From aea4bf23b699b7ef5d7007b81f296b77324d5b6c Mon Sep 17 00:00:00 2001 From: Manolis Ragkousis Date: Sun, 7 Aug 2016 17:48:30 +0300 Subject: [PATCH] daemon: Break CHROOT_ENABLED into smaller macros. We need to check for CLONE_NEWNS only when we want to use the Linux specific clone(). Otherwise we use fork(). Also we define pivot_root() only if SYS_pivot_root is defined. * nix/libstore/build.cc (CHROOT_ENABLED): Break into CHROOT_ENABLED and CLONE_ENABLED. Define pivot_root() only if SYS_pivot_root is defined. (DerivationGoal::startBuilder): Replace CHROOT_ENABLED with CLONE_ENABLED. --- nix/libstore/build.cc | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/nix/libstore/build.cc b/nix/libstore/build.cc index ae78e65..156ae8c 100644 --- a/nix/libstore/build.cc +++ b/nix/libstore/build.cc @@ -51,7 +51,12 @@ #include #endif -#define CHROOT_ENABLED HAVE_CHROOT && HAVE_SYS_MOUNT_H && defined(MS_BIND) && defined(MS_PRIVATE) && defined(CLONE_NEWNS) && defined(SYS_pivot_root) +#define CHROOT_ENABLED HAVE_CHROOT && HAVE_SYS_MOUNT_H && defined(MS_BIND) && defined(MS_PRIVATE) +#define CLONE_ENABLED defined(CLONE_NEWNS) + +#if defined(SYS_pivot_root) +#define pivot_root(new_root, put_old) (syscall(SYS_pivot_root, new_root,put_old)) +#endif #if CHROOT_ENABLED #include @@ -1998,7 +2003,7 @@ void DerivationGoal::startBuilder() - The UTS namespace ensures that builders see a hostname of localhost rather than the actual hostname. */ -#if CHROOT_ENABLED +#if CLONE_ENABLED if (useChroot) { char stack[32 * 1024]; int flags = CLONE_NEWPID | CLONE_NEWNS | CLONE_NEWIPC | CLONE_NEWUTS | SIGCHLD; @@ -2179,10 +2184,8 @@ void DerivationGoal::runChild() if (mkdir("real-root", 0) == -1) throw SysError("cannot create real-root directory"); -#define pivot_root(new_root, put_old) (syscall(SYS_pivot_root, new_root, put_old)) if (pivot_root(".", "real-root") == -1) throw SysError(format("cannot pivot old root directory onto '%1%'") % (chrootRootDir + "/real-root")); -#undef pivot_root if (chroot(".") == -1) throw SysError(format("cannot change root directory to '%1%'") % chrootRootDir); -- 2.9.2