* changes:
tree-wide: fix various lint warnings
flake & doxygen: update tagline
nix flake metadata: print modified dates for input flakes
cli: eat terminal codes from stdout also
Implement forcing CLI colour on, and document it better
manual: fix a syntax error in redirects.js that made it not do anything
misc docs/meson tidying
build: implement clang-tidy using our plugin
The growth of the seccomp filter in 127ee1a101
made its compilation time significant (roughly 10 milliseconds have been
measured on one machine). For this reason, it is now precompiled and cached in
the parent process so that this overhead is not hit for every single build. It
is still not optimal when going through the daemon, because compilation still
happens once per client, but it's better than before and doing it only once for
the entire daemon requires excessive crimes with the current architecture.
Fixes: lix-project/lix#461
Change-Id: I2277eaaf6bab9bd74bbbfd9861e52392a54b61a3
This is a preparation for precompiling the filter, which is done separately.
The behaviour should be unchanged for now.
Change-Id: I899aa7242962615949208597aca88913feba1cb8
The seccomp setup code was a huge chunk of conditionally compiled
platform-specific code. For this reason, it is appropriate to move it to the
platform-specific implementation file. Ideally its setup could be moved a bit
to make it happen at the same place as the Darwin restrictions, but that change
is going to be less mechanical.
Change-Id: I496aa3c4fabf34656aba1e32b0089044ab5b99f8
this begins a long and arduous journey to remove all result state from
Goal, to eventually drop the std::enable_shared_from_this base, and to
completely eliminate all unsynchronized modification of states of both
Goal and Worker. by the end of this we will hopefully be able to start
and reap multiple derivation builds in parallel, which should speed up
the process quite a bit (at least for short local builds, others might
not notice a large difference. the build hooks will remain a problem.)
Change-Id: I57dcd9b2cab4636ed4aa24cdec67124fef883345
In the SSH code, the logger was conditionally paused, but unconditionally
resumed. This was fine as long as resuming the logger was idempotent. Starting
with 0dd1d8ca1c, it isn't any more, and the
behaviour of the code in question was missed. Consequently, an assertion
failure is triggered for example when performing builds against an "SSH" store
on localhost. Fix the issue by only resuming the logger when it has actually
been paused.
Fixes: lix-project/lix#458
Change-Id: Ib1e4d047744a129f15730b7216f9c9368c2f4211
we still mutate goal state to store the results of any given goal run,
but now we also have that information in Worker and could in theory do
something else with it. we could return a map of goal to goal results,
which would also let us better diagnose failures of subgoals (at all).
Change-Id: I1df956bbd9fa8cc9485fb6df32918d68dda3ff48
this is the first step towards removing all result-related mutation of
Goal state from goal implementations themselves, and into Worker state
instead. once that is done we can treat all non-const Goal fields like
private state of the goal itself, and make threading of goals possible
Change-Id: I69ff7d02a6fd91a65887c6640bfc4f5fb785b45c
once goals run on multiple threads these fields must by synchronized as
one, or we try to run build hooks to often (or worse, not often enough)
Change-Id: I47860e46fe5c6db41755b2a3a1d9dbb5701c4ca4
there are no other uses for this yet, but asking for just a subset of
outputs does seem at least somewhat useful to have as a generic thing
Change-Id: I30ff5055a666c351b1b086b8d05b9d7c9fb1c77a
limiting CA substitutions was a rather recent addition, and it used a
dedicated counter to not interfere with regular substitutions. though
this works fine it somewhat contradicts the documentation; job limits
should apply to all kinds of substitutions, or be one limit for each.
Change-Id: I1505105b14260ecc1784039b2cc4b7afcf9115c8
all goals do this. it makes no sense to not notify a goal of EOF
conditions because this is the universal signal for "child done"
Change-Id: Ic3980de312547e616739c57c6248a8e81308b5ee
just update progress every time a goal has returned from work(). there
seem to be no performance penalties, and the code is much simpler now.
Change-Id: I288ee568b764ee61f40a498d986afda49987cb50
Unfortunately, io_uring is totally opaque to seccomp, and while currently there
are no dangerous operations implemented, there is no guarantee that it remains
this way. This means that io_uring should be blocked entirely to ensure that
the sandbox is future-proof. This has not been observed to cause issues in
practice.
Change-Id: I45d3895f95abe1bc103a63969f444c334dbbf50d
Previously, system call filtering (to prevent builders from storing files with
setuid/setgid permission bits or extended attributes) was performed using a
blocklist. While this looks simple at first, it actually carries significant
security and maintainability risks: after all, the kernel may add new syscalls
to achieve the same functionality one is trying to block, and it can even be
hard to actually add the syscall to the blocklist when building against a C
library that doesn't know about it yet. For a recent demonstration of this
happening in practice to Nix, see the introduction of fchmodat2 [0] [1].
The allowlist approach does not share the same drawback. While it does require
a rather large list of harmless syscalls to be maintained in the codebase,
failing to update this list (and roll out the update to all users) in time has
rather benign effects; at worst, very recent programs that already rely on new
syscalls will fail with an error the same way they would on a slightly older
kernel that doesn't support them yet. Most importantly, no unintended new ways
of performing dangerous operations will be silently allowed.
Another possible drawback is reduced system call performance due to the larger
filter created by the allowlist requiring more computation [2]. However, this
issue has not convincingly been demonstrated yet in practice, for example in
systemd or various browsers. To the contrary, it has been measured that the the
actual filter constructed here has approximately the same overhead as a very
simple filter blocking only one system call.
This commit tries to keep the behavior as close to unchanged as possible. The
system call list is in line with libseccomp 2.5.5 and glibc 2.39, which are the
latest versions at the point of writing. Since libseccomp 2.5.5 is already a
requirement and the distributions shipping this together with older versions of
glibc are mostly not a thing any more, this should not lead to more build
failures any more.
[0] https://github.com/NixOS/nixpkgs/issues/300635
[1] https://github.com/NixOS/nix/issues/10424
[2] https://github.com/flatpak/flatpak/pull/4462#issuecomment-1061690607
Change-Id: I541be3ea9b249bcceddfed6a5a13ac10b11e16ad
In f047e4357b, I missed the behavior that if
building without a dedicated build user (i.e. in single-user setups), seccomp
setup failures are silently ignored. This was introduced without explanation 7
years ago (ff6becafa8). Hopefully the only
use-case nowadays is causing spurious test suite successes when messing up the
seccomp filter during development. Let's try removing it.
Change-Id: Ibe51416d9c7a6dd635c2282990224861adf1ceab
Use libprocstat to find garbage collector roots on FreeBSD.
Tested working on a FreeBSD machine, although there is no CI yet
Change-Id: Id36bac8c3de6cc4de94e2d76e9663dd4b76068a9
Error is pretty large, and most goals do not fail. this alone more than
halves the size of Goal on x86_64-linux, from 720 bytes down to 344. in
derived classes the difference is not as dramatic, but even the largest
derived class (`LocalDerivationGoal`) loses almost 20% of its footprint
Change-Id: Ifda8f94c81b6566eeb3e52d55d9796ec40c7bce8
the goals are either already using std::async and merely forgot to
remove std::thread vestiges or they emulate async with threads and
promises. we can simply use async directly everywhere for clarity.
Change-Id: I3f05098310a25984f10fff1e68c573329002b500
under owner_less it's equivalent to insert(), only sometimes a little
bit faster because it does not construct a weak_ptr if the goal is in
the set already. this small difference in performance does not matter
here and c++23 will make insert transparent anyway, so we can drop it
Change-Id: I7cbd7d6e0daa95d67145ec58183162f6c4743b15
*accidentally* overriding a function is almost guaranteed to be an
error. overriding a function without labeling it as such is merely
bad style, but bad style that makes the code harder to understand.
Change-Id: Ic0594f3d1604ab6b3c1a75cb5facc246effe45f0
Due to a leftover from a previous version where the buffer was allocated on the
stack, the change introduced in commit 4ec87742a1
accidentally passes the size of a pointer as the size of the buffer to the
decompressor. Since the former is much smaller (usually 8 bytes instead of 64
kilobytes), this is safe, but leads to considerable overhead; most notably, due
to excessive progress reports, which happen for each chunk. Pass the proper
buffer size instead.
Change-Id: If4bf472d33e21587acb5235a2d99e3cb10914633
SimpleLogger is not fully thread-safe, and all loggers that wrap it are
also not safe accordingly. this does not affect much, but in rare cases
it can cause interleaving of messages on stderr when used with the json
or raw log formats. the fix applied here is a bit of a hack, but fixing
this properly requires rearchitecting the logger infrastructure. nested
loggers are not the most natural abstraction here, and it is biting us.
Change-Id: Ifbf34fe1e85c60e73b59faee50e7411c7b5e7c12
If useChroot = false, and user namespaces aren't available for some
reason (e.g. within a Docker container), this fixes a pointless warning
being emitted, as we would never attempt to use them even if they were
available.
Change-Id: Ibcee91c088edd2cd19e70218d5a5802bff8f537b
This removes a *whole load* of variables from scope and enforces thread
boundaries with the type system.
There is not much change of significance in here, so the things to watch
out for while reviewing it are primarily that the destructor ordering
may have changed inadvertently, I think.
Change-Id: I3cd87e6d5a08dfcf368637407251db22a8906316