|author||Thomas Petazzoni <email@example.com>||2016-09-15 10:58:28 +0200|
|committer||Peter Korsgaard <firstname.lastname@example.org>||2016-09-15 11:59:07 +0200|
toolchain-external: fix potential entire root filesystem removal
This reverts commit a0aa7e0e1750f6ace2879ea8adb1425a41431b79 and reworks the code to fix a major and potentially catastrophic bug when the following conditions are met: - The user has selected a "known toolchain profile", such as a Linaro toolchain, a Sourcery CodeBench toolchain etc. People using "custom toolchain profile" are not affected. - The user has enabled BR2_TOOLCHAIN_EXTERNAL_PREINSTALLED=y to indicate that the toolchain is already locally available (as opposed to having Buildroot download and extract the toolchain) - The user has left BR2_TOOLCHAIN_EXTERNAL_PATH empty, because his toolchain is directly available through the PATH environment variable. When BR2_TOOLCHAIN_EXTERNAL_PATH is non-empty, Buildroot will do something silly (remove the toolchain contents), but that are limited to the toolchain itself. When such conditions are met, Buildroot will run "rm -rf /*" due to TOOLCHAIN_EXTERNAL_INSTALL_DIR being empty. This bug does not exist in 2016.05, and appeared in 2016.08 due to commit a0aa7e0e1750f6ace2879ea8adb1425a41431b79. Commit a0aa7e0e1750f6ace2879ea8adb1425a41431b79 removed the assignment of TOOLCHAIN_EXTERNAL_SOURCE and TOOLCHAIN_EXTERNAL_SITE to empty, as part of a global cleanup to remove such assignments that supposedly had become unneeded following a fix of the package infrastructure (75630eba22b20d6140a5b58a6d1e35598fb3c0d3: core: do not attempt downloads with no _VERSION set). However, this causes TOOLCHAIN_EXTERNAL_SOURCE to be non-empty even for BR2_TOOLCHAIN_EXTERNAL_PREINSTALLED=y configuration, with the following consequences: - Buildroot downloads the toolchain tarball (while we're saying the toolchain is already available). Not dramatic, but clearly buggy. - Buildroot registers a post-extract hook that moves the toolchain from its extract directory (output/build/toolchain-external-.../ to its final location in host/opt/ext-toolchain/). Before doing this, it removes everything in TOOLCHAIN_EXTERNAL_INSTALL_DIR (which should normally be host/opt/ext-toolchain/). Another mistake that caused the bug is commit b731dc7bfb9c8ce7be502711f0b44ccab5515f1d ("toolchain-external: make extraction idempotent"), which introduce the dangerous call "rm -rf $(var)/*", which can be catastrophic if by mistake $(var) is empty. Instead, this commit should have just used rm -rf $(var) to remove the directory instead: it would have failed without consequences if $(var) is empty, and the directory was anyway already re-created right after with a mkdir. To address this problem, we: - Revert commit a0aa7e0e1750f6ace2879ea8adb1425a41431b79, so that _SOURCE and _SITE are empty in the pre-installed toolchain case. - Rework the code to ensure that similar problems will no happen in the future, by: - Registering the TOOLCHAIN_EXTERNAL_MOVE hook only when BR2_TOOLCHAIN_EXTERNAL_DOWNLOAD=y, since moving the toolchain is only needed when Buildroot downloaded the toolchain. - Introduce a variable TOOLCHAIN_EXTERNAL_DOWNLOAD_INSTALL_DIR which is the path in which Buildroot installs external toolchains when it is in charge of downloading/extracting them. Then, the TOOLCHAIN_EXTERNAL_MOVE hook is changed to use this variable, which is guaranteed to be non-empty. - Replace the removal of the directory contents $(var)/* by removing the directory itself $(var). The directory was anyway already re-created if needed afterwards. Thanks to doing this, if $(var) ever becomes empty, we will do "rm -rf" which will fail and abort the build, and not the catastrophic "rm -rf /*". Reported-by: Mason <email@example.com> Cc: Mason <firstname.lastname@example.org> Signed-off-by: Thomas Petazzoni <email@example.com> Signed-off-by: Peter Korsgaard <firstname.lastname@example.org>
1 files changed, 16 insertions, 6 deletions
diff --git a/toolchain/toolchain-external/toolchain-external.mk b/toolchain/toolchain-external/toolchain-external.mk
index 8de324726e..ad258b86be 100644
@@ -138,8 +138,10 @@ TOOLCHAIN_EXTERNAL_LIBS += $(call qstrip,$(BR2_TOOLCHAIN_EXTRA_EXTERNAL_LIBS))
TOOLCHAIN_EXTERNAL_PREFIX = $(call qstrip,$(BR2_TOOLCHAIN_EXTERNAL_PREFIX))
+TOOLCHAIN_EXTERNAL_DOWNLOAD_INSTALL_DIR = $(HOST_DIR)/opt/ext-toolchain
-TOOLCHAIN_EXTERNAL_INSTALL_DIR = $(HOST_DIR)/opt/ext-toolchain
+TOOLCHAIN_EXTERNAL_INSTALL_DIR = $(TOOLCHAIN_EXTERNAL_DOWNLOAD_INSTALL_DIR)
TOOLCHAIN_EXTERNAL_INSTALL_DIR = $(call qstrip,$(BR2_TOOLCHAIN_EXTERNAL_PATH))
@@ -454,21 +456,29 @@ TOOLCHAIN_EXTERNAL_ACTUAL_SOURCE_TARBALL ?= \
$(subst -i686-pc-linux-gnu.tar.bz2,.src.tar.bz2,$(subst -i686-pc-linux-gnu-i386-linux.tar.bz2,-i686-pc-linux-gnu.src.tar.bz2,$(TOOLCHAIN_EXTERNAL_SOURCE)))
+# In fact, we don't need to download the toolchain, since it is already
+# available on the system, so force the site and source to be empty so
+# that nothing will be downloaded/extracted.
TOOLCHAIN_EXTERNAL_ADD_TOOLCHAIN_DEPENDENCY = NO
TOOLCHAIN_EXTERNAL_INSTALL_STAGING = YES
# Normal handling of downloaded toolchain tarball extraction.
TOOLCHAIN_EXTERNAL_EXCLUDES = usr/lib/locale/*
# As a regular package, the toolchain gets extracted in $(@D), but
# since it's actually a fairly special package, we need it to be moved
-# into TOOLCHAIN_EXTERNAL_INSTALL_DIR.
+# into TOOLCHAIN_EXTERNAL_DOWNLOAD_INSTALL_DIR.
- rm -rf $(TOOLCHAIN_EXTERNAL_INSTALL_DIR)/*
- mkdir -p $(TOOLCHAIN_EXTERNAL_INSTALL_DIR)
- mv $(@D)/* $(TOOLCHAIN_EXTERNAL_INSTALL_DIR)/
+ rm -rf $(TOOLCHAIN_EXTERNAL_DOWNLOAD_INSTALL_DIR)
+ mkdir -p $(TOOLCHAIN_EXTERNAL_DOWNLOAD_INSTALL_DIR)
+ mv $(@D)/* $(TOOLCHAIN_EXTERNAL_DOWNLOAD_INSTALL_DIR)/
TOOLCHAIN_EXTERNAL_POST_EXTRACT_HOOKS += \