The add_pattern() function has a subtle and undocumented gotcha: the
pattern string you pass in must remain valid as long as the pattern_list
is in use (and nor do we take ownership of it). This is easy to get
wrong, causing either subtle bugs (because you free or reuse the string
buffer) or leaks (because you copy the string, but don't track ownership
separately).
All of this "pattern" code was originally the "exclude" mechanism. So
this _usually_ works OK because you add entries in one of two ways:
1. From the command-line (e.g., "--exclude"), in which case we're
pointing to an argv entry which remains valid for the lifetime of
the program.
2. From a file (e.g., ".gitignore"), in which case we read the whole
file into a buffer, attach it to the pattern_list's "filebuf"
entry, then parse the buffer in-place (adding NULs). The strings
point into the filebuf, which is cleaned up when the whole
pattern_list goes away.
But other code, like sparse-checkout, reads individual lines from stdin
and passes them one by one to add_pattern(), leaking each. We could fix
this by refactoring it to take in the whole buffer at once, like (2)
above, and stuff it in "filebuf". But given how subtle the interface is,
let's just fix it to always copy the string.
That seems at first like we'd be wasting extra memory, but we can
mitigate that:
a. The path_pattern struct already uses a FLEXPTR, since we sometimes
make a copy (when we see "foo/", we strip off the trailing slash,
requiring a modifiable copy of the string).
Since we'll now always embed the string inside the struct, we can
switch to the regular FLEX_ARRAY pattern, saving us 8 bytes of
pointer. So patterns with a trailing slash and ones under 8 bytes
actually get smaller.
b. Now that we don't need the original string to hang around, we can
get rid of the "filebuf" mechanism entirely, and just free the file
contents after parsing. Since files are the sources we'd expect to
have the largest pattern sets, we should mostly break even on
stuffing the same data into the individual structs.
This patch just adjusts the add_pattern() interface; it doesn't fix any
leaky callers yet.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In add_pattern_to_hashsets(), we remove entries from the
recursive_hashmap when adding similar ones to the parent_hashmap. I
won't pretend to understand all of what's going on here, but there's an
obvious leak: whatever we removed from recursive_hashmap is not
referenced anywhere else, and is never free()d.
We can easily fix this by asking the hashmap to return a pointer to the
old entry. This makes t7002 now completely leak-free.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In sparse_checkout_init(), we first try to load patterns from an
existing file. If we found any, we return immediately, but end up
leaking the patterns we parsed. Fixing this reduces the number of leaks
in t7002 from 9 down to 5.
Note that there are two other exits from the function, but they don't
need the same treatment:
- if we can't resolve HEAD, we write out a hard-coded sparse file and
return. But we know the pattern list is empty there, since we didn't
find any in the on-disk file and we haven't yet added any of our
own.
- otherwise, we do populate the list and then tail-call into
write_patterns_and_update(). But that function frees the
pattern_list itself, so we don't need to.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The pattern_list structs used for cone-mode sparse lookups use a few
extra hashmaps. These store pattern_entry structs, each of which has its
own heap-allocated pattern string. When we clean up the hashmaps, we
free the individual pattern_entry structs, but forget to clean up the
embedded strings, causing memory leaks.
We can fix this by iterating over the hashmaps to free the extra
strings. This reduces the numbers of leaks in t7002 from 22 to 9.
One alternative here would be to make the string a FLEX_ARRAY member of
the pattern_entry. Then there's no extra free() required, and as a bonus
it would be a little more efficient. However, some of the refactoring
gets awkward, as we are often assigning strings allocated by helper
functions. So let's just fix the leak for now, and we can explore bigger
refactoring separately.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The add_pattern() function takes a pattern string, but neither makes a
copy of it nor takes ownership of the memory. So it is the caller's
responsibility to make sure the string hangs around as long as the
pattern_list which references it.
There are a few cases in sparse-checkout where we use string literal
patterns by stuffing them into a strbuf, detaching the buffer, and then
passing the result into add_pattern(). This creates a leak when the
pattern_list is eventually cleared, since we don't retain a copy of the
detached buffer to free.
But we can observe that the whole strbuf dance is unnecessary. The point
was presumably[1] to satisfy the lifetime requirement of the string. But
string literals have static duration; we can count on them lasting for
the whole program.
So we can fix the leak by just passing them directly. And as a bonus,
that simplifies the code. The leaks can be seen in t7002, which drops
from 25 leaks to 22 with this patch. It also makes t3602 and t1090
leak-free.
In the long run, we will also want to clean up this (undocumented!)
memory lifetime requirement of add_pattern(). But that can come in a
later patch; passing the string literals directly will be the right
thing either way.
[1] The code in question comes from 416adc8711 (sparse-checkout: update
working directory in-process for 'init', 2019-11-21) and 99dfa6f970
(sparse-checkout: use in-process update for disable subcommand,
2019-11-21), but I didn't see anything in their commit messages or
on the list explaining the strbufs.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We use a string list to hold sorted and de-duped patterns, but don't
free it before leaving the function, causing a leak.
This drops the number of leaks found in t7002 from 27 to 25.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* jk/leakfixes:
mv: replace src_dir with a strvec
mv: factor out empty src_dir removal
mv: move src_dir cleanup to end of cmd_mv()
t-strvec: mark variable-arg helper with LAST_ARG_MUST_BE_NULL
t-strvec: use va_end() to match va_start()
We manually manage the src_dir array with ALLOC_GROW. Using a strvec is
a little more ergonomic, and makes the memory ownership more clear. It
does mean that we copy the strings (which were otherwise just pointers
into the "sources" strvec), but using the same rationale as 9fcd9e4e72
(builtin/mv duplicate string list memory, 2024-05-27), it's just not
enough to be worth worrying about here.
As a bonus, this gets rid of some "int"s used for allocation management
(though in practice these were limited to command-line sizes and thus
not overflowable).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This pulls the loop added by b6f51e3db9 (mv: cleanup empty
WORKING_DIRECTORY, 2022-08-09) into a sub-function. That reduces clutter
in cmd_mv() and makes it easier to see that the lifetime of the
a_src_dir strbuf is limited to this code (and thus its cleanup doesn't
need to go after the "out" label).
Another option would be to just declare the strbuf inside the loop,
since it is only used there. But this refactor retains the existing
property that we can reuse the allocated buffer for each iteration of
the loop. That optimization is probably overkill, but I think the
sub-function is more readable anyway, and then keeping the optimization
is basically free.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit b6f51e3db9 (mv: cleanup empty WORKING_DIRECTORY, 2022-08-09)
added an auxiliary array where we store directory arguments that we see
while processing the incoming arguments. After actually moving things,
we then use that array to remove now-empty directories, and then
immediately free the array.
But if the actual move queues any errors in only_match_skip_worktree,
that can cause us to jump straight to the "out" label to clean up,
skipping the free() and leaking the array.
Let's push the free() down past the "out" label so that we always clean
up (the array is initialized to NULL, so this is always safe). We'll
hold on to the memory a little longer than necessary, but clarity is
more important than micro-optimizing here.
Note that the adjacent "a_src_dir" strbuf does not suffer the same
problem; it is only allocated during the removal step.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This will let the compiler catch a problem like:
/* oops, we forgot the NULL */
check_strvec(&vec, "foo");
rather than triggering undefined behavior at runtime.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Our check_strvec_loc() helper uses a variable argument list. When we
va_start(), we must be sure to va_end() before leaving the function.
This is required by the standard (though the effect of forgetting will
vary between platforms).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* ps/leakfixes:
builtin/mv: fix leaks for submodule gitfile paths
builtin/mv: refactor to use `struct strvec`
builtin/mv duplicate string list memory
builtin/mv: refactor `add_slash()` to always return allocated strings
strvec: add functions to replace and remove strings
submodule: fix leaking memory for submodule entries
commit-reach: fix memory leak in `ahead_behind()`
builtin/credential: clear credential before exit
config: plug various memory leaks
config: clarify memory ownership in `git_config_string()`
builtin/log: stop using globals for format config
builtin/log: stop using globals for log config
convert: refactor code to clarify ownership of check_roundtrip_encoding
diff: refactor code to clarify memory ownership of prefixes
config: clarify memory ownership in `git_config_pathname()`
http: refactor code to clarify memory ownership
checkout: clarify memory ownership in `unique_tracking_name()`
strbuf: fix leak when `appendwholeline()` fails with EOF
transport-helper: fix leaking helper name
The credential helper that talks with osx keychain learned to avoid
storing back the authentication material it just got received from
the keychain.
* kn/osxkeychain-skip-idempotent-store:
osxkeychain: state to skip unnecessary store operations
osxkeychain: exclusive lock to serialize execution of operations
The default "creation-factor" used by "git format-patch" has been
raised to make it more aggressively find matching commits.
* jc/format-patch-more-aggressive-range-diff:
format-patch: run range-diff with larger creation-factor
Preliminary code clean-up for "git send-email".
* ds/send-email-per-message-block:
send-email: move newline characters out of a few translatable strings
The command line completion script (in contrib/) has been adjusted
to the recent update to "git config" that adopted subcommand based
UI.
* ps/complete-config-w-subcommands:
completion: adapt git-config(1) to complete subcommands
The documentation for "git diff --name-only" has been clarified
that it is about showing the names in the post-image tree.
* jc/doc-diff-name-only:
diff: document what --name-only shows
The pack bitmap code saw some clean-up to prepare for a follow-up topic.
* tb/pack-bitmap-write-cleanups:
pack-bitmap: introduce `bitmap_writer_free()`
pack-bitmap-write.c: avoid uninitialized 'write_as' field
pack-bitmap: drop unused `max_bitmaps` parameter
pack-bitmap: avoid use of static `bitmap_writer`
pack-bitmap-write.c: move commit_positions into commit_pos fields
object.h: add flags allocated by pack-bitmap.h
Code clean-up to reduce inter-function communication inside
builtin/config.c done via the use of global variables.
* ps/builtin-config-cleanup: (21 commits)
builtin/config: pass data between callbacks via local variables
builtin/config: convert flags to a local variable
builtin/config: track "fixed value" option via flags only
builtin/config: convert `key` to a local variable
builtin/config: convert `key_regexp` to a local variable
builtin/config: convert `regexp` to a local variable
builtin/config: convert `value_pattern` to a local variable
builtin/config: convert `do_not_match` to a local variable
builtin/config: move `respect_includes_opt` into location options
builtin/config: move default value into display options
builtin/config: move type options into display options
builtin/config: move display options into local variables
builtin/config: move location options into local variables
builtin/config: refactor functions to have common exit paths
config: make the config source const
builtin/config: check for writeability after source is set up
builtin/config: move actions into `cmd_config_actions()`
builtin/config: move legacy options into `cmd_config()`
builtin/config: move subcommand options into `cmd_config()`
builtin/config: move legacy mode into its own function
...
Terminology to call various ref-like things are getting
straightened out.
* ps/pseudo-ref-terminology:
refs: refuse to write pseudorefs
ref-filter: properly distinuish pseudo and root refs
refs: pseudorefs are no refs
refs: classify HEAD as a root ref
refs: do not check ref existence in `is_root_ref()`
refs: rename `is_special_ref()` to `is_pseudo_ref()`
refs: rename `is_pseudoref()` to `is_root_ref()`
Documentation/glossary: define root refs as refs
Documentation/glossary: clarify limitations of pseudorefs
Documentation/glossary: redefine pseudorefs as special refs
The SubmittingPatches document now refers folks to manpages
translation project.
* jc/doc-manpages-l10n:
SubmittingPatches: advertise git-manpages-l10n project a bit
Similar to the preceding commit, we have effectively given tracking
memory ownership of submodule gitfile paths. Refactor the code to start
tracking allocated strings in a separate `struct strvec` such that we
can easily plug those leaks. Mark now-passing tests as leak free.
Note that ideally, we wouldn't require two separate data structures to
track those paths. But we do need to store `NULL` pointers for the
gitfile paths such that we can indicate that its corresponding entries
in the other arrays do not have such a path at all. And given that
`struct strvec`s cannot store `NULL` pointers we cannot use them to
store this information.
There is another small gotcha that is easy to miss: you may be wondering
why we don't want to store `SUBMODULE_WITH_GITDIR` in the strvec. This
is because this is a mere sentinel value and not actually a string at
all.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Memory allocation patterns in git-mv(1) are extremely hard to follow:
We copy around string pointers into manually-managed arrays, some of
which alias each other, but only sometimes, while we also drop some of
those strings at other times without ever daring to free them.
While this may be my own subjective feeling, it seems like others have
given up as the code has multiple calls to `UNLEAK()`. These are not
sufficient though, and git-mv(1) is still leaking all over the place
even with them.
Refactor the code to instead track strings in `struct strvec`. While
this has the effect of effectively duplicating some of the strings
without an actual need, it is way easier to reason about and fixes all
of the aliasing of memory that has been going on. It allows us to get
rid of the `UNLEAK()` calls and also fixes leaks that those calls did
not paper over.
Mark tests which are now leak-free accordingly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
makes the next patch easier, where we will migrate to the paths being
owned by a strvec. given that we are talking about command line
parameters here it's also not like we have tons of allocations that this
would save
while at it, fix a memory leak
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `add_slash()` function will only conditionally return an allocated
string when the passed-in string did not yet have a trailing slash. This
makes the memory ownership harder to track than really necessary.
It's dubious whether this optimization really buys us all that much. The
number of times we execute this function is bounded by the number of
arguments to git-mv(1), so in the typical case we may end up saving an
allocation or two.
Simplify the code to unconditionally return allocated strings.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add two functions that allow to replace and remove strings contained in
the strvec. This will be used by a subsequent commit that refactors
git-mv(1).
While at it, add a bunch of unit tests that cover both old and new
functionality.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In `free_one_config()` we never end up freeing the `url` and `ignore`
fields and thus leak memory. Fix those leaks and mark now-passing tests
as leak free.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We use a priority queue in `ahead_behind()` to compute the ahead/behind
count for commits. We may not iterate through all commits part of that
queue though in case all of its entries are stale. Consequently, as we
never make the effort to release the remaining commits, we end up
leaking bit arrays that we have allocated for each of the contained
commits.
Plug this leak and mark the corresponding test as leak free.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We never release memory associated with `struct credential`. Fix this
and mark the corresponding test as leak free.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that memory ownership rules around `git_config_string()` and
`git_config_pathname()` are clearer, it also got easier to spot that
the returned memory needs to be free'd. Plug a subset of those cases and
mark now-passing tests as leak free.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The out parameter of `git_config_string()` is a `const char **` even
though we transfer ownership of memory to the caller. This is quite
misleading and has led to many memory leaks all over the place. Adapt
the parameter to instead be `char **`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit does the exact same as the preceding commit, only for the
format configuration instead of the log configuration.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We're using global variables to store the log configuration. Many of
these can be set both via the command line and via the config, and
depending on how they are being set, they may contain allocated strings.
This leads to hard-to-track memory ownership and memory leaks.
Refactor the code to instead use a `struct log_config` that is being
allocated on the stack. This allows us to more clearly scope the
variables, track memory ownership and ultimately release the memory.
This also prepares us for a change to `git_config_string()`, which will
be adapted to have a `char **` out parameter instead of `const char **`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `check_roundtrip_encoding` variable is tracked in a `const char *`
even though it may contain allocated strings at times. The result is
that those strings may be leaking because we never free them.
Refactor the code to always store allocated strings in this variable.
The default value is handled in `check_roundtrip()` now, which is the
only user of the variable.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The source and destination prefixes are tracked in a `const char *`
array, but may at times contain allocated strings. The result is that
those strings may be leaking because we never free them.
Refactor the code to always store allocated strings in those variables,
freeing them as required. This requires us to handle the default values
a bit different compared to before. But given that there is only a
single callsite where we use the variables to `struct diff_options` it's
easy to handle the defaults there.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The out parameter of `git_config_pathname()` is a `const char **` even
though we transfer ownership of memory to the caller. This is quite
misleading and has led to many memory leaks all over the place. Adapt
the parameter to instead be `char **`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are various variables assigned via `git_config_string()` and
`git_config_pathname()` which are never free'd. This bug is relatable
because the out parameter of those functions are a `const char **`, even
though memory ownership is transferred to the caller.
We're about to adapt the functions to instead use `char **`. Prepare the
code accordingly. Note that the `(const char **)` casts will go away
once we have adapted the functions.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The function `unique_tracking_name()` returns an allocated string, but
does not clearly indicate this because its return type is `const char *`
instead of `char *`. This has led to various callsites where we never
free its returned memory at all, which causes memory leaks.
Plug those leaks and mark now-passing tests as leak free.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In `strbuf_appendwholeline()` we call `strbuf_getwholeline()` with a
temporary buffer. In case the call returns an error we indicate this by
returning EOF, but never release the temporary buffer. This can cause a
leak though because `strbuf_getwholeline()` calls getline(3). Quoting
its documentation:
If *lineptr was set to NULL before the call, then the buffer
should be freed by the user program even on failure.
Consequently, the temporary buffer may hold allocated memory even when
the call to `strbuf_getwholeline()` fails.
Fix this by releasing the temporary buffer on error.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are a bunch of tests which do not have any leaks:
- t0411: Introduced via 5c5a4a1c05 (t0411: add tests for cloning from
partial repo, 2024-01-28), passes since its inception.
- t0610: Introduced via 57db2a094d (refs: introduce reftable backend,
2024-02-07), passes since its inception.
- t2405: Passes since 6741e917de (repository: avoid leaking
`fsmonitor` data, 2024-04-12).
- t7423: Introduced via b20c10fd9b (t7423: add tests for symlinked
submodule directories, 2024-01-28), passes since e8d0608944
(submodule: require the submodule path to contain directories only,
2024-03-26). The fix is not obviously related, but probably works
because we now die early in many code paths.
- t9xxx: All of these are exercising CVS-related tooling and pass
since at least Git v2.40. It's likely that these pass for a long
time already, but nobody ever noticed because Git developers do not
tend to have CVS on their machines.
Mark all of these tests as passing.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When initializing the transport helper in `transport_get()`, we
allocate the name of the helper. We neither end up transferring
ownership of the name, nor do we free it. The associated memory thus
leaks.
Fix this memory leak by freeing the string at the calling side in
`transport_get()`. `transport_helper_init()` now creates its own copy of
the string and thus can free it as required.
An alterantive way to fix this would be to transfer ownership of the
string passed into `transport_helper_init()`, which would avoid the call
to xstrdup(1). But it does make for a more surprising calling convention
as we do not typically transfer ownership of strings like this.
Mark now-passing tests as leak free.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In "t/lib-terminal.sh", we declare a lazy prerequisite for tests that
require a TTY. The prerequisite uses a Perl script to figure out whether
we do have a usable TTY or not and thus implicitly depends on the PERL
prerequisite, as well. Furthermore though, the script requires another
dependency that is easy to miss, namely on the IO::Pty module. If that
module is not installed, then the script will exit early due to an
reason unrelated to missing TTYs.
This easily leads to missing test coverage. But most importantly, our CI
systems are missing this dependency and thus don't execute those tests
at all. Fix this.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
