Makefile: drop ldconfig handling

The ldconfig handling in the main Makefile is utterly broken, as it calls the build machine ldconfig to generate the ld.so.cache of the target. Unfortunately, the format of the ld.so.cache is architecture specific, and therefore the build machine ldconfig cannot be used as-is.

This patch therefore simply drops using ldconfig entirely, and removes /etc/ld.so.conf.d/ from the target skeleton. The idea is that all libraries that should be loaded by the dynamic linker must be installed in paths where the dynamic linker searches them by default (typically /lib or /usr/lib).

This might potentially break a few packages, but the only way to know is to actually stop handling ldconfig.

In order to be notified of such cases, we add a check in target-finalize to verify that there is no /etc/ld.so.conf file as well as no /etc/ld.so.conf.d directory. Such checks are done after the rootfs overlays are copied and post-build scripts are executed, in order to also catch the cases where such mechanisms would add ld.so related configuration.

Signed-off-by Thomas Petazzoni <[email protected]>

---
Changes from v1:
- Add check for /etc/ld.so.conf.d suggested by Yann
- Move the checks after copying the rootfs overlays and running the post build scripts, in order to catch cases where the ld.so configuration would be added by an overlay or a post-build script. This was suggested by Arnout.

---
 Makefile                                | 17 +++++------------
 system/skeleton/etc/ld.so.conf.d/.empty |  0
 2 files changed, 5 insertions(+), 12 deletions(-)
 delete mode 100644 system/skeleton/etc/ld.so.conf.d/.empty

Makefile +5 -12

index 1d69192..8953b02 100644
@@ -598,18 +598,6 @@ endif
 		xargs -r $(STRIPCMD) $(STRIP_STRIP_DEBUG)
 
 	mkdir -p $(TARGET_DIR)/etc
-	# Mandatory configuration file and auxiliary cache directory
-	# for recent versions of ldconfig
-	touch $(TARGET_DIR)/etc/ld.so.conf
-	mkdir -p $(TARGET_DIR)/var/cache/ldconfig
-	if [ -x "$(TARGET_CROSS)ldconfig" ]; \
-	then \
-		$(TARGET_CROSS)ldconfig -r $(TARGET_DIR) \
-					-f $(TARGET_DIR)/etc/ld.so.conf; \
-	else \
-		/sbin/ldconfig -r $(TARGET_DIR) \
-			       -f $(TARGET_DIR)/etc/ld.so.conf; \
-	fi
 	( \
 		echo "NAME=Buildroot"; \
 		echo "VERSION=$(BR2_VERSION_FULL)"; \

@@ -628,6 +616,11 @@ endif
 		$(call MESSAGE,"Executing post-build script $(s)"); \
 		$(EXTRA_ENV) $(s) $(TARGET_DIR) $(call qstrip,$(BR2_ROOTFS_POST_SCRIPT_ARGS))$(sep))
 
+	test -f $(TARGET_DIR)/etc/ld.so.conf && \
+		{ echo "ERROR: we shouldn't have a /etc/ld.so.conf file"; exit 1; } || true
+	test -d $(TARGET_DIR)/etc/ld.so.conf.d && \
+		{ echo "ERROR: we shouldn't have a /etc/ld.so.conf.d directory"; exit 1; } || true
+
 target-post-image: $(TARGETS_ROOTFS) target-finalize
 	@$(foreach s, $(call qstrip,$(BR2_ROOTFS_POST_IMAGE_SCRIPT)), \
 		$(call MESSAGE,"Executing post-image script $(s)"); \

system/skeleton/etc/ld.so.conf.d/.empty deleted +0 -0

deleted file mode 100644
index e69de29..0000000

Signature · 1 line

2.6.4

I disagree on that one.

We basically tell user that they can do "whatever they want" in a post-build-script. So, if a user has a mean to create the ld.so.cache, we should not prevent him to do so.

For example, a user may have a first-install procedure on his machine, that runs ldocnfig natively on the machine. Custom (aka br2-external packages may install libraries in weird locations (proprietary stuff) and can not change that (because other proprietary binary-only stuff). In this vase a "first-install" procedure may run ldconfig natively on the target, and that would be OK.

Or he may have a cross-ldconfig (from wherever that comes) so he could run that in a post-build script.

So I believe this check should be before the overlay and post-build scripts.