From 08fc0a47e153735d54362823b8824988252c08d3 Mon Sep 17 00:00:00 2001 From: "Yann E. MORIN" Date: Tue, 10 Nov 2015 22:36:30 +0100 Subject: [PATCH] package/skeleton: ensure custom skeleton uses merged /usr if needed When using systemd, the policy in Buildroot is to use a merged /usr (see c5bd8af6, "system: add options for /bin /sbin and /lib to be symlinks into /usr" for more info). So, we apply a few tricks in some packages to account for the merged /usr case. However, when using a custom skeleton, we have no say in how that skeleton is organised, so it may well have a split /usr. In that case, our little tricks might not work as expected. So, when the user uses a custom skeleton and wants systemd as an init system, we must check that the custom skeleton is setup with a merged /usr. We do that by checking that each pair of {/lib,/usr/lib} {/bin,/usr/bin} and {/sbin,/usr/sbin} have the same inode numbers, i.e. /lib must have the same inode number as /usr/lib (and so on...). When a pair does not share the same inode number, this is not a merged /usr and we abort. We implement that check with make constructs, so it is done very early in the build process, and we can abort early if need be. Signed-off-by: "Yann E. MORIN" Cc: Maxime Hadjinlian Cc: Peter Korsgaard Signed-off-by: Peter Korsgaard --- package/skeleton/skeleton.mk | 38 ++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) diff --git a/package/skeleton/skeleton.mk b/package/skeleton/skeleton.mk index 38391def82..46e8cc4a03 100644 --- a/package/skeleton/skeleton.mk +++ b/package/skeleton/skeleton.mk @@ -14,7 +14,45 @@ SKELETON_SOURCE = SKELETON_ADD_TOOLCHAIN_DEPENDENCY = NO ifeq ($(BR2_ROOTFS_SKELETON_CUSTOM),y) + SKELETON_PATH = $(call qstrip,$(BR2_ROOTFS_SKELETON_CUSTOM_PATH)) + +ifeq ($(BR2_ROOTFS_MERGED_USR),y) + +# Ensure the user has prepared a merged /usr. +# +# Extract the inode numbers for all of those directories. In case any is +# a symlink, we want to get the inode of the pointed-to directory, so we +# append '/.' to be sure we get the target directory. Since the symlinks +# can be anyway (/bin -> /usr/bin or /usr/bin -> /bin), we do that for +# all of them. +# +SKELETON_LIB_INODE = $(shell stat -c '%i' $(SKELETON_PATH)/lib/.) +SKELETON_BIN_INODE = $(shell stat -c '%i' $(SKELETON_PATH)/bin/.) +SKELETON_SBIN_INODE = $(shell stat -c '%i' $(SKELETON_PATH)/sbin/.) +SKELETON_USR_LIB_INODE = $(shell stat -c '%i' $(SKELETON_PATH)/usr/lib/.) +SKELETON_USR_BIN_INODE = $(shell stat -c '%i' $(SKELETON_PATH)/usr/bin/.) +SKELETON_USR_SBIN_INODE = $(shell stat -c '%i' $(SKELETON_PATH)/usr/sbin/.) + +ifneq ($(SKELETON_LIB_INODE),$(SKELETON_USR_LIB_INODE)) +SKELETON_CUSTOM_NOT_MERGED_USR += /lib +endif +ifneq ($(SKELETON_BIN_INODE),$(SKELETON_USR_BIN_INODE)) +SKELETON_CUSTOM_NOT_MERGED_USR += /bin +endif +ifneq ($(SKELETON_SBIN_INODE),$(SKELETON_USR_SBIN_INODE)) +SKELETON_CUSTOM_NOT_MERGED_USR += /sbin +endif + +ifneq ($(SKELETON_CUSTOM_NOT_MERGED_USR),) +$(error Use of systemd as an init system requires a merged /usr. \ + However, the custom skeleton in $(SKELETON_PATH) is not \ + using a merged /usr for the following directories: \ + $(SKELETON_CUSTOM_NOT_MERGED_USR)) +endif + +endif # merged /usr + else # ! custom skeleton SKELETON_PATH = system/skeleton -- 2.30.2