Fix numerous and mostly long-standing segfaults in consumers of
the *_config_*value_multi() API. As discussed in the preceding commit
an empty key in the config syntax yields a "NULL" string, which these
users would give to strcmp() (or similar), resulting in segfaults.
As this change shows, most users users of the *_config_*value_multi()
API didn't really want such an an unsafe and low-level API, let's give
them something with the safety of git_config_get_string() instead.
This fix is similar to what the *_string() functions and others
acquired in[1] and [2]. Namely introducing and using a safer
"*_get_string_multi()" variant of the low-level "_*value_multi()"
function.
This fixes segfaults in code introduced in:
- d811c8e17c (versionsort: support reorder prerelease suffixes, 2015-02-26)
- c026557a37 (versioncmp: generalize version sort suffix reordering, 2016-12-08)
- a086f921a7 (submodule: decouple url and submodule interest, 2017-03-17)
- a6be5e6764 (log: add log.excludeDecoration config option, 2020-04-16)
- 92156291ca (log: add default decoration filter, 2022-08-05)
- 50a044f1e4 (gc: replace config subprocesses with API calls, 2022-09-27)
There are now two users ofthe low-level API:
- One in "builtin/for-each-repo.c", which we'll convert in a
subsequent commit.
- The "t/helper/test-config.c" code added in [3].
As seen in the preceding commit we need to give the
"t/helper/test-config.c" caller these "NULL" entries.
We could also alter the underlying git_configset_get_value_multi()
function to be "string safe", but doing so would leave no room for
other variants of "*_get_value_multi()" that coerce to other types.
Such coercion can't be built on the string version, since as we've
established "NULL" is a true value in the boolean context, but if we
coerced it to "" for use in a list of strings it'll be subsequently
coerced to "false" as a boolean.
The callback pattern being used here will make it easy to introduce
e.g. a "multi" variant which coerces its values to "bool", "int",
"path" etc.
1. 40ea4ed903 (Add config_error_nonbool() helper function,
2008-02-11)
2. 6c47d0e8f3 (config.c: guard config parser from value=NULL,
2008-02-11).
3. 4c715ebb96 (test-config: add tests for the config_set API,
2014-07-28)
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As we'll discuss in the subsequent commit these tests all
show *_get_value_multi() API users unable to handle there being a
value-less key in the config, which is represented with a "NULL" for
that entry in the "string" member of the returned "struct
string_list", causing a segfault.
These added tests exhaustively test for that issue, as we'll see in a
subsequent commit we'll need to change all of the API users
of *_get_value_multi(). These cases were discovered by triggering each
one individually, and then adding these tests.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As noted in 6c62f01552 (for-each-repo: do nothing on empty config,
2021-01-08) this command wants to ignore a non-existing config key,
but let's not conflate that with bad config.
Before this, all these added tests would pass with an exit code of 0.
We could preserve the comment added in 6c62f01552, but now that we're
directly using the documented repo_config_get_value_multi() value it's
just narrating something that should be obvious from the API use, so
let's drop it.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Have the "git_configset_get_value_multi()" function and its siblings
return an "int" and populate a "**dest" parameter like every other
git_configset_get_*()" in the API.
As we'll take advantage of in subsequent commits, this fixes a blind
spot in the API where it wasn't possible to tell whether a list was
empty from whether a config key existed. For now we don't make use of
those new return values, but faithfully convert existing API users.
Most of this is straightforward, commentary on cases that stand out:
- To ensure that we'll properly use the return values of this function
in the future we're using the "RESULT_MUST_BE_USED" macro introduced
in [1].
As git_die_config() now has to handle this return value let's have
it BUG() if it can't find the config entry. As tested for in a
preceding commit we can rely on getting the config list in
git_die_config().
- The loops after getting the "list" value in "builtin/gc.c" could
also make use of "unsorted_string_list_has_string()" instead of using
that loop, but let's leave that for now.
- In "versioncmp.c" we now use the return value of the functions,
instead of checking if the lists are still non-NULL.
1. 1e8697b5c4 (submodule--helper: check repo{_submodule,}_init()
return values, 2022-09-01),
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Refactor the reading of the versionSort.suffix and
versionSort.prereleaseSuffix configuration variables to stay within
the bounds of our CodingGuidelines when it comes to line length, and
to avoid repeating ourselves.
Renaming "deprecated_prereleases" to "oldl" doesn't help us to avoid
line wrapping now, but it will in a subsequent commit.
Let's also split out the names of the config variables into variables
of our own, and refactor the nested if/else to avoid indenting it, and
the existing bracing style issue.
This all helps with the subsequent commit, where we'll need to start
checking different git_config_get_value_multi() return value. See
c026557a37 (versioncmp: generalize version sort suffix reordering,
2016-12-08) for the original implementation of most of this.
Moving the "initialized = 1" assignment allows us to move some of this
to the variable declarations in the subsequent commit.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We already have the basic "git_config_get_value()" function and its
"repo_*" and "configset" siblings to get a given "key" and assign the
last key found to a provided "value".
But some callers don't care about that value, but just want to use the
return value of the "get_value()" function to check whether the key
exist (or another non-zero return value).
The immediate motivation for this is that a subsequent commit will
need to change all callers of the "*_get_value_multi()" family of
functions. In two cases here we (ab)used it to check whether we had
any values for the given key, but didn't care about the return value.
The rest of the callers here used various other config API functions
to do the same, all of which resolved to the same underlying functions
to provide the answer.
Some of these were using either git_config_get_string() or
git_config_get_string_tmp(), see fe4c750fb1 (submodule--helper: fix a
configure_added_submodule() leak, 2022-09-01) for a recent example. We
can now use a helper function that doesn't require a throwaway
variable.
We could have changed git_configset_get_value_multi() (and then
git_config_get_value() etc.) to accept a "NULL" as a "dest" for all
callers, but let's avoid changing the behavior of existing API
users. Having an "unused" value that we throw away internal to
config.c is cheap.
A "NULL as optional dest" pattern is also more fragile, as the intent
of the caller might be misinterpreted if he were to accidentally pass
"NULL", e.g. when "dest" is passed in from another function.
Another name for this function could have been
"*_config_key_exists()", as suggested in [1]. That would work for all
of these callers, and would currently be equivalent to this function,
as the git_configset_get_value() API normalizes all non-zero return
values to a "1".
But adding that API would set us up to lose information, as e.g. if
git_config_parse_key() in the underlying configset_find_element()
fails we'd like to return -1, not 1.
Let's change the underlying configset_find_element() function to
support this use-case, we'll make further use of it in a subsequent
commit where the git_configset_get_value_multi() function itself will
expose this new return value.
This still leaves various inconsistencies and clobbering or ignoring
of the return value in place. E.g here we're modifying
configset_add_value(), but ever since it was added in [2] we've been
ignoring its "int" return value, but as we're changing the
configset_find_element() it uses, let's have it faithfully ferry that
"ret" along.
Let's also use the "RESULT_MUST_BE_USED" macro introduced in [3] to
assert that we're checking the return value of
configset_find_element().
We're leaving the same change to configset_add_value() for some future
series. Once we start paying attention to its return value we'd need
to ferry it up as deep as do_config_from(), and would need to make
least read_{,very_}early_config() and git_protected_config() return an
"int" instead of "void". Let's leave that for now, and focus on
the *_get_*() functions.
1. 3c8687a73e (add `config_set` API for caching config-like files, 2014-07-28)
2. https://lore.kernel.org/git/xmqqczadkq9f.fsf@gitster.g/
3. 1e8697b5c4 (submodule--helper: check repo{_submodule,}_init()
return values, 2022-09-01),
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A less well known edge case in the config format is that keys can be
value-less, a shorthand syntax for "true" boolean keys. I.e. these two
are equivalent as far as "--type=bool" is concerned:
[a]key
[a]key = true
But as far as our parser is concerned the values for these two are
NULL, and "true". I.e. for a sequence like:
[a]key=x
[a]key
[a]key=y
We get a "struct string_list" with "string" members with ".string"
values of:
{ "x", NULL, "y" }
This behavior goes back to the initial implementation of
git_config_bool() in 17712991a5 (Add ".git/config" file parser,
2005-10-10).
When parts of the config_set API were tested for in [1] they didn't
add coverage for 3/4 of the "(NULL)" cases handled in
"t/helper/test-config.c". We'd test that case for "get_value", but not
"get_value_multi", "configset_get_value" and
"configset_get_value_multi".
We now cover all of those cases, which in turn expose the details of
how this part of the config API works.
1. 4c715ebb96 (test-config: add tests for the config_set API,
2014-07-28)
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There were no tests checking for the output of the git_die_config()
function in the config API, added in 5a80e97c82 (config: add
`git_die_config()` to the config-set API, 2014-08-07). We only tested
"test_must_fail", but didn't assert the output.
We need tests for this because a subsequent commit will alter the
return value of git_config_get_value_multi(), which is used to get the
config values in the git_die_config() function. This test coverage
helps to build confidence in that subsequent change.
These tests cover different interactions with git_die_config():
- The "notes.mergeStrategy" test in
"t/t3309-notes-merge-auto-resolve.sh" is a case where a function
outside of config.c (git_config_get_notes_strategy()) calls
git_die_config().
- The "gc.pruneExpire" test in "t5304-prune.sh" is a case where
git_config_get_expiry() calls git_die_config(), covering a different
"type" than the "string" test for "notes.mergeStrategy".
- The "fetch.negotiationAlgorithm" test in
"t/t5552-skipping-fetch-negotiator.sh" is a case where
git_config_get_string*() calls git_die_config().
We also cover both the "from command-line config" and "in file..at
line" cases here.
The clobbering of existing ".git/config" files here is so that we're
not implicitly testing the line count of the default config.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git receive-pack" used to use all the local refs as the boundary for
checking connectivity of the data "git push" sent, but now it uses
only the refs that it advertised to the pusher. In a repository with
the .hideRefs configuration, this reduces the resources needed to
perform the check.
cf. <221028.86bkpw805n.gmgdl@evledraar.gmail.com>
cf. <xmqqr0yrizqm.fsf@gitster.g>
* ps/receive-use-only-advertised:
receive-pack: only use visible refs for connectivity check
rev-parse: add `--exclude-hidden=` option
revision: add new parameter to exclude hidden refs
revision: introduce struct to handle exclusions
revision: move together exclusion-related functions
refs: get rid of global list of hidden refs
refs: fix memory leak when parsing hideRefs config
Fix an issue where core.fsmonitor on macOS would not notice created
or modified symbolic links.
* sz/macos-fsmonitor-symlinks:
fsmonitor--daemon: on macOS support symlink
A pair of bugfixes to the Documentation/howto/maintain-git.txt guide.
* tb/howto-maintain-git-fixes:
Documentation: build redo-seen.sh from jch..seen
Documentation: build redo-jch.sh from master..jch
Teach chainlint.pl to show corresponding line numbers when printing
the source of a test.
* es/chainlint-lineno:
chainlint: prefix annotated test definition with line numbers
chainlint: latch line numbers at which each token starts and ends
chainlint: sidestep impoverished macOS "terminfo"
Fix a source of flakiness in CI when compiling with SANITIZE=leak.
* ab/t7610-timeout:
t7610: use "file:///dev/null", not "/dev/null", fixes MinGW
t7610: fix flaky timeout issue, don't clone from example.com
'git maintenance register' is taught to write configuration to an
arbitrary path, and 'git for-each-repo' is taught to expand tilde
characters in paths.
* rp/maintenance-qol:
builtin/gc.c: fix use-after-free in maintenance_unregister()
maintenance --unregister: fix uninit'd data use & -Wdeclaration-after-statement
maintenance: add option to register in a specific config
for-each-repo: interpolate repo path arguments
Correct an error where `git rebase` would mistakenly use a branch or
tag named "refs/rewritten/xyz" when missing a rebase label.
* pw/strict-label-lookups:
sequencer: tighten label lookups
sequencer: unify label lookup
Redact headers from cURL's h2h3 module in GIT_CURL_VERBOSE and
others.
* gc/redact-h2h3-headers:
http: redact curl h2h3 headers in info
t: run t5551 tests with both HTTP and HTTP/2
"make coccicheck" is time consuming. It has been made to run more
incrementally.
* ab/coccicheck-incremental:
Makefile: don't create a ".build/.build/" for cocci, fix output
spatchcache: add a ccache-alike for "spatch"
cocci: run against a generated ALL.cocci
cocci rules: remove <id>'s from rules that don't need them
Makefile: copy contrib/coccinelle/*.cocci to build/
cocci: optimistically use COMPUTE_HEADER_DEPENDENCIES
cocci: make "coccicheck" rule incremental
cocci: split off "--all-includes" from SPATCH_FLAGS
cocci: split off include-less "tests" from SPATCH_FLAGS
Makefile: split off SPATCH_BATCH_SIZE comment from "cocci" heading
Makefile: have "coccicheck" re-run if flags change
Makefile: add ability to TAB-complete cocci *.patch rules
cocci rules: remove unused "F" metavariable from pending rule
Makefile + shared.mak: rename and indent $(QUIET_SPATCH_T)
Teach chainlint.pl to annotate the original test definition instead
of the token stream.
* es/chainlint-output:
chainlint: annotate original test definition rather than token stream
chainlint: latch start/end position of each token
chainlint: tighten accuracy when consuming input stream
chainlint: add explanatory comments
'scalar reconfigure -a' is taught to automatically remove
scalar.repo entires which no longer exist.
* js/remove-stale-scalar-repos:
tests(scalar): tighten the stale `scalar.repo` test some
scalar reconfigure -a: remove stale `scalar.repo` entries
Fix a regression in the bisect-helper which mistakenly treats
arguments to the command given to 'git bisect run' as arguments to
the helper.
* dd/bisect-helper-subcommand:
bisect--helper: parse subcommand with OPT_SUBCOMMAND
bisect--helper: move all subcommands into their own functions
bisect--helper: remove unused options
Preparation to remove git-submodule.sh and replace it with a builtin.
* ab/submodule-helper-prep-only:
submodule--helper: use OPT_SUBCOMMAND() API
submodule--helper: drop "update --prefix <pfx>" for "-C <pfx> update"
submodule--helper: remove --prefix from "absorbgitdirs"
submodule API & "absorbgitdirs": remove "----recursive" option
submodule.c: refactor recursive block out of absorb function
submodule tests: test for a "foreach" blind-spot
submodule--helper: fix a memory leak in "status"
submodule tests: add tests for top-level flag output
submodule--helper: move "config" to a test-tool
Avoid calling 'cache_tree_update()' when doing so would be redundant.
* vd/skip-cache-tree-update:
rebase: use 'skip_cache_tree_update' option
read-tree: use 'skip_cache_tree_update' option
reset: use 'skip_cache_tree_update' option
unpack-trees: add 'skip_cache_tree_update' option
cache-tree: add perf test comparing update and prime
Update the credential-cache documentation to provide a more realistic
example.
* mh/increase-credential-cache-timeout:
Documentation: increase example cache timeout to 1 hour
`git rebase --update-refs` would delete references when all `update-ref`
commands in the sequencer were removed, which has been corrected.
* vd/update-refs-delete:
rebase --update-refs: avoid unintended ref deletion
"git repack" learns to send cruft objects out of the way into
packfiles outside the repository.
* tb/repack-expire-to:
builtin/repack.c: implement `--expire-to` for storing pruned objects
builtin/repack.c: write cruft packs to arbitrary locations
builtin/repack.c: pass "cruft_expiration" to `write_cruft_pack`
builtin/repack.c: pass "out" to `prepare_pack_objects`
Makefile comments updates and reordering to clarify knobs used to
choose SHA implementations.
* ab/sha-makefile-doc:
Makefile: discuss SHAttered in *_SHA{1,256} discussion
Makefile: document default SHA-1 backend on OSX
Makefile & test-tool: replace "DC_SHA1" variable with a "define"
Makefile: document SHA-1 and SHA-256 default and selection order
Makefile: document default SHA-256 backend
Makefile: rephrase the discussion of *_SHA1 knobs
Makefile: create and use sections for "define" flag listing
Makefile: correct DC_SHA1 documentation
INSTALL: remove discussion of SHA-1 backends
Makefile: always (re)set DC_SHA1 on fallback
Various test updates.
* ab/misc-hook-submodule-run-command:
run-command tests: test stdout of run_command_parallel()
submodule tests: reset "trace.out" between "grep" invocations
hook tests: fix redirection logic error in 96e7225b31
On my use case involving 771 islands of Linux on kernel.org,
this reduces memory usage by around 25MB. The bulk of that
comes from free_remote_islands, since free_config_regexes only
saves around 40k.
This memory is saved early in the memory-intensive pack process,
making it available for the remainder of the long process.
Signed-off-by: Eric Wong <e@80x24.org>
Co-authored-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
When serving a push, git-receive-pack(1) needs to verify that the
packfile sent by the client contains all objects that are required by
the updated references. This connectivity check works by marking all
preexisting references as uninteresting and using the new reference tips
as starting point for a graph walk.
Marking all preexisting references as uninteresting can be a problem
when it comes to performance. Git forges tend to do internal bookkeeping
to keep alive sets of objects for internal use or make them easy to find
via certain references. These references are typically hidden away from
the user so that they are neither advertised nor writeable. At GitLab,
we have one particular repository that contains a total of 7 million
references, of which 6.8 million are indeed internal references. With
the current connectivity check we are forced to load all these
references in order to mark them as uninteresting, and this alone takes
around 15 seconds to compute.
We can optimize this by only taking into account the set of visible refs
when marking objects as uninteresting. This means that we may now walk
more objects until we hit any object that is marked as uninteresting.
But it is rather unlikely that clients send objects that make large
parts of objects reachable that have previously only ever been hidden,
whereas the common case is to push incremental changes that build on top
of the visible object graph.
This provides a huge boost to performance in the mentioned repository,
where the vast majority of its refs hidden. Pushing a new commit into
this repo with `transfer.hideRefs` set up to hide 6.8 million of 7 refs
as it is configured in Gitaly leads to a 4.5-fold speedup:
Benchmark 1: main
Time (mean ± σ): 30.977 s ± 0.157 s [User: 30.226 s, System: 1.083 s]
Range (min … max): 30.796 s … 31.071 s 3 runs
Benchmark 2: pks-connectivity-check-hide-refs
Time (mean ± σ): 6.799 s ± 0.063 s [User: 6.803 s, System: 0.354 s]
Range (min … max): 6.729 s … 6.850 s 3 runs
Summary
'pks-connectivity-check-hide-refs' ran
4.56 ± 0.05 times faster than 'main'
As we mostly go through the same codepaths even in the case where there
are no hidden refs at all compared to the code before there is no change
in performance when no refs are hidden:
Benchmark 1: main
Time (mean ± σ): 48.188 s ± 0.432 s [User: 49.326 s, System: 5.009 s]
Range (min … max): 47.706 s … 48.539 s 3 runs
Benchmark 2: pks-connectivity-check-hide-refs
Time (mean ± σ): 48.027 s ± 0.500 s [User: 48.934 s, System: 5.025 s]
Range (min … max): 47.504 s … 48.500 s 3 runs
Summary
'pks-connectivity-check-hide-refs' ran
1.00 ± 0.01 times faster than 'main'
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Add a new `--exclude-hidden=` option that is similar to the one we just
added to git-rev-list(1). Given a section name `uploadpack` or `receive`
as argument, it causes us to exclude all references that would be hidden
by the respective `$section.hideRefs` configuration.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Users can optionally hide refs from remote users in git-upload-pack(1),
git-receive-pack(1) and others via the `transfer.hideRefs`, but there is
not an easy way to obtain the list of all visible or hidden refs right
now. We'll require just that though for a performance improvement in our
connectivity check.
Add a new option `--exclude-hidden=` that excludes any hidden refs from
the next pseudo-ref like `--all` or `--branches`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
The functions that handle exclusion of refs work on a single string
list. We're about to add a second mechanism for excluding refs though,
and it makes sense to reuse much of the same architecture for both kinds
of exclusion.
Introduce a new `struct ref_exclusions` that encapsulates all the logic
related to excluding refs and move the `struct string_list` that holds
all wildmatch patterns of excluded refs into it. Rename functions that
operate on this struct to match its name.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Move together the definitions of functions that handle exclusions of
refs so that related functionality sits in a single place, only.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
We're about to add a new argument to git-rev-list(1) that allows it to
add all references that are visible when taking `transfer.hideRefs` et
al into account. This will require us to potentially parse multiple sets
of hidden refs, which is not easily possible right now as there is only
a single, global instance of the list of parsed hidden refs.
Refactor `parse_hide_refs_config()` and `ref_is_hidden()` so that both
take the list of hidden references as input and adjust callers to keep a
local list, instead. This allows us to easily use multiple hidden-ref
lists. Furthermore, it allows us to properly free this list before we
exit.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
When parsing the hideRefs configuration, we first duplicate the config
value so that we can modify it. We then subsequently append it to the
`hide_refs` string list, which is initialized with `strdup_strings`
enabled. As a consequence we again reallocate the string, but never
free the first duplicate and thus have a memory leak.
While we never clean up the static `hide_refs` variable anyway, this is
no excuse to make the leak worse by leaking every value twice. We are
also about to change the way this variable will be handled so that we do
indeed start to clean it up. So let's fix the memory leak by using the
`string_list_append_nodup()` so that we pass ownership of the allocated
string to `hide_refs`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
When `git notes` prepares the template it adds an empty newline between
the comment header and the content:
>
> #
> # Write/edit the notes for the following object:
>
> # commit 0f3c55d4c2b7864bffb2d92278eff08d0b2e083f
> # etc
This is wrong structurally because that newline is part of the comment,
too, and thus should be commented. Also, it throws off some positioning
strategies of editors and plugins, and it differs from how we do commit
templates.
Change this to follow the standard set by `git commit`:
>
> #
> # Write/edit the notes for the following object:
> #
> # commit 0f3c55d4c2b7864bffb2d92278eff08d0b2e083f
>
Tests pass unchanged after this code change.
Signed-off-by: Michael J Gruber <git@grubix.eu>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
On MinGW the "/dev/null" is translated to "nul" on command-lines, even
though as in this case it'll never end up referring to an actual file.
So on Windows the fix for the previous "example.com" timeout issue in
8354cf752e (t7610: fix flaky timeout issue, don't clone from
example.com, 2022-11-05) would yield:
fatal: repo URL: 'nul' must be absolute or begin with ./|../
Let's evade this yet again by prefixing this with "file://", which
makes this pass in the Windows CI.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
While trying to fix a move based on an uninitialized value (along with a
declaration after the first statement), be0fd57228
(maintenance --unregister: fix uninit'd data use &
-Wdeclaration-after-statement, 2022-11-15) unintentionally introduced a
use-after-free.
The problem arises when `maintenance_unregister()` sees a non-NULL
`config_file` string and thus tries to call
git_configset_get_value_multi() to lookup the corresponding values.
We store the result off, and then call git_configset_clear(), which
frees the pointer that we just stored. We then try to read that
now-freed pointer a few lines below, and there we have our
use-after-free:
$ ./t7900-maintenance.sh -vxi --run=23 --valgrind
[...]
+ git maintenance unregister --config-file ./other
==3048727== Invalid read of size 8
==3048727== at 0x1869CA: maintenance_unregister (gc.c:1590)
==3048727== by 0x188F42: cmd_maintenance (gc.c:2651)
==3048727== by 0x128C62: run_builtin (git.c:466)
==3048727== by 0x12907E: handle_builtin (git.c:721)
==3048727== by 0x1292EC: run_argv (git.c:788)
==3048727== by 0x12988E: cmd_main (git.c:926)
==3048727== by 0x21ED39: main (common-main.c:57)
==3048727== Address 0x4b38bc8 is 24 bytes inside a block of size 64 free'd
==3048727== at 0x484617B: free (vg_replace_malloc.c:872)
==3048727== by 0x2D207E: free_individual_entries (hashmap.c:188)
==3048727== by 0x2D2153: hashmap_clear_ (hashmap.c:207)
==3048727== by 0x270B5C: git_configset_clear (config.c:2375)
==3048727== by 0x1869AC: maintenance_unregister (gc.c:1585)
==3048727== by 0x188F42: cmd_maintenance (gc.c:2651)
==3048727== by 0x128C62: run_builtin (git.c:466)
==3048727== by 0x12907E: handle_builtin (git.c:721)
==3048727== by 0x1292EC: run_argv (git.c:788)
==3048727== by 0x12988E: cmd_main (git.c:926)
==3048727== by 0x21ED39: main (common-main.c:57)
[...]
Resolve this via a partial-revert of be0fd57228. The config_set struct
now gets a zero initialization, which makes free()-ing it a noop even
without calling git_configset_init(). When we do initialize it to a
non-zero value, it is only free()'d after our last read of `list`.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Since (maintenance: add option to register in a specific config,
2022-11-09) we've been unable to build with "DEVELOPER=1" without
"DEVOPTS=no-error", as the added code triggers a
"-Wdeclaration-after-statement" warning.
And worse than that, the data handed to git_configset_clear() is
uninitialized, as can be spotted with e.g.:
./t7900-maintenance.sh -vixd --run=23 --valgrind
[...]
+ git maintenance unregister --force
Conditional jump or move depends on uninitialised value(s)
at 0x6B5F1E: git_configset_clear (config.c:2367)
by 0x4BA64E: maintenance_unregister (gc.c:1619)
by 0x4BD278: cmd_maintenance (gc.c:2650)
by 0x409905: run_builtin (git.c:466)
by 0x40A21C: handle_builtin (git.c:721)
by 0x40A58E: run_argv (git.c:788)
by 0x40AF68: cmd_main (git.c:926)
by 0x5D39FE: main (common-main.c:57)
Uninitialised value was created by a stack allocation
at 0x4BA22C: maintenance_unregister (gc.c:1557)
Let's fix both of these issues, and also move the scope of the
variable to the "if" statement it's used in, to make it obvious where
it's used.
Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
maintenance register currently records the maintenance repo exclusively
within the user's global configuration, but other configuration files
may be relevant when running maintenance if they are included from the
global config. This option allows the user to choose where maintenance
repos are recorded.
Signed-off-by: Ronan Pigott <ronan@rjp.ie>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
