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7754 commits

Author SHA1 Message Date
Guillaume Bouchard 5a34a473dd builtins.readFile: do not truncate content
This closes #3026 by allowing `builtins.readFile` to read a file with a
wrongly reported file size, for example, files in `/proc` may report a
file size of 0. Reading file in `/proc` is not a good enough motivation,
however I do think it just makes nix more robust by allowing more file
to be read.  Especially, I do considerer the previous behavior to be
dangerous because nix was previously reading truncated files. Examples
of file system which incorrectly report file size may be network file
system or dynamic file system (for performance reason, a dynamic file
system such as FUSE may generate the content of the file on demand).

```
nix-repl> builtins.readFile "/proc/version"
""
```

With this commit:

```
nix-repl> builtins.readFile "/proc/version"
"Linux version 5.6.7 (nixbld@localhost) (gcc version 9.3.0 (GCC)) #1-NixOS SMP Thu Apr 23 08:38:27 UTC 2020\n"
```

Here is a summary of the behavior changes:

- If the reported size is smaller, previous implementation
was silently returning a truncated file content. The new implementation
is returning the correct file content.

- If a file had a bigger reported file size, previous implementation was
failing with an exception, but the new implementation is returning the
correct file content. This change of behavior is coherent with this pull
request.

Open questions

- The behavior is unchanged for correctly reported file size, however
performances may vary because it uses the more complex sink interface.
Considering that sink is used a lot, I don't think this impacts the
performance a lot.
- `builtins.readFile` on an infinite file, such as `/dev/random` may
fill the memory.
- it does not support adding file to store, such as `${/proc/version}`.
2020-04-29 14:50:52 +02:00
Ben Burdette 22e6490311 Error classname as name 2020-04-28 21:06:08 -06:00
Eelco Dolstra 06849c3090
Merge pull request #3542 from mkenigs/gcroots
Set GCROOT to store path to prevent garbage collection
2020-04-28 21:04:06 +02:00
Matthew Kenigsberg 6d40fe573c rename to NIX_GCROOT 2020-04-28 11:18:54 -06:00
Eelco Dolstra 52a3ca823d Tweak warning message 2020-04-28 17:56:01 +02:00
Eelco Dolstra 6a8cba83bb Merge branch 'nix-env-warn-unmatched' of https://github.com/lheckemann/nix 2020-04-28 17:45:25 +02:00
Eelco Dolstra ee754f0f41
Merge pull request #3541 from alyssais/gcdos
Fix long paths permanently breaking GC
2020-04-28 16:33:45 +02:00
Ben Burdette e51a757720 astyle format 2020-04-27 15:15:08 -06:00
Alyssa Ross c05e20daa1
Fix long paths permanently breaking GC
Suppose I have a path /nix/store/[hash]-[name]/a/a/a/a/a/[...]/a,
long enough that everything after "/nix/store/" is longer than 4096
(MAX_PATH) bytes.

Nix will happily allow such a path to be inserted into the store,
because it doesn't look at all the nested structure.  It just cares
about the /nix/store/[hash]-[name] part.  But, when the path is deleted,
we encounter a problem.  Nix will move the path to /nix/store/trash, but
then when it's trying to recursively delete the trash directory, it will
at some point try to unlink
/nix/store/trash/[hash]-[name]/a/a/a/a/a/[...]/a.  This will fail,
because the path is too long.  After this has failed, any store deletion
operation will never work again, because Nix needs to delete the trash
directory before recreating it to move new things to it.  (I assume this
is because otherwise a path being deleted could already exist in the
trash, and then moving it would fail.)

This means that if I can trick somebody into just fetching a tarball
containing a path of the right length, they won't be able to delete
store paths or garbage collect ever again, until the offending path is
manually removed from /nix/store/trash.  (And even fixing this manually
is quite difficult if you don't understand the issue, because the
absolute path that Nix says it failed to remove is also too long for
rm(1).)

This patch fixes the issue by making Nix's recursive delete operation
use unlinkat(2).  This function takes a relative path and a directory
file descriptor.  We ensure that the relative path is always just the
name of the directory entry, and therefore its length will never exceed
255 bytes.  This means that it will never even come close to AX_PATH,
and Nix will therefore be able to handle removing arbitrarily deep
directory hierachies.

Since the directory file descriptor is used for recursion after being
used in readDirectory, I made a variant of readDirectory that takes an
already open directory stream, to avoid the directory being opened
multiple times.  As we have seen from this issue, the less we have to
interact with paths, the better, and so it's good to reuse file
descriptors where possible.

I left _deletePath as succeeding even if the parent directory doesn't
exist, even though that feels wrong to me, because without that early
return, the linux-sandbox test failed.

Reported-by: Alyssa Ross <hi@alyssa.is>
Thanks-to: Puck Meerburg <puck@puckipedia.com>
Tested-by: Puck Meerburg <puck@puckipedia.com>
Reviewed-by: Puck Meerburg <puck@puckipedia.com>
2020-04-27 20:50:17 +00:00
Matthew Kenigsberg 9e95b95a5d comment 2020-04-27 13:18:26 -06:00
Matthew Kenigsberg a3bc695e7d Set GCROOT to store path to prevent garbage collection 2020-04-27 11:22:20 -06:00
Ben Burdette 1ff42722ce error.hh 2020-04-26 14:47:41 -06:00
Ben Burdette d4fd7b543e print dashes instead of empty name string 2020-04-25 12:05:26 -06:00
Linus Heckemann f59404e1a6 nix-env: refactor uninstallDerivations
Reduces the number of store queries it performs. Also prints a warning
if any of the selectors did not match any installed derivations.

UX Caveats:
- Will print a warning that nothing matched if a previous selector
  already removed the path
- Will not do anything if no selectors were provided (no change from
  before).

Fixes #3531
2020-04-25 16:30:42 +02:00
Ben Burdette cdac083dc5 don't print blank lines for blank description 2020-04-24 21:40:13 -06:00
Ben Burdette d8d4844b88 all things error to error.hh 2020-04-24 14:57:51 -06:00
Ben Burdette d9632765a8 add has_value check; remove obslete friend class 2020-04-24 12:44:23 -06:00
Ben Burdette 833501f6f1 'what' string 2020-04-23 15:55:34 -06:00
Ben Burdette 3bc9155dfc a few more 'format's rremoved 2020-04-22 15:00:11 -06:00
Eelco Dolstra c9d0cf7e02
Don't include error.hh in util.hh to prevent header bloat 2020-04-22 15:29:27 +02:00
Eelco Dolstra 7114f088fc
Don't install error-demo 2020-04-22 15:29:22 +02:00
Eelco Dolstra 16e3bf4537
Merge branch 'error-format' of https://github.com/bburdette/nix 2020-04-22 15:29:10 +02:00
Eelco Dolstra 2ea4d45449
Path fetcher: Fix store path name
(cherry picked from commit c7af247bea)
2020-04-22 15:27:06 +02:00
Eelco Dolstra 4a2a45f53d
Merge pull request #3522 from HackerFoo/replace-select-with-poll
Replace select() with poll()
2020-04-22 12:25:41 +02:00
Dustin DeWeese c0d940978a Replace select() with poll() to allow waiting on more than FD_SETSIZE fds 2020-04-21 16:21:28 -07:00
Ben Burdette e4fb9a3849 remove 'format' from Error constructor calls 2020-04-21 17:07:07 -06:00
Ben Burdette d3052197fe add ErrorInfo to BaseError 2020-04-21 13:25:41 -06:00
Ben Burdette 15e9564fd1 logEI for tunnelLogger and progressbar 2020-04-19 17:16:51 -06:00
Domen Kožar 25ed842725
Merge pull request #3502 from NixOS/more-pos
pass Pos to forceValue to improve infinite recursion error
2020-04-18 14:05:21 +02:00
Ben Burdette 4697552948 demoing other error levels than warn/error; rename line and file fields in errPos 2020-04-17 15:50:46 -06:00
Ben Burdette 3d5b1032a1 logError, logWarning; Logger functions; switch to Verbosity enum 2020-04-17 15:07:44 -06:00
Ben Burdette 12814806ef iomanip no longer needed 2020-04-16 10:48:15 -06:00
Eelco Dolstra efaffaa9d1 Use Logger::stdout()
(cherry picked from commit 8f41847394)
2020-04-16 18:14:01 +02:00
Eelco Dolstra 67a5941472 Logger: Add method for writing to stdout
Usually this just writes to stdout, but for ProgressBar, we need to
clear the current line, write the line to stdout, and then redraw the
progress bar.

(cherry picked from commit 696c026006)
2020-04-16 18:03:38 +02:00
Eelco Dolstra fcd048a526 Use RootValue 2020-04-16 18:02:59 +02:00
Ben Burdette 96262e744e switch to structs, which don't need public: 2020-04-16 09:55:38 -06:00
Eelco Dolstra 9f46f54de4 JSONSax: Use a RootValue
More #3377.
2020-04-16 17:30:18 +02:00
Eelco Dolstra 10e17eaa58 ValueMap, VectorVector: Use traceable_allocator
We want to *trace* the 'Value *' arrays, not garbage-collect them!
Otherwise the vectors/maps can end up pointing to nowhere.

Fixes #3377. Closes #3384.
2020-04-16 17:30:13 +02:00
Eelco Dolstra b3e5eea4a9 Add function to allocate a Value in traceable memory 2020-04-16 17:30:05 +02:00
Eelco Dolstra 1290411c2d fetchMercurial: Use inputFromAttrs() 2020-04-16 17:29:30 +02:00
Domen Kožar b865b5b40c
pass Pos to forceValue to improve infinite recursion error 2020-04-16 12:32:07 +02:00
Ben Burdette 057e5b6b2e move implementation to cc 2020-04-15 10:09:43 -06:00
Ben Burdette adf03b0b8e Merge branch 'initializer-style' into error-format 2020-04-15 10:06:20 -06:00
Eelco Dolstra 2f9789c2e6
Merge pull request #3492 from andir/nix-build-gc-free
SourceExprCommand: allocate the vSourceExpr via uncollectable memory
2020-04-15 13:01:04 +02:00
Eelco Dolstra a118293bd0
Merge pull request #3458 from zimbatm/nix-user-conf-dir
NIX_USER_CONF_FILES
2020-04-15 13:00:28 +02:00
Jonas Chevalier 895516cadf
add NIX_USER_CONF_FILES
Motivation: maintain project-level configuration files.

Document the whole situation a bit better so that it corresponds to the
implementation, and add NIX_USER_CONF_FILES that allows overriding
which user files Nix will load during startup.
2020-04-14 18:45:06 +02:00
Andreas Rammhold d2c371927e SourceExprCommand: allocate the vSourceExpr via uncollectable memory
Previously the memory would occasionally be collected during eval since
the GC doesn't consider the member variable as alive / doesn't scan the
region of memory where the pointer lives.

By using the traceable_allocator<T> allocator provided by Boehm GC we
can ensure the memory isn't collected. It should be properly freed when
SourceExprCommand goes out of scope.
2020-04-13 21:23:54 +02:00
Eelco Dolstra 512753f824
Merge pull request #3488 from LnL7/darwin-tmpdir
never use /var/folders for TMPDIR on darwin
2020-04-12 16:23:34 +02:00
Daiderd Jordan 4d9db420ff
never use /var/folders for TMPDIR on darwin
This doesn't just cause problems for nix-store --serve but also results
in certain build failures. Builds that use unix domain sockets in their
tests often fail because the /var/folders prefix already consumes more
than half of the maximum length of socket paths.

    struct sockaddr_un {
       sa_family_t sun_family;               /* AF_UNIX */
       char        sun_path[108];            /* Pathname */
    };
2020-04-12 09:57:22 +02:00
Domen Kožar ea2148f47c
Merge pull request #2688 from tollb/fix/build_check_keep_failed_sandbox_perms
Fix nix-build --check -K in sandbox w/o root
2020-04-11 20:03:17 +02:00