[tip: objtool/urgent] objtool: Use HOSTCFLAGS for HAVE_XXHASH test

[tip-bot2 for HONG Yifan]

The following commit has been merged into the objtool/urgent branch of tip:

Commit-ID:     32234049107d012703d50547e815f198f147968b
Gitweb:        https://git.kernel.org/tip/32234049107d012703d50547e815f198f147968b
Author:        HONG Yifan <elsk@xxxxxxxxxx>
AuthorDate:    Tue, 03 Mar 2026 01:03:39 
Committer:     Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
CommitterDate: Fri, 06 Mar 2026 07:48:41 -08:00

objtool: Use HOSTCFLAGS for HAVE_XXHASH test

Previously, HAVE_XXHASH is tested by invoking HOSTCC without HOSTCFLAGS.

Consider the following scenario:

- The host machine has libxxhash installed
- We build the kernel with HOSTCFLAGS containing a --sysroot that does
  not have xxhash.h (for hermetic builds)

In this case, HAVE_XXHASH is set to y, but when it builds objtool with
HOSTCFLAGS, because the --sysroot does not contain xxhash.h, the
following error is raised:

<...>/common/tools/objtool/include/objtool/checksum_types.h:12:10: fatal error: 'xxhash.h' file not found
   12 | #include <xxhash.h>
      |          ^~~~~~~~~~

To resolve the error, we test HAVE_XXHASH by invoking HOSTCC with
HOSTCFLAGS.

Signed-off-by: HONG Yifan <elsk@xxxxxxxxxx>
Reviewed-by: Carlos Llamas <cmllamas@xxxxxxxxxx>
Link: https://patch.msgid.link/20260303010340.306164-1-elsk@xxxxxxxxxx
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
 tools/objtool/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
index 6964175..b8b8529 100644
--- a/tools/objtool/Makefile
+++ b/tools/objtool/Makefile
@@ -13,7 +13,7 @@ endif
 
 ifeq ($(ARCH_HAS_KLP),y)
 	HAVE_XXHASH = $(shell printf "$(pound)include <xxhash.h>\nXXH3_state_t *state;int main() {}" | \
-		      $(HOSTCC) -xc - -o /dev/null -lxxhash 2> /dev/null && echo y || echo n)
+		      $(HOSTCC) $(HOSTCFLAGS) -xc - -o /dev/null -lxxhash 2> /dev/null && echo y || echo n)
 	ifeq ($(HAVE_XXHASH),y)
 		BUILD_KLP	 := y
 		LIBXXHASH_CFLAGS := $(shell $(HOSTPKG_CONFIG) libxxhash --cflags 2>/dev/null) \