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From:   Michal Suchanek <msuchanek@suse.de>
To:     linux-modules@vger.kernel.org
Cc:     Michal Suchanek <msuchanek@suse.de>, Takashi Iwai <tiwai@suse.com>,
        Lucas De Marchi <lucas.de.marchi@gmail.com>,
        =?UTF-8?q?Michal=20Koutn=C3=BD?= <mkoutny@suse.com>,
        Jiri Slaby <jslaby@suse.com>, Jan Engelhardt <jengelh@inai.de>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Nicolas Schier <nicolas@fjasle.eu>,
        linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH kmod v4 2/4] libkmod, depmod: Load modprobe.d, depmod.d from $prefix/lib.
Date:   Mon, 17 Jul 2023 12:39:51 +0200
Message-ID: <16e4442b788ad02048d499f36e2304e59fb7a072.1689589902.git.msuchanek@suse.de>
In-Reply-To: <cover.1689589902.git.msuchanek@suse.de>
References: <20230711153126.28876-1-msuchanek@suse.de> <cover.1689589902.git.msuchanek@suse.de>
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There is an ongoing effort to limit use of files outside of /usr (or
$prefix on general). Currently all modprobe.d paths are hardcoded to
outside of $prefix. Teach kmod to load modprobe.d from $prefix/lib.

On some distributions /usr/lib and /lib are the same directory because
of a compatibility symlink, and it is possible to craft configuration
files with sideeffects that would behave differently when loaded twice.
However, the override semantic ensures that one 'overrides' the other,
and only one configuration file of the same name is loaded from any of
the search directories.

Signed-off-by: Michal Suchanek <msuchanek@suse.de>
---
v2: Fix commit message typo
v3: Fix modprobe.d path list in code comment
---
 Makefile.am        | 1 +
 libkmod/libkmod.c  | 7 ++++---
 man/Makefile.am    | 9 +++++++--
 man/depmod.d.xml   | 1 +
 man/modprobe.d.xml | 1 +
 tools/depmod.c     | 1 +
 6 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/Makefile.am b/Makefile.am
index 8ba85c91a0f3..7aa5bfa5638d 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -19,6 +19,7 @@ AM_CPPFLAGS = \
 	-include $(top_builddir)/config.h \
 	-I$(top_srcdir) \
 	-DSYSCONFDIR=\""$(sysconfdir)"\" \
+	-DPREFIX=\""$(prefix)"\" \
 	${zlib_CFLAGS}
 
 AM_CFLAGS = $(OUR_CFLAGS)
diff --git a/libkmod/libkmod.c b/libkmod/libkmod.c
index 2670f9a4611a..f3139c1cef97 100644
--- a/libkmod/libkmod.c
+++ b/libkmod/libkmod.c
@@ -65,6 +65,7 @@ static const char *const default_config_paths[] = {
 	SYSCONFDIR "/modprobe.d",
 	"/run/modprobe.d",
 	"/usr/local/lib/modprobe.d",
+	PREFIX "/lib/modprobe.d",
 	"/lib/modprobe.d",
 	NULL
 };
@@ -237,9 +238,9 @@ static char *get_kernel_release(const char *dirname)
  *                to load from user-defined configuration parameters such as
  *                alias, blacklists, commands (install, remove). If NULL
  *                defaults to /etc/modprobe.d, /run/modprobe.d,
- *                /usr/local/lib/modprobe.d and /lib/modprobe.d. Give an empty
- *                vector if configuration should not be read. This array must
- *                be null terminated.
+ *                /usr/local/lib/modprobe.d, PREFIX/lib/modprobe.d, and
+ *                /lib/modprobe.d. Give an empty vector if configuration should
+ *                not be read. This array must be null terminated.
  *
  * Create kmod library context. This reads the kmod configuration
  * and fills in the default values.
diff --git a/man/Makefile.am b/man/Makefile.am
index 11514d52a190..ad07c30bbd24 100644
--- a/man/Makefile.am
+++ b/man/Makefile.am
@@ -17,9 +17,14 @@ EXTRA_DIST = $(MAN5:%.5=%.xml) $(MAN8:%.8=%.xml)
 CLEANFILES = $(dist_man_MANS)
 
 %.5 %.8: %.xml
-	$(AM_V_XSLT)$(XSLT) \
+	$(AM_V_XSLT)if [ -n '$(prefix)' ] ; then \
+		sed -e 's|@PREFIX@|$(prefix)|g' $< ; \
+	else \
+		sed -e '/@PREFIX@/d' $< ; \
+	fi | \
+	$(XSLT) \
 		-o $@ \
 		--nonet \
 		--stringparam man.output.quietly 1 \
 		--param funcsynopsis.style "'ansi'" \
-		http://docbook.sourceforge.net/release/xsl/current/manpages/docbook.xsl $<
+		http://docbook.sourceforge.net/release/xsl/current/manpages/docbook.xsl -
diff --git a/man/depmod.d.xml b/man/depmod.d.xml
index 8d3d821cddc8..431ebca6654b 100644
--- a/man/depmod.d.xml
+++ b/man/depmod.d.xml
@@ -40,6 +40,7 @@
 
   <refsynopsisdiv>
     <para><filename>/lib/depmod.d/*.conf</filename></para>
+    <para><filename>@PREFIX@/lib/depmod.d/*.conf</filename></para>
     <para><filename>/usr/local/lib/depmod.d/*.conf</filename></para>
     <para><filename>/run/depmod.d/*.conf</filename></para>
     <para><filename>/etc/depmod.d/*.conf</filename></para>
diff --git a/man/modprobe.d.xml b/man/modprobe.d.xml
index 0ab3e9110a7e..e8a91d7668af 100644
--- a/man/modprobe.d.xml
+++ b/man/modprobe.d.xml
@@ -41,6 +41,7 @@
 
   <refsynopsisdiv>
     <para><filename>/lib/modprobe.d/*.conf</filename></para>
+    <para><filename>@PREFIX@/lib/modprobe.d/*.conf</filename></para>
     <para><filename>/usr/local/lib/modprobe.d/*.conf</filename></para>
     <para><filename>/run/modprobe.d/*.conf</filename></para>
     <para><filename>/etc/modprobe.d/*.conf</filename></para>
diff --git a/tools/depmod.c b/tools/depmod.c
index 1d1d41db860f..7e9339923809 100644
--- a/tools/depmod.c
+++ b/tools/depmod.c
@@ -54,6 +54,7 @@ static const char *const default_cfg_paths[] = {
 	SYSCONFDIR "/depmod.d",
 	"/run/depmod.d",
 	"/usr/local/lib/depmod.d",
+	PREFIX "/lib/depmod.d",
 	"/lib/depmod.d",
 	NULL
 };
-- 
2.41.0