Commit graph

1774 commits

Author SHA1 Message Date
Eelco Dolstra
47701677e8 Add integer ‘-’, ‘*’ and ‘/’ operators 2013-08-02 16:03:02 +00:00
Eelco Dolstra
5d147e125c Add a unary integer negation operator
This allows saying "-1" instead of "builtins.sub 0 1".
2013-08-02 15:43:31 +00:00
Eelco Dolstra
159e621d1a Overload the ‘+’ operator to support integer addition 2013-08-02 15:21:17 +00:00
Eelco Dolstra
0a470fc345 Make Env smaller
Commit 20866a7031 added a ‘withAttrs’
field to Env, which is annoying because it makes every Env structure
bigger and we allocate millions of them.  E.g. NixOS evaluation took
18 MiB more.  So this commit squeezes ‘withAttrs’ into values[0].
Probably should use a union...
2013-07-31 12:44:21 +02:00
Eelco Dolstra
8ae6d55db1 Don't use NULL 2013-07-31 12:11:14 +02:00
Shea Levy
e068f49f7d Avoid thunks when a fromWith var can be looked up without evaluation
Signed-off-by: Shea Levy <shea@shealevy.com>
2013-07-31 11:48:39 +02:00
Shea Levy
20866a7031 Delay evaulation of with attrs until a variable lookup needs them
Evaluation of attribute sets is strict in the attribute names, which
means immediate evaluation of `with` attribute sets rules out some
potentially interesting use cases (e.g. where the attribute names of one
set depend in some way on another but we want to bring those names into
scope for some values in the second set).

The major example of this is overridable self-referential package sets
(e.g. all-packages.nix). With immediate `with` evaluation, the only
options for such sets are to either make them non-recursive and
explicitly use the name of the overridden set in non-overridden one
every time you want to reference another package, or make the set
recursive and use the `__overrides` hack. As shown in the test case that
comes with this commit, though, delayed `with` evaluation allows a nicer
third alternative.

Signed-off-by: Shea Levy <shea@shealevy.com>
2013-07-31 11:48:39 +02:00
Eelco Dolstra
70e68e0ec6 Detect stack overflows
Previously, if the Nix evaluator gets a stack overflow due to a deep
or infinite recursion in the Nix expression, the user gets an
unhelpful message ("Segmentation fault") that doesn't indicate that
the problem is in the user's code rather than Nix itself.  Now it
prints:

  error: stack overflow (possible infinite recursion)

This only works on x86_64-linux and i686-linux.

Fixes #35.
2013-07-30 23:37:10 +02:00
Shea Levy
e87d1a63bd killUser: Don't let the child kill itself on Apple
The kill(2) in Apple's libc follows POSIX semantics, which means that
kill(-1, SIGKILL) will kill the calling process too. Since nix has no
way to distinguish between the process successfully killing everything
and the process being killed by a rogue builder in that case, it can't
safely conclude that killUser was successful.

Luckily, the actual kill syscall takes a parameter that determines
whether POSIX semantics are followed, so we can call that syscall
directly and avoid the issue on Apple.

Signed-off-by: Shea Levy <shea@shealevy.com>
2013-07-30 21:25:16 +02:00
Eelco Dolstra
a4921b8ceb Revert "build-remote.pl: Enforce timeouts locally"
This reverts commit 69b8f9980f.

The timeout should be enforced remotely.  Otherwise, if the garbage
collector is running either locally or remotely, if will block the
build or closure copying for some time.  If the garbage collector
takes too long, the build may time out, which is not what we want.
Also, on heavily loaded systems, copying large paths to and from the
remote machine can take a long time, also potentially resulting in a
timeout.
2013-07-18 12:52:29 +02:00
Shea Levy
16591eb3cc Allow bind-mounting regular files into the chroot
mount(2) with MS_BIND allows mounting a regular file on top of a regular
file, so there's no reason to only bind directories. This allows finer
control over just which files are and aren't included in the chroot
without having to build symlink trees or the like.

Signed-off-by: Shea Levy <shea@shealevy.com>
2013-07-15 16:01:33 +02:00
Eelco Dolstra
aeb810b01e Garbage collector: Don't follow symlinks arbitrarily
Only indirect roots (symlinks to symlinks to the Nix store) are now
supported.
2013-07-12 14:03:36 +02:00
Ludovic Courtès
212e96f39c Leave `HAVE_HUP_NOTIFICATION' undefined on GNU/Hurd. 2013-07-07 13:21:06 +02:00
Eelco Dolstra
7ccd946407 Don't set $preferLocalBuild and $requiredSystemFeatures in builders
With C++ std::map, doing a comparison like ‘map["foo"] == ...’ has the
side-effect of adding a mapping from "foo" to the empty string if
"foo" doesn't exist in the map.  So we ended up setting some
environment variables by accident.
2013-06-20 18:07:27 +00:00
Eelco Dolstra
5558652709 Don't substitute derivations that have preferLocalBuild set
In particular this means that "trivial" derivations such as writeText
are not substituted, reducing the number of GET requests to the binary
cache by about 200 on a typical NixOS configuration.
2013-06-20 19:26:31 +02:00
Eelco Dolstra
1906cce6fc Increase SQLite's auto-checkpoint interval
Common operations like instantiating a NixOS system config no longer
fitted in 8192 pages, leading to more fsyncs.  So increase this limit.
2013-06-20 14:01:33 +00:00
Eelco Dolstra
9b11165aec Disable the copy-from-other-stores substituter
This substituter basically cannot work reliably since we switched to
SQLite, since SQLite databases may need write access to open them even
just for reading (and in WAL mode they always do).
2013-06-20 12:01:33 +02:00
Eelco Dolstra
22144afa8d Don't keep "disabled" substituters running
For instance, it's pointless to keep copy-from-other-stores running if
there are no other stores, or download-using-manifests if there are no
manifests.  This also speeds things up because we don't send queries
to those substituters.
2013-06-20 11:55:15 +02:00
Eelco Dolstra
1b6ee8f4c7 Allow hard links between the outputs of a derivation 2013-06-13 17:29:56 +02:00
Eelco Dolstra
cd49ee0897 Fix a security bug in hash rewriting
Before calling dumpPath(), we have to make sure the files are owned by
the build user.  Otherwise, the build could contain a hard link to
(say) /etc/shadow, which would then be read by the daemon and
rewritten as a world-readable file.

This only affects systems that don't have hard link restrictions
enabled.
2013-06-13 17:12:24 +02:00
Eelco Dolstra
1e2c7c04b1 Fix assertion failure in canonicalisePathMetaData() after hash rewriting
The assertion in canonicalisePathMetaData() failed because the
ownership of the path already changed due to the hash rewriting.  The
solution is not to check the ownership of rewritten paths.

Issue #122.
2013-06-13 17:12:06 +02:00
Eelco Dolstra
6cc2a8f8ed computeFSClosure: Only process the missing/corrupt paths
Issue #122.
2013-06-13 16:43:20 +02:00
Eelco Dolstra
f9ff67e948 In repair mode, update the hash of rebuilt paths
Otherwise subsequent invocations of "--repair" will keep rebuilding
the path.  This only happens if the path content differs between
builds (e.g. due to timestamps).
2013-06-13 14:46:07 +02:00
Eelco Dolstra
6b05f688ee nix-daemon: Trust options like binary-caches when the client is root
Fixes #127.
2013-06-12 12:10:26 +02:00
Eelco Dolstra
ca70fba0bf Remove obsolete EOF checks 2013-06-07 15:10:23 +02:00
Eelco Dolstra
5959c591a0 Process stderr from substituters while doing have/info queries 2013-06-07 15:02:14 +02:00
Eelco Dolstra
c5f9d0d080 Buffer reads from the substituter
This greatly reduces the number of system calls.
2013-06-07 14:00:23 +02:00
Eelco Dolstra
b09b87321c nix-store --export: Export paths in topologically sorted order
Fixes #118.
2013-05-23 14:55:36 -04:00
Eelco Dolstra
18a48d80a0 Show function names in error messages
Functions in Nix are anonymous, but if they're assigned to a
variable/attribute, we can use the variable/attribute name in error
messages, e.g.

while evaluating `concatMapStrings' at `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/strings.nix:18:25':
...
2013-05-16 19:08:02 +02:00
Eelco Dolstra
1b3a03f161 Show which function argument was unexpected
Fixes #116.
2013-05-16 17:56:14 +02:00
Eelco Dolstra
229567293c Shut up a compiler warning 2013-05-16 17:48:19 +02:00
Eelco Dolstra
2ee9da9e22 In trace messages, don't print the output path
This doesn't work if there is no output named "out".  Hydra didn't use
it anyway.
2013-05-10 00:24:33 +02:00
Eelco Dolstra
6eba05613a Communicate build timeouts to Hydra 2013-05-09 18:39:04 +02:00
Eelco Dolstra
69b8f9980f build-remote.pl: Enforce timeouts locally
Don't pass --timeout / --max-silent-time to the remote builder.
Instead, let the local Nix process terminate the build if it exceeds a
timeout.  The remote builder will be killed as a side-effect.  This
gives better error reporting (since the timeout message from the
remote side wasn't properly propagated) and handles non-Nix problems
like SSH hangs.
2013-05-09 17:17:17 +02:00
Eelco Dolstra
470553bd05 Don't let stderr writes in substituters cause a deadlock 2013-05-01 13:21:39 +02:00
Eelco Dolstra
0374d94437 addAdditionalRoots(): Check each path only once 2013-04-26 12:07:25 +02:00
Eelco Dolstra
772b70952f Fix --timeout
I'm not sure if it has ever worked correctly.  The line "lastWait =
after;" seems to mean that the timer was reset every time a build
produced log output.

Note that the timeout is now per build, as documented ("the maximum
number of seconds that a builder can run").
2013-04-23 18:04:59 +02:00
Eelco Dolstra
934cf2d1f4 Nix daemon: respect build timeout from the client 2013-04-23 16:59:06 +02:00
Eelco Dolstra
258897c265 Complain if /homeless-shelter exists 2013-04-04 11:16:26 +02:00
Shea Levy
cc63db1dd5 makeStoreWritable: Ask forgiveness, not permission
It is surprisingly impossible to check if a mountpoint is a bind mount
on Linux, and in my previous commit I forgot to check if /nix/store was
even a mountpoint at all. statvfs.f_flag is not populated with MS_BIND
(and even if it were, my check was wrong in the previous commit).

Luckily, the semantics of mount with MS_REMOUNT | MS_BIND make both
checks unnecessary: if /nix/store is not a mountpoint, then mount will
fail with EINVAL, and if /nix/store is not a bind-mount, then it will
not be made writable. Thus, if /nix/store is not a mountpoint, we fail
immediately (since we don't know how to make it writable), and if
/nix/store IS a mountpoint but not a bind-mount, we fail at first write
(see below for why we can't check and fail immediately).

Note that, due to what is IMO buggy behavior in Linux, calling mount
with MS_REMOUNT | MS_BIND on a non-bind readonly mount makes the
mountpoint appear writable in two places: In the sixth (but not the
10th!) column of mountinfo, and in the f_flags member of struct statfs.
All other syscalls behave as if the mount point were still readonly (at
least for Linux 3.9-rc1, but I don't think this has changed recently or
is expected to soon). My preferred semantics would be for MS_REMOUNT |
MS_BIND to fail on a non-bind mount, as it doesn't make sense to remount
a non bind-mount as a bind mount.
2013-03-25 19:00:16 +01:00
Shea Levy
2c9cf50746 makeStoreWritable: Use statvfs instead of /proc/self/mountinfo to find out if /nix/store is a read-only bind mount
/nix/store could be a read-only bind mount even if it is / in its own filesystem, so checking the 4th field in mountinfo is insufficient.

Signed-off-by: Shea Levy <shea@shealevy.com>
2013-03-25 19:00:16 +01:00
Eelco Dolstra
804709706c Fix building against Bison 2.6 2013-03-14 18:31:08 +01:00
Eelco Dolstra
c56bc3d81c Make sure that thunks are restored properly if an exception occurs
Fixes Hydra bug #67.
2013-03-14 17:21:13 +01:00
Eelco Dolstra
bdd4646338 Revert "Prevent config.h from being clobbered"
This reverts commit 28bba8c44f.
2013-03-08 01:24:59 +01:00
Eelco Dolstra
28bba8c44f Prevent config.h from being clobbered 2013-03-07 23:55:55 +01:00
Eelco Dolstra
8057a192e3 Handle systems without lutimes() or lchown() 2013-02-28 19:55:09 +01:00
Eelco Dolstra
f45c731cd7 Handle symlinks properly
Now it's really brown paper bag time...
2013-02-28 14:51:08 +01:00
Eelco Dolstra
0111ba98ea Handle hard links to other files in the output 2013-02-27 17:18:41 +01:00
Eelco Dolstra
b008674e46 Refactoring: Split off the non-recursive canonicalisePathMetaData()
Also, change the file mode before changing the owner.  This prevents a
slight time window in which a setuid binary would be setuid root.
2013-02-27 16:42:19 +01:00
Eelco Dolstra
5526a282b5 Security: Don't allow builders to change permissions on files they don't own
It turns out that in multi-user Nix, a builder may be able to do

  ln /etc/shadow $out/foo

Afterwards, canonicalisePathMetaData() will be applied to $out/foo,
causing /etc/shadow's mode to be set to 444 (readable by everybody but
writable by nobody).  That's obviously Very Bad.

Fortunately, this fails in NixOS's default configuration because
/nix/store is a bind mount, so "ln" will fail with "Invalid
cross-device link".  It also fails if hard-link restrictions are
enabled, so a workaround is:

  echo 1 > /proc/sys/fs/protected_hardlinks

The solution is to check that all files in $out are owned by the build
user.  This means that innocuous operations like "ln
${pkgs.foo}/some-file $out/" are now rejected, but that already failed
in chroot builds anyway.
2013-02-26 02:30:19 +01:00