Back when 1a9d15db25 (tempfile: a new module for handling temporary
files, 2015-08-10) added this comment, tempfile structs were held in
memory for the life of a process, and there were various guarantees
about which fields were valid in which states.
Since 422a21c6a0 (tempfile: remove deactivated list entries, 2017-09-05)
and 076aa2cbda (tempfile: auto-allocate tempfiles on heap, 2017-09-05),
the flow is quite different: objects come and go from the list, and
inactive ones are deallocated. And the previous commit removed the
"active" flag from the struct entirely.
Let's bring the comment up to date with the current code.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Our tempfile struct contains an "active" flag. Long ago, this flag was
important: tempfile structs were always allocated for the lifetime of
the program and added to a global linked list, and the active flag was
what told us whether a struct's tempfile needed to be cleaned up on
exit.
But since 422a21c6a0 (tempfile: remove deactivated list entries,
2017-09-05) and 076aa2cbda (tempfile: auto-allocate tempfiles on heap,
2017-09-05), we actually remove items from the list, and the active flag
is generally always set to true for any allocated struct. We set it to
true in all of the creation functions, and in the normal code flow it
becomes false only in deactivate_tempfile(), which then immediately
frees the struct.
So the flag isn't performing that role anymore, and in fact makes things
more confusing. Dscho noted that delete_tempfile() is a noop for an
inactive struct. Since 076aa2cbda taught it to free the struct when
deactivating, we'd leak any struct whose active flag is unset. But in
practice it's not a leak, because again, we'll free when we unset the
flag, and never see the allocated-but-inactive state.
Can we just get rid of the flag? The answer is yes, but it requires
looking at a few other spots:
1. I said above that the flag only becomes false before we deallocate,
but there's one exception: when we call remove_tempfiles() from a
signal or atexit handler, we unset the active flag as we remove
each file. This isn't important for delete_tempfile(), as nobody
would call it anymore, since we're exiting.
It does in theory provide us some protection against racily
double-removing a tempfile. If we receive a second signal while we
are already in the cleanup routines, we'll start the cleanup loop
again, and may visit the same tempfile. But this race already
exists, because calling unlink() and unsetting the active flag
aren't atomic! And it's OK in practice, because unlink() is
idempotent (barring the unlikely event that some other process
chooses our exact temp filename in that instant).
So dropping the active flag widens the race a bit, but it was
already there, and is fairly harmless in practice. If we really
care about addressing it, the right thing is probably to block
further signals while we're doing our cleanup (which we could
actually do atomically).
2. The active flag is declared as "volatile sig_atomic_t". The idea is
that it's the final bit that gets set to tell the cleanup routines
that the tempfile is ready to be used (or not used), and it's safe
to receive a signal racing with regular code which adds or removes
a tempfile from the list.
In practice, I don't think this is buying us anything. The presence
on the linked list is really what tells the cleanup routines to
look at the struct. That is already marked as "volatile". It's not
a sig_atomic_t, so it's possible that we could see a sheared write
there as an entry is added or removed. But that is true of the
current code, too! Before we can even look at the "active" flag,
we'd have to follow a link to the struct itself. If we see a
sheared write in the pointer to the struct, then we'll look at
garbage memory anyway, and there's not much we can do.
This patch removes the active flag entirely, using presence on the
global linked list as an indicator that a tempfile ought to be cleaned
up. We are already careful to add to the list as the final step in
activating. On deactivation, we'll make sure to remove from the list as
the first step, before freeing any fields. The use of the volatile
keyword should mean that those things happen in the expected order.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix broken "&&-" chains and failures in early iterations of a loop.
* es/fix-chained-tests:
t5329: notice a failure within a loop
t: detect and signal failure within loop
t1092: fix buggy sparse "blame" test
t2407: fix broken &&-chains in compound statement
Update the version of Ubuntu used for GitHub Actions CI from 18.04
to 22.04.
* ds/github-actions-use-newer-ubuntu:
ci: update 'static-analysis' to Ubuntu 22.04
The preload-index codepath made copies of pathspec to give to
multiple threads, which were left leaked.
* ad/preload-plug-memleak:
preload-index: fix memleak
xcalloc(), imitating calloc(), takes "number of elements of the
array", and "size of a single element", in this order. A call that
does not follow this ordering has been corrected.
* sg/xcalloc-cocci-fix:
promisor-remote: fix xcalloc() argument order
The sequencer machinery translated messages left in the reflog by
mistake, which has been corrected.
* mg/sequencer-untranslate-reflog:
sequencer: do not translate command names
sequencer: do not translate parameters to error_resolve_conflict()
sequencer: do not translate reflog messages
Code clean-up to remove unused function parameters.
* jk/unused-fixes:
xdiff: drop unused mmfile parameters from xdl_do_patience_diff()
reflog: assert PARSE_OPT_NONEG in parse-options callbacks
reftable: drop unused parameter from reader_seek_linear()
verify_one_sparse(): drop unused parameters
match_pathname(): drop unused "flags" parameter
log-tree: drop unused commit param in remerge_diff()
xdiff: drop unused mmfile parameters from xdl_do_histogram_diff()
The bash prompt (in contrib/) learned to optionally indicate when
the index is unmerged.
* jd/prompt-show-conflict:
git-prompt: show presence of unresolved conflicts at command prompt
"scalar" now enables built-in fsmonitor on enlisted repositories,
when able.
* vd/scalar-enables-fsmonitor:
scalar: update technical doc roadmap with FSMonitor support
scalar unregister: stop FSMonitor daemon
scalar: enable built-in FSMonitor on `register`
scalar: move config setting logic into its own function
scalar-delete: do not 'die()' in 'delete_enlistment()'
scalar-[un]register: clearly indicate source of error
scalar-unregister: handle error codes greater than 0
scalar: constrain enlistment search
"git rev-list --ancestry-path=C A..B" is a natural extension of
"git rev-list A..B"; instead of choosing a subset of A..B to those
that have ancestry relationship with A, it lets a subset with
ancestry relationship with C.
* en/ancestry-path-in-a-range:
revision: allow --ancestry-path to take an argument
t6019: modernize tests with helper
rev-list-options.txt: fix simple typo
Test portability improvements.
* mt/rot13-in-c:
tests: use the new C rot13-filter helper to avoid PERL prereq
t0021: implementation the rot13-filter.pl script in C
t0021: avoid grepping for a Perl-specific string at filter output
The namespaces used by "log --decorate" from "refs/" hierarchy by
default has been tightened.
* ds/decorate-filter-tweak:
fetch: use ref_namespaces during prefetch
maintenance: stop writing log.excludeDecoration
log: create log.initialDecorationSet=all
log: add --clear-decorations option
log: add default decoration filter
log-tree: use ref_namespaces instead of if/else-if
refs: use ref_namespaces for replace refs base
refs: add array of ref namespaces
t4207: test coloring of grafted decorations
t4207: modernize test
refs: allow "HEAD" as decoration filter
The temporary directory created by mks_tempfile_dt() is deleted by first
deleting the file within, then truncating the filename strbuf and
passing the resulting string to rmdir(2). When the cleanup routine is
invoked concurrently by a signal handler we can end up passing the now
truncated string to unlink(2), however, which could cause problems on
some systems.
Avoid that issue by remembering the directory name separately. This way
the paths stay unchanged. A signal handler can still race with normal
cleanup, but deleting the same files and directories twice is harmless.
Reported-by: Jeff King <peff@peff.net>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Documentation for "git add --renormalize" has been improved.
source: <20220810144450.470-2-philipoakley@iee.email>
* po/doc-add-renormalize:
doc add: renormalize is not idempotent for CRCRLF
Fixes to sparse index compatibility work for "reset" and "checkout"
commands.
source: <pull.1312.v3.git.1659985672.gitgitgadget@gmail.com>
* vd/sparse-reset-checkout-fixes:
unpack-trees: unpack new trees as sparse directories
cache.h: create 'index_name_pos_sparse()'
oneway_diff: handle removed sparse directories
checkout: fix nested sparse directory diff in sparse index
"git fsck" reads mode from tree objects but canonicalizes the mode
before passing it to the logic to check object sanity, which has
hid broken tree objects from the checking logic. This has been
corrected, but to help exiting projects with broken tree objects
that they cannot fix retroactively, the severity of anomalies this
code detects has been demoted to "info" for now.
source: <YvQcNpizy9uOZiAz@coredump.intra.peff.net>
* jk/fsck-tree-mode-bits-fix:
fsck: downgrade tree badFilemode to "info"
fsck: actually detect bad file modes in trees
tree-walk: add a mechanism for getting non-canonicalized modes
Platform-specific code that determines if a directory is OK to use
as a repository has been taught to report more details, especially
on Windows.
source: <pull.1286.v2.git.1659965270.gitgitgadget@gmail.com>
* js/safe-directory-plus:
mingw: handle a file owned by the Administrators group correctly
mingw: be more informative when ownership check fails on FAT32
mingw: provide details about unsafe directories' ownership
setup: prepare for more detailed "dubious ownership" messages
setup: fix some formatting
Avoid repeatedly running getconf to ask libc version in the test
suite, and instead just as it once per script.
source: <pull.1311.git.1659620305757.gitgitgadget@gmail.com>
* pw/use-glibc-tunable-for-malloc-optim:
tests: cache glibc version check
A follow-up fix to a fix for a regression in 2.36.
source: <patch-1.1-2450e3e65cf-20220805T141402Z-avarab@gmail.com>
* ab/hooks-regression-fix:
hook API: don't segfault on strbuf_addf() to NULL "out"
Plug memory leaks in the failure code path in the "merge-ort" merge
strategy backend.
source: <pull.1307.v2.git.1659114727.gitgitgadget@gmail.com>
* js/ort-clean-up-after-failed-merge:
merge-ort: do leave trace2 region even if checkout fails
merge-ort: clean up after failed merge
Older gcc with -Wall complains about the universal zero initializer
"struct s = { 0 };" idiom, which makes developers' lives
inconvenient (as -Werror is enabled by DEVELOPER=YesPlease). The
build procedure has been tweaked to help these compilers.
source: <YuQ60ZUPBHAVETD7@coredump.intra.peff.net>
* jk/struct-zero-init-with-older-gcc:
config.mak.dev: squelch -Wno-missing-braces for older gcc
Conditionally allow building Python interpreter on Windows
source: <pull.1306.v2.git.1659109272.gitgitgadget@gmail.com>
* js/mingw-with-python:
mingw: remove unneeded `NO_CURL` directive
mingw: remove unneeded `NO_GETTEXT` directive
windows: include the Python bits when building Git for Windows
Fix build procedure for Windows that uses CMake so that it can pick
up the shell interpreter from local installation location.
source: <pull.1304.git.1658912756815.gitgitgadget@gmail.com>
* ca/unignore-local-installation-on-windows:
cmake: support local installations of git
The "diagnose" feature to create a zip archive for diagnostic
material has been lifted from "scalar" and made into a feature of
"git bugreport".
* vd/scalar-generalize-diagnose:
scalar: update technical doc roadmap
scalar-diagnose: use 'git diagnose --mode=all'
builtin/bugreport.c: create '--diagnose' option
builtin/diagnose.c: add '--mode' option
builtin/diagnose.c: create 'git diagnose' builtin
diagnose.c: add option to configure archive contents
scalar-diagnose: move functionality to common location
scalar-diagnose: move 'get_disk_info()' to 'compat/'
scalar-diagnose: add directory to archiver more gently
scalar-diagnose: avoid 32-bit overflow of size_t
scalar-diagnose: use "$GIT_UNZIP" in test
Fix deadlocks between main Git process and subprocess spawned via
the pipe_command() API, that can kill "git add -p" that was
reimplemented in C recently.
* jk/pipe-command-nonblock:
pipe_command(): mark stdin descriptor as non-blocking
pipe_command(): handle ENOSPC when writing to a pipe
pipe_command(): avoid xwrite() for writing to pipe
git-compat-util: make MAX_IO_SIZE define globally available
nonblock: support Windows
compat: add function to enable nonblocking pipes
The common ancestor negotiation exchange during a "git fetch"
session now leaves trace log.
* js/fetch-negotiation-trace:
fetch-pack: add tracing for negotiation rounds
An earlier optimization discarded a tree-object buffer that is
still in use, which has been corrected.
* jk/is-promisor-object-keep-tree-in-use:
is_promisor_object(): fix use-after-free of tree buffer
Further update the help messages given while merging submodules.
* en/submodule-merge-messages-fixes:
merge-ort: provide helpful submodule update message when possible
merge-ort: avoid surprise with new sub_flag variable
merge-ort: remove translator lego in new "submodule conflict suggestion"
submodule merge: update conflict error message
We try to write "|| return 1" (or "|| exit 1" in a subshell) at the
end of a sequence of &&-chained command in a loop of our tests, so
that a failure of any step during the earlier iteration of the loop
can properly be caught.
There is one loop in this test script that is used to compute the
expected result, that will be later compared with an actual output
produced by the "test-tool pack-mtimes" command. This particular
loop, however, is placed on the upstream side of a pipe, whose
non-zero exit code does not get noticed.
Emit a line that will never be produced by the "test-tool pack-mtimes"
to cause the later comparison to fail. As we use test_cmp to compare
this "expected output" file with the "actual output", the "error
message" we are emitting into the expected output stream will stand
out and shown to the tester.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
GitHub Actions scheduled a brownout of Ubuntu 18.04, which canceled all
runs of the 'static-analysis' job in our CI runs. Update to 22.04 to
avoid this as the brownout later turns into a complete deprecation.
The use of 18.04 was set in d051ed77ee (.github/workflows/main.yml: run
static-analysis on bionic, 2021-02-08) due to the lack of Coccinelle
being available on 20.04 (which continues today).
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Pass the number of elements first and their size second, as expected
by xcalloc().
Patch generated with:
make SPATCH_FLAGS=--recursive-includes contrib/coccinelle/xcalloc.cocci.patch
Our default SPATCH_FLAGS ('--all-includes') doesn't catch this
transformation by default, unless used in combination with a large-ish
SPATCH_BATCH_SIZE which happens to put 'promisor-remote.c' with a file
that includes 'repository.h' directly in the same batch.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix a memory leak occuring in case of pathspec copy in preload_index.
Direct leak of 8 byte(s) in 8 object(s) allocated from:
#0 0x7f0a353ead47 in __interceptor_malloc (/usr/lib/gcc/x86_64-pc-linux-gnu/11.3.0/libasan.so.6+0xb5d47)
#1 0x55750995e840 in do_xmalloc /home/anthony/src/c/git/wrapper.c:51
#2 0x55750995e840 in xmalloc /home/anthony/src/c/git/wrapper.c:72
#3 0x55750970f824 in copy_pathspec /home/anthony/src/c/git/pathspec.c:684
#4 0x557509717278 in preload_index /home/anthony/src/c/git/preload-index.c:135
#5 0x55750975f21e in refresh_index /home/anthony/src/c/git/read-cache.c:1633
#6 0x55750915b926 in cmd_status builtin/commit.c:1547
#7 0x5575090e1680 in run_builtin /home/anthony/src/c/git/git.c:466
#8 0x5575090e1680 in handle_builtin /home/anthony/src/c/git/git.c:720
#9 0x5575090e284a in run_argv /home/anthony/src/c/git/git.c:787
#10 0x5575090e284a in cmd_main /home/anthony/src/c/git/git.c:920
#11 0x5575090dbf82 in main /home/anthony/src/c/git/common-main.c:56
#12 0x7f0a348230ab (/lib64/libc.so.6+0x290ab)
Signed-off-by: Anthony Delannoy <anthony.2lannoy@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Failures within `for` and `while` loops can go unnoticed if not detected
and signaled manually since the loop itself does not abort when a
contained command fails, nor will a failure necessarily be detected when
the loop finishes since the loop returns the exit code of the last
command it ran on the final iteration, which may not be the command
which failed. Therefore, detect and signal failures manually within
loops using the idiom `|| return 1` (or `|| exit 1` within subshells).
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This test wants to verify that `git blame` errors out when asked to
blame a file _not_ in the sparse checkout. However, the very first file
it asks to blame _is_ present in the checkout, thus `test_must_fail git
blame $file` gives an unexpected result (the "blame" succeeds). This
problem went unnoticed because the test invokes `test_must_fail git
blame $file` in loop but forgets to break out of the loop early upon
failure, thus the failure gets swallowed.
Fix the test by having it not ask to blame a file present in the sparse
checkout, and instead only blame files not present, as intended. While
at it, also add the missing `|| return 1` which allowed this bug to go
unnoticed.
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The breaks in the &&-chain in this test went unnoticed because the
"magic exit code 117" &&-chain checker built into test-lib.sh only
recognizes broken &&-chains at the top-level; it does not work within
`{...}` groups, `(...)` subshells, `$(...)` substitutions, or within
bodies of compound statements, such as `if`, `for`, `while`, `case`,
etc. Furthermore, `chainlint.sed` detects broken &&-chains only in
`(...)` subshells. Thus, the &&-chain breaks in this test fall into the
blind spots of the &&-chain linters.
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The entry point to the patience-diff algorithm takes two mmfile_t
structs with the original file contents, but it doesn't actually do
anything useful with them. This is similar to the case recently cleaned
up in the histogram code via f1d019071e (xdiff: drop unused mmfile
parameters from xdl_do_histogram_diff(), 2022-08-19), but there's a bit
more subtlety going on.
We pass them into the recursive patience_diff(), which in turn passes
them into fill_hashmap(), which stuffs the pointers into a struct. But
the only thing which reads the struct fields is our recursion into
patience_diff()!
So it's unlikely that something like -Wunused-parameter could find this
case: it would have to detect the circular dependency caused by the
recursion (not to mention tracing across struct field assignments).
But once found, it's easy to have the compiler confirm what's going on:
1. Drop the "file1" and "file2" fields from the hashmap struct
definition. Remove the assignments in fill_hashmap(), and
temporarily substitute NULL in the recursive call to
patience_diff(). Compiling shows that no other code touched those
fields.
2. Now fill_hashmap() will trigger -Wunused-parameter. Drop "file1"
and "file2" from its definition and callsite.
3. Now patience_diff() will trigger -Wunused-parameter. Drop them
there, too. One of the callsites is the recursion with our
NULL values, so those temporary values go away.
4. Now xdl_do_patience_diff() will trigger -Wunused-parameter. Drop
them there. And we're done.
Suggested-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King
Junio C Hamano
René Scharfe
Derrick Stolee
SZEDER Gábor
Anthony Delannoy
Eric Sunshine