https://patch.msgid.link/20260904150710.2997558-1-umendez@google.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

1 files changed, 78 insertions, 0 deletions

diff --git a/drivers/thunderbolt/Kconfig b/drivers/thunderbolt/Kconfig
new file mode 100644
index 000000000..294b3227a
--- /dev/null
+++ b/drivers/thunderbolt/Kconfig
@@ -0,0 +1,78 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menuconfig USB4
+	tristate "Unified support for USB4 and Thunderbolt"
+	depends on PCI
+	select APPLE_PROPERTIES if EFI_STUB && X86
+	select CRC32
+	select CRYPTO_LIB_SHA256
+	select CRYPTO_LIB_UTILS
+	select NVMEM
+	help
+	  USB4 and Thunderbolt driver. USB4 is the public specification
+	  based on the Thunderbolt 3 protocol. This driver is required if
+	  you want to hotplug Thunderbolt and USB4 compliant devices on
+	  Apple hardware or on PCs with Intel Falcon Ridge or newer.
+
+	  To compile this driver a module, choose M here. The module will be
+	  called thunderbolt.
+
+if USB4
+
+config USB4_CONFIGFS
+	def_tristate USB4
+	depends on CONFIGFS_FS && !(USB4=y && CONFIGFS_FS=m)
+
+config USB4_DEBUGFS_WRITE
+	bool "Enable write by debugfs to configuration spaces (DANGEROUS)"
+	help
+	  Enables writing to device configuration registers through
+	  debugfs interface. You can use tools such as Thunderbolt/USB4
+	  debugging tools to access these registers. For more
+	  information see:
+
+	    https://github.com/intel/tbtools
+
+	  Only enable this if you know what you are doing! Never enable
+	  this for production systems or distro kernels.
+
+config USB4_DEBUGFS_MARGINING
+	bool "Expose receiver lane margining operations under USB4 ports and retimers (DANGEROUS)"
+	depends on DEBUG_FS
+	depends on USB4_DEBUGFS_WRITE
+	help
+	  Enables hardware and software based receiver lane margining
+	  support under each USB4 port and retimer, including retimers
+	  on the other side of the cable. Used for electrical quality
+	  and robustness validation during manufacturing. Should not be
+	  enabled by distro kernels.
+
+config USB4_KUNIT_TEST
+	bool "KUnit tests" if !KUNIT_ALL_TESTS
+	depends on USB4 && KUNIT=y
+	default KUNIT_ALL_TESTS
+
+config USB4_DMA_TEST
+	tristate "DMA traffic test driver"
+	depends on DEBUG_FS
+	help
+	  This allows sending and receiving DMA traffic through loopback
+	  connection. Loopback connection can be done by either special
+	  dongle that has TX/RX lines crossed, or by simply connecting a
+	  cable back to the host. Only enable this if you know what you
+	  are doing. Normal users and distro kernels should say N here.
+
+	  To compile this driver a module, choose M here. The module will be
+	  called thunderbolt_dma_test.
+
+config USB4_STREAM
+	tristate "Stream data over Thunderbolt/USB4 cable"
+	depends on USB4_CONFIGFS
+	help
+	  This adds support for USB4STREAM protocol that allows two
+	  hosts to stream data directly over Thunderbolt/USB4 cable
+	  through /dev/tbstreamX devices.
+
+	  To compile this driver a module, choose M here. The module will be
+	  called thunderbolt_stream.
+
+endif # USB4