kernel-module-split: fix conf file generation when KERNEL_SPLIT_MODULES=0

KERNEL_MODULE_AUTOLOAD defines the list of the kernel modules to be autoloaded
on boot. kernel-module-split.bbclass generates the required modules.load.d and
conf files for each kernel module. This conf files inturn read by system service
to perform module loading and configuration. When a kernel module is added to
KERNEL_MODULE_AUTOLOAD the conf files must be generated in all cases.
When KERNEL_SPLIT_MODULES=0 modprobe and autoload conf files are not
getting generated for the kernel modules.
To fix that enhanced the class implementation by separating out conf
file handling mechanism in two functions, generate_conf_files() and
frob_metadata(). generate_conf_files() handles no-split case where as
frob_metadata() keeps handling the existing case for spliting the modules.
Splitted common handling/generation of conf files stuff in to handle_conf_files()
function which gets invoked by both frob_metadata() and generate_conf_files()
on top of the scenario specific handling done in respective functions.
This implementation covers generation of the conf files for in-tree kernel
modules as well as standalone kernel module built as seperate package/recipe.

[YOCTO #15145]

Signed-off-by: Dixit Parmar <dixitparmar19@gmail.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>

Author: dixitparmar19

meta/classes-recipe/kernel-module-split.bbclass

@@ -86,11 +86,7 @@ python split_kernel_module_packages () {
             vals[m.group(1)] = m.group(2)
         return vals
 
-    def frob_metadata(file, pkg, pattern, format, basename):
-        vals = extract_modinfo(file)
-
-        dvar = d.getVar('PKGD')
-
+    def handle_conf_files(d, basename, pkg):
         # If autoloading is requested, output ${modulesloaddir}/<name>.conf and append
         # appropriate modprobe commands to the postinst
         autoloadlist = (d.getVar("KERNEL_MODULE_AUTOLOAD") or "").split()
@@ -102,7 +98,7 @@ python split_kernel_module_packages () {
 
         # The .conf file can either be installed by a recipe or generated from module_autoload_*
         conf = '%s/%s.conf' % (d.getVar('modulesloaddir'), basename)
-        name = '%s%s' % (dvar, conf)
+        name = '%s%s' % (d.getVar('PKGD'), conf)
         # If module name is in KERNEL_MODULE_AUTOLOAD, then generate the .conf file and write to `name`.
         if basename in autoloadlist:
             os.makedirs(os.path.dirname(name), exist_ok=True)
@@ -120,7 +116,7 @@ python split_kernel_module_packages () {
             d.appendVar('CONFFILES:%s' % pkg, conf2append)
             postinst = d.getVar('pkg_postinst:%s' % pkg)
             if not postinst:
-                bb.fatal("pkg_postinst:%s not defined" % pkg)
+                postinst = d.getVar('pkg_postinst:modules')
             postinst += d.getVar('autoload_postinst_fragment') % (autoload or basename)
             d.setVar('pkg_postinst:%s' % pkg, postinst)
 
@@ -130,7 +126,7 @@ python split_kernel_module_packages () {
 
         # The .conf file can either be installed by a recipe or generated from module_conf_*
         conf = '%s/%s.conf' % (d.getVar('modprobedir'), basename)
-        name = '%s%s' % (dvar, conf)
+        name = '%s%s' % (d.getVar('PKGD'), conf)
         # If module name is in KERNEL_MODULE_PROBECONF, then generate the .conf file and write to `name`.
         if modconf and basename in modconflist:
             os.makedirs(os.path.dirname(name), exist_ok=True)
@@ -145,6 +141,55 @@ python split_kernel_module_packages () {
             d.appendVar('FILES:%s' % pkg, conf2append)
             d.appendVar('CONFFILES:%s' % pkg, conf2append)
 
+    def generate_conf_files(d, root, file_regex, output_pattern):
+        """
+        Arguments:
+        root           -- the path in which to search. Contains system lib path
+                          so needs expansion.
+        file_regex     -- regular expression to match searched files. Use
+                          parentheses () to mark the part of this expression
+                          that should be used to derive the module name (to be
+                          substituted where %s is used in other function
+                          arguments as noted below)
+        output_pattern -- pattern to use for the package names. Must include %s.
+        """
+        import re, stat
+
+        dvar = d.getVar('PKGD')
+        root = d.expand(root)
+
+        # if the root directory doesn't exist, it's fatal - exit from the current execution.
+        if not os.path.exists(dvar + root):
+            bb.fatal("kernel module root directory path does not exist")
+
+        # walk through kernel module directory. for each entry in the directory, check if it
+        # matches the desired regex pattern and file type. if it fullfills, process it to generate
+        # it's conf file based on its package name.
+        for walkroot, dirs, files in os.walk(dvar + root):
+            for file in files:
+                relpath = os.path.join(walkroot, file).replace(dvar + root + '/', '', 1)
+                if not relpath:
+                    continue
+                m = re.match(file_regex, os.path.basename(relpath))
+                if not m:
+                    continue
+                file_f = os.path.join(dvar + root, relpath)
+                mode = os.lstat(file_f).st_mode
+                if not (stat.S_ISREG(mode) or (allow_links and stat.S_ISLNK(mode)) or (allow_dirs and stat.S_ISDIR(mode))):
+                    continue
+
+                basename = m.group(1)
+                on = legitimize_package_name(basename)
+                pkg = output_pattern % on
+                handle_conf_files(d, basename, pkg)
+
+
+    def frob_metadata(file, pkg, pattern, format, basename):
+        vals = extract_modinfo(file)
+        dvar = d.getVar('PKGD')
+
+        handle_conf_files(d, basename, pkg)
+
         if "description" in vals:
             old_desc = d.getVar('DESCRIPTION:' + pkg) or ""
             d.setVar('DESCRIPTION:' + pkg, old_desc + "; " + vals["description"])
@@ -178,19 +223,20 @@ python split_kernel_module_packages () {
     postinst = d.getVar('pkg_postinst:modules')
     postrm = d.getVar('pkg_postrm:modules')
 
-    if splitmods != '1':
-        d.appendVar('FILES:' + metapkg, '%s %s %s/modules' %
-            (d.getVar('modulesloaddir'), d.getVar('modprobedir'), d.getVar("nonarch_base_libdir")))
-        d.appendVar('pkg_postinst:%s' % metapkg, postinst)
-        d.prependVar('pkg_postrm:%s' % metapkg, postrm);
-        return
-
     module_regex = r'^(.*)\.k?o(?:\.(gz|xz|zst))?$'
 
     module_pattern_prefix = d.getVar('KERNEL_MODULE_PACKAGE_PREFIX')
     module_pattern_suffix = d.getVar('KERNEL_MODULE_PACKAGE_SUFFIX')
     module_pattern = module_pattern_prefix + kernel_package_name + '-module-%s' + module_pattern_suffix
 
+    if splitmods != '1':
+        d.appendVar('FILES:' + metapkg, '%s %s %s/modules' %
+            (d.getVar('modulesloaddir'), d.getVar('modprobedir'), d.getVar("nonarch_base_libdir")))
+        d.appendVar('pkg_postinst:%s' % metapkg, postinst)
+        d.prependVar('pkg_postrm:%s' % metapkg, postrm)
+        generate_conf_files(d, root='${nonarch_base_libdir}/modules', file_regex=module_regex, output_pattern=module_pattern)
+        return
+
     modules = do_split_packages(d, root='${nonarch_base_libdir}/modules', file_regex=module_regex, output_pattern=module_pattern, description='%s kernel module', postinst=postinst, postrm=postrm, recursive=True, hook=frob_metadata, extra_depends='%s-%s' % (kernel_package_name, kernel_version))
     if modules:
         d.appendVar('RDEPENDS:' + metapkg, ' '+' '.join(modules))