Commit graph

380 commits

Author SHA1 Message Date
Eelco Dolstra bbe97dff8b Make the Store API more type-safe
Most functions now take a StorePath argument rather than a Path (which
is just an alias for std::string). The StorePath constructor ensures
that the path is syntactically correct (i.e. it looks like
<store-dir>/<base32-hash>-<name>). Similarly, functions like
buildPaths() now take a StorePathWithOutputs, rather than abusing Path
by adding a '!<outputs>' suffix.

Note that the StorePath type is implemented in Rust. This involves
some hackery to allow Rust values to be used directly in C++, via a
helper type whose destructor calls the Rust type's drop()
function. The main issue is the dynamic nature of C++ move semantics:
after we have moved a Rust value, we should not call the drop function
on the original value. So when we move a value, we set the original
value to bitwise zero, and the destructor only calls drop() if the
value is not bitwise zero. This should be sufficient for most types.

Also lots of minor cleanups to the C++ API to make it more modern
(e.g. using std::optional and std::string_view in some places).
2019-12-10 22:06:05 +01:00
Eelco Dolstra 98ef11677c EvalState::callFunction(): Make FunctionCallTrace use less stack space
The FunctionCallTrace object consumes a few hundred bytes of stack
space, even when tracing is disabled. This was causing stack overflows:

  $ nix-instantiate '<nixpkgs> -A texlive.combined.scheme-full --dry-run
  error: stack overflow (possible infinite recursion)

This is with the default stack size of 8 MiB.

Putting the object on the heap reduces stack usage to < 5 MiB.
2019-12-10 13:32:30 +01:00
Eelco Dolstra 0678e4d56a Move #include
(cherry picked from commit 8beedd4486)
2019-12-05 20:30:29 +01:00
Eelco Dolstra 2d6f1ddbb5
Remove builtins.valueSize
Fixes #3246.
2019-11-28 13:52:42 +01:00
puck cd55f91ad2 Ensure enough space in attrset bindings when using both __overrides and dynamic attributes 2019-11-25 12:37:14 +00:00
Eelco Dolstra d12d69ea1a
Turn NIX_PATH into a config setting
This allows it to be set in nix.conf.
2019-11-22 23:07:35 +01:00
Eelco Dolstra ec9dd9a5ae
Provide a default value for NIX_PATH 2019-11-22 22:08:51 +01:00
Eelco Dolstra ba87b08f85
getEnv(): Return std::optional
This allows distinguishing between an empty value and no value.
2019-11-22 16:18:13 +01:00
Eelco Dolstra 5ee23c35b9
Merge pull request #3219 from Ericson2314/semicolons
Fix extra semicolons warnings
2019-11-11 12:13:51 +01:00
John Ericson 4c34054673 Remove unneeded semicolons 2019-11-10 11:24:47 -05:00
Eelco Dolstra e012384fe9
Merge branch 'tojson-tostring-fix' of https://github.com/mayflower/nix 2019-10-27 12:18:35 +01:00
Robin Gloster e583df5280
builtins.toJSON: fix __toString usage 2019-10-27 10:15:51 +01:00
Eelco Dolstra 99b73fb507
OCD performance fix: {find,count}+insert => insert 2019-10-09 16:06:29 +02:00
Graham Christensen ee9c988a1b
Track function start and ends for flame graphs
With this patch, and this file I called `log.py`:

    #!/usr/bin/env nix-shell
    #!nix-shell -i python3 -p python3 --pure

    import sys
    from pprint import pprint

    stack = []
    timestack = []

    for line in open(sys.argv[1]):
        components = line.strip().split(" ", 2)
        if components[0] != "function-trace":
            continue

        direction = components[1]
        components = components[2].rsplit(" ", 2)

        loc = components[0]
        _at = components[1]
        time = int(components[2])

        if direction == "entered":
            stack.append(loc)
            timestack.append(time)
        elif direction == "exited":
            dur = time - timestack.pop()
            vst = ";".join(stack)
            print(f"{vst} {dur}")
            stack.pop()

and:

    nix-instantiate --trace-function-calls -vvvv ../nixpkgs/pkgs/top-level/release.nix -A unstable > log.matthewbauer 2>&1
    ./log.py ./log.matthewbauer > log.matthewbauer.folded
    flamegraph.pl --title matthewbauer-post-pr log.matthewbauer.folded > log.matthewbauer.folded.svg

I can make flame graphs like: http://gsc.io/log.matthewbauer.folded.svg

---

Includes test cases around function call failures and tryEval. Uses
RAII so the finish is always called at the end of the function.
2019-08-14 16:09:35 -04:00
Eelco Dolstra bb6e6923f2 Add environment variable NIX_SHOW_SYMBOLS for dumping the symbol table 2019-04-11 23:04:13 +02:00
Linus Heckemann 2aa89daab3 eval: improve type description for primops and applied primops
This can make type errors a little easier to understand.
2019-03-21 15:31:46 +01:00
Will Dietz 21ea00d3ec EvalState::resetFileCache: clear parse cache as well as eval cache
Fixes #2546.

(at least the basic reproduction I've been testing)
2018-12-31 10:18:28 -06:00
Eelco Dolstra 91405986f4
Convert NIX_COUNT_CALLS to JSON too 2018-09-05 21:57:54 +02:00
Eelco Dolstra 0a2545f95c
Log stats to stderr
We shouldn't pollute stdout.
2018-09-05 21:35:58 +02:00
Michael Bishop 4b034f390c remove the old text format output 2018-09-02 18:25:23 -03:00
Michael Bishop 2fd1008c70 add JSON to NIX_SHOW_STATS 2018-09-01 20:05:06 -03:00
Michael Bishop c29e5fbb13 improve the stats when profiling 2018-09-01 17:11:56 -03:00
Eelco Dolstra bc65e02d96
Merge pull request #2326 from aszlig/fix-symlink-leak
Fix symlink leak in restricted eval mode
2018-08-03 17:01:34 +02:00
aszlig 43e28a1b75
Fix symlink leak in restricted eval mode
In EvalState::checkSourcePath, the path is checked against the list of
allowed paths first and later it's checked again *after* resolving
symlinks.

The resolving of the symlinks is done via canonPath, which also strips
out "../" and "./". However after the canonicalisation the error message
pointing out that the path is not allowed prints the symlink target in
the error message.

Even if we'd suppress the message, symlink targets could still be leaked
if the symlink target doesn't exist (in this case the error is thrown in
canonPath).

So instead, we now do canonPath() without symlink resolving first before
even checking against the list of allowed paths and then later do the
symlink resolving and checking the allowed paths again.

The first call to canonPath() should get rid of all the "../" and "./",
so in theory the only way to leak a symlink if the attacker is able to
put a symlink in one of the paths allowed by restricted evaluation mode.

For the latter I don't think this is part of the threat model, because
if the attacker can write to that path, the attack vector is even
larger.

Signed-off-by: aszlig <aszlig@nix.build>
2018-08-03 06:46:43 +02:00
Eelco Dolstra 45bcf5416a
Merge branch 'prim_mapAttr-fix' of https://github.com/volth/nix 2018-07-31 20:05:07 +02:00
Eelco Dolstra 875cd9da2b
Remove unused function printStats2()
Closes #2282.
2018-07-11 20:29:18 +02:00
volth 627e28ba33 prim_mapAttrs: `f' must be evaluated lazily to avoid infinite recursion 2018-07-06 21:52:54 +00:00
Eelco Dolstra c905d8b0a8
GC_malloc -> GC_MALLOC
This makes it possible to build with -DGC_DEBUG.
2018-06-12 17:49:55 +02:00
Eelco Dolstra 455d1f01d0
Don't scan for roots in dynamic libraries
This reduces the risk of object liveness misdetection. For example,
Glibc has an internal variable "mp_" that often points to a Boehm
object, keeping it alive unnecessarily. Since we don't store any
actual roots in global variables, we can just disable data segment
scanning.

With this, the max RSS doing 100 evaluations of
nixos.tests.firefox.x86_64-linux.drvPath went from 718 MiB to 455 MiB.
2018-06-12 17:49:55 +02:00
Eelco Dolstra 30964103dc
Add temporary stats 2018-06-12 17:49:55 +02:00
Eelco Dolstra 24c6806994
Cache parse trees
This prevents EvalState::resetFileCache() from parsing everything all
over again.
2018-06-12 17:49:55 +02:00
Eelco Dolstra 6ad0a2f749
Remove duplicate definition of allocBytes() 2018-06-12 17:49:51 +02:00
Eelco Dolstra 5d4a9d5677
Fix static assertion failure on 32-bit systems 2018-05-30 17:47:30 +02:00
Eelco Dolstra 1672bcd230
Move evaluator-specific settings out of libstore 2018-05-30 13:29:50 +02:00
Will Dietz 93ae90de0f eval.cc: add message to static_assert, message can be omitted w/c++17 2018-05-26 14:04:41 -05:00
Eelco Dolstra 4bb8741b98
Make Env self-describing
If the Env denotes a 'with', then values[0] may be an Expr* cast to a
Value*. For code that generically traverses Values/Envs, it's useful
to know this.
2018-05-22 16:02:32 +02:00
Eelco Dolstra 9fd7cf98db
Memoise checkSourcePath()
This prevents hydra-eval-jobs from statting the same files over and
over again.
2018-05-22 13:02:14 +02:00
Eelco Dolstra a91c4ca01f
In restricted eval mode, allow access to the closure of store paths
E.g. this makes

  nix eval --restrict-eval -I /nix/store/foo '(builtins.readFile "/nix/store/foo/symlink/bla")'

(where /nix/store/foo/symlink is a symlink to another path in the
closure of /nix/store/foo) succeed.

This fixes a regression in Hydra compared to Nix 1.x (where there were
no restrictions at all on access to the Nix store).
2018-05-09 15:45:05 +02:00
Eelco Dolstra 53ec5ac69f
Fix some random -Wconversion warnings 2018-05-02 13:56:34 +02:00
Tuomas Tynkkynen af86132e1a libexpr: Make unsafeGetAttrPos not crash on noPos
Currently e.g. `builtins.unsafeGetAttrPos "abort" builtins` will
eventually segfault because pos->file is an unset Symbol.

Found by afl-fuzz.
2018-04-03 15:54:42 +03:00
Shea Levy e2088febf3
concatLists: Don't pass NULL pointers to memcpy.
This is UB, even if the size is 0. See #1976.

Fixes #1976.
2018-03-14 23:44:02 -04:00
Shea Levy 14ca85688c
Actually fix nixDataDir in non-canonical path 2018-02-28 06:19:40 -05:00
Eelco Dolstra 179b896acb
Merge branch 'data-dir-non-canon' of https://github.com/shlevy/nix 2018-02-22 14:20:43 +01:00
Shea Levy ddbcd01c83
Fix restricted mode when installing in non-canonical data dir 2018-02-22 07:18:14 -05:00
Tuomas Tynkkynen 7e0360504d libexpr: Optimize prim_derivationStrict by using more symbol comparisons 2018-02-17 16:54:21 +02:00
Tuomas Tynkkynen 0845cdf944 libexpr: Rely on Boehm returning zeroed memory in EvalState::allocEnv()
Boehm guarantees that memory returned by GC_malloc() is zeroed, so take
advantage of that.
2018-02-17 16:54:21 +02:00
Eelco Dolstra 7828dca9e8
Merge branch 'register-constant' of https://github.com/shlevy/nix 2018-02-13 12:24:48 +01:00
Frederik Rietdijk 60eca58533 Nix stats: flatten statistics
Flattens the list of statistics as suggested in
https://github.com/NixOS/ofborg/issues/67. This makes it easier to work
with.
2018-02-11 14:37:50 +01:00
Shea Levy 081f14a169
Allow using RegisterPrimop to define constants.
This enables plugins to add new constants, as well as new primops.
2018-02-08 14:35:50 -05:00
Eelco Dolstra abe6be578b
Merge pull request #1816 from shlevy/add-path
Add path primop.
2018-02-07 13:32:35 +01:00