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, 137 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-class-rc b/Documentation/ABI/testing/sysfs-class-rc
new file mode 100644
index 000000000..84e46d70d
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-rc
@@ -0,0 +1,137 @@
+What:		/sys/class/rc/
+Date:		Apr 2010
+KernelVersion:	2.6.35
+Contact:	Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
+Description:
+		The rc/ class sub-directory belongs to the Remote Controller
+		core and provides a sysfs interface for configuring infrared
+		remote controller receivers.
+
+What:		/sys/class/rc/rc<N>/
+Date:		Apr 2010
+KernelVersion:	2.6.35
+Contact:	Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
+Description:
+		A /sys/class/rc/rcN directory is created for each remote
+		control receiver device where N is the number of the receiver.
+
+What:		/sys/class/rc/rc<N>/protocols
+Date:		Jun 2010
+KernelVersion:	2.6.36
+Contact:	Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
+Description:
+		Reading this file returns a list of available protocols,
+		something like::
+
+		    "rc5 [rc6] nec jvc [sony]"
+
+		Enabled protocols are shown in [] brackets.
+
+		Writing "+proto" will add a protocol to the list of enabled
+		protocols.
+
+		Writing "-proto" will remove a protocol from the list of enabled
+		protocols.
+
+		Writing "proto" will enable only "proto".
+
+		Writing "none" will disable all protocols.
+
+		Write fails with EINVAL if an invalid protocol combination or
+		unknown protocol name is used.
+
+What:		/sys/class/rc/rc<N>/filter
+Date:		Jan 2014
+KernelVersion:	3.15
+Contact:	Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
+Description:
+		Sets the scancode filter expected value.
+
+		Use in combination with /sys/class/rc/rcN/filter_mask to set the
+		expected value of the bits set in the filter mask.
+		If the hardware supports it then scancodes which do not match
+		the filter will be ignored. Otherwise the write will fail with
+		an error.
+
+		This value may be reset to 0 if the current protocol is altered.
+
+What:		/sys/class/rc/rc<N>/filter_mask
+Date:		Jan 2014
+KernelVersion:	3.15
+Contact:	Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
+Description:
+		Sets the scancode filter mask of bits to compare.
+		Use in combination with /sys/class/rc/rcN/filter to set the bits
+		of the scancode which should be compared against the expected
+		value. A value of 0 disables the filter to allow all valid
+		scancodes to be processed.
+
+		If the hardware supports it then scancodes which do not match
+		the filter will be ignored. Otherwise the write will fail with
+		an error.
+
+		This value may be reset to 0 if the current protocol is altered.
+
+What:		/sys/class/rc/rc<N>/wakeup_protocols
+Date:		Feb 2017
+KernelVersion:	4.11
+Contact:	Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
+Description:
+		Reading this file returns a list of available protocols to use
+		for the wakeup filter, something like::
+
+		    "rc-5 nec nec-x rc-6-0 rc-6-6a-24 [rc-6-6a-32] rc-6-mce"
+
+		Note that protocol variants are listed, so "nec", "sony",
+		"rc-5", "rc-6" have their different bit length encodings
+		listed if available.
+
+		The enabled wakeup protocol is shown in [] brackets.
+
+		Only one protocol can be selected at a time.
+
+		Writing "proto" will use "proto" for wakeup events.
+
+		Writing "none" will disable wakeup.
+
+		Write fails with EINVAL if an invalid protocol combination or
+		unknown protocol name is used, or if wakeup is not supported by
+		the hardware.
+
+What:		/sys/class/rc/rc<N>/wakeup_filter
+Date:		Jan 2014
+KernelVersion:	3.15
+Contact:	Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
+Description:
+		Sets the scancode wakeup filter expected value.
+
+		Use in combination with /sys/class/rc/rcN/wakeup_filter_mask to
+		set the expected value of the bits set in the wakeup filter mask
+		to trigger a system wake event.
+
+		If the hardware supports it and wakeup_filter_mask is not 0 then
+		scancodes which match the filter will wake the system from e.g.
+		suspend to RAM or power off.
+
+		Otherwise the write will fail with an error.
+
+		This value may be reset to 0 if the wakeup protocol is altered.
+
+What:		/sys/class/rc/rc<N>/wakeup_filter_mask
+Date:		Jan 2014
+KernelVersion:	3.15
+Contact:	Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
+Description:
+		Sets the scancode wakeup filter mask of bits to compare.
+
+		Use in combination with /sys/class/rc/rcN/wakeup_filter to set
+		the bits of the scancode which should be compared against the
+		expected value to trigger a system wake event.
+
+		If the hardware supports it and wakeup_filter_mask is not 0 then
+		scancodes which match the filter will wake the system from e.g.
+		suspend to RAM or power off.
+
+		Otherwise the write will fail with an error.
+
+		This value may be reset to 0 if the wakeup protocol is altered.