dcd36d47d2
This reverts commita0aa7e0e17and 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 commita0aa7e0e17. Commita0aa7e0e17removed 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 (75630eba22: 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 commitb731dc7bfb("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 commita0aa7e0e17, 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 <slash.tmp@free.fr> Cc: Mason <slash.tmp@free.fr> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Peter Korsgaard <peter@korsgaard.com> (cherry picked from commitb171466c44)
Buildroot is a simple, efficient and easy-to-use tool to generate embedded Linux systems through cross-compilation. The documentation can be found in docs/manual. You can generate a text document with 'make manual-text' and read output/docs/manual/manual.text. Online documentation can be found at http://buildroot.org/docs.html To build and use the buildroot stuff, do the following: 1) run 'make menuconfig' 2) select the target architecture and the packages you wish to compile 3) run 'make' 4) wait while it compiles 5) find the kernel, bootloader, root filesystem, etc. in output/images You do not need to be root to build or run buildroot. Have fun! Buildroot comes with a basic configuration for a number of boards. Run 'make list-defconfigs' to view the list of provided configurations. Please feed suggestions, bug reports, insults, and bribes back to the buildroot mailing list: buildroot@buildroot.org You can also find us on #buildroot on Freenode IRC. If you would like to contribute patches, please read https://buildroot.org/manual.html#submitting-patches