1 files changed, 34 insertions, 5 deletions
diff --git a/support/scripts/check-kernel-headers.sh b/support/scripts/check-kernel-headers.sh
index d7fe7d4bc2..b511a086c1 100755
--- a/support/scripts/check-kernel-headers.sh
+++ b/support/scripts/check-kernel-headers.sh
@@ -8,14 +8,43 @@ HDR_M="${HDR_VER%%.*}"
 HDR_V="${HDR_VER#*.}"
 HDR_m="${HDR_V%%.*}"
 
+EXEC="/tmp/br.check-headers.$(uuidgen)"
+
+# By the time we get here, we do not always have the staging-dir
+# already populated (think external toolchain), so we can not use
+# it.
+# So we just ask the cross compiler what its default sysroot is.
+# For multilib-aware toolchains where we should use a non-default
+# sysroot, it's not really a problem since the version of the kernel
+# headers is the same for all sysroots.
+SYSROOT=$(${CC} -print-sysroot)
+
 # We do not want to account for the patch-level, since headers are
 # not supposed to change for different patchlevels, so we mask it out.
 # This only applies to kernels >= 3.0, but those are the only one
 # we actually care about; we treat all 2.6.x kernels equally.
+${HOSTCC} -imacros "${SYSROOT}/usr/include/linux/version.h" \
+          -x c -o "${EXEC}" - <<_EOF_
+#include <stdio.h>
+#include <stdlib.h>
 
-exec ${CC} -E -x c -o - - >/dev/null 2>&1 <<_EOF_
-#include <linux/version.h>
-#if (LINUX_VERSION_CODE & ~0xFF) != KERNEL_VERSION(${HDR_M},${HDR_m},0)
-#error Incorrect kernel header version.
-#endif
+int main(int argc __attribute__((unused)),
+         char** argv __attribute__((unused)))
+{
+    if((LINUX_VERSION_CODE & ~0xFF)
+        != KERNEL_VERSION(${HDR_M},${HDR_m},0))
+    {
+        printf("Incorrect selection of kernel headers: ");
+        printf("expected %d.%d.x, got %d.%d.x\n", ${HDR_M}, ${HDR_m},
+               ((LINUX_VERSION_CODE>>16) & 0xFF),
+               ((LINUX_VERSION_CODE>>8) & 0xFF));
+        return 1;
+    }
+    return 0;
+}
 _EOF_
+
+"${EXEC}"
+ret=${?}
+rm -f "${EXEC}"
+exit ${ret}