[Mod] First commit

support/scripts/check-kernel-headers.sh

@@ -0,0 +1,69 @@
+#!/bin/sh
+
+# This script (and the embedded C code) will check that the actual
+# headers version match the user told us they were:
+#
+# - if both versions are the same, all is well.
+#
+# - if the actual headers are older than the user told us, this is
+#   an error.
+#
+# - if the actual headers are more recent than the user told us, and
+#   we are doing a strict check, then this is an error.
+#
+# - if the actual headers are more recent than the user told us, and
+#   we are doing a loose check, then a warning is printed, but this is
+#   not an error.
+
+BUILDDIR="${1}"
+SYSROOT="${2}"
+# Make sure we have enough version components
+HDR_VER="${3}.0.0"
+CHECK="${4}"  # 'strict' or 'loose'
+
+HDR_M="${HDR_VER%%.*}"
+HDR_V="${HDR_VER#*.}"
+HDR_m="${HDR_V%%.*}"
+
+# Exit on any error, so we don't try to run an unexisting program if the
+# compilation fails.
+set -e
+
+# Set the clean-up trap in advance to prevent a race condition in which we
+# create the file but get a SIGTERM before setting it. Notice that we don't
+# need to care about EXEC being empty, since 'rm -f ""' does nothing.
+trap 'rm -f "${EXEC}"' EXIT
+
+EXEC="$(mktemp -p "${BUILDDIR}" -t .check-headers.XXXXXX)"
+
+# 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 "${EXEC}" - <<_EOF_
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int main(int argc __attribute__((unused)),
+         char** argv __attribute__((unused)))
+{
+    int l = LINUX_VERSION_CODE & ~0xFF;
+    int h = KERNEL_VERSION(${HDR_M},${HDR_m},0);
+
+    if ((l >= h) && !strcmp("${CHECK}", "loose"))
+        return 0;
+
+    if (l != h) {
+        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}"