Sandbox: Fix /dev/ptmx on recent kernels
This fixes "No such file or directory" when opening /dev/ptmx (e.g. http://hydra.nixos.org/build/51094249). The reason appears to be some changes to /dev/ptmx / /dev/pts handling between Linux 4.4 and 4.9. See https://patchwork.kernel.org/patch/7832531/. The fix is to go back to mounting a proper /dev/pts instance inside the sandbox. Happily, this now works inside user namespaces, even for unprivileged users. So NIX_REMOTE=local?root=/tmp/nix nix-build \ '<nixpkgs/nixos/tests/misc.nix>' -A test works for non-root users. The downside is that the fix breaks sandbox builds on older kernels (probably pre-4.6), since mounting a devpts fails inside user namespaces for some reason I've never been able to figure out. Builds on those systems will fail with error: while setting up the build environment: mounting /dev/pts: Invalid argument Ah well.
This commit is contained in:
parent
3ecb09a40a
commit
29d35805c6
1 changed files with 1 additions and 8 deletions
|
@ -2391,8 +2391,6 @@ void DerivationGoal::runChild()
|
|||
ss.push_back("/dev/tty");
|
||||
ss.push_back("/dev/urandom");
|
||||
ss.push_back("/dev/zero");
|
||||
ss.push_back("/dev/ptmx");
|
||||
ss.push_back("/dev/pts");
|
||||
createSymlink("/proc/self/fd", chrootRootDir + "/dev/fd");
|
||||
createSymlink("/proc/self/fd/0", chrootRootDir + "/dev/stdin");
|
||||
createSymlink("/proc/self/fd/1", chrootRootDir + "/dev/stdout");
|
||||
|
@ -2448,17 +2446,13 @@ void DerivationGoal::runChild()
|
|||
fmt("size=%s", settings.get("sandbox-dev-shm-size", std::string("50%"))).c_str()) == -1)
|
||||
throw SysError("mounting /dev/shm");
|
||||
|
||||
#if 0
|
||||
// FIXME: can't figure out how to do this in a user
|
||||
// namespace.
|
||||
|
||||
/* Mount a new devpts on /dev/pts. Note that this
|
||||
requires the kernel to be compiled with
|
||||
CONFIG_DEVPTS_MULTIPLE_INSTANCES=y (which is the case
|
||||
if /dev/ptx/ptmx exists). */
|
||||
if (pathExists("/dev/pts/ptmx") &&
|
||||
!pathExists(chrootRootDir + "/dev/ptmx")
|
||||
&& dirsInChroot.find("/dev/pts") == dirsInChroot.end())
|
||||
&& !dirsInChroot.count("/dev/pts"))
|
||||
{
|
||||
if (mount("none", (chrootRootDir + "/dev/pts").c_str(), "devpts", 0, "newinstance,mode=0620") == -1)
|
||||
throw SysError("mounting /dev/pts");
|
||||
|
@ -2468,7 +2462,6 @@ void DerivationGoal::runChild()
|
|||
Linux versions, it is created with permissions 0. */
|
||||
chmod_(chrootRootDir + "/dev/pts/ptmx", 0666);
|
||||
}
|
||||
#endif
|
||||
|
||||
/* Do the chroot(). */
|
||||
if (chdir(chrootRootDir.c_str()) == -1)
|
||||
|
|
Loading…
Reference in a new issue