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, 58 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-class-rnbd-server b/Documentation/ABI/testing/sysfs-class-rnbd-server
new file mode 100644
index 000000000..6c5996cd7
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-rnbd-server
@@ -0,0 +1,58 @@
+What:		/sys/class/rnbd-server
+Date:		Feb 2020
+KernelVersion:	5.7
+Contact:	Jack Wang <jinpu.wang@cloud.ionos.com> Danil Kipnis <danil.kipnis@cloud.ionos.com>
+Description:	provide information about RNBD-server.
+
+What:		/sys/class/rnbd-server/ctl/
+Date:		Feb 2020
+KernelVersion:	5.7
+Contact:	Jack Wang <jinpu.wang@cloud.ionos.com> Danil Kipnis <danil.kipnis@cloud.ionos.com>
+Description:	When a client maps a device, a directory entry with the name of the
+		block device is created under /sys/class/rnbd-server/ctl/devices/.
+
+What:		/sys/class/rnbd-server/ctl/devices/<device_name>/block_dev
+Date:		Feb 2020
+KernelVersion:	5.7
+Contact:	Jack Wang <jinpu.wang@cloud.ionos.com> Danil Kipnis <danil.kipnis@cloud.ionos.com>
+Description:	Is a symlink to the sysfs entry of the exported device.
+
+		Example:
+		block_dev -> ../../../../class/block/ram0
+
+What:		/sys/class/rnbd-server/ctl/devices/<device_name>/sessions/
+Date:		Feb 2020
+KernelVersion:	5.7
+Contact:	Jack Wang <jinpu.wang@cloud.ionos.com> Danil Kipnis <danil.kipnis@cloud.ionos.com>
+Description:	For each client a particular device is exported to, following directory will be
+		created:
+
+		/sys/class/rnbd-server/ctl/devices/<device_name>/sessions/<session-name>/
+
+		When the device is unmapped by that client, the directory will be removed.
+
+What:		/sys/class/rnbd-server/ctl/devices/<device_name>/sessions/<session-name>/read_only
+Date:		Feb 2020
+KernelVersion:	5.7
+Contact:	Jack Wang <jinpu.wang@cloud.ionos.com> Danil Kipnis <danil.kipnis@cloud.ionos.com>
+Description:	Contains '1' if device is mapped read-only, otherwise '0'.
+
+What:		/sys/class/rnbd-server/ctl/devices/<device_name>/sessions/<session-name>/mapping_path
+Date:		Feb 2020
+KernelVersion:	5.7
+Contact:	Jack Wang <jinpu.wang@cloud.ionos.com> Danil Kipnis <danil.kipnis@cloud.ionos.com>
+Description:	Contains the relative device path provided by the user during mapping.
+
+What:		/sys/class/rnbd-server/ctl/devices/<device_name>/sessions/<session-name>/access_mode
+Date:		Feb 2020
+KernelVersion:	5.7
+Contact:	Jack Wang <jinpu.wang@cloud.ionos.com> Danil Kipnis <danil.kipnis@cloud.ionos.com>
+Description:	Contains the device access mode: ro, rw or migration.
+
+What:		/sys/class/rnbd-server/ctl/devices/<device_name>/sessions/<session-name>/force_close
+Date:		Nov 2020
+KernelVersion:	5.10
+Contact:	Jack Wang <jinpu.wang@cloud.ionos.com> Danil Kipnis <danil.kipnis@cloud.ionos.com>
+Description:	Write "1" to the file to close the device on server side. Please
+		note that the client side device will not be closed, read or
+		write to the device will get -ENOTCONN.