diff options
| -rw-r--r-- | nix/libstore/build.cc | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/nix/libstore/build.cc b/nix/libstore/build.cc index 3861a1ffd9..c8b778362a 100644 --- a/nix/libstore/build.cc +++ b/nix/libstore/build.cc @@ -2091,6 +2091,18 @@ void DerivationGoal::runChild() for (auto & i : ss) dirsInChroot[i] = i; + /* Make new mounts for the store and for /tmp. That way, when + 'chrootRootDir' is made read-only below, these two mounts will + remain writable (the store needs to be writable so derivation + outputs can be written to it, and /tmp is writable by + convention). */ + auto chrootStoreDir = chrootRootDir + settings.nixStore; + if (mount(chrootStoreDir.c_str(), chrootStoreDir.c_str(), 0, MS_BIND, 0) == -1) + throw SysError(format("read-write mount of store '%1%' failed") % chrootStoreDir); + auto chrootTmpDir = chrootRootDir + "/tmp"; + if (mount(chrootTmpDir.c_str(), chrootTmpDir.c_str(), 0, MS_BIND, 0) == -1) + throw SysError(format("read-write mount of temporary directory '%1%' failed") % chrootTmpDir); + /* Bind-mount all the directories from the "host" filesystem that we want in the chroot environment. */ @@ -2164,6 +2176,10 @@ void DerivationGoal::runChild() if (rmdir("real-root") == -1) throw SysError("cannot remove real-root directory"); + + /* Remount root as read-only. */ + if (mount("/", "/", 0, MS_BIND | MS_REMOUNT | MS_RDONLY, 0) == -1) + throw SysError(format("read-only remount of build root '%1%' failed") % chrootRootDir); } #endif |