The build procedure has been taught to notice older version of zlib
and enable our replacement uncompress2() automatically.
* ab/auto-detect-zlib-compress2:
compat: auto-detect if zlib has uncompress2()
Pick a better random number generator and use it when we prepare
temporary filenames.
* bc/csprng-mktemps:
wrapper: use a CSPRNG to generate random file names
wrapper: add a helper to generate numbers from a CSPRNG
We have a copy of uncompress2() implementation in compat/ so that we
can build with an older version of zlib that lack the function, and
the build procedure selects if it is used via the NO_UNCOMPRESS2
$(MAKE) variable. This is yet another "annoying" knob the porters
need to tweak on platforms that are not common enough to have the
default set in the config.mak.uname file.
Attempt to instead ask the system header <zlib.h> to decide if we
need the compatibility implementation. This is a deviation from the
way we have been handling the "compatiblity" features so far, and if
it can be done cleanly enough, it could work as a model for features
that need compatibility definition we discover in the future. With
that goal in mind, avoid expedient but ugly hacks, like shoving the
code that is conditionally compiled into an unrelated .c file, which
may not work in future cases---instead, take an approach that uses a
file that is independently compiled and stands on its own.
Compile and link compat/zlib-uncompress2.c file unconditionally, but
conditionally hide the implementation behind #if/#endif when zlib
version is 1.2.9 or newer, and unconditionally archive the resulting
object file in the libgit.a to be picked up by the linker.
There are a few things to note in the shape of the code base after
this change:
- We no longer use NO_UNCOMPRESS2 knob; if the system header
<zlib.h> claims a version that is more cent than the library
actually is, this would break, but it is easy to add it back when
we find such a system.
- The object file compat/zlib-uncompress2.o is always compiled and
archived in libgit.a, just like a few other compat/ object files
already are.
- The inclusion of <zlib.h> is done in <git-compat-util.h>; we used
to do so from <cache.h> which includes <git-compat-util.h> as the
first thing it does, so from the *.c codes, there is no practical
change.
- Until objects in libgit.a that is already used gains a reference
to the function, the reftable code will be the only one that
wants it, so libgit.a on the linker command line needs to appear
once more at the end to satisify the mutual dependency.
- Beat found a trick used by OpenSSL to avoid making the
conditionally-compiled object truly empty (apparently because
they had to deal with compilers that do not want to see an
effectively empty input file). Our compat/zlib-uncompress2.c
file borrows the same trick for portabilty.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Helped-by: Beat Bolli <dev+git@drbeat.li>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are many situations in which having access to a cryptographically
secure pseudorandom number generator (CSPRNG) is helpful. In the
future, we'll encounter one of these when dealing with temporary files.
To make this possible, let's add a function which reads from a system
CSPRNG and returns some bytes.
We know that all systems will have such an interface. A CSPRNG is
required for a secure TLS or SSH implementation and a Git implementation
which provided neither would be of little practical use. In addition,
POSIX is set to standardize getentropy(2) in the next version, so in the
(potentially distant) future we can rely on that.
For systems which lack one of the other interfaces, we provide the
ability to use OpenSSL's CSPRNG. OpenSSL is highly portable and
functions on practically every known OS, and we know it will have access
to some source of cryptographically secure randomness. We also provide
support for the arc4random in libbsd for folks who would prefer to use
that.
Because this is a security sensitive interface, we take some
precautions. We either succeed by filling the buffer completely as we
requested, or we fail. We don't return partial data because the caller
will almost never find that to be a useful behavior.
Specify a makefile knob which users can use to specify one or more
suitable CSPRNGs, and turn the multiple string options into a set of
defines, since we cannot match on strings in the preprocessor. We allow
multiple options to make the job of handling this in autoconf easier.
The order of options is important here. On systems with arc4random,
which is most of the BSDs, we use that, since, except on MirBSD and
macOS, it uses ChaCha20, which is extremely fast, and sits entirely in
userspace, avoiding a system call. We then prefer getrandom over
getentropy, because the former has been available longer on Linux, and
then OpenSSL. Finally, if none of those are available, we use
/dev/urandom, because most Unix-like operating systems provide that API.
We prefer options that don't involve device files when possible because
those work in some restricted environments where device files may not be
available.
Set the configuration variables appropriately for Linux and the BSDs,
including macOS, as well as Windows and NonStop. We specifically only
consider versions which receive publicly available security support
here. For the same reason, we don't specify getrandom(2) on Linux,
because CentOS 7 doesn't support it in glibc (although its kernel does)
and we don't want to resort to making syscalls.
Finally, add a test helper to allow this to be tested by hand and in
tests. We don't add any tests, since invoking the CSPRNG is not likely
to produce interesting, reproducible results.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code clean-up to hide vreportf() from public API.
* ab/usage-die-message:
config API: use get_error_routine(), not vreportf()
usage.c + gc: add and use a die_message_errno()
gc: return from cmd_gc(), don't call exit()
usage.c API users: use die_message() for error() + exit 128
usage.c API users: use die_message() for "fatal :" + exit 128
usage.c: add a die_message() routine
The conditions to choose different definitions of the FLEX_ARRAY
macro for vendor compilers has been simplified to make it easier to
maintain.
* jc/flex-array-definition:
flex-array: simplify compiler-specific workaround
We use "type array[];" syntax for the flex-array member at the end
of a struct under C99 or later, except when we are building with
older SUNPRO_C compilers. As we find more vendor compilers that
claim to grok C99 but not understand the flex-array syntax, the
existing "If we are using C99, but not with these compilers..."
conditional will keep growing.
Make it more manageable by listing vendor-specific exceptions
earlier, with the expectation that new exceptions will not be
combined into existing ones to make the condition longer, and
instead will be implemented as a new "#elif" in the cascade of
similar to old SUNPRO_C, we can just add a single line
#elif defined(_MSC_VER)
immediately before "#elif defined(__GNUC__)" to cause us to fallback
to the safer but a bit wasteful version.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change the git_die_config() function added in 5a80e97c82 (config: add
`git_die_config()` to the config-set API, 2014-08-07) to use the
public callbacks in the usage.[ch] API instead of the the underlying
vreportf() function.
In preceding commits the rest of the vreportf() users outside of
usage.c was migrated to die_message(), so we can now make it "static".
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change the "error: " output when we exit with 128 due to gc.log errors
to use a "fatal: " prefix instead. To do this add a
die_message_errno() a sibling function to the die_errno() added in a
preceding commit.
Before this we'd expect report_last_gc_error() to return -1 from
error_errno() in this case. It already treated a status of 0 and 1
specially. Let's just document that anything that's not 0 or 1 should
be returned.
We could also retain the "ret < 0" behavior here without hardcoding
128 by returning -128, and having the caller do a "return -ret", but I
think this makes more sense, and preserves the path from
die_message*()'s return value to the "return" without hardcoding
"128".
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have code in various places that would like to call die(), but
wants to defer the exit(128) it would invoke, e.g. to print an
additional message, or adjust the exit code. Add a die_message()
helper routine to bridge this gap in the API.
Functionally this behaves just like the error() routine, except it'll
print a "fatal: " prefix, and it will return with 128 instead of -1,
this is so that caller can pass the return value to "exit()", instead
of having to hardcode "exit(128)".
Note that as with the other routines the "die_message_builtin" needs
to return "void" and otherwise conform to the "report_fn"
signature.
As we'll see in a subsequent commit callers will want to replace
e.g. their default "die_routine" with a "die_message_routine".
For now we're just adding the routine and making die_builtin() in
usage.c itself use it. In order to do that we need to add a
get_die_message_routine() function, which works like the other
get_*_routine() functions in usage.c. There is no
set_die_message_rotine(), as it hasn't been needed yet. We can add it
if we ever need it.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The C99 standard was released in January 1999, now 22 years ago. It
provides a variety of useful features, including variadic arguments for
macros, declarations after statements, designated initializers, and a
wide variety of other useful features, many of which we already use.
We'd like to take advantage of these features, but we want to be
cautious. As far as we know, all major compilers now support C99 or a
later C standard, such as C11 or C17. POSIX has required C99 support as
a requirement for the 2001 revision, so we can safely assume any POSIX
system which we are interested in supporting has C99.
Even MSVC, long a holdout against modern C, now supports both C11 and
C17 with an appropriate update. Moreover, even if people are using an
older version of MSVC on these systems, they will generally need some
implementation of the standard Unix utilities for the testsuite, and GNU
coreutils, the most common option, has required C99 since 2009.
Therefore, we can safely assume that a suitable version of GCC or clang
is available to users even if their version of MSVC is not sufficiently
capable.
Let's add a test balloon to git-compat-util.h to see if anyone is using
an older compiler. We'll add a comment telling people how to enable
this functionality on GCC and Clang, even though modern versions of both
will automatically do the right thing, and ask people still experiencing
a problem to report that to us on the list.
Note that C89 compilers don't provide the __STDC_VERSION__ macro, so we
use a well-known hack of using "- 0". On compilers with this macro, it
doesn't change the value, and on C89 compilers, the macro will be
replaced with nothing, and our value will be 0.
For sparse, we explicitly request the gnu99 style because we've
traditionally taken advantage of some GCC- and clang-specific extensions
when available and we'd like to retain the ability to do that. sparse
also defaults to C89 without it, so things will fail for us if we don't.
Update the cmake configuration to require C11 for MSVC. We do this
because this will make MSVC to use C11, since it does not explicitly
support C99. We do this with a compiler options because setting the
C_STANDARD option does not work in our CI on MSVC and at the moment, we
don't want to require C11 for Unix compilers.
In the Makefile, don't set any compiler flags for the compiler itself,
since on some systems, such as FreeBSD, we actually need C11, and asking
for C99 causes things to fail to compile. The error message should make
it obvious what's going wrong and allow a user to set the appropriate
option when building in the event they're using a Unix compiler that
doesn't support it by default.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The clean/smudge conversion code path has been prepared to better
work on platforms where ulong is narrower than size_t.
* mc/clean-smudge-with-llp64:
clean/smudge: allow clean filters to process extremely large files
odb: guard against data loss checking out a huge file
git-compat-util: introduce more size_t helpers
odb: teach read_blob_entry to use size_t
t1051: introduce a smudge filter test for extremely large files
test-lib: add prerequisite for 64-bit platforms
test-tool genzeros: generate large amounts of data more efficiently
test-genzeros: allow more than 2G zeros in Windows
The compatibility implementation for unsetenv(3) were written to
mimic ancient, non-POSIX, variant seen in an old glibc; it has been
changed to return an integer to match the more modern era.
* jc/unsetenv-returns-an-int:
unsetenv(3) returns int, not void
mingw-w64's pthread_unistd.h had a bug that mistakenly (because there is
no support for the *lockfile() functions required[1]) defined
_POSIX_THREAD_SAFE_FUNCTIONS and that was being worked around since
3ecd153a3b (compat/mingw: support MSys2-based MinGW build, 2016-01-14).
The bug was fixed in winphtreads, but as a side effect, leaves the
reentrant functions from time.h no longer visible and therefore breaks
the build.
Since the intention all along was to avoid using the fallback functions,
formalize the use of POSIX by setting the corresponding feature flag and
compile out the implementation for the fallback functions.
[1] https://unix.org/whitepapers/reentrant.html
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Acked-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This compatilibity implementation has been returning a wrong type,
ever since 731043fd (Add compat/unsetenv.c ., 2006-01-25) added to
the system, yet nobody noticed it in the past 16 years, presumably
because no code checks failures in their unsetenv() calls. Sigh.
For now, make it always succeed.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Remove the unused wrapper function.
Reported-by: Randall S. Becker <rsbecker@nexbridge.com>
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code cleanup.
* ab/repo-settings-cleanup:
repository.h: don't use a mix of int and bitfields
repo-settings.c: simplify the setup
read-cache & fetch-negotiator: check "enum" values in switch()
environment.c: remove test-specific "ignore_untracked..." variable
wrapper.c: add x{un,}setenv(), and use xsetenv() in environment.c
Adjust credential-cache helper to Windows.
* cb/unix-sockets-with-windows:
git-compat-util: include declaration for unix sockets in windows
credential-cache: check for windows specific errors
t0301: fixes for windows compatibility
Add fatal wrappers for setenv() and unsetenv(). In d7ac12b25d (Add
set_git_dir() function, 2007-08-01) we started checking its return
value, and since 48988c4d0c (set_git_dir: die when setenv() fails,
2018-03-30) we've had set_git_dir_1() die if we couldn't set it.
Let's provide a wrapper for both, this will be useful in many other
places, a subsequent patch will make another use of xsetenv().
The checking of the return value here is over-eager according to
setenv(3) and POSIX. It's documented as returning just -1 or 0, so
perhaps we should be checking -1 explicitly.
Let's just instead die on any non-zero, if our C library is so broken
as to return something else than -1 on error (and perhaps not set
errno?) the worst we'll do is die with a nonsensical errno value, but
we'll want to die in either case.
Let's make these return "void" instead of "int". As far as I can tell
there's no other x*() wrappers that needed to make the decision of
deviating from the signature in the C library, but since their return
value is only used to indicate errors (so we'd die here), we can catch
unreachable code such as
if (xsetenv(...) < 0)
[...];
I think it would be OK skip the NULL check of the "name" here for the
calls to die_errno(). Almost all of our setenv() callers are taking a
constant string hardcoded in the source as the first argument, and for
the rest we can probably assume they've done the NULL check
themselves. Even if they didn't, modern C libraries are forgiving
about it (e.g. glibc formatting it as "(null)"), on those that aren't,
well, we were about to die anyway. But let's include the check anyway
for good measure.
1. https://pubs.opengroup.org/onlinepubs/009604499/functions/setenv.html
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Available since Windows 10 release 1803 and Windows Server 2019.
NO_UNIX_SOCKETS is still the default for Windows builds, as they need
to keep backward compatibility with releases up to Windows 7, but allow
including the header otherwise.
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Remove the USE_PARENS_AROUND_GETTEXT_N compile-time option which was
meant to catch an inadvertent mistake which is too obscure to
maintain this facility.
The backstory of how USE_PARENS_AROUND_GETTEXT_N came about is: When I
added the N_() macro in 6578483036 (i18n: add no-op _() and N_()
wrappers, 2011-02-22) it was defined as:
#define N_(msgid) (msgid)
This is non-standard C, as was noticed and fixed in 642f85faab (i18n:
avoid parenthesized string as array initializer, 2011-04-07).
I.e. this needed to be defined as:
#define N_(msgid) msgid
Then in e62cd35a3e (i18n: log: mark parseopt strings for translation,
2012-08-20) when "builtin_log_usage" was marked for translation the
string concatenation for passing to usage() added in 1c370ea4e5
(Show usage string for 'git log -h', 'git show -h' and 'git diff -h',
2009-08-06) was faithfully preserved:
- "git log [<options>] [<since>..<until>] [[--] <path>...]\n"
- " or: git show [options] <object>...",
+ N_("git log [<options>] [<since>..<until>] [[--] <path>...]\n")
+ N_(" or: git show [options] <object>..."),
This was then fixed to be the expected array of usage strings in
e66dc0cc4b (log.c: fix translation markings, 2015-01-06) rather than
a string with multiple "\n"-delimited usage strings, and finally in
290c8e7a3f (gettext.h: add parentheses around N_ expansion if
supported, 2015-01-11) USE_PARENS_AROUND_GETTEXT_N was added to ensure
this mistake didn't happen again.
I think that even if this was a N_()-specific issue this
USE_PARENS_AROUND_GETTEXT_N facility wouldn't be worth it, the issue
would be too rare to worry about.
But I also think that 290c8e7a3f which introduced
USE_PARENS_AROUND_GETTEXT_N misattributed the problem. The issue
wasn't with the N_() macro added in e62cd35a3e, but that before the
N_() macro existed in the codebase the initial migration to
parse_options() in 1c370ea4e5 continued passsing in a "\n"-delimited
string, when the new API it was migrating to supported and expected
the passing of an array.
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Linux users may benefit from additional information on how to
avoid ENOMEM from mmap despite the system having enough RAM to
accomodate them. We can't reliably unmap pack windows to work
around the issue since malloc and other library routines may
mmap without our knowledge.
Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix typos in documentation, code comments, and RelNotes which repeat
various words. In trivial cases, just delete the duplicated word and
rewrap text, if needed. Reword the affected sentence in
Documentation/RelNotes/1.8.4.txt for it to make sense.
Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The xsize_t helper aims to safely convert an off_t to a size_t,
erroring out when a file offset is too large to fit into a memory
address. It does this by using two casts:
size_t size = (size_t) len;
if (len != (off_t) size)
... error out ...
On a platform with sizeof(size_t) < sizeof(off_t), this check is safe
and correct. The first cast truncates to a size_t by finding the
remainder modulo SIZE_MAX+1 (see C99 section 6.3.1.3 Signed and
unsigned integers) and the second promotes to an off_t, meaning the
result is true if and only if len is representable as a size_t.
On other platforms, this two-casts strategy still works well (always
succeeds) for len >= 0. But for len < 0, when the first cast succeeds
and produces SIZE_MAX + 1 + len, the resulting value is too large to
be represented as an off_t, so the second cast produces implementation
defined behavior. In practice, it is likely to produce a result of
true despite len not being representable as size_t.
Simplify by replacing with a more straightforward check: compare len
to the relevant bounds and then cast it. (To avoid a -Wsign-compare
warning, after checking that len >= 0, we explicitly convert to a
sufficiently-large unsigned type before comparing to SIZE_MAX.)
In practice, this is not likely to come up since typical callers use
nonnegative len. Still, it's helpful to handle this case to make the
behavior easy to reason about.
Historical note: the original bounds-checking in 46be82dfd0 (xsize_t:
check whether we lose bits, 2010-07-28) did not produce this
implementation-defined behavior, though it still did not handle
negative offsets. It was not until 73560c793a (git-compat-util.h:
xsize_t() - avoid -Wsign-compare warnings, 2017-09-21) introduced the
double cast that the implementation-defined behavior was triggered.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Streamline the codepath to fix the UTF-8 encoding issues in the
argv[] and the prefix on macOS.
* tb/precompose-prefix-simplify:
macOS: precompose startup_info->prefix
precompose_utf8: make precompose_string_if_needed() public
commit 5c327502 (MacOS: precompose_argv_prefix(), 2021-02-03) uses
the function precompose_string_if_needed() internally. It is only
used from precompose_argv_prefix() and therefore static in
compat/precompose_utf8.c
Expose this function, it will be used in the next commit.
While there, allow passing a NULL pointer, which will return NULL.
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It does not make sense to make ".gitattributes", ".gitignore" and
".mailmap" symlinks, as they are supposed to be usable from the
object store (think: bare repositories where HEAD:.mailmap etc. are
used). When these files are symbolic links, we used to read the
contents of the files pointed by them by mistake, which has been
corrected.
* jk/open-dotgitx-with-nofollow:
mailmap: do not respect symlinks for in-tree .mailmap
exclude: do not respect symlinks for in-tree .gitignore
attr: do not respect symlinks for in-tree .gitattributes
exclude: add flags parameter to add_patterns()
attr: convert "macro_ok" into a flags field
add open_nofollow() helper
Make CALLOC_ARRAY usable like a function by requiring callers to supply
the trailing semicolon, which all of the current ones already do. With
the extra semicolon e.g. the following code wouldn't compile because it
disconnects the "else" from the "if":
if (condition)
CALLOC_ARRAY(ptr, n);
else
whatever();
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Work around platforms whose open() is reported to return EINTR (it
shouldn't, as we do our signals with SA_RESTART).
* jk/open-returns-eintr:
config.mak.uname: enable OPEN_RETURNS_EINTR for macOS Big Sur
Makefile: add OPEN_RETURNS_EINTR knob
On some platforms, open() reportedly returns EINTR when opening regular
files and we receive a signal (usually SIGALRM from our progress meter).
This shouldn't happen, as open() should be a restartable syscall, and we
specify SA_RESTART when setting up the alarm handler. So it may actually
be a kernel or libc bug for this to happen. But it has been reported on
at least one version of Linux (on a network filesystem):
https://lore.kernel.org/git/c8061cce-71e4-17bd-a56a-a5fed93804da@neanderfunk.de/
as well as on macOS starting with Big Sur even on a regular filesystem.
We can work around it by retrying open() calls that get EINTR, just as
we do for read(), etc. Since we don't ever _want_ to interrupt an open()
call, we can get away with just redefining open, rather than insisting
all callsites use xopen().
We actually do have an xopen() wrapper already (and it even does this
retry, though there's no indication of it being an observed problem back
then; it seems simply to have been lifted from xread(), etc). But it is
used hardly anywhere, and isn't suitable for general use because it will
die() on error. In theory we could combine the two, but it's awkward to
do so because of the variable-args interface of open().
This patch adds a Makefile knob for enabling the workaround. It's not
enabled by default for any platforms in config.mak.uname yet, as we
don't have enough data to decide how common this is (I have not been
able to reproduce on either Linux or Big Sur myself). It may be worth
enabling preemptively anyway, since the cost is pretty low (if we don't
see an EINTR, it's just an extra conditional).
However, note that we must not enable this on Windows. It doesn't do
anything there, and the macro overrides the existing mingw_open()
redirection. I've added a preemptive #undef here in the mingw header
(which is processed first) to just quietly disable it (we could also
make it an #error, but there is little point in being so aggressive).
Reported-by: Aleksey Kliger <alklig@microsoft.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some callers of open() would like to use O_NOFOLLOW, but it is not
available on all platforms. Let's abstract this into a helper function
so we can provide system-specific implementations.
Some light web-searching reveals that we might be able to get something
similar on Windows using FILE_FLAG_OPEN_REPARSE_POINT. I didn't dig into
this further.
For other systems without O_NOFOLLOW or any equivalent, we have two
options for fallback:
- we can just open anyway, following symlinks; this may have security
implications (e.g., following untrusted in-tree symlinks)
- we can determine whether the path is a symlink with lstat().
This is slower (two syscalls instead of one), but that may be
acceptable for infrequent uses like looking up .gitattributes files
(especially because we can get away with a single syscall for the
common case of ENOENT).
It's also racy, but should be sufficient for our needs (we are
worried about in-tree symlinks that we ourselves would have
previously created). We could make it non-racy at the cost of making
it even slower, by doing an fstat() on the opened descriptor and
comparing the dev/ino fields to the original lstat().
This patch implements the lstat() option in its slightly-faster racy
form.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When commands are started from a subdirectory, they may have to
compare the path to the subdirectory (called prefix and found out
from $(pwd)) with the tracked paths. On macOS, $(pwd) and
readdir() yield decomposed path, while the tracked paths are
usually normalized to the precomposed form, causing mismatch. This
has been fixed by taking the same approach used to normalize the
command line arguments.
* tb/precompose-prefix-too:
MacOS: precompose_argv_prefix()
* maint-2.22:
Git 2.22.5
Git 2.21.4
Git 2.20.5
Git 2.19.6
Git 2.18.5
Git 2.17.6
unpack_trees(): start with a fresh lstat cache
run-command: invalidate lstat cache after a command finished
checkout: fix bug that makes checkout follow symlinks in leading path
* maint-2.21:
Git 2.21.4
Git 2.20.5
Git 2.19.6
Git 2.18.5
Git 2.17.6
unpack_trees(): start with a fresh lstat cache
run-command: invalidate lstat cache after a command finished
checkout: fix bug that makes checkout follow symlinks in leading path
* maint-2.20:
Git 2.20.5
Git 2.19.6
Git 2.18.5
Git 2.17.6
unpack_trees(): start with a fresh lstat cache
run-command: invalidate lstat cache after a command finished
checkout: fix bug that makes checkout follow symlinks in leading path
* maint-2.19:
Git 2.19.6
Git 2.18.5
Git 2.17.6
unpack_trees(): start with a fresh lstat cache
run-command: invalidate lstat cache after a command finished
checkout: fix bug that makes checkout follow symlinks in leading path
* maint-2.18:
Git 2.18.5
Git 2.17.6
unpack_trees(): start with a fresh lstat cache
run-command: invalidate lstat cache after a command finished
checkout: fix bug that makes checkout follow symlinks in leading path
* maint-2.17:
Git 2.17.6
unpack_trees(): start with a fresh lstat cache
run-command: invalidate lstat cache after a command finished
checkout: fix bug that makes checkout follow symlinks in leading path
Before checking out a file, we have to confirm that all of its leading
components are real existing directories. And to reduce the number of
lstat() calls in this process, we cache the last leading path known to
contain only directories. However, when a path collision occurs (e.g.
when checking out case-sensitive files in case-insensitive file
systems), a cached path might have its file type changed on disk,
leaving the cache on an invalid state. Normally, this doesn't bring
any bad consequences as we usually check out files in index order, and
therefore, by the time the cached path becomes outdated, we no longer
need it anyway (because all files in that directory would have already
been written).
But, there are some users of the checkout machinery that do not always
follow the index order. In particular: checkout-index writes the paths
in the same order that they appear on the CLI (or stdin); and the
delayed checkout feature -- used when a long-running filter process
replies with "status=delayed" -- postpones the checkout of some entries,
thus modifying the checkout order.
When we have to check out an out-of-order entry and the lstat() cache is
invalid (due to a previous path collision), checkout_entry() may end up
using the invalid data and thrusting that the leading components are
real directories when, in reality, they are not. In the best case
scenario, where the directory was replaced by a regular file, the user
will get an error: "fatal: unable to create file 'foo/bar': Not a
directory". But if the directory was replaced by a symlink, checkout
could actually end up following the symlink and writing the file at a
wrong place, even outside the repository. Since delayed checkout is
affected by this bug, it could be used by an attacker to write
arbitrary files during the clone of a maliciously crafted repository.
Some candidate solutions considered were to disable the lstat() cache
during unordered checkouts or sort the entries before passing them to
the checkout machinery. But both ideas include some performance penalty
and they don't future-proof the code against new unordered use cases.
Instead, we now manually reset the lstat cache whenever we successfully
remove a directory. Note: We are not even checking whether the directory
was the same as the lstat cache points to because we might face a
scenario where the paths refer to the same location but differ due to
case folding, precomposed UTF-8 issues, or the presence of `..`
components in the path. Two regression tests, with case-collisions and
utf8-collisions, are also added for both checkout-index and delayed
checkout.
Note: to make the previously mentioned clone attack unfeasible, it would
be sufficient to reset the lstat cache only after the remove_subtree()
call inside checkout_entry(). This is the place where we would remove a
directory whose path collides with the path of another entry that we are
currently trying to check out (possibly a symlink). However, in the
interest of a thorough fix that does not leave Git open to
similar-but-not-identical attack vectors, we decided to intercept
all `rmdir()` calls in one fell swoop.
This addresses CVE-2021-21300.
Co-authored-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
The following sequence leads to a "BUG" assertion running under MacOS:
DIR=git-test-restore-p
Adiarnfd=$(printf 'A\314\210')
DIRNAME=xx${Adiarnfd}yy
mkdir $DIR &&
cd $DIR &&
git init &&
mkdir $DIRNAME &&
cd $DIRNAME &&
echo "Initial" >file &&
git add file &&
echo "One more line" >>file &&
echo y | git restore -p .
Initialized empty Git repository in /tmp/git-test-restore-p/.git/
BUG: pathspec.c:495: error initializing pathspec_item
Cannot close git diff-index --cached --numstat
[snip]
The command `git restore` is run from a directory inside a Git repo.
Git needs to split the $CWD into 2 parts:
The path to the repo and "the rest", if any.
"The rest" becomes a "prefix" later used inside the pathspec code.
As an example, "/path/to/repo/dir-inside-repå" would determine
"/path/to/repo" as the root of the repo, the place where the
configuration file .git/config is found.
The rest becomes the prefix ("dir-inside-repå"), from where the
pathspec machinery expands the ".", more about this later.
If there is a decomposed form, (making the decomposing visible like this),
"dir-inside-rep°a" doesn't match "dir-inside-repå".
Git commands need to:
(a) read the configuration variable "core.precomposeunicode"
(b) precocompose argv[]
(c) precompose the prefix, if there was any
The first commit,
76759c7dff "git on Mac OS and precomposed unicode"
addressed (a) and (b).
The call to precompose_argv() was added into parse-options.c,
because that seemed to be a good place when the patch was written.
Commands that don't use parse-options need to do (a) and (b) themselfs.
The commands `diff-files`, `diff-index`, `diff-tree` and `diff`
learned (a) and (b) in
commit 90a78b83e0 "diff: run arguments through precompose_argv"
Branch names (or refs in general) using decomposed code points
resulting in decomposed file names had been fixed in
commit 8e712ef6fc "Honor core.precomposeUnicode in more places"
The bug report from above shows 2 things:
- more commands need to handle precomposed unicode
- (c) should be implemented for all commands using pathspecs
Solution:
precompose_argv() now handles the prefix (if needed), and is renamed into
precompose_argv_prefix().
Inside this function the config variable core.precomposeunicode is read
into the global variable precomposed_unicode, as before.
This reading is skipped if precomposed_unicode had been read before.
The original patch for preocomposed unicode, 76759c7dff, placed
precompose_argv() into parse-options.c
Now add it into git.c::run_builtin() as well. Existing precompose
calls in diff-files.c and others may become redundant, and if we
audit the callflows that reach these places to make sure that they
can never be reached without going through the new call added to
run_builtin(), we might be able to remove these existing ones.
But in this commit, we do not bother to do so and leave these
precompose callsites as they are. Because precompose() is
idempotent and can be called on an already precomposed string
safely, this is safer than removing existing calls without fully
vetting the callflows.
There is certainly room for cleanups - this change intends to be a bug fix.
Cleanups needs more tests in e.g. t/t3910-mac-os-precompose.sh, and should
be done in future commits.
[1] git-bugreport-2021-01-06-1209.txt (git can't deal with special characters)
[2] https://lore.kernel.org/git/A102844A-9501-4A86-854D-E3B387D378AA@icloud.com/
Reported-by: Daniel Troger <random_n0body@icloud.com>
Helped-By: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We allow variadic macros in the code base, but only if there is fallback
code for platforms that lack it. This leads to some annoyances:
- the code is more complicated because of the fallbacks (e.g.,
trace_printf(), etc, is implemented twice with a set of parallel
wrappers).
- some constructs are just impossible and we've had to live without
them (e.g., a cross between FLEX_ALLOC and xstrfmt)
Since this feature is present in C99, we may be able to start counting
on it being available everywhere. Let's start with a weather balloon
patch to find out.
This patch makes the absolute minimal change by always setting
HAVE_VARIADIC_MACROS. If somebody runs into a platform where it's a
problem, they can undo it by commenting out the define. Likewise, if we
have to revert this, it would be quite unlikely to cause conflicts.
Once we feel comfortable that this is the right direction, then we can
start ripping out all the spots that actually look at the flag, and
removing the dead code.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When 15b52a44 (compat-util: type-check parameters of no-op
replacement functions, 2020-08-06) turned a handful of no-op
C-preprocessor macros into static inline functions to give the
callers a better type checking for their parameters, it forgot
to return anything from the stubbed out setitimer() function,
even though the function was defined to return an int just like the
real thing.
Since the original C-preprocessor macro implementation was to just
turn the call to the function an empty statement, we know that the
existing callers do not check the return value from it, and it does
not matter what value we return. But it is safer to pretend that
the call succeeded by returning 0 than making it fail by returning -1
and clobbering errno with some value.
Reported-by: Randall S. Becker <rsbecker@nexbridge.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The sleep function is defined in wrapper.c, so it makes more sense to be a in
system compatibility header.
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The usage, die, warning, and error routines all work with a function
pointer that takes the message to be reported. We usually just mention
the function's full type inline. But this makes the use of these
pointers hard to read, especially because C's syntax for returning a
function pointer is so awful:
void (*get_error_routine(void))(const char *err, va_list params);
Unless you read it very carefully, this looks like a function pointer
declaration. Let's instead use a single typedef to define a reporting
function, which is the same for all four types.
Note that this also removes the "extern" from these declarations to
match the surrounding functions. They were missed in 554544276a (*.[ch]:
remove extern from function declarations using spatch, 2019-04-29)
presumably because of the unusual syntax.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When there is no need to run a specific function on certain platforms,
we often #define an empty function to swallow its parameters and
make it into a no-op, e.g.
#define precompose_argv(c,v) /* no-op */
While this guarantees that no unneeded code is generated, it also
discards type and other checks on these parameters, e.g. a new code
written with the argv-array API (diff_args is of type "struct
argv_array" that has .argc and .argv members):
precompose_argv(diff_args.argc, diff_args.argv);
must be updated to use "struct strvec diff_args" with .nr and .v
members, like so:
precompose_argv(diff_args.nr, diff_args.v);
after the argv-array API has been updated to the strvec API.
However, the "no oop" C preprocessor macro is too aggressive to
discard what is unused, and did not catch such a call that was left
unconverted.
Using a "static inline" function whose body is a no-op should still
result in the same binary with decent compilers yet catch such a
reference to a missing field or passing a value of a wrong type.
While at it, I notice that precompute_str() has never been used
anywhere in the code, since it was introduced at 76759c7d (git on
Mac OS and precomposed unicode, 2012-07-08). Instead of turning it
into a static inline, just remove it.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
SHA-256 migration work continues.
* bc/sha-256-part-2: (44 commits)
remote-testgit: adapt for object-format
bundle: detect hash algorithm when reading refs
t5300: pass --object-format to git index-pack
t5704: send object-format capability with SHA-256
t5703: use object-format serve option
t5702: offer an object-format capability in the test
t/helper: initialize the repository for test-sha1-array
remote-curl: avoid truncating refs with ls-remote
t1050: pass algorithm to index-pack when outside repo
builtin/index-pack: add option to specify hash algorithm
remote-curl: detect algorithm for dumb HTTP by size
builtin/ls-remote: initialize repository based on fetch
t5500: make hash independent
serve: advertise object-format capability for protocol v2
connect: parse v2 refs with correct hash algorithm
connect: pass full packet reader when parsing v2 refs
Documentation/technical: document object-format for protocol v2
t1302: expect repo format version 1 for SHA-256
builtin/show-index: provide options to determine hash algo
t5302: modernize test formatting
...
When parsing capabilities for the pack protocol, there are times we'll
want to compare the value of a capability to a NUL-terminated string.
Since the data we're reading will be space-terminated, not
NUL-terminated, we need a function that compares the two strings, but
also checks that they're the same length. Otherwise, if we used strncmp
to compare these strings, we might accidentally accept a parameter that
was a prefix of the expected value.
Add a function, xstrncmpz, that takes a NUL-terminated string and a
non-NUL-terminated string, plus a length, and compares them, ensuring
that they are the same length.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
ccd469450a (date.c: switch to reentrant {gm,local}time_r, 2019-11-28)
removes the only gmtime() call we had and moves to gmtime_r() which
doesn't have the same portability problems.
Remove the compat gmtime code since it is no longer needed, and confirm
by successfull running t4212 in FreeBSD 9.3 amd64 (the oldest I could
get a hold off).
Further work might be needed to ensure 32bit time_t systems (like FreeBSD
i386) will handle correctly the overflows tested in t4212, but that is
orthogonal to this change, and it doesn't change the current behaviour
as neither gmtime() or gmtime_r() will ever return NULL on those systems
because time_t is unsigned.
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
On Cygwin, the codepath for POSIX-like systems is taken in
run-command.c::start_command(). The prepare_cmd() helper
function is called to decide if the command needs to be looked
up in the PATH. The logic there is to do the PATH-lookup if
and only if it does not have any slash '/' in it. If this test
passes we end up attempting to run the command by appending the
string after each colon-separated component of PATH.
The Cygwin environment supports both Windows and POSIX style
paths, so both forwardslahes '/' and back slashes '\' can be
used as directory separators for any external program the user
supplies.
Examples for path strings which are being incorrectly searched
for in the PATH instead of being executed as is:
- "C:\Program Files\some-program.exe"
- "a\b\c.exe"
To handle these, the PATH lookup detection logic in prepare_cmd()
is taught to know about this Cygwin quirk, by introducing
has_dir_sep(path) helper function to abstract away the difference
between true POSIX and Cygwin systems.
Signed-off-by: Andras Kucsma <r0maikx02b@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* maint-2.23: (44 commits)
Git 2.23.1
Git 2.22.2
Git 2.21.1
mingw: sh arguments need quoting in more circumstances
mingw: fix quoting of empty arguments for `sh`
mingw: use MSYS2 quoting even when spawning shell scripts
mingw: detect when MSYS2's sh is to be spawned more robustly
t7415: drop v2.20.x-specific work-around
Git 2.20.2
t7415: adjust test for dubiously-nested submodule gitdirs for v2.20.x
Git 2.19.3
Git 2.18.2
Git 2.17.3
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
...
* maint-2.22: (43 commits)
Git 2.22.2
Git 2.21.1
mingw: sh arguments need quoting in more circumstances
mingw: fix quoting of empty arguments for `sh`
mingw: use MSYS2 quoting even when spawning shell scripts
mingw: detect when MSYS2's sh is to be spawned more robustly
t7415: drop v2.20.x-specific work-around
Git 2.20.2
t7415: adjust test for dubiously-nested submodule gitdirs for v2.20.x
Git 2.19.3
Git 2.18.2
Git 2.17.3
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
...
* maint-2.21: (42 commits)
Git 2.21.1
mingw: sh arguments need quoting in more circumstances
mingw: fix quoting of empty arguments for `sh`
mingw: use MSYS2 quoting even when spawning shell scripts
mingw: detect when MSYS2's sh is to be spawned more robustly
t7415: drop v2.20.x-specific work-around
Git 2.20.2
t7415: adjust test for dubiously-nested submodule gitdirs for v2.20.x
Git 2.19.3
Git 2.18.2
Git 2.17.3
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
...
* maint-2.20: (36 commits)
Git 2.20.2
t7415: adjust test for dubiously-nested submodule gitdirs for v2.20.x
Git 2.19.3
Git 2.18.2
Git 2.17.3
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
t6130/t9350: prepare for stringent Win32 path validation
quote-stress-test: allow skipping some trials
quote-stress-test: accept arguments to test via the command-line
tests: add a helper to stress test argument quoting
mingw: fix quoting of arguments
Disallow dubiously-nested submodule git directories
...
* maint-2.19: (34 commits)
Git 2.19.3
Git 2.18.2
Git 2.17.3
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
t6130/t9350: prepare for stringent Win32 path validation
quote-stress-test: allow skipping some trials
quote-stress-test: accept arguments to test via the command-line
tests: add a helper to stress test argument quoting
mingw: fix quoting of arguments
Disallow dubiously-nested submodule git directories
protect_ntfs: turn on NTFS protection by default
path: also guard `.gitmodules` against NTFS Alternate Data Streams
...
* maint-2.18: (33 commits)
Git 2.18.2
Git 2.17.3
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
t6130/t9350: prepare for stringent Win32 path validation
quote-stress-test: allow skipping some trials
quote-stress-test: accept arguments to test via the command-line
tests: add a helper to stress test argument quoting
mingw: fix quoting of arguments
Disallow dubiously-nested submodule git directories
protect_ntfs: turn on NTFS protection by default
path: also guard `.gitmodules` against NTFS Alternate Data Streams
is_ntfs_dotgit(): speed it up
...
* maint-2.17: (32 commits)
Git 2.17.3
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
t6130/t9350: prepare for stringent Win32 path validation
quote-stress-test: allow skipping some trials
quote-stress-test: accept arguments to test via the command-line
tests: add a helper to stress test argument quoting
mingw: fix quoting of arguments
Disallow dubiously-nested submodule git directories
protect_ntfs: turn on NTFS protection by default
path: also guard `.gitmodules` against NTFS Alternate Data Streams
is_ntfs_dotgit(): speed it up
mingw: disallow backslash characters in tree objects' file names
...
* maint-2.16: (31 commits)
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
t6130/t9350: prepare for stringent Win32 path validation
quote-stress-test: allow skipping some trials
quote-stress-test: accept arguments to test via the command-line
tests: add a helper to stress test argument quoting
mingw: fix quoting of arguments
Disallow dubiously-nested submodule git directories
protect_ntfs: turn on NTFS protection by default
path: also guard `.gitmodules` against NTFS Alternate Data Streams
is_ntfs_dotgit(): speed it up
mingw: disallow backslash characters in tree objects' file names
path: safeguard `.git` against NTFS Alternate Streams Accesses
...
* maint-2.15: (29 commits)
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
t6130/t9350: prepare for stringent Win32 path validation
quote-stress-test: allow skipping some trials
quote-stress-test: accept arguments to test via the command-line
tests: add a helper to stress test argument quoting
mingw: fix quoting of arguments
Disallow dubiously-nested submodule git directories
protect_ntfs: turn on NTFS protection by default
path: also guard `.gitmodules` against NTFS Alternate Data Streams
is_ntfs_dotgit(): speed it up
mingw: disallow backslash characters in tree objects' file names
path: safeguard `.git` against NTFS Alternate Streams Accesses
clone --recurse-submodules: prevent name squatting on Windows
is_ntfs_dotgit(): only verify the leading segment
...
* maint-2.14: (28 commits)
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
t6130/t9350: prepare for stringent Win32 path validation
quote-stress-test: allow skipping some trials
quote-stress-test: accept arguments to test via the command-line
tests: add a helper to stress test argument quoting
mingw: fix quoting of arguments
Disallow dubiously-nested submodule git directories
protect_ntfs: turn on NTFS protection by default
path: also guard `.gitmodules` against NTFS Alternate Data Streams
is_ntfs_dotgit(): speed it up
mingw: disallow backslash characters in tree objects' file names
path: safeguard `.git` against NTFS Alternate Streams Accesses
clone --recurse-submodules: prevent name squatting on Windows
is_ntfs_dotgit(): only verify the leading segment
test-path-utils: offer to run a protectNTFS/protectHFS benchmark
...
When creating a directory on Windows whose path ends in a space or a
period (or chains thereof), the Win32 API "helpfully" trims those. For
example, `mkdir("abc ");` will return success, but actually create a
directory called `abc` instead.
This stems back to the DOS days, when all file names had exactly 8
characters plus exactly 3 characters for the file extension, and the
only way to have shorter names was by padding with spaces.
Sadly, this "helpful" behavior is a bit inconsistent: after a successful
`mkdir("abc ");`, a `mkdir("abc /def")` will actually _fail_ (because
the directory `abc ` does not actually exist).
Even if it would work, we now have a serious problem because a Git
repository could contain directories `abc` and `abc `, and on Windows,
they would be "merged" unintentionally.
As these paths are illegal on Windows, anyway, let's disallow any
accesses to such paths on that Operating System.
For practical reasons, this behavior is still guarded by the
config setting `core.protectNTFS`: it is possible (and at least two
regression tests make use of it) to create commits without involving the
worktree. In such a scenario, it is of course possible -- even on
Windows -- to create such file names.
Among other consequences, this patch disallows submodules' paths to end
in spaces on Windows (which would formerly have confused Git enough to
try to write into incorrect paths, anyway).
While this patch does not fix a vulnerability on its own, it prevents an
attack vector that was exploited in demonstrations of a number of
recently-fixed security bugs.
The regression test added to `t/t7417-submodule-path-url.sh` reflects
that attack vector.
Note that we have to adjust the test case "prevent git~1 squatting on
Windows" in `t/t7415-submodule-names.sh` because of a very subtle issue.
It tries to clone two submodules whose names differ only in a trailing
period character, and as a consequence their git directories differ in
the same way. Previously, when Git tried to clone the second submodule,
it thought that the git directory already existed (because on Windows,
when you create a directory with the name `b.` it actually creates `b`),
but with this patch, the first submodule's clone will fail because of
the illegal name of the git directory. Therefore, when cloning the
second submodule, Git will take a different code path: a fresh clone
(without an existing git directory). Both code paths fail to clone the
second submodule, both because the the corresponding worktree directory
exists and is not empty, but the error messages are worded differently.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Git's code base already seems to be using `PRIdMAX` without any such
fallback definition for quite a while (75459410ed (json_writer: new
routines to create JSON data, 2018-07-13), to be precise, and the
first Git version to include that commit was v2.19.0). Having a
fallback definition only for `PRIuMAX` is a bit inconsistent.
We do sometimes get portability reports more than a year after the
problem was introduced. This one should be fairly safe. PRIuMAX is
in C99 (for that matter, SCNuMAX, PRIu32 and others also are), and
we've been picking up other C99-isms without complaint.
The PRIuMAX fallback definition was originally added in 3efb1f343a
(Check for PRIuMAX rather than NO_C99_FORMAT in fast-import.c.,
2007-02-20). But it was replacing a construct that was introduced in
an even earlier commit, 579d1fbfaf (Add NO_C99_FORMAT to support
older compilers., 2006-07-30), which talks about gcc 2.95.
That's pretty ancient at this point.
Signed-off-by: Hariom Verma <hariom18599@gmail.com>
Helped-by: Jeff King <peff@peff.net>
[jc: tweaked both message and code, taking what peff wrote]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The parameter marker for x was garbled in its introduction in 89c855ed3c
("git-compat-util.h: implement a different ARRAY_SIZE macro for for
safely deriving the size of array", 2015-04-30).
Signed-off-by: Beat Bolli <dev+git@drbeat.li>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The rename detection logic sorts a list of rename source candidates
by similarity to pick the best candidate, which means that a tie
between sources with the same similarity is broken by the original
location in the original candidate list (which is sorted by path).
Force the sorting by similarity done with a stable sort, which is
not promised by system supplied qsort(3), to ensure consistent
results across platforms.
* js/diff-rename-force-stable-sort:
diffcore_rename(): use a stable sort
Move git_sort(), a stable sort, into into libgit.a
While we cannot rely on a `__typeof__' operator being portable
to use with `offsetof'; we can calculate the pointer offset
using an existing pointer and the address of a member using
pointer arithmetic for compilers without `__typeof__'.
This allows us to simplify usage of hashmap iterator macros
by not having to specify a type when a pointer of that type
is already given.
In the future, list iterator macros (e.g. list_for_each_entry)
may also be implemented using OFFSETOF_VAR to save hackers the
trouble of using container_of/list_entry macros and without
relying on non-portable `__typeof__'.
v3: use `__typeof__' to avoid clang warnings
Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Using `container_of' can be verbose and choosing names for
intermediate "struct hashmap_entry" pointers is a hard problem.
So introduce "*_entry" APIs inspired by similar linked-list
APIs in the Linux kernel.
Unfortunately, `__typeof__' is not portable C, so we need an
extra parameter to specify the type.
Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This macro is popular within the Linux kernel for supporting
intrusive data structures such as linked lists, red-black trees,
and chained hash tables while allowing the compiler to do
type checking.
Later patches will use container_of() to remove the limitation
of "hashmap_entry" being location-dependent. This will complete
the transition to compile-time type checking for the hashmap API.
This macro already exists in our source as "list_entry" in
list.h and making "list_entry" an alias to "container_of"
as the Linux kernel has done is a possibility.
Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `qsort()` function is not guaranteed to be stable, i.e. it does not
promise to maintain the order of items it is told to consider equal. In
contrast, the `git_sort()` function we carry in `compat/qsort.c` _is_
stable, by virtue of implementing a merge sort algorithm.
In preparation for using a stable sort in Git's rename detection, move
the stable sort into `libgit.a` so that it is compiled in
unconditionally, and rename it to `git_stable_qsort()`.
Note: this also makes the hack obsolete that was introduced in
fe21c6b285 (mingw: reencode environment variables on the fly (UTF-16
<-> UTF-8), 2018-10-30), where we included `compat/qsort.c` directly in
`compat/mingw.c` to use the stable sort.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When 'git name-rev' is invoked with commit-ish parameters, it tries to
save some work, and doesn't visit commits older than the committer
date of the oldest given commit minus a one day worth of slop. Since
our 'timestamp_t' is an unsigned type, this leads to a timestamp
underflow when the committer date of the oldest given commit is within
a day of the UNIX epoch. As a result the cutoff timestamp ends up
far-far in the future, and 'git name-rev' doesn't visit any commits,
and names each given commit as 'undefined'.
Check whether subtracting the slop from the oldest committer date
would lead to an underflow, and use no cutoff in that case. We don't
have a TIME_MIN constant, dddbad728c (timestamp_t: a new data type for
timestamps, 2017-04-26) didn't add one, so do it now.
Note that the type of the cutoff timestamp variable used to be signed
before 5589e87fd8 (name-rev: change a "long" variable to timestamp_t,
2017-05-20). The behavior was still the same even back then, but the
underflow didn't happen when substracting the slop from the oldest
committer date, but when comparing the signed cutoff timestamp with
unsigned committer dates in name_rev(). IOW, this underflow bug is as
old as 'git name-rev' itself.
Helped-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Long ago, in 97bfeb34df (Release pack windows before reporting out of
memory., 2006-12-24), we taught xmalloc() and friends to try unmapping
pack windows when malloc() failed. It's unlikely that his helps a lot in
practice, and it has some downsides. First, the downsides:
1. It makes xmalloc() not thread-safe. We've worked around this in
pack-objects.c, which installs its own locking version of the
try_to_free_routine(). But other threaded code doesn't.
2. It makes the system as a whole harder to reason about. Functions
which allocate heap memory under the hood may have farther-reaching
effects than expected.
That might be worth the tradeoff if there's a benefit. But in practice,
it seems unlikely. We're generally dealing with mmap'd files, so the OS
is going to do a much better job at responding to memory pressure by
dropping individual pages (the exception is systems with NO_MMAP, but
even there the OS can probably respond just as well with swapping).
So the only thing we're really freeing is address space. On 64-bit
systems, we have plenty of that to go around. On 32-bit systems, it
could possibly help. But around the same time we made two other changes:
77ccc5bbd1 (Introduce new config option for mmap limit., 2006-12-23) and
60bb8b1453 (Fully activate the sliding window pack access., 2006-12-23).
Together that means that a 32-bit system should have no more than 256MB
total of packed-git mmaps at one time, split between a few 32MB windows.
It's unlikely we have any address space problems since then, but we
don't have any data since the features were all added at the same time.
Likewise, xmmap() will try to free memory. At first glance, it seems
like we'd need this (when we try to mmap a new window, we might need to
close an old one to save address space on a 32-bit system). But we're
saved again by core.packedGitLimit: if we're going to exceed our 256MB
limit, we'll close an existing window before we even call mmap().
So it seems unlikely that this feature is actually doing anything
useful. And while we don't have reports of it harming anything (probably
because it rarely if ever kicks in), it would be nice to simplify the
system overall. This patch drops the whole try_to_free system from
xmalloc(), as well as the manual pack memory release in xmmap().
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
MS Visual C comes with a few neat features we can use to analyze the
heap consumption (i.e. leaks, max memory, etc).
With this patch, we introduce support via the build-time flag
`USE_MSVC_CRTDBG`.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Workaround for standard-compliant but less-than-useful behaviour of
access(2) for the root user.
* cc/access-on-aix-workaround:
git-compat-util: work around for access(X_OK) under root
Mechanically and systematically drop "extern" from function
declarlation.
* dl/no-extern-in-func-decl:
*.[ch]: manually align parameter lists
*.[ch]: remove extern from function declarations using sed
*.[ch]: remove extern from function declarations using spatch
An earlier update for MinGW and Cygwin accidentally broke MSVC build,
which has been fixed.
* ss/msvc-path-utils-fix:
MSVC: include compat/win32/path-utils.h for MSVC, too, for real_path()
In previous patches, extern was mechanically removed from function
declarations without care to formatting, causing parameter lists to be
misaligned. Manually format changed sections such that the parameter
lists should be realigned.
Viewing this patch with 'git diff -w' should produce no output.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There has been a push to remove extern from function declarations.
Finish the job by removing all instances of "extern" for function
declarations in headers using sed.
This was done by running the following on my system with sed 4.2.2:
$ git ls-files \*.{c,h} |
grep -v ^compat/ |
xargs sed -i'' -e 's/^\(\s*\)extern \([^(]*([^*]\)/\1\2/'
Files under `compat/` are intentionally excluded as some are directly
copied from external sources and we should avoid churning them as much
as possible.
Then, leftover instances of extern were found by running
$ git grep -w -C3 extern \*.{c,h}
and manually checking the output. No other instances were found.
Note that the regex used specifically excludes function variables which
_should_ be left as extern.
Not the most elegant way to do it but it gets the job done.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There has been a push to remove extern from function declarations.
Remove some instances of "extern" for function declarations which are
caught by Coccinelle. Note that Coccinelle has some difficulty with
processing functions with `__attribute__` or varargs so some `extern`
declarations are left behind to be dealt with in a future patch.
This was the Coccinelle patch used:
@@
type T;
identifier f;
@@
- extern
T f(...);
and it was run with:
$ git ls-files \*.{c,h} |
grep -v ^compat/ |
xargs spatch --sp-file contrib/coccinelle/noextern.cocci --in-place
Files under `compat/` are intentionally excluded as some are directly
copied from external sources and we should avoid churning them as much
as possible.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
On AIX, access(X_OK) may succeed when run as root even if the
execution isn't possible. This behavior is allowed by POSIX
which says:
... for a process with appropriate privileges, an implementation
may indicate success for X_OK even if execute permission is not
granted to any user.
It can lead hook programs to have their execution refused:
git commit -m content
fatal: cannot exec '.git/hooks/pre-commit': Permission denied
Add NEED_ACCESS_ROOT_HANDLER in order to use an access helper function.
It checks with stat if any executable flags is set when the current user
is root.
Signed-off-by: Clément Chigot <clement.chigot@atos.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A path such as 'c:/somepath/submodule/../.git/modules/submodule' wasn't
resolved correctly any more, because the *nix variant of offset_1st_component
is used instead of the Win32 specific version.
Regression was introduced in commit 1cadad6f6 when mingw_offset_1st_component
was moved from mingw.c which is included by msvc.c to a separate file. Then,
the new file "compat/win32/path-utils.h" was only included for the __CYGWIN__
and __MINGW32__ cases in git-compat-util.h, the case for _MSC_VER was missing.
Signed-off-by: Sven Strickroth <email@cs-ware.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Create a new unified tracing facility for git. The eventual intent is to
replace the current trace_printf* and trace_performance* routines with a
unified set of git_trace2* routines.
In addition to the usual printf-style API, trace2 provides higer-level
event verbs with fixed-fields allowing structured data to be written.
This makes post-processing and analysis easier for external tools.
Trace2 defines 3 output targets. These are set using the environment
variables "GIT_TR2", "GIT_TR2_PERF", and "GIT_TR2_EVENT". These may be
set to "1" or to an absolute pathname (just like the current GIT_TRACE).
* GIT_TR2 is intended to be a replacement for GIT_TRACE and logs command
summary data.
* GIT_TR2_PERF is intended as a replacement for GIT_TRACE_PERFORMANCE.
It extends the output with columns for the command process, thread,
repo, absolute and relative elapsed times. It reports events for
child process start/stop, thread start/stop, and per-thread function
nesting.
* GIT_TR2_EVENT is a new structured format. It writes event data as a
series of JSON records.
Calls to trace2 functions log to any of the 3 output targets enabled
without the need to call different trace_printf* or trace_performance*
routines.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
On various BSD's, fileno(fp) is implemented as a macro that directly
accesses the fields in the FILE * object, which breaks a function that
accepts a "void *fp" parameter and calls fileno(fp) and expect it to
work.
Work it around by adding a compile-time knob FILENO_IS_A_MACRO that
inserts a real helper function in the middle of the callchain.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Portability updates for the HPE NonStop platform.
* rb/hpe:
compat/regex/regcomp.c: define intptr_t and uintptr_t on NonStop
git-compat-util.h: add FLOSS headers for HPE NonStop
config.mak.uname: support for modern HPE NonStop config.
transport-helper: drop read/write errno checks
transport-helper: use xread instead of read
The HPE NonStop (a.k.a. __TANDEM) platform cannot build git without
using the FLOSS package supplied by HPE. The convenient location
for including the relevant headers is in this file.
The NSIG define is also not defined on __TANDEM, so we define it
here as 100 if it is not defined only for __TANDEM builds.
Signed-off-by: Randall S. Becker <rsbecker@nexbridge.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A regression for cygwin users was introduced with commit 05b458c,
"real_path: resolve symlinks by hand".
In the the commit message we read:
The current implementation of real_path uses chdir() in order to resolve
symlinks. Unfortunately this isn't thread-safe as chdir() affects a
process as a whole...
The old (and non-thread-save) OS calls chdir()/pwd() had been
replaced by a string operation.
The cygwin layer "knows" that "C:\cygwin" is an absolute path,
but the new string operation does not.
"git clone <url> C:\cygwin\home\USER\repo" fails like this:
fatal: Invalid path '/home/USER/repo/C:\cygwin\home\USER\repo'
The solution is to implement has_dos_drive_prefix(), skip_dos_drive_prefix()
is_dir_sep(), offset_1st_component() and convert_slashes() for cygwin
in the same way as it is done in 'Git for Windows' in compat/mingw.[ch]
Extract the needed code into compat/win32/path-utils.[ch] and use it
for cygwin as well.
Reported-by: Steven Penny <svnpenn@gmail.com>
Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We indent with TABs and sometimes for fine alignment, TABs followed by
spaces, but never all spaces (unless the indentation is less than 8
columns). Indenting with spaces slips through in some places. Fix
them.
Imported code and compat/ are left alone on purpose. The former should
remain as close as upstream as possible. The latter pretty much has
separate maintainers, it's up to them to decide.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A few issues in the implementation of "delta-islands" feature has
been corrected.
* cc/delta-islands:
pack-objects: fix off-by-one in delta-island tree-depth computation
pack-objects: zero-initialize tree_depth/layer arrays
pack-objects: fix tree_depth and layer invariants
Commit 108f530385 (pack-objects: move tree_depth into 'struct
packing_data', 2018-08-16) started maintaining a tree_depth array that
matches the "objects" array. We extend the array when:
1. The objects array is extended, in which case we use realloc to
extend the tree_depth array.
2. A caller asks to store a tree_depth for object N, and this is the
first such request; we create the array from scratch and store the
value for N.
In the latter case, though, we use regular xmalloc(), and the depth
values for any objects besides N is undefined. This happens to not
trigger a bug with the current code, but the reasons are quite subtle:
- we never ask about the depth for any object with index i < N. This is
because we store the depth immediately for all trees and blobs. So
any such "i" must be a non-tree, and therefore we will never need to
care about its depth (in fact, we really only care about the depth of
trees).
- there are no objects at this point with index i > N, because we
always fill in the depth for a tree immediately after its object
entry is created (we may still allocate uninitialized depth entries,
but they'll be initialized by packlist_alloc() when it initializes
the entry in the "objects" array).
So it works, but only by chance. To be defensive, let's zero the array,
which matches the "unset" values which would be handed out by
oe_tree_depth() already.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
POSIX specifies that <poll.h> is the correct header for poll(2)
whereas <sys/poll.h> is only needed for some old libc.
Let's follow the POSIX way by default.
This effectively eliminates musl's warning:
warning redirecting incorrect #include <sys/poll.h> to <poll.h>
Signed-off-by: Đoàn Trần Công Danh <congdanhqx@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the Git for Windows project, we have ample precendent for config
settings that apply to Windows, and to Windows only.
Let's formalize this concept by introducing a platform_core_config()
function that can be #define'd in a platform-specific manner.
This will allow us to contain platform-specific code better, as the
corresponding variables no longer need to be exported so that they can
be defined in environment.c and be set in config.c
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The logic to select the default user name and e-mail on Windows has
been improved.
* js/mingw-default-ident:
mingw: use domain information for default email
getpwuid(mingw): provide a better default for the user name
getpwuid(mingw): initialize the structure only once
after 36da893114 ("config.mak.dev: enable -Wunused-function", 2018-10-18)
it is expected to be used to prevent -Wunused-function warnings for code
that was macro generated
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When a user is registered in a Windows domain, it is really easy to
obtain the email address. So let's do that.
Suggested by Lutz Roeder.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Quite some time ago, a last plea to the XP users out there who want to
see Windows XP support in Git for Windows, asking them to get engaged
and help, vanished into the depths of the universe.
We tried for a long time to play nice with the last remaining XP users
who somehow manage to build Git from source, but a recent update of
mingw-w64 (7.0.0.5233.e0c09544 -> 7.0.0.5245.edf66197) finally dropped
the last sign of XP support, and Git for Windows' SDK is no longer able
to build core Git's `master` branch as a consequence. (Git for Windows'
`master` branch already bumped the minimum Windows version to Vista a
while ago, so it is fine.)
It is time to require Windows Vista or later to build Git from source.
This, incidentally, lets us use quite a few nice new APIs.
It also means that we no longer need the inet_pton() and inet_ntop()
emulation, which is nice.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Previously, we only ever declared a target Windows version if compiling
with Visual C.
Which meant that we were relying on the MinGW headers to guess which
Windows version we want to target...
Let's be explicit about it, in particular because we actually want to
bump the target Windows version to Vista (which we will do in the next
commit).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The words "save" and "safe" are both very wonderful words, each with
their own set of meanings. Let's not confuse them with one another save
on occasion of a pun.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are a few standard C functions (like strcpy) which are
easy to misuse. E.g.:
char path[PATH_MAX];
strcpy(path, arg);
may overflow the "path" buffer. Sometimes there's an earlier
constraint on the size of "arg", but even in such a case
it's hard to verify that the code is correct. If the size
really is unbounded, you're better off using a dynamic
helper like strbuf:
struct strbuf path = STRBUF_INIT;
strbuf_addstr(path, arg);
or if it really is bounded, then use xsnprintf to show your
expectation (and get a run-time assertion):
char path[PATH_MAX];
xsnprintf(path, sizeof(path), "%s", arg);
which makes further auditing easier.
We'd usually catch undesirable code like this in a review,
but there's no automated enforcement. Adding that
enforcement can help us be more consistent and save effort
(and a round-trip) during review.
This patch teaches the compiler to report an error when it
sees strcpy (and will become a model for banning a few other
functions). This has a few advantages over a separate
linting tool:
1. We know it's run as part of a build cycle, so it's
hard to ignore. Whereas an external linter is an extra
step the developer needs to remember to do.
2. Likewise, it's basically free since the compiler is
parsing the code anyway.
3. We know it's robust against false positives (unlike a
grep-based linter).
The two big disadvantages are:
1. We'll only check code that is actually compiled, so it
may miss code that isn't triggered on your particular
system. But since presumably people don't add new code
without compiling it (and if they do, the banned
function list is the least of their worries), we really
only care about failing to clean up old code when
adding new functions to the list. And that's easy
enough to address with a manual audit when adding a new
function (which is what I did for the functions here).
2. If this ends up generating false positives, it's going
to be harder to disable (as opposed to a separate
linter, which may have mechanisms for overriding a
particular case).
But the intent is to only ban functions which are
obviously bad, and for which we accept using an
alternative even when this particular use isn't buggy
(e.g., the xsnprintf alternative above).
The implementation here is simple: we'll define a macro for
the banned function which replaces it with a reference to a
descriptively named but undeclared identifier. Replacing it
with any invalid code would work (since we just want to
break compilation). But ideally we'd meet these goals:
- it should be portable; ideally this would trigger
everywhere, and does not need to be part of a DEVELOPER=1
setup (because unlike warnings which may depend on the
compiler or system, this is a clear indicator of
something wrong in the code).
- it should generate a readable error that gives the
developer a clue what happened
- it should avoid generating too much other cruft that
makes it hard to see the actual error
- it should mention the original callsite in the error
The output with this patch looks like this (using gcc 7, on
a checkout with 022d2ac1f3 reverted, which removed the final
strcpy from blame.c):
CC builtin/blame.o
In file included from ./git-compat-util.h:1246,
from ./cache.h:4,
from builtin/blame.c:8:
builtin/blame.c: In function ‘cmd_blame’:
./banned.h:11:22: error: ‘sorry_strcpy_is_a_banned_function’ undeclared (first use in this function)
#define BANNED(func) sorry_##func##_is_a_banned_function
^~~~~~
./banned.h:14:21: note: in expansion of macro ‘BANNED’
#define strcpy(x,y) BANNED(strcpy)
^~~~~~
builtin/blame.c:1074:4: note: in expansion of macro ‘strcpy’
strcpy(repeated_meta_color, GIT_COLOR_CYAN);
^~~~~~
./banned.h:11:22: note: each undeclared identifier is reported only once for each function it appears in
#define BANNED(func) sorry_##func##_is_a_banned_function
^~~~~~
./banned.h:14:21: note: in expansion of macro ‘BANNED’
#define strcpy(x,y) BANNED(strcpy)
^~~~~~
builtin/blame.c:1074:4: note: in expansion of macro ‘strcpy’
strcpy(repeated_meta_color, GIT_COLOR_CYAN);
^~~~~~
This prominently shows the phrase "strcpy is a banned
function", along with the original callsite in blame.c and
the location of the ban code in banned.h. Which should be
enough to get even a developer seeing this for the first
time pointed in the right direction.
This doesn't match our ideals perfectly, but it's a pretty
good balance. A few alternatives I tried:
1. Instead of using an undeclared variable, using an
undeclared function. This shortens the message, because
the "each undeclared identifier" message is not needed
(and as you can see above, it triggers a separate
mention of each of the expansion points).
But it doesn't actually stop compilation unless you use
-Werror=implicit-function-declaration in your CFLAGS.
This is the case for DEVELOPER=1, but not for a default
build (on the other hand, we'd eventually produce a
link error pointing to the correct source line with the
descriptive name).
2. The linux kernel uses a similar mechanism in its
BUILD_BUG_ON_MSG(), where they actually declare the
function but do so with gcc's error attribute. But
that's not portable to other compilers (and it also
runs afoul of our error() macro).
We could make a gcc-specific technique and fallback on
other compilers, but it's probably not worth the
complexity. It also isn't significantly shorter than
the error message shown above.
3. We could drop the BANNED() macro, which would shorten
the number of lines in the error. But curiously,
removing it (and just expanding strcpy directly to the
bogus identifier) causes gcc _not_ to report the
original line of code.
So this strategy seems to be an acceptable mix of
information, portability, simplicity, and robustness,
without _too_ much extra clutter. I also tested it with
clang, and it looks as good (actually, slightly less
cluttered than with gcc).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Developer support update, by using BUG() macro instead of die() to
mark codepaths that should not happen more clearly.
* js/use-bug-macro:
BUG_exit_code: fix sparse "symbol not declared" warning
Convert remaining die*(BUG) messages
Replace all die("BUG: ...") calls by BUG() ones
run-command: use BUG() to report bugs, not die()
test-tool: help verifying BUG() code paths
"git gc" in a large repository takes a lot of time as it considers
to repack all objects into one pack by default. The command has
been taught to pretend as if the largest existing packfile is
marked with ".keep" so that it is left untouched while objects in
other packs and loose ones are repacked.
* nd/repack-keep-pack:
pack-objects: show some progress when counting kept objects
gc --auto: exclude base pack if not enough mem to "repack -ad"
gc: handle a corner case in gc.bigPackThreshold
gc: add gc.bigPackThreshold config
gc: add --keep-largest-pack option
repack: add --keep-pack option
t7700: have closing quote of a test at the beginning of line
* maint-2.16:
Git 2.16.4
Git 2.15.2
Git 2.14.4
Git 2.13.7
verify_path: disallow symlinks in .gitmodules
update-index: stat updated files earlier
verify_dotfile: mention case-insensitivity in comment
verify_path: drop clever fallthrough
skip_prefix: add case-insensitive variant
is_{hfs,ntfs}_dotgitmodules: add tests
is_ntfs_dotgit: match other .git files
is_hfs_dotgit: match other .git files
is_ntfs_dotgit: use a size_t for traversing string
submodule-config: verify submodule names as paths
* maint-2.15:
Git 2.15.2
Git 2.14.4
Git 2.13.7
verify_path: disallow symlinks in .gitmodules
update-index: stat updated files earlier
verify_dotfile: mention case-insensitivity in comment
verify_path: drop clever fallthrough
skip_prefix: add case-insensitive variant
is_{hfs,ntfs}_dotgitmodules: add tests
is_ntfs_dotgit: match other .git files
is_hfs_dotgit: match other .git files
is_ntfs_dotgit: use a size_t for traversing string
submodule-config: verify submodule names as paths
* maint-2.14:
Git 2.14.4
Git 2.13.7
verify_path: disallow symlinks in .gitmodules
update-index: stat updated files earlier
verify_dotfile: mention case-insensitivity in comment
verify_path: drop clever fallthrough
skip_prefix: add case-insensitive variant
is_{hfs,ntfs}_dotgitmodules: add tests
is_ntfs_dotgit: match other .git files
is_hfs_dotgit: match other .git files
is_ntfs_dotgit: use a size_t for traversing string
submodule-config: verify submodule names as paths
* maint-2.13:
Git 2.13.7
verify_path: disallow symlinks in .gitmodules
update-index: stat updated files earlier
verify_dotfile: mention case-insensitivity in comment
verify_path: drop clever fallthrough
skip_prefix: add case-insensitive variant
is_{hfs,ntfs}_dotgitmodules: add tests
is_ntfs_dotgit: match other .git files
is_hfs_dotgit: match other .git files
is_ntfs_dotgit: use a size_t for traversing string
submodule-config: verify submodule names as paths
We have the convenient skip_prefix() helper, but if you want
to do case-insensitive matching, you're stuck doing it by
hand. We could add an extra parameter to the function to
let callers ask for this, but the function is small and
somewhat performance-critical. Let's just re-implement it
for the case-insensitive version.
Signed-off-by: Jeff King <peff@peff.net>
The new "checkout-encoding" attribute can ask Git to convert the
contents to the specified encoding when checking out to the working
tree (and the other way around when checking in).
* ls/checkout-encoding:
convert: add round trip check based on 'core.checkRoundtripEncoding'
convert: add tracing for 'working-tree-encoding' attribute
convert: check for detectable errors in UTF encodings
convert: add 'working-tree-encoding' attribute
utf8: add function to detect a missing UTF-16/32 BOM
utf8: add function to detect prohibited UTF-16/32 BOM
utf8: teach same_encoding() alternative UTF encoding names
strbuf: add a case insensitive starts_with()
strbuf: add xstrdup_toupper()
strbuf: remove unnecessary NUL assignment in xstrdup_tolower()
These were not caught by the previous commit, as they did not match the
regular expression.
While at it, remove the localization from one instance: we never want
BUG() messages to be translated, as they target Git developers, not the
end user (hence it would be quite unhelpful to not only burden the
translators, but then even end up with a bug report in a language that
no core Git contributor understands).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
pack-objects could be a big memory hog especially on large repos,
everybody knows that. The suggestion to stick a .keep file on the
giant base pack to avoid this problem is also known for a long time.
Recent patches add an option to do just this, but it has to be either
configured or activated manually. This patch lets `git gc --auto`
activate this mode automatically when it thinks `repack -ad` will use
a lot of memory and start affecting the system due to swapping or
flushing OS cache.
gc --auto decides to do this based on an estimation of pack-objects
memory usage, which is quite accurate at least for the heap part, and
whether that fits in half of system memory (the assumption here is for
desktop environment where there are many other applications running).
This mechanism only kicks in if gc.bigBasePackThreshold is not configured.
If it is, it is assumed that the user already knows what they want.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Check in a case insensitive manner if one string is a prefix of another
string.
This function is used in a subsequent commit.
Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rename C++ keyword in order to bring the codebase closer to being able
to be compiled with a C++ compiler.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We often accept both a "--key" option and a "--key=<val>" option.
These options currently are parsed using something like:
if (!strcmp(arg, "--key")) {
/* do something */
} else if (skip_prefix(arg, "--key=", &arg)) {
/* do something with arg */
}
which is a bit cumbersome compared to just:
if (skip_to_optional_arg(arg, "--key", &arg)) {
/* do something with arg */
}
This also introduces skip_to_optional_arg_default() for the few
cases where something different should be done when the first
argument is exactly "--key" than when it is exactly "--key=".
In general it is better for UI consistency and simplicity if
"--key" and "--key=" do the same thing though, so that using
skip_to_optional_arg() should be encouraged compared to
skip_to_optional_arg_default().
Note that these functions can be used to parse any "key=value"
string where "key" is also considered as valid, not just
command line options.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 0e5bba5 ("add UNLEAK annotation for reducing leak false
positives", 2017-09-08) introduced an UNLEAK macro to be used as
"UNLEAK(var);", but its existing definitions leave semicolons that act
as empty statements, which will lead to syntax errors, e.g.
if (condition)
UNLEAK(var);
else
something_else(var);
would be broken with two statements between if (condition) and else.
Lose the excess semicolon from the end of the macro replacement text.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It's a common pattern in git commands to allocate some
memory that should last for the lifetime of the program and
then not bother to free it, relying on the OS to throw it
away.
This keeps the code simple, and it's fast (we don't waste
time traversing structures or calling free at the end of the
program). But it also triggers warnings from memory-leak
checkers like valgrind or LSAN. They know that the memory
was still allocated at program exit, but they don't know
_when_ the leaked memory stopped being useful. If it was
early in the program, then it's probably a real and
important leak. But if it was used right up until program
exit, it's not an interesting leak and we'd like to suppress
it so that we can see the real leaks.
This patch introduces an UNLEAK() macro that lets us do so.
To understand its design, let's first look at some of the
alternatives.
Unfortunately the suppression systems offered by
leak-checking tools don't quite do what we want. A
leak-checker basically knows two things:
1. Which blocks were allocated via malloc, and the
callstack during the allocation.
2. Which blocks were left un-freed at the end of the
program (and which are unreachable, but more on that
later).
Their suppressions work by mentioning the function or
callstack of a particular allocation, and marking it as OK
to leak. So imagine you have code like this:
int cmd_foo(...)
{
/* this allocates some memory */
char *p = some_function();
printf("%s", p);
return 0;
}
You can say "ignore allocations from some_function(),
they're not leaks". But that's not right. That function may
be called elsewhere, too, and we would potentially want to
know about those leaks.
So you can say "ignore the callstack when main calls
some_function". That works, but your annotations are
brittle. In this case it's only two functions, but you can
imagine that the actual allocation is much deeper. If any of
the intermediate code changes, you have to update the
suppression.
What we _really_ want to say is that "the value assigned to
p at the end of the function is not a real leak". But
leak-checkers can't understand that; they don't know about
"p" in the first place.
However, we can do something a little bit tricky if we make
some assumptions about how leak-checkers work. They
generally don't just report all un-freed blocks. That would
report even globals which are still accessible when the
leak-check is run. Instead they take some set of memory
(like BSS) as a root and mark it as "reachable". Then they
scan the reachable blocks for anything that looks like a
pointer to a malloc'd block, and consider that block
reachable. And then they scan those blocks, and so on,
transitively marking anything reachable from a global as
"not leaked" (or at least leaked in a different category).
So we can mark the value of "p" as reachable by putting it
into a variable with program lifetime. One way to do that is
to just mark "p" as static. But that actually affects the
run-time behavior if the function is called twice (you
aren't likely to call main() twice, but some of our cmd_*()
functions are called from other commands).
Instead, we can trick the leak-checker by putting the value
into _any_ reachable bytes. This patch keeps a global
linked-list of bytes copied from "unleaked" variables. That
list is reachable even at program exit, which confers
recursive reachability on whatever values we unleak.
In other words, you can do:
int cmd_foo(...)
{
char *p = some_function();
printf("%s", p);
UNLEAK(p);
return 0;
}
to annotate "p" and suppress the leak report.
But wait, couldn't we just say "free(p)"? In this toy
example, yes. But UNLEAK()'s byte-copying strategy has
several advantages over actually freeing the memory:
1. It's recursive across structures. In many cases our "p"
is not just a pointer, but a complex struct whose
fields may have been allocated by a sub-function. And
in some cases (e.g., dir_struct) we don't even have a
function which knows how to free all of the struct
members.
By marking the struct itself as reachable, that confers
reachability on any pointers it contains (including those
found in embedded structs, or reachable by walking
heap blocks recursively.
2. It works on cases where we're not sure if the value is
allocated or not. For example:
char *p = argc > 1 ? argv[1] : some_function();
It's safe to use UNLEAK(p) here, because it's not
freeing any memory. In the case that we're pointing to
argv here, the reachability checker will just ignore
our bytes.
3. Likewise, it works even if the variable has _already_
been freed. We're just copying the pointer bytes. If
the block has been freed, the leak-checker will skip
over those bytes as uninteresting.
4. Because it's not actually freeing memory, you can
UNLEAK() before we are finished accessing the variable.
This is helpful in cases like this:
char *p = some_function();
return another_function(p);
Writing this with free() requires:
int ret;
char *p = some_function();
ret = another_function(p);
free(p);
return ret;
But with unleak we can just write:
char *p = some_function();
UNLEAK(p);
return another_function(p);
This patch adds the UNLEAK() macro and enables it
automatically when Git is compiled with SANITIZE=leak. In
normal builds it's a noop, so we pay no runtime cost.
It also adds some UNLEAK() annotations to show off how the
feature works. On top of other recent leak fixes, these are
enough to get t0000 and t0001 to pass when compiled with
LSAN.
Note the case in commit.c which actually converts a
strbuf_release() into an UNLEAK. This code was already
non-leaky, but the free didn't do anything useful, since
we're exiting. Converting it to an annotation means that
non-leak-checking builds pay no runtime cost. The cost is
minimal enough that it's probably not worth going on a
crusade to convert these kinds of frees to UNLEAKS. I did it
here for consistency with the "sb" leak (though it would
have been equally correct to go the other way, and turn them
both into strbuf_release() calls).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The function unuse_one_window() needs to be temporarily made global. Its
scope will be restored to static in a subsequent commit.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code clean-up.
* rs/move-array:
ls-files: don't try to prune an empty index
apply: use COPY_ARRAY and MOVE_ARRAY in update_image()
use MOVE_ARRAY
add MOVE_ARRAY
Code clean-up.
* rs/move-array:
ls-files: don't try to prune an empty index
apply: use COPY_ARRAY and MOVE_ARRAY in update_image()
use MOVE_ARRAY
add MOVE_ARRAY
On Cygwin, similar to Windows, "git push //server/share/repository"
ought to mean a repository on a network share that can be accessed
locally, but this did not work correctly due to stripping the double
slashes at the beginning.
This may need to be heavily tested before it gets unleashed to the
wild, as the change is at a fairly low-level code and would affect
not just the code to decide if the push destination is local. There
may be unexpected fallouts in the path normalization.
* tb/push-to-cygwin-unc-path:
cygwin: allow pushing to UNC paths
Similar to COPY_ARRAY (introduced in 60566cbb58), add a safe and
convenient helper for moving potentially overlapping ranges of array
entries. It infers the element size, multiplies automatically and
safely to get the size in bytes, does a basic type safety check by
comparing element sizes and unlike memmove(3) it supports NULL
pointers iff 0 elements are to be moved.
Also add a semantic patch to demonstrate the helper's intended usage.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
cygwin can use an UNC path like //server/share/repo
$ cd //server/share/dir
$ mkdir test
$ cd test
$ git init --bare
However, when we try to push from a local Git repository to this repo,
there is a problem: Git converts the leading "//" into a single "/".
As cygwin handles an UNC path so well, Git can support them better:
- Introduce cygwin_offset_1st_component() which keeps the leading "//",
similar to what Git for Windows does.
- Move CYGWIN out of the POSIX in the tests for path normalization in t0060
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a FREE_AND_NULL() wrapper marco for the common pattern of freeing
a pointer and assigning NULL to it right afterwards.
The implementation is similar to the (currently unused) XDL_PTRFREE
macro in xdiff/xmacros.h added in commit 3443546f6e ("Use a *real*
built-in diff generator", 2006-03-24). The only difference is that
free() is called unconditionally, see [1].
See [2] for a suggested alternative which does this via a function
instead of a macro. As covered in replies to that message, while it's
a viable approach, it would introduce caveats which this approach
doesn't have, so that potential change is left to a future follow-up
change.
This merely allows us to translate exactly what we're doing now to a
less verbose & idiomatic form using a macro, while guaranteeing that
we don't introduce any functional changes.
1. <alpine.DEB.2.20.1608301948310.129229@virtualbox>
(http://public-inbox.org/git/alpine.DEB.2.20.1608301948310.129229@virtualbox/)
2. <20170610032143.GA7880@starla>
(https://public-inbox.org/git/20170610032143.GA7880@starla/)
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We often try to open a file for reading whose existence is
optional, and silently ignore errors from open/fopen; report such
errors if they are not due to missing files.
* nd/fopen-errors:
mingw_fopen: report ENOENT for invalid file names
mingw: verify that paths are not mistaken for remote nicknames
log: fix memory leak in open_next_file()
rerere.c: move error_errno() closer to the source system call
print errno when reporting a system call error
wrapper.c: make warn_on_inaccessible() static
wrapper.c: add and use fopen_or_warn()
wrapper.c: add and use warn_on_fopen_errors()
config.mak.uname: set FREAD_READS_DIRECTORIES for Darwin, too
config.mak.uname: set FREAD_READS_DIRECTORIES for Linux and FreeBSD
clone: use xfopen() instead of fopen()
use xfopen() in more places
git_fopen: fix a sparse 'not declared' warning
Our code often opens a path to an optional file, to work on its
contents when we can successfully open it. We can ignore a failure
to open if such an optional file does not exist, but we do want to
report a failure in opening for other reasons (e.g. we got an I/O
error, or the file is there, but we lack the permission to open).
The exact errors we need to ignore are ENOENT (obviously) and
ENOTDIR (less obvious). Instead of repeating comparison of errno
with these two constants, introduce a helper function to do so.
* jc/noent-notdir:
treewide: use is_missing_file_error() where ENOENT and ENOTDIR are checked
compat-util: is_missing_file_error()
The "run-command" API implementation has been made more robust
against dead-locking in a threaded environment.
* bw/forking-and-threading:
usage.c: drop set_error_handle()
run-command: restrict PATH search to executable files
run-command: expose is_executable function
run-command: block signals between fork and execve
run-command: add note about forking and threading
run-command: handle dup2 and close errors in child
run-command: eliminate calls to error handling functions in child
run-command: don't die in child when duping /dev/null
run-command: prepare child environment before forking
string-list: add string_list_remove function
run-command: use the async-signal-safe execv instead of execvp
run-command: prepare command before forking
t0061: run_command executes scripts without a #! line
t5550: use write_script to generate post-update hook
