Junio C Hamano [Fri, 22 Nov 2024 05:34:17 +0000 (14:34 +0900)]
Merge branch 'jk/fetch-prefetch-double-free-fix'
Double-free fix.
* jk/fetch-prefetch-double-free-fix:
refspec: store raw refspecs inside refspec_item
refspec: drop separate raw_nr count
fetch: adjust refspec->raw_nr when filtering prefetch refspecs
Junio C Hamano [Wed, 20 Nov 2024 05:47:16 +0000 (14:47 +0900)]
Merge branch 'jt/repack-local-promisor'
"git gc" discards any objects that are outside promisor packs that
are referred to by an object in a promisor pack, and we do not
refetch them from the promisor at runtime, resulting an unusable
repository. Work it around by including these objects in the
referring promisor pack at the receiving end of the fetch.
* jt/repack-local-promisor:
index-pack: repack local links into promisor packs
t5300: move --window clamp test next to unclamped
t0410: use from-scratch server
t0410: make test description clearer
Junio C Hamano [Wed, 20 Nov 2024 05:42:58 +0000 (14:42 +0900)]
Merge branch 'ps/cache-tree-w-broken-index-entry' into maint-2.47
Fail gracefully instead of crashing when attempting to write the
contents of a corrupt in-core index as a tree object.
* ps/cache-tree-w-broken-index-entry:
unpack-trees: detect mismatching number of cache-tree/index entries
cache-tree: detect mismatching number of index entries
cache-tree: refactor verification to return error codes
Junio C Hamano [Wed, 20 Nov 2024 05:42:57 +0000 (14:42 +0900)]
Merge branch 'jk/fsmonitor-event-listener-race-fix' into maint-2.47
On macOS, fsmonitor can fall into a race condition that results in
a client waiting forever to be notified for an event that have
already happened. This problem has been corrected.
* jk/fsmonitor-event-listener-race-fix:
fsmonitor: initialize fs event listener before accepting clients
simple-ipc: split async server initialization and running
Junio C Hamano [Fri, 15 Nov 2024 17:27:40 +0000 (02:27 +0900)]
Clean up RelNotes for 2.48
There somehow ended up too many bogus "merge X later to maint"
comments for topics that cannot be merged ever down to 'maint'
because they were forked from more recent integration branches
in the draft release notes. Remove them, as they are inviting
for mistakes later.
Taylor Blau [Thu, 14 Nov 2024 13:42:12 +0000 (08:42 -0500)]
pack-objects: only perform verbatim reuse on the preferred pack
When reusing objects from source pack(s), write_reused_pack_verbatim()
is responsible for reusing objects whole eword_t's at a time. It works
by taking the longest continuous run of objects from the beginning of
each source pack that the caller wants, and reuses the entirety of that
section from each pack.
This is based on the assumption that we don't have any gaps within the
region. This assumption relieves us from having to patch any
OFS_DELTAs, since we know that there aren't any gaps between any delta
and its base in that region.
To illustrate why this assumption is necessary, suppose we have some
pack P, which has objects X, Y, and Z. If the MIDX's copy of Y was
selected from a pack other than P, then the bit corresponding to object
Y will appear earlier in the bitmap than the bits corresponding to X and
Z.
If pack-objects already has or will use the copy of Y from the pack it
was selected from in the MIDX, then it is an error to reuse all objects
between X and Z in the source pack. Doing so will cause us to reuse Y
from a different pack than the one which represents Y in the MIDX,
causing us to either:
- include the object twice, assuming that the caller wants Y in the
pack, or
- include the object once, resulting in us packing more objects than
necessary.
This regression comes from ca0fd69e37 (pack-objects: prepare
`write_reused_pack_verbatim()` for multi-pack reuse, 2023-12-14), which
incorrectly assumed that there would be no gaps in reusable regions of
non-preferred packs.
Instead, we can only safely perform the whole-word reuse optimization on
the preferred pack, where we know with certainty that no gaps exist in
that region of the bitmap. We can still reuse objects from non-preferred
packs, but we have to inspect them individually in write_reused_pack()
to ensure that any gaps that may exist are accounted for.
This allows us to simplify the implementation of
write_reused_pack_verbatim() back to almost its pre-multi-pack reuse
form, since we can now assume that the beginning of the pack appears at
the beginning of the bitmap, meaning that we don't have to account for
any bits up to the first word boundary (like we had to special case in ca0fd69e37).
The only significant changes from the pre-ca0fd69e37 implementation are:
- that we can no longer inspect words up to the end of
reuse_packfile_bitmap->word_alloc, since we only want to look at
words whose bits all correspond to objects in the given packfile, and
- that we return early when given a reuse_packfile which is not
preferred, making the call a noop.
In the future, it might be possible to restore this optimization if we
could guarantee that some reuse packs don't contain any gaps by
construction (similar to the "disjoint packs" idea in very early
versions of multi-pack reuse).
Helped-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The former is responsible for copying the bytes for a single object out
of an existing source pack. The latter does the same but for a region of
objects aligned at eword_t boundaries.
Demonstrate a bug whereby write_reused_pack_verbatim() can be tricked
into writing out objects from some source pack, even when those objects
were selected from a different source pack in the MIDX bitmap.
When the caller wants at least one of the objects in that region,
pack-objects will write the same object twice as a result of this bug.
In the other case where the caller doesn't want any of the objects in
the region of interest, we will write out objects that weren't
requested.
Demonstrate this bug by creating two packs, where the preferred one of
those packs contains a single object which also appears in the main
(non-preferred) pack. A separate bug[^1] prevents us from triggering the
main bug when the duplicated object is the last one in the main pack,
but any earlier object will suffice.
We could fix that separate bug, but the following commit will simplify
write_reused_pack_verbatim() and only call it on the preferred pack, so
doing so would have little point.
[^1]: Because write_reused_pack_verbatim() only reuses bits in the range
/* We're recording one chunk, not one object. */
record_reused_object(pack_start_off,
pack_start_off - (hashfile_total(out) - pack_start));
, or in other words excluding the object beginning at position 'pos -
reuse_packfile->bitmap_pos' in the source pack. But since
reuse_packfile->bitmap_pos is '1' in the non-preferred pack
(accounting for the single-object pack which is preferred), we don't
actually copy the bytes from the last object.
Helped-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Thu, 14 Nov 2024 01:39:12 +0000 (20:39 -0500)]
test-lib: move malloc-debug setup after $PATH setup
Originally, the conditional definition of the setup/teardown functions
for malloc checking could be run at any time, because they depended only
on command-line options and the system getconf function.
But since 02d900361c (test-lib: check malloc debug LD_PRELOAD before
using, 2024-11-11), we probe the system by running "git version". Since
this code runs before we've set $PATH to point to the version of Git we
intend to test, we actually run the system version of git.
This mostly works, since what we really care about is whether the
LD_PRELOAD works, and it should work the same with any program. But
there are some corner cases:
1. You might not have a system git at all, in which case the preload
will appear to fail, even though it could work with the actual
built version of git.
2. Your system git could be linked in a different way. For example, if
it was built statically, then it will ignore LD_PRELOAD entirely,
and we might assume that the preload works, even though it might
not when used with a dynamic build.
We could give a more complete path to the version of Git we intend to
test, but features like GIT_TEST_INSTALLED make that not entirely
trivial. So instead, let's just bump the setup until after we've set up
the $PATH. There's no need for us to do it early, as long as it is done
before the first test runs.
Reported-by: Toon Claes <toon@iotcl.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Tue, 12 Nov 2024 23:35:34 +0000 (08:35 +0900)]
Merge branch 'ps/mingw-rename'
The MinGW compatibility layer has been taught to support POSIX
semantics for atomic renames when other process(es) have a file
opened at the destination path.
* ps/mingw-rename:
compat/mingw: support POSIX semantics for atomic renames
compat/mingw: allow deletion of most opened files
compat/mingw: share file handles created via `CreateFileW()`
Simon Marchi [Tue, 12 Nov 2024 16:22:57 +0000 (11:22 -0500)]
builtin/difftool: intialize some hashmap variables
When running a dir-diff command that produces no diff, variables
`wt_modified` and `tmp_modified` are used while uninitialized, causing:
$ /home/smarchi/src/git/git-difftool --dir-diff master
free(): invalid pointer
[1] 334004 IOT instruction (core dumped) /home/smarchi/src/git/git-difftool --dir-diff master
$ valgrind --track-origins=yes /home/smarchi/src/git/git-difftool --dir-diff master
...
Invalid free() / delete / delete[] / realloc()
at 0x48478EF: free (vg_replace_malloc.c:989)
by 0x422CAC: hashmap_clear_ (hashmap.c:208)
by 0x283830: run_dir_diff (difftool.c:667)
by 0x284103: cmd_difftool (difftool.c:801)
by 0x238E0F: run_builtin (git.c:484)
by 0x2392B9: handle_builtin (git.c:750)
by 0x2399BC: cmd_main (git.c:921)
by 0x356FEF: main (common-main.c:64)
Address 0x1ffefff180 is on thread 1's stack
in frame #2, created by run_dir_diff (difftool.c:358)
...
If taking any `goto finish` path before these variables are initialized,
`hashmap_clear_and_free()` operates on uninitialized data, sometimes
causing a crash.
This regression was introduced in 7f795a1715 (builtin/difftool: plug
several trivial memory leaks, 2024-09-26).
Fix it by initializing those variables with the `HASHMAP_INIT` macro.
Add a test comparing the main branch to itself, resulting in no diff.
Signed-off-by: Simon Marchi <simon.marchi@efficios.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Tue, 12 Nov 2024 08:39:37 +0000 (03:39 -0500)]
refspec: store raw refspecs inside refspec_item
The refspec struct keeps two matched arrays: one for the refspec_item
structs and one for the original raw refspec strings. The main reason
for this is that there are other users of refspec_item that do not care
about the raw strings. But it does make managing the refspec struct
awkward, as we must keep the two arrays in sync. This has led to bugs in
the past (both leaks and double-frees).
Let's just store a copy of the raw refspec string directly in each
refspec_item struct. This simplifies the handling at a small cost:
1. Direct callers of refspec_item_init() will now get an extra copy of
the refspec string, even if they don't need it. This should be
negligible, as the struct is already allocating two strings for the
parsed src/dst values (and we tend to only do it sparingly anyway
for things like the TAG_REFSPEC literal).
2. Users of refspec_appendf() will now generate a temporary string,
copy it, and then free the result (versus handing off ownership of
the temporary string). We could get around this by having a "nodup"
variant of refspec_item_init(), but it doesn't seem worth the extra
complexity for something that is not remotely a hot code path.
Code which accesses refspec->raw now needs to look at refspec->item.raw.
Other callers which just use refspec_item directly can remain the same.
We'll free the allocated string in refspec_item_clear(), which they
should be calling anyway to free src/dst.
One subtle note: refspec_item_init() can return an error, in which case
we'll still have set its "raw" field. But that is also true of the "src"
and "dst" fields, so any caller which does not _clear() the failed item
is already potentially leaking. In practice most code just calls die()
on an error anyway, but you can see the exception in valid_fetch_refspec(),
which does correctly call _clear() even on error.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Tue, 12 Nov 2024 08:36:10 +0000 (03:36 -0500)]
refspec: drop separate raw_nr count
A refspec struct contains zero or more refspec_item structs, along with
matching "raw" strings. The items and raw strings are kept in separate
arrays, but those arrays will always have the same length (because we
write them only via refspec_append_nodup(), which grows both). This can
lead to bugs when manipulating the array, since the arrays and lengths
must be modified in lockstep. For example, the bug fixed in the previous
commit, which forgot to decrement raw_nr.
So let's get rid of "raw_nr" and have only "nr", making this kind of bug
impossible (and also making it clear that the two are always matched,
something that existing code already assumed but was not guaranteed by
the interface).
Even though we'd expect "alloc" and "raw_alloc" to likewise move in
lockstep, we still need to keep separate counts there if we want to
continue to use ALLOC_GROW() for both.
Conceptually this would all be simpler if refspec_item just held onto
its own raw string, and we had a single array. But there are callers
which use refspec_item outside of "struct refspec" (and so don't hold on
to a matching "raw" string at all), which we'd possibly need to adjust.
So let's not worry about refactoring that for now, and just get rid of
the redundant count variable. That is the first step on the road to
combining them anyway.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Tue, 12 Nov 2024 08:34:00 +0000 (03:34 -0500)]
fetch: adjust refspec->raw_nr when filtering prefetch refspecs
In filter_prefetch_refspecs(), we may remove one or more refspecs if
they point into refs/tags/. When we do, we remove the item from the
refspec->items array, shifting subsequent items down, and then decrement
the refspec->nr count.
We also remove the item from the refspec->raw array, but fail to
decrement refspec->raw_nr. This leaves us with a count that is too high,
and anybody looking at the "raw" array will erroneously see either:
1. The removed entry, if there were no subsequent items to shift down.
2. A duplicate of the final entry, as everything is shifted down but
there was nothing to overwrite the final item.
The obvious culprit to run into this is calling refspec_clear(), which
will try to free the removed entry (case 1) or double-free the final
entry (case 2). But even though the bug has existed since the function
was added in 2e03115d0c (fetch: add --prefetch option, 2021-04-16), we
did not trigger it in the test suite. The --prefetch option is normally
only used with configured refspecs, and we never bother to call
refspec_clear() on those (they are stored as part of a struct remote,
which is held in a global variable).
Ironically you couldn't trigger case 1, because the code accidentally
leaked the string in the raw array, and the two bugs (the leak and the
double-free) cancelled out. But when we fixed the leak in ea4780307c
(fetch: free "raw" string when shrinking refspec, 2024-09-24), it became
possible to trigger that, too, with a single item:
git fetch --prefetch . refs/tags/foo
We can fix both cases by just correctly decrementing "raw_nr" when we
shrink the array. Even though we don't expect people to use --prefetch
with command-line refspecs, we'll add a test to make sure it behaves
well (like the test just before it, we're just confirming that the
filtered prefetch succeeds at all).
Reported-by: Eric Mills <ermills@epic.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jonathan Tan [Fri, 1 Nov 2024 20:11:48 +0000 (13:11 -0700)]
index-pack: repack local links into promisor packs
Teach index-pack to, when processing the objects in a pack with
--promisor specified on the CLI, repack local objects (and the local
objects that they refer to, recursively) referenced by these objects
into promisor packs.
This prevents the situation in which, when fetching from a promisor
remote, we end up with promisor objects (newly fetched) referring
to non-promisor objects (locally created prior to the fetch). This
situation may arise if the client had previously pushed objects to the
remote, for example. One issue that arises in this situation is that,
if the non-promisor objects become inaccessible except through promisor
objects (for example, if the branch pointing to them has moved to
point to the promisor object that refers to them), then GC will garbage
collect them. There are other ways to solve this, but the simplest
seems to be to enforce the invariant that we don't have promisor objects
referring to non-promisor objects.
This repacking is done from index-pack to minimize the performance
impact. During a fetch, the only time most objects are fully inflated
in memory is when their object ID is computed, so we also scan the
objects (to see which objects they refer to) during this time.
Also to minimize the performance impact, an object is calculated to be
local if it's a loose object or present in a non-promisor pack. (If it's
also in a promisor pack or referred to by an object in a promisor pack,
it is technically already a promisor object. But a misidentification
of a promisor object as a non-promisor object is relatively benign
here - we will thus repack that promisor object into a promisor pack,
duplicating it in the object store, but there is no correctness issue,
just an issue of inefficiency.)
Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Mon, 11 Nov 2024 07:01:34 +0000 (02:01 -0500)]
test-lib: check malloc debug LD_PRELOAD before using
This fixes test failures across the suite on glibc platforms that don't
have libc_malloc_debug.so.0.
We added support for glibc's malloc checking routines long ago in a731fa916e (Add MALLOC_CHECK_ and MALLOC_PERTURB_ libc env to the test
suite for detecting heap corruption, 2012-09-14). Back then we didn't
need to do any checks to see if the platform supported it. We were just
setting some environment variables which would either enable it or not.
That changed in 131b94a10a (test-lib.sh: Use GLIBC_TUNABLES instead of
MALLOC_CHECK_ on glibc >= 2.34, 2022-03-04). Now that glibc split this
out into libc_malloc_debug.so, we have to add it to LD_PRELOAD. We only
do that when we detect glibc, but it's possible to have glibc but not
the malloc debug library. In that case LD_PRELOAD will complain to
stderr, and tests which check for an empty stderr will fail.
You can work around this by setting TEST_NO_MALLOC_CHECK, which disables
the feature entirely. But it's not obvious to know you need to do that.
Instead, since this malloc checking is best-effort anyway, let's just
automatically disable it when the LD_PRELOAD appears not to work. We can
check it by running something simple that should work (and produce
nothing on stderr) like "git version".
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Fri, 8 Nov 2024 03:56:27 +0000 (12:56 +0900)]
Merge branch 'ps/upgrade-clar'
Buildfix and upgrade of Clar to a newer version.
* ps/upgrade-clar:
cmake: set up proper dependencies for generated clar headers
cmake: fix compilation of clar-based unit tests
Makefile: extract script to generate clar declarations
Makefile: adjust sed command for generating "clar-decls.h"
t/unit-tests: update clar to 206accb
compat/mingw: support POSIX semantics for atomic renames
By default, Windows restricts access to files when those files have been
opened by another process. As explained in the preceding commits, these
restrictions can be loosened such that reads, writes and/or deletes of
files with open handles _are_ allowed.
While we set up those sharing flags in most relevant code paths now, we
still don't properly handle POSIX-style atomic renames in case the
target path is open. This is failure demonstrated by t0610, where one of
our tests spawns concurrent writes in a reftable-enabled repository and
expects all of them to succeed. This test fails most of the time because
the process that has acquired the "tables.list" lock is unable to rename
it into place while other processes are busy reading that file.
Windows 10 has introduced the `FILE_RENAME_FLAG_POSIX_SEMANTICS` flag
that allows us to fix this usecase [1]. When set, it is possible to
rename a file over a preexisting file even when the target file still
has handles open. Those handles must have been opened with the
`FILE_SHARE_DELETE` flag, which we have ensured in the preceding
commits.
Careful readers might have noticed that [1] does not mention the above
flag, but instead mentions `FILE_RENAME_POSIX_SEMANTICS`. This flag is
not for use with `SetFileInformationByHandle()` though, which is what we
use. And while the `FILE_RENAME_FLAG_POSIX_SEMANTICS` flag exists, it is
not documented on [2] or anywhere else as far as I can tell.
Unfortunately, we still support Windows systems older than Windows 10
that do not yet have this new flag. Our `_WIN32_WINNT` SDK version still
targets 0x0600, which is Windows Vista and later. And even though that
Windows version is out-of-support, bumping the SDK version all the way
to 0x0A00, which is Windows 10 and later, is not an option as it would
make it impossible to compile on Windows 8.1, which is still supported.
Instead, we have to manually declare the relevant infrastructure to make
this feature available and have fallback logic in place in case we run
on a Windows version that does not yet have this flag.
On another note: `mingw_rename()` has a retry loop that is used in case
deleting a file failed because it's still open in another process. One
might be pressed to not use this loop anymore when we can use POSIX
semantics. But unfortunately, we have to keep it around due to our
dependence on the `FILE_SHARE_DELETE` flag. While we know to set that
sharing flag now, other applications may not do so and may thus still
cause sharing violations when we try to rename a file.
This fixes concurrent writes in the reftable backend as demonstrated in
t0610, but may also end up fixing other usecases where Git wants to
perform renames.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Taylor Blau <me@ttaylorr.com> Reviewed-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jonathan Tan [Tue, 5 Nov 2024 19:24:19 +0000 (11:24 -0800)]
fetch-pack: die if in commit graph but not obj db
When fetching, there is a step in which sought objects are first checked
against the local repository; only objects that are not in the local
repository are then fetched. This check first looks up the commit graph
file, and returns "present" if the object is in there.
However, the action of first looking up the commit graph file is not
done everywhere in Git, especially if the type of the object at the time
of lookup is not known. This means that in a repo corruption situation,
a user may encounter an "object missing" error, attempt to fetch it, and
still encounter the same error later when they reattempt their original
action, because the object is present in the commit graph file but not in
the object DB.
Therefore, make it a fatal error when this occurs. (Note that we cannot
proceed to include this object in the list of objects to be fetched
without changing at least the fetch negotiation code: what would happen
is that the client will send "want X" and "have X" and when I tested
at $DAYJOB with a work server that uses JGit, the server reasonably
returned an empty packfile. And changing the fetch negotiation code to
only use the object DB when deciding what to report as "have" would be
an unnecessary slowdown, I think.)
This was discovered when a lazy fetch of a missing commit completed with
nothing actually fetched, and the writing of the commit graph file after
every fetch then attempted to read said missing commit, triggering a
lazy fetch of said missing commit, resulting in an infinite loop with no
user-visible indication (until they check the list of processes running
on their computer). With this fix, there is no infinite loop. Note that
although the repo corruption we discovered was caused by a bug in GC in
a partial clone, the behavior that this patch teaches Git to warn about
applies to any repo with commit graph enabled and with a missing commit,
whether it is a partial clone or not.
t5330, introduced in 3a1ea94a49 (commit-graph.c: no lazy fetch in
lookup_commit_in_graph(), 2022-07-01), tests that an interaction between
fetch and the commit graph does not cause an infinite loop. This patch
changes the exit code in that situation, so that test had to be changed.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
This revert simplifies the next patch in this patch set.
The commit message of that commit mentions that the new function "will
be used for the bundle-uri client in a subsequent commit", but it seems
that eventually it wasn't used.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Mon, 4 Nov 2024 19:02:44 +0000 (19:02 +0000)]
doc: correct misleading descriptions for --shallow-exclude
The documentation for the --shallow-exclude option to clone/fetch/etc.
claims that the option takes a revision, but it does not. As per
upload-pack.c's process_deepen_not(), it passes the option to
expand_ref() and dies if it does not find exactly one ref matching the
name passed. Further, this has always been the case ever since these
options were introduced by the commits merged in a460ea4a3cb1 (Merge
branch 'nd/shallow-deepen', 2016-10-10). Fix the documentation to
match the implementation.
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
list-objects-filter-options: work around reported leak on error
This one is a little bit more curious. In t6112, we have a test that
exercises the `git rev-list --filter` option with invalid filters. We
execute git-rev-list(1) via `test_must_fail`, which means that we check
for leaks even though Git exits with an error code. This causes the
following leak:
Direct leak of 27 byte(s) in 1 object(s) allocated from:
#0 0x5555555e6946 in realloc.part.0 lsan_interceptors.cpp.o
#1 0x5555558fb4b6 in xrealloc wrapper.c:137:8
#2 0x5555558b6e06 in strbuf_grow strbuf.c:112:2
#3 0x5555558b7550 in strbuf_add strbuf.c:311:2
#4 0x5555557c1a88 in strbuf_addstr strbuf.h:310:2
#5 0x5555557c1d4c in parse_list_objects_filter list-objects-filter-options.c:261:3
#6 0x555555885ead in handle_revision_pseudo_opt revision.c:2899:3
#7 0x555555884e20 in setup_revisions revision.c:3014:11
#8 0x5555556c4b42 in cmd_rev_list builtin/rev-list.c:588:9
#9 0x5555555ec5e3 in run_builtin git.c:483:11
#10 0x5555555eb1e4 in handle_builtin git.c:749:13
#11 0x5555555ec001 in run_argv git.c:819:4
#12 0x5555555eaf94 in cmd_main git.c:954:19
#13 0x5555556fd569 in main common-main.c:64:11
#14 0x7ffff7ca714d in __libc_start_call_main (.../lib/libc.so.6+0x2a14d)
#15 0x7ffff7ca7208 in __libc_start_main@GLIBC_2.2.5 (.../libc.so.6+0x2a208)
#16 0x5555555ad064 in _start (git+0x59064)
This leak is valid, as we call `die()` and do not clean up the memory at
all. But what's curious is that this is the only leak reported, because
we don't clean up any other allocated memory, either, and I have no idea
why the leak sanitizer treats this buffer specially.
In any case, we can work around the leak by shuffling things around a
bit. Instead of calling `gently_parse_list_objects_filter()` and dying
after we have modified the filter spec, we simply do so beforehand. Like
this we don't allocate the buffer in the error case, which makes the
reported leak go away.
It's not pretty, but it manages to make t6112 leak free.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
builtin/merge: release output buffer after performing merge
The `obuf` member of `struct merge_options` is used to buffer output in
some cases. In order to not discard its allocated memory we only release
its contents in `merge_finalize()` when we're not currently recursing
into a subtree.
This results in some situations where we seemingly do not release the
buffer reliably. We thus have calls to `strbuf_release()` for this
buffer scattered across the codebase. But we're missing one callsite in
git-merge(1), which causes a memory leak.
We should ideally refactor this interface so that callers don't have to
know about any such internals. But for now, paper over the issue by
adding one more `strbuf_release()` call.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
dir: fix leak when parsing "status.showUntrackedFiles"
We use `repo_config_get_string()` to read "status.showUntrackedFiles"
from the config subsystem. This function allocates the result, but we
never free the result after parsing it.
The value never leaves the scope of the calling function, so refactor it
to instead use `repo_config_get_string_tmp()`, which does not hand over
ownership to the caller.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
t/helper: stop re-initialization of `the_repository`
While "common-main.c" already initializes `the_repository` for us, we do
so a second time in the "read-cache" test helper. This causes a memory
leak because the old repository's contents isn't released.
Stop calling `initialize_repository()` to plug this leak.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
While we free the `fsmonitor_dirty` member of `struct index_state`, we
do not free the contents of that EWAH. Do so by using `ewah_free()`
instead of `FREE_AND_NULL()`.
This leak is exposed by t7519, but plugging it alone does not make the
test suite pass.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are several cases where we invalidate untracked cache directory
entries where we do not free the underlying data, but reset the number
of entries. This causes us to leak memory because `free_untracked()`
will not iterate over any potential entries which we still had in the
array.
Fix this issue by freeing old entries. The leak is exposed by t7519, but
plugging it alone does not make the whole test suite pass.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `cnt` variable tracks the number of lines in a patch diff. It can
happen though that there are no newlines, in which case we'd still end
up allocating our array of `sline`s. In fact, we always allocate it with
`cnt + 2` entries: one extra entry for the deletion hunk at the end, and
another entry that we don't seem to ever populate at all but acts as a
kind of sentinel value.
When we loop through the array to clear it at the end of this function
we only loop until `lno < cnt`, and thus we may not end up releasing
whatever the two extra `sline`s contain. While that shouldn't matter for
the sentinel value, it does matter for the extra deletion hunk sline.
Regardless of that, plug this memory leak by releasing both extra
entries, which makes the logic a bit easier to reason about.
While at it, fix the formatting of a local comment, which incidentally
also provides the necessary context for why we overallocate the `sline`
array.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The cleanup string set by the config is leaking when it is being
overridden by an option. Fix this by tracking these via two separate
variables such that we can free the old value.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
trailer: fix leaking strbufs when formatting trailers
When formatting trailer lines we iterate through each of the trailers
and munge their respective token/value pairs according to the trailer
options. When formatting a trailer that has its `item->token` pointer
set we perform the munging in two local buffers. In the case where we
figure out that the value is empty and `trim_empty` is set we just skip
over the trailer item. But the buffers are local to the loop and we
don't release their contents, leading to a memory leak.
Plug this leak by lifting the buffers outside of the loop and releasing
them on function return. This fixes the memory leaks, but also optimizes
the loop as we don't have to reallocate the buffers on every single
iteration.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff-lib: fix leaking diffopts in `do_diff_cache()`
In `do_diff_cache()` we initialize a new `rev_info` and then overwrite
its `diffopt` with a user-provided set of options. This can leak memory
because `repo_init_revisions()` may end up allocating memory for the
`diffopt` itself depending on the configuration. And since that field is
overwritten we won't ever free it.
Plug the memory leak by releasing the diffopts before we overwrite them.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
In `grep_splice_or()` we search for the next `TRUE` node in our tree of
grep expressions and replace it with the given new expression. But we
don't free the old node, which causes a memory leak. Plug it.
This leak is exposed by t7810, but plugging it alone isn't sufficient to
make the test suite pass.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Mon, 4 Nov 2024 19:02:43 +0000 (19:02 +0000)]
upload-pack: fix ambiguous error message
upload-pack.c takes any --shallow-exclude argument(s) from
clone/fetch/etc. and passes them through expand_ref(). If it does not
get back exactly one ref from the call to expand_ref(), it will die with
the following error:
fatal: git upload-pack: ambiguous deepen-not: %s
Given that the documentation suggests to users that --shallow-exclude
accepts a revision rather than a ref (which will be corrected in a
subsequent commit), users may try to pass a revision. In such a case,
expand_ref() will return 0 matches, but the error message we print will
be misleading since "ambiguous" suggests there are multiple matches.
Provide a clearer error message for such a case.
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jonathan Tan [Fri, 1 Nov 2024 20:11:47 +0000 (13:11 -0700)]
t5300: move --window clamp test next to unclamped
A subsequent commit will change the behavior of "git index-pack
--promisor", which is exercised in "build pack index for an existing
pack", causing the unclamped and clamped versions of the --window
test to exhibit different behavior. Move the clamp test closer to the
unclamped test that it references.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jonathan Tan [Fri, 1 Nov 2024 20:11:46 +0000 (13:11 -0700)]
t0410: use from-scratch server
A subsequent commit will add functionality: when fetching from a
promisor remote, existing non-promisor objects that are ancestors of any
fetched object will be repacked into promisor packs (since if a promisor
remote has an object, it also has all its ancestors).
This means that sometimes, a fetch from a promisor remote results in 2
new promisor packs (instead of the 1 that you would expect). There is a
test that fetches a descendant of a local object from a promisor remote,
but also specifically tests that there is exactly 1 promisor pack as
a result of the fetch. This means that this test will fail when the
subsequent commit is added.
Since the ancestry of the fetched object is not the concern of this
test, make the fetched objects have no ancestry in common with the
objets in the client repo. This is done by making the server from
scratch, instead of using an existing repo that has objects in common
with the client.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jonathan Tan [Fri, 1 Nov 2024 20:11:45 +0000 (13:11 -0700)]
t0410: make test description clearer
Commit 9a4c507886 (t0410: test fetching from many promisor remotes,
2019-06-25) adds some tests that demonstrate not the automatic fetching
of missing objects, but the direct fetching from another promisor remote
(configured explicitly in one test and implicitly via --filter on the
"git fetch" CLI invocation in the other test) - thus demonstrating
support for multiple promisor remotes, as described in the commit
message.
Change the test descriptions accordingly to make this clearer.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taylor Blau [Fri, 1 Nov 2024 16:53:31 +0000 (12:53 -0400)]
Merge branch 'jk/dumb-http-finalize'
The dumb-http code regressed when the result of re-indexing a pack
yielded an *.idx file that differs in content from the *.idx file it
downloaded from the remote. This has been corrected by no longer
relying on the *.idx file we got from the remote.
* jk/dumb-http-finalize:
packfile: use oidread() instead of hashcpy() to fill object_id
packfile: use object_id in find_pack_entry_one()
packfile: convert find_sha1_pack() to use object_id
http-walker: use object_id instead of bare hash
packfile: warn people away from parse_packed_git()
packfile: drop sha1_pack_index_name()
packfile: drop sha1_pack_name()
packfile: drop has_pack_index()
dumb-http: store downloaded pack idx as tempfile
t5550: count fetches in "previously-fetched .idx" test
midx: avoid duplicate packed_git entries
Taylor Blau [Fri, 1 Nov 2024 16:53:26 +0000 (12:53 -0400)]
Merge branch 'ua/atoi'
Replace various calls to atoi() with strtol_i() and strtoul_ui(), and
add improved error handling.
* ua/atoi:
imap: replace atoi() with strtol_i() for UIDVALIDITY and UIDNEXT parsing
merge: replace atoi() with strtol_i() for marker size validation
daemon: replace atoi() with strtoul_ui() and strtol_i()
Taylor Blau [Fri, 1 Nov 2024 16:53:19 +0000 (12:53 -0400)]
Merge branch 'rj/cygwin-exit'
Treat ECONNABORTED the same as ECONNRESET in 'git credential-cache' to
work around a possible Cygwin regression. This resolves a race condition
caused by changes in Cygwin's handling of socket closures, allowing the
client to exit cleanly when encountering ECONNABORTED.
* rj/cygwin-exit:
credential-cache: treat ECONNABORTED like ECONNRESET
Taylor Blau [Fri, 1 Nov 2024 16:53:16 +0000 (12:53 -0400)]
Merge branch 'ps/platform-compat-fixes'
Various platform compatibility fixes split out of the larger effort
to use Meson as the primary build tool.
* ps/platform-compat-fixes:
t6006: fix prereq handling with `test_format ()`
http: fix build error on FreeBSD
builtin/credential-cache: fix missing parameter for stub function
t7300: work around platform-specific behaviour with long paths on MinGW
t5500, t5601: skip tests which exercise paths with '[::1]' on Cygwin
t3404: work around platform-specific behaviour on macOS 10.15
t1401: make invocation of tar(1) work with Win32-provided one
t/lib-gpg: fix setup of GNUPGHOME in MinGW
t/lib-gitweb: test against the build version of gitweb
t/test-lib: wire up NO_ICONV prerequisite
t/test-lib: fix quoting of TEST_RESULTS_SAN_FILE
will produce output without any left-right markers, since the bitmap
traversal returns only a single set of reachable commits. Instead we
should refuse to use bitmaps here and produce the correct output using a
traditional traversal.
This is probably not the only remaining option that misbehaves with
bitmaps, but it's particularly egregious in that it feels like it
_could_ work. Doing two separate traversals for the left/right sides and
then taking the symmetric set differences should yield the correct
answer, but our traversal code doesn't know how to do that.
It's not clear if naively doing two separate traversals would always be
a performance win. A traditional traversal only needs to walk down to
the merge base, but bitmaps always fill out the full reachability set.
So depending on your bitmap coverage, we could end up walking old bits
of history twice to fill out the same uninteresting bits on both sides.
We'd also of course end up with a very large --boundary set, if the user
asked for that.
So this might or might not be something worth implementing later. But
for now, let's make sure we don't produce the wrong answer if somebody
tries it.
The test covers this, but also the same thing with "--count" (which is
what I originally tried in a real-world case). Ironically the
try_bitmap_count() code already realizes that "--left-right" won't work
there. But that just causes us to fall back to the regular bitmap
traversal code, which itself doesn't handle counting (we produce a list
of objects rather than a count).
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com>
In df383b5842 (t/test-lib: wire up NO_ICONV prerequisite, 2024-10-16) we
have introduced a new NO_ICONV prerequisite that makes us skip tests in
case Git is not compiled with support for iconv. This change subtly
broke t6006: while the test suite still passes, some of its tests won't
execute because they run into an error.
./t6006-rev-list-format.sh: line 92: test_expect_%e: command not found
The broken tests use `test_format ()`, and the mentioned commit simply
prepended the new prerequisite to its arguments. But that does not work,
as the function is not aware of prereqs at all and will now treat all of
its arguments incorrectly.
Fix this by making the function aware of prereqs by accepting an
optional fourth argument. Adapt the callsites accordingly.
Reported-by: Josh Steadmon <steadmon@google.com> Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Taylor Blau <me@ttaylorr.com>
On Windows, we emulate open(3p) via `mingw_open()`. This function
implements handling of some platform-specific quirks that are required
to make it behave as closely as possible like open(3p) would, but for
most cases we just call the Windows-specific `_wopen()` function.
This function has a major downside though: it does not allow us to
specify the sharing mode. While there is `_wsopen()` that allows us to
pass sharing flags, those sharing flags are not the same `FILE_SHARE_*`
flags as `CreateFileW()` accepts. Instead, `_wsopen()` only allows
concurrent read- and write-access, but does not allow for concurrent
deletions. Unfortunately though, we have to allow concurrent deletions
if we want to have POSIX-style atomic renames on top of an existing file
that has open file handles.
Implement a new function that emulates open(3p) for existing files via
`CreateFileW()` such that we can set the required sharing flags.
While we have the same issue when calling open(3p) with `O_CREAT`,
implementing that mode would be more complex due to the required
permission handling. Furthermore, atomic updates via renames typically
write to exclusive lockfile and then perform the rename, and thus we
don't have to handle the case where the locked path has been created
with `O_CREATE`. So while it would be nice to have proper POSIX
semantics in all paths, we instead aim for a minimum viable fix here.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Taylor Blau <me@ttaylorr.com>
compat/mingw: share file handles created via `CreateFileW()`
Unless told otherwise, Windows will keep other processes from reading,
writing and deleting files when one has an open handle that was created
via `CreateFileW()`. This behaviour can be altered via `FILE_SHARE_*`
flags:
- `FILE_SHARE_READ` allows a concurrent process to open the file for
reading.
- `FILE_SHARE_WRITE` allows a concurrent process to open the file for
writing.
- `FILE_SHARE_DELETE` allows a concurrent process to delete the file
or to replace it via an atomic rename.
This sharing mechanism is quite important in the context of Git, as we
assume POSIX semantics all over the place. But there are two callsites
where we don't pass all three of these flags:
- We don't set `FILE_SHARE_DELETE` when creating a file for appending
via `mingw_open_append()`. This makes it impossible to delete the
file from another process or to replace it via an atomic rename. The
function was introduced via d641097589 (mingw: enable atomic
O_APPEND, 2018-08-13) and has been using `FILE_SHARE_READ |
FILE_SHARE_WRITE` since the inception. There aren't any indicators
that the omission of `FILE_SHARE_DELETE` was intentional.
- We don't set any sharing flags in `mingw_utime()`, which changes the
access and modification of a file. This makes it impossible to
perform any kind of operation on this file at all from another
process. While we only open the file for a short amount of time to
update its timestamps, this still opens us up for a race condition
with another process.
`mingw_utime()` was originally implemented via `_wopen()`, which
doesn't give you full control over the sharing mode. Instead, it
calls `_wsopen()` with `_SH_DENYNO`, which ultimately translates to
`FILE_SHARE_READ | FILE_SHARE_WRITE`. It was then refactored via 090a3085bc (t/helper/test-chmtime: update mingw to support chmtime
on directories, 2022-03-02) to use `CreateFileW()`, but we stopped
setting any sharing flags at all, which seems like an unintentional
side effect. By restoring `FILE_SHARE_READ | FILE_SHARE_WRITE` we
thus fix this and get back the old behaviour of `_wopen()`.
The fact that we didn't set the equivalent of `FILE_SHARE_DELETE`
can be explained, as well: neither `_wopen()` nor `_wsopen()` allow
you to do so. So overall, it doesn't seem intentional that we didn't
allow deletions here, either.
Adapt both of these callsites to pass all three sharing flags.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Taylor Blau <me@ttaylorr.com>
Jeff King [Fri, 25 Oct 2024 07:08:10 +0000 (03:08 -0400)]
packfile: use oidread() instead of hashcpy() to fill object_id
When chasing a REF_DELTA, we need to pull the raw hash bytes out of the
mmap'd packfile into an object_id struct. We do that with a raw
hashcpy() of the appropriate length (that happens directly now, though
before the previous commit it happened inside find_pack_entry_one(),
also using a hashcpy).
But I think this creates a potentially dangerous situation due to d4d364b2c7 (hash: convert `oidcmp()` and `oideq()` to compare whole
hash, 2024-06-14). When using sha1, we'll have uninitialized bytes in
the latter part of the object_id.hash buffer, which could fool oideq(),
etc.
We should use oidread() instead, which correctly zero-pads the extra
bytes, as of c98d762ed9 (global: ensure that object IDs are always
padded, 2024-06-14).
As far as I can see, this has not been a problem in practice because the
object_id we feed to find_pack_entry_one() is never used with oideq(),
etc. It is being compared to the bytes mmap'd from a pack idx file,
which of course do not have the extra padding bytes themselves. So
there's no bug here, but this just puzzled me while looking at the code.
We should do the more obviously safe thing, both for future-proofing and
to avoid confusing readers.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com>
projects / thirdparty / git.git / log
