Enable extraction of debug information for kmods

This hack temporary adds executable permission for the *.ko files
during post-install stage so they are picked up by find-debuginfo.sh.
Since the intention is to avoid changing of behaviour in non-kmod
workloads, it's done by adding two additional brp-* scripts to the
__spec_install_post macro when kernel_module_package is instantiated.

* brp-kmod-restore-perms: New file.
* brp-kmod-set-exec-bit: Likewise.
* macros.kmp (%__brp_kmod_set_exec_bit, %__brp_kmod_restore_perms,
%__kmod_brps_added): New macros.
(%kernel_module_package): Rewrite __spec_install_post macro.
* redhat-rpm-config.spec (Source701, Source702): Add
brp-kmod-restore-perms and brp-kmod-set-exec-bit.
(Requires): Add find requirement for brp-kmod-set-exec-bit.
(%files): Explicitly list brp-* scripts for redhat-rpm-config and
kernel-rpm-macros packages.

Resolves: #2002887
Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com>

brp-kmod-restore-perms

@@ -0,0 +1,20 @@
+#! /bin/bash -efu
+
+## A counterpart of brp-kmod-set-exec-bits that restores original kmod
+## file permissions
+
+# If using normal root, avoid changing anything.
+[ -n "$RPM_BUILD_ROOT" -a "$RPM_BUILD_ROOT" != "/" ] || exit 0
+
+# Checking for required programs
+which chmod >/dev/null || exit 0
+
+[ -r "$RPM_BUILD_ROOT/kmod-permissions.list" ] || exit 0
+
+while read perm path; do
+	[ -n "$perm" ] || continue
+
+	chmod "$perm" "$RPM_BUILD_ROOT/$path"
+done < "$RPM_BUILD_ROOT/kmod-permissions.list"
+
+rm -f "$RPM_BUILD_ROOT/kmod-permissions.list"

brp-kmod-set-exec-bit

@@ -0,0 +1,14 @@
+#! /bin/bash -efux
+
+## A hack for making brp-strip taking into account kmod files
+
+# If using normal root, avoid changing anything.
+[ -n "$RPM_BUILD_ROOT" -a "$RPM_BUILD_ROOT" != "/" ] || exit 0
+
+# Checking for required programs
+which find chmod >/dev/null || exit 0
+
+find "$RPM_BUILD_ROOT" \
+	-name '*.ko' \
+	-printf '%#m %P\n' \
+	-exec chmod u+x '{}' \; > "$RPM_BUILD_ROOT/kmod-permissions.list"

kernel-srpm-macros.spec

@@ -34,6 +34,10 @@ Source302:      symset-table
 Source400: kabi.attr
 Source401: kabi.sh
 
+# BRPs
+Source500: brp-kmod-set-exec-bit
+Source501: brp-kmod-restore-perms
+
 %global rrcdir /usr/lib/rpm/redhat
 
 
@@ -48,6 +52,9 @@ Release: %{release}%{?dist}.1
 Summary: Macros and scripts for building kernel module packages
 Requires: redhat-rpm-config >= 13
 
+# for brp-kmod-set-exec-bit
+Requires: %{_bindir}/find
+
 %description -n kernel-rpm-macros
 Macros and scripts for building kernel module packages.
 
@@ -75,6 +82,7 @@ mkdir -p %{buildroot}%{_fileattrsdir}
 install -p -m 755 -t %{buildroot}%{rrcdir} kmodtool rpmsort symset-table
 install -p -m 755 -t %{buildroot}%{rrcdir} find-provides.ksyms find-requires.ksyms
 install -p -m 644 -t %{buildroot}%{rrcdir}/find-provides.d firmware.prov modalias.prov
+install -p -m 755 -t %{buildroot}%{rrcdir} brp-kmod-restore-perms brp-kmod-set-exec-bit
 install -p -m 644 -t %{buildroot}%{_rpmconfigdir}/macros.d macros.kmp
 install -p -m 644 -t %{buildroot}%{_fileattrsdir} kmod.attr
 
@@ -90,6 +98,8 @@ install -p -m 755 -t "%{buildroot}%{_rpmconfigdir}" kabi.sh
 %{_rpmconfigdir}/macros.d/macros.kmp
 %{_fileattrsdir}/kabi.attr
 %dir %{rrcdir}/find-provides.d
+%{rrcdir}/brp-kmod-restore-perms
+%{rrcdir}/brp-kmod-set-exec-bit
 %{rrcdir}/kmodtool
 %{rrcdir}/rpmsort
 %{rrcdir}/symset-table

macros.kmp

@@ -2,6 +2,11 @@
 redhat_kernel_module_package	1
 kernel_module_package_release	1
 
+%__brp_kmod_set_exec_bit  /usr/lib/rpm/redhat/brp-kmod-set-exec-bit
+%__brp_kmod_restore_perms /usr/lib/rpm/redhat/brp-kmod-restore-perms
+
+%__kmod_brps_added 0
+
 %__find_provides        /usr/lib/rpm/redhat/find-provides
 %__find_requires        /usr/lib/rpm/redhat/find-requires
 
@@ -12,6 +17,41 @@ kernel_module_package_release	1
 					kernel-devel kernel-abi-stablelists redhat-rpm-config kernel-rpm-macros elfutils-libelf-devel kmod
 
 %kernel_module_package(n:v:r:s:f:xp:) %{expand:%( \
+	## An ugly hack: we want kmods to be processed by find-debuginfo,
+	## but it processes only files with executable permission set.
+	## It is important now since, as of now, if debuginfo package
+	## is enabled (and it is enabled), there's an RPM build error
+	## as a result of lack of ether absence or emptiness of
+	## debugsourcefiles.list (which is likely a bug in RPM, but it looks
+	## like that there's no obvious fix and apparently no one have
+	## any issues with this).
+	## In order to minimise intrusiveness, usually (in Red Hat-built kmod
+	## RPMs) *.ko files just have executable permission being set as a part
+	## of %build section. There are two caveats with kmp, however:
+	##  * We have no control over %build section itself (and it wasn't
+	##    required previously)
+	##  * Changing the criteria used in find-debuginfo.sh/brp-strip
+	##    for selecting files that have to undergo debug section separation
+	##    may introduce regression.
+	## As a result, we insert additional hooks in __spec_install_post
+	## (__brp_kmod_set_exec_bit in the beginning and
+	## __brp_kmod_restore_perms in the end) that (temporarily) set
+	## executable permission for *.ko files so find-debuginfo.sh will pick
+	## them up.
+	## Unfortunately, __spec_install_post's body is copied here since
+	## we want that __debug_package macro expansion has been performed
+	## lazily and  it looks like RPM has no ability to provide a body
+	## of a macro verbatim.
+	if [ 0 = "%{__kmod_brps_added}" ]; then \
+		echo "%%global __spec_install_post \\\\" \
+		echo "	%%{?__brp_kmod_set_exec_bit} \\\\" \
+		echo "	%%%%{?__debug_package:%%%%{__debug_install_post}} \\\\" \
+		echo "	%%{__arch_install_post} \\\\" \
+		echo "	%%{__os_install_post} \\\\" \
+		echo "	%%{?__brp_kmod_restore_perms} \\\\" \
+		echo "%%{nil}" \
+	fi \
+	%global __kmod_brps_added 1 \
 	%global kmodtool %{-s*}%{!-s:/usr/lib/rpm/redhat/kmodtool} \
 	%global kmod_version %{-v*}%{!-v:%{version}} \
 	%global kmod_release %{-r*}%{!-r:%{release}} \