diff options
Diffstat (limited to 'src/libstore/build/local-derivation-goal.cc')
| -rw-r--r-- | src/libstore/build/local-derivation-goal.cc | 250 |
1 files changed, 67 insertions, 183 deletions
diff --git a/src/libstore/build/local-derivation-goal.cc b/src/libstore/build/local-derivation-goal.cc index d2798888b..a961d8eed 100644 --- a/src/libstore/build/local-derivation-goal.cc +++ b/src/libstore/build/local-derivation-goal.cc @@ -15,6 +15,8 @@ #include "callback.hh" #include "json-utils.hh" #include "cgroup.hh" +#include "personality.hh" +#include "namespaces.hh" #include <regex> #include <queue> @@ -24,7 +26,6 @@ #include <termios.h> #include <unistd.h> #include <sys/mman.h> -#include <sys/utsname.h> #include <sys/resource.h> #include <sys/socket.h> @@ -37,7 +38,6 @@ #include <sys/ioctl.h> #include <net/if.h> #include <netinet/ip.h> -#include <sys/personality.h> #include <sys/mman.h> #include <sched.h> #include <sys/param.h> @@ -168,7 +168,8 @@ void LocalDerivationGoal::killSandbox(bool getStats) } -void LocalDerivationGoal::tryLocalBuild() { +void LocalDerivationGoal::tryLocalBuild() +{ unsigned int curBuilds = worker.getNrLocalBuilds(); if (curBuilds >= settings.maxBuildJobs) { state = &DerivationGoal::tryToBuild; @@ -206,6 +207,17 @@ void LocalDerivationGoal::tryLocalBuild() { #endif } + #if __linux__ + if (useChroot) { + if (!mountAndPidNamespacesSupported()) { + if (!settings.sandboxFallback) + throw Error("this system does not support the kernel namespaces that are required for sandboxing; use '--no-sandbox' to disable sandboxing"); + debug("auto-disabling sandboxing because the prerequisite namespaces are not available"); + useChroot = false; + } + } + #endif + if (useBuildUsers()) { if (!buildUser) buildUser = acquireUserLock(parsedDrv->useUidRange() ? 65536 : 1, useChroot); @@ -230,7 +242,7 @@ void LocalDerivationGoal::tryLocalBuild() { outputLocks.unlock(); buildUser.reset(); worker.permanentFailure = true; - done(BuildResult::InputRejected, {}, e); + done(BuildResult::InputRejected, {}, std::move(e)); return; } @@ -373,12 +385,6 @@ void LocalDerivationGoal::cleanupPostOutputsRegisteredModeNonCheck() } -int childEntry(void * arg) -{ - ((LocalDerivationGoal *) arg)->runChild(); - return 1; -} - #if __linux__ static void linkOrCopy(const Path & from, const Path & to) { @@ -664,7 +670,8 @@ void LocalDerivationGoal::startBuilder() nobody account. The latter is kind of a hack to support Samba-in-QEMU. */ createDirs(chrootRootDir + "/etc"); - chownToBuilder(chrootRootDir + "/etc"); + if (parsedDrv->useUidRange()) + chownToBuilder(chrootRootDir + "/etc"); if (parsedDrv->useUidRange() && (!buildUser || buildUser->getUIDCount() < 65536)) throw Error("feature 'uid-range' requires the setting '%s' to be enabled", settings.autoAllocateUids.name); @@ -889,12 +896,7 @@ void LocalDerivationGoal::startBuilder() userNamespaceSync.create(); - Path maxUserNamespaces = "/proc/sys/user/max_user_namespaces"; - static bool userNamespacesEnabled = - pathExists(maxUserNamespaces) - && trim(readFile(maxUserNamespaces)) != "0"; - - usingUserNamespace = userNamespacesEnabled; + usingUserNamespace = userNamespacesSupported(); Pid helper = startProcess([&]() { @@ -909,76 +911,21 @@ void LocalDerivationGoal::startBuilder() if (getuid() == 0 && setgroups(0, 0) == -1) throw SysError("setgroups failed"); - size_t stackSize = 1 * 1024 * 1024; - char * stack = (char *) mmap(0, stackSize, - PROT_WRITE | PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, -1, 0); - if (stack == MAP_FAILED) throw SysError("allocating stack"); - - int flags = CLONE_NEWPID | CLONE_NEWNS | CLONE_NEWIPC | CLONE_NEWUTS | CLONE_PARENT | SIGCHLD; + ProcessOptions options; + options.cloneFlags = CLONE_NEWPID | CLONE_NEWNS | CLONE_NEWIPC | CLONE_NEWUTS | CLONE_PARENT | SIGCHLD; if (privateNetwork) - flags |= CLONE_NEWNET; + options.cloneFlags |= CLONE_NEWNET; if (usingUserNamespace) - flags |= CLONE_NEWUSER; - - pid_t child = clone(childEntry, stack + stackSize, flags, this); - if (child == -1 && errno == EINVAL) { - /* Fallback for Linux < 2.13 where CLONE_NEWPID and - CLONE_PARENT are not allowed together. */ - flags &= ~CLONE_NEWPID; - child = clone(childEntry, stack + stackSize, flags, this); - } - if (usingUserNamespace && child == -1 && (errno == EPERM || errno == EINVAL)) { - /* Some distros patch Linux to not allow unprivileged - * user namespaces. If we get EPERM or EINVAL, try - * without CLONE_NEWUSER and see if that works. - * Details: https://salsa.debian.org/kernel-team/linux/-/commit/d98e00eda6bea437e39b9e80444eee84a32438a6 - */ - usingUserNamespace = false; - flags &= ~CLONE_NEWUSER; - child = clone(childEntry, stack + stackSize, flags, this); - } - if (child == -1) { - switch(errno) { - case EPERM: - case EINVAL: { - int errno_ = errno; - if (!userNamespacesEnabled && errno==EPERM) - notice("user namespaces appear to be disabled; they are required for sandboxing; check /proc/sys/user/max_user_namespaces"); - if (userNamespacesEnabled) { - Path procSysKernelUnprivilegedUsernsClone = "/proc/sys/kernel/unprivileged_userns_clone"; - if (pathExists(procSysKernelUnprivilegedUsernsClone) - && trim(readFile(procSysKernelUnprivilegedUsernsClone)) == "0") { - notice("user namespaces appear to be disabled; they are required for sandboxing; check /proc/sys/kernel/unprivileged_userns_clone"); - } - } - Path procSelfNsUser = "/proc/self/ns/user"; - if (!pathExists(procSelfNsUser)) - notice("/proc/self/ns/user does not exist; your kernel was likely built without CONFIG_USER_NS=y, which is required for sandboxing"); - /* Otherwise exit with EPERM so we can handle this in the - parent. This is only done when sandbox-fallback is set - to true (the default). */ - if (settings.sandboxFallback) - _exit(1); - /* Mention sandbox-fallback in the error message so the user - knows that having it disabled contributed to the - unrecoverability of this failure */ - throw SysError(errno_, "creating sandboxed builder process using clone(), without sandbox-fallback"); - } - default: - throw SysError("creating sandboxed builder process using clone()"); - } - } + options.cloneFlags |= CLONE_NEWUSER; + + pid_t child = startProcess([&]() { runChild(); }, options); + writeFull(builderOut.writeSide.get(), fmt("%d %d\n", usingUserNamespace, child)); _exit(0); }); - int res = helper.wait(); - if (res != 0 && settings.sandboxFallback) { - useChroot = false; - initTmpDir(); - goto fallback; - } else if (res != 0) + if (helper.wait() != 0) throw Error("unable to start build process"); userNamespaceSync.readSide = -1; @@ -1046,9 +993,6 @@ void LocalDerivationGoal::startBuilder() } else #endif { -#if __linux__ - fallback: -#endif pid = startProcess([&]() { runChild(); }); @@ -1460,7 +1404,7 @@ struct RestrictedStore : public virtual RestrictedStoreConfig, public virtual Lo unknown, downloadSize, narSize); } - virtual std::optional<std::string> getBuildLog(const StorePath & path) override + virtual std::optional<std::string> getBuildLogExact(const StorePath & path) override { return std::nullopt; } virtual void addBuildLog(const StorePath & path, std::string_view log) override @@ -1517,8 +1461,7 @@ void LocalDerivationGoal::startDaemon() FdSink to(remote.get()); try { daemon::processConnection(store, from, to, - daemon::NotTrusted, daemon::Recursive, - [&](Store & store) { store.createUser("nobody", 65535); }); + daemon::NotTrusted, daemon::Recursive); debug("terminated daemon connection"); } catch (SysError &) { ignoreException(); @@ -1908,6 +1851,10 @@ void LocalDerivationGoal::runChild() } } + /* Make /etc unwritable */ + if (!parsedDrv->useUidRange()) + chmod_(chrootRootDir + "/etc", 0555); + /* Unshare this mount namespace. This is necessary because pivot_root() below changes the root of the mount namespace. This means that the call to setns() in @@ -1964,33 +1911,7 @@ void LocalDerivationGoal::runChild() /* Close all other file descriptors. */ closeMostFDs({STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO}); -#if __linux__ - /* Change the personality to 32-bit if we're doing an - i686-linux build on an x86_64-linux machine. */ - struct utsname utsbuf; - uname(&utsbuf); - if ((drv->platform == "i686-linux" - && (settings.thisSystem == "x86_64-linux" - || (!strcmp(utsbuf.sysname, "Linux") && !strcmp(utsbuf.machine, "x86_64")))) - || drv->platform == "armv7l-linux" - || drv->platform == "armv6l-linux") - { - if (personality(PER_LINUX32) == -1) - throw SysError("cannot set 32-bit personality"); - } - - /* Impersonate a Linux 2.6 machine to get some determinism in - builds that depend on the kernel version. */ - if ((drv->platform == "i686-linux" || drv->platform == "x86_64-linux") && settings.impersonateLinux26) { - int cur = personality(0xffffffff); - if (cur != -1) personality(cur | 0x0020000 /* == UNAME26 */); - } - - /* Disable address space randomization for improved - determinism. */ - int cur = personality(0xffffffff); - if (cur != -1) personality(cur | ADDR_NO_RANDOMIZE); -#endif + setPersonality(drv->platform); /* Disable core dumps by default. */ struct rlimit limit = { 0, RLIM_INFINITY }; @@ -2077,10 +1998,14 @@ void LocalDerivationGoal::runChild() sandboxProfile += "(deny default (with no-log))\n"; } - sandboxProfile += "(import \"sandbox-defaults.sb\")\n"; + sandboxProfile += + #include "sandbox-defaults.sb" + ; if (!derivationType.isSandboxed()) - sandboxProfile += "(import \"sandbox-network.sb\")\n"; + sandboxProfile += + #include "sandbox-network.sb" + ; /* Add the output paths we'll use at build-time to the chroot */ sandboxProfile += "(allow file-read* file-write* process-exec\n"; @@ -2123,7 +2048,9 @@ void LocalDerivationGoal::runChild() sandboxProfile += additionalSandboxProfile; } else - sandboxProfile += "(import \"sandbox-minimal.sb\")\n"; + sandboxProfile += + #include "sandbox-minimal.sb" + ; debug("Generated sandbox profile:"); debug(sandboxProfile); @@ -2148,8 +2075,6 @@ void LocalDerivationGoal::runChild() args.push_back(sandboxFile); args.push_back("-D"); args.push_back("_GLOBAL_TMP_DIR=" + globalTmpDir); - args.push_back("-D"); - args.push_back("IMPORT_DIR=" + settings.nixDataDir + "/nix/sandbox/"); if (allowLocalNetworking) { args.push_back("-D"); args.push_back(std::string("_ALLOW_LOCAL_NETWORKING=1")); @@ -2260,7 +2185,6 @@ DrvOutputs LocalDerivationGoal::registerOutputs() InodesSeen inodesSeen; Path checkSuffix = ".check"; - bool keepPreviousRound = settings.keepFailed || settings.runDiffHook; std::exception_ptr delayedException; @@ -2347,11 +2271,28 @@ DrvOutputs LocalDerivationGoal::registerOutputs() buildUser ? std::optional(buildUser->getUIDRange()) : std::nullopt, inodesSeen); - debug("scanning for references for output '%s' in temp location '%s'", outputName, actualPath); + bool discardReferences = false; + if (auto structuredAttrs = parsedDrv->getStructuredAttrs()) { + if (auto udr = get(*structuredAttrs, "unsafeDiscardReferences")) { + settings.requireExperimentalFeature(Xp::DiscardReferences); + if (auto output = get(*udr, outputName)) { + if (!output->is_boolean()) + throw Error("attribute 'unsafeDiscardReferences.\"%s\"' of derivation '%s' must be a Boolean", outputName, drvPath.to_string()); + discardReferences = output->get<bool>(); + } + } + } - /* Pass blank Sink as we are not ready to hash data at this stage. */ - NullSink blank; - auto references = scanForReferences(blank, actualPath, referenceablePaths); + StorePathSet references; + if (discardReferences) + debug("discarding references of output '%s'", outputName); + else { + debug("scanning for references for output '%s' in temp location '%s'", outputName, actualPath); + + /* Pass blank Sink as we are not ready to hash data at this stage. */ + NullSink blank; + references = scanForReferences(blank, actualPath, referenceablePaths); + } outputReferencesIfUnregistered.insert_or_assign( outputName, @@ -2688,10 +2629,8 @@ DrvOutputs LocalDerivationGoal::registerOutputs() debug("unreferenced input: '%1%'", worker.store.printStorePath(i)); } - if (curRound == nrRounds) { - localStore.optimisePath(actualPath, NoRepair); // FIXME: combine with scanForReferences() - worker.markContentsGood(newInfo.path); - } + localStore.optimisePath(actualPath, NoRepair); // FIXME: combine with scanForReferences() + worker.markContentsGood(newInfo.path); newInfo.deriver = drvPath; newInfo.ultimate = true; @@ -2720,61 +2659,6 @@ DrvOutputs LocalDerivationGoal::registerOutputs() /* Apply output checks. */ checkOutputs(infos); - /* Compare the result with the previous round, and report which - path is different, if any.*/ - if (curRound > 1 && prevInfos != infos) { - assert(prevInfos.size() == infos.size()); - for (auto i = prevInfos.begin(), j = infos.begin(); i != prevInfos.end(); ++i, ++j) - if (!(*i == *j)) { - buildResult.isNonDeterministic = true; - Path prev = worker.store.printStorePath(i->second.path) + checkSuffix; - bool prevExists = keepPreviousRound && pathExists(prev); - hintformat hint = prevExists - ? hintfmt("output '%s' of '%s' differs from '%s' from previous round", - worker.store.printStorePath(i->second.path), worker.store.printStorePath(drvPath), prev) - : hintfmt("output '%s' of '%s' differs from previous round", - worker.store.printStorePath(i->second.path), worker.store.printStorePath(drvPath)); - - handleDiffHook( - buildUser ? buildUser->getUID() : getuid(), - buildUser ? buildUser->getGID() : getgid(), - prev, worker.store.printStorePath(i->second.path), - worker.store.printStorePath(drvPath), tmpDir); - - if (settings.enforceDeterminism) - throw NotDeterministic(hint); - - printError(hint); - - curRound = nrRounds; // we know enough, bail out early - } - } - - /* If this is the first round of several, then move the output out of the way. */ - if (nrRounds > 1 && curRound == 1 && curRound < nrRounds && keepPreviousRound) { - for (auto & [_, outputStorePath] : finalOutputs) { - auto path = worker.store.printStorePath(outputStorePath); - Path prev = path + checkSuffix; - deletePath(prev); - Path dst = path + checkSuffix; - renameFile(path, dst); - } - } - - if (curRound < nrRounds) { - prevInfos = std::move(infos); - return {}; - } - - /* Remove the .check directories if we're done. FIXME: keep them - if the result was not determistic? */ - if (curRound == nrRounds) { - for (auto & [_, outputStorePath] : finalOutputs) { - Path prev = worker.store.printStorePath(outputStorePath) + checkSuffix; - deletePath(prev); - } - } - /* Register each output path as valid, and register the sets of paths referenced by each of them. If there are cycles in the outputs, this will fail. */ @@ -2816,7 +2700,7 @@ DrvOutputs LocalDerivationGoal::registerOutputs() signRealisation(thisRealisation); worker.store.registerDrvOutput(thisRealisation); } - if (wantOutput(outputName, wantedOutputs)) + if (wantedOutputs.contains(outputName)) builtOutputs.emplace(thisRealisation.id, thisRealisation); } |