Граф коммитов

594 Коммитов

Автор SHA1 Сообщение Дата
Junio C Hamano 4b51386bbf Merge branch 'ab/usage-die-message'
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
2022-01-10 11:52:53 -08:00
Junio C Hamano d0c99fcc61 Merge branch 'jc/flex-array-definition'
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
2022-01-05 14:01:27 -08:00
Junio C Hamano 25be7ec4bf Merge branch 'cb/mingw-gmtime-r'
Build fix on Windows.

* cb/mingw-gmtime-r:
  mingw: avoid fallback for {local,gm}time_r()
2021-12-10 14:35:15 -08:00
Junio C Hamano d67fc4bf0b Merge branch 'bc/require-c99'
Weather balloon to break people with compilers that do not support
C99.

* bc/require-c99:
  git-compat-util: add a test balloon for C99 support
2021-12-10 14:35:14 -08:00
Junio C Hamano deefc2d9f6 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>
2021-12-08 17:45:16 -08:00
Ævar Arnfjörð Bjarmason f5c39c3268 config API: use get_error_routine(), not vreportf()
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>
2021-12-07 13:25:16 -08:00
Ævar Arnfjörð Bjarmason 24f6e6d626 usage.c + gc: add and use a die_message_errno()
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>
2021-12-07 13:25:16 -08:00
Ævar Arnfjörð Bjarmason 18568ee8f8 usage.c: add a die_message() routine
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>
2021-12-07 13:25:15 -08:00
brian m. carlson 7bc341e21b git-compat-util: add a test balloon for C99 support
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>
2021-12-01 14:50:01 -08:00
Junio C Hamano f9ba6acaa9 Merge branch 'mc/clean-smudge-with-llp64'
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
2021-11-29 15:41:51 -08:00
Junio C Hamano 0ae87432aa Merge branch 'jc/unsetenv-returns-an-int'
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
2021-11-29 15:41:48 -08:00
Carlo Marcelo Arenas Belón 9e12400da8 mingw: avoid fallback for {local,gm}time_r()
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>
2021-11-27 23:49:20 -08:00
Johannes Schindelin e2ffeae3f6 git-compat-util: introduce more size_t helpers
We will use them in the next commit.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-11-03 11:22:27 -07:00
Junio C Hamano a38989bd5b unsetenv(3) returns int, not void
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>
2021-10-29 15:00:58 -07:00
Carlo Marcelo Arenas Belón 6fc527a8d0 wrapper: remove xunsetenv()
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>
2021-10-29 14:59:29 -07:00
Junio C Hamano d8d33378ed Merge branch 'ab/repo-settings-cleanup'
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
2021-10-06 13:40:11 -07:00
Junio C Hamano c2e799012b Merge branch 'cb/unix-sockets-with-windows'
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
2021-09-23 13:44:48 -07:00
Ævar Arnfjörð Bjarmason 3540c71ea5 wrapper.c: add x{un,}setenv(), and use xsetenv() in environment.c
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>
2021-09-22 13:15:00 -07:00
Carlo Marcelo Arenas Belón bb390b1f49 git-compat-util: include declaration for unix sockets in windows
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>
2021-09-14 09:30:54 -07:00
Ævar Arnfjörð Bjarmason 153fb49e60 gettext: remove optional non-standard parens in N_() definition
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>
2021-09-03 11:40:30 -07:00
Junio C Hamano a93c6fd677 Merge branch 'ew/mmap-failures'
Error message update.

* ew/mmap-failures:
  xmmap: inform Linux users of tuning knobs on ENOMEM
2021-07-16 17:42:47 -07:00
Junio C Hamano a515f26eac Merge branch 'ar/typofix'
Typofixes.

* ar/typofix:
  *: fix typos which duplicate a word
2021-07-08 13:14:59 -07:00
Eric Wong dc05929411 xmmap: inform Linux users of tuning knobs on ENOMEM
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>
2021-06-29 23:14:25 -07:00
Andrei Rybak abcb66c614 *: fix typos which duplicate a word
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>
2021-06-14 10:16:06 +09:00
Junio C Hamano d6e35a2644 Merge branch 'jn/size-t-casted-to-off-t-fix'
Rewrite code that triggers undefined behaiour warning.

* jn/size-t-casted-to-off-t-fix:
  xsize_t: avoid implementation defined behavior when len < 0
2021-06-10 12:04:23 +09:00
Jonathan Nieder aafa5df0df xsize_t: avoid implementation defined behavior when len < 0
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>
2021-05-19 15:00:30 +09:00
Junio C Hamano 4c6ac2da2c Merge branch 'tb/precompose-prefix-simplify'
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
2021-04-13 15:28:51 -07:00
Torsten Bögershausen 5020774aef 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>
2021-04-05 17:30:04 -07:00
Junio C Hamano 204333b015 Merge branch 'jk/open-dotgitx-with-nofollow'
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
2021-03-22 14:00:22 -07:00
René Scharfe f1121499e6 git-compat-util.h: drop trailing semicolon from macro definition
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>
2021-03-13 15:56:13 -08:00
Junio C Hamano 56a57652ef Sync with Git 2.30.2 for CVE-2021-21300
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-08 16:09:07 -08:00
Junio C Hamano 921846fa22 Merge branch 'jk/open-returns-eintr'
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
2021-03-04 15:34:45 -08:00
Jeff King 2b08101204 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>
2021-02-26 14:15:51 -08:00
Jeff King 00611d8440 add open_nofollow() helper
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>
2021-02-16 09:41:32 -08:00
Junio C Hamano 8b25dee615 Merge branch 'tb/precompose-prefix-too'
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()
2021-02-12 14:21:04 -08:00
Johannes Schindelin e4e68081bb Sync with 2.29.3
* maint-2.29:
  Git 2.29.3
  Git 2.28.1
  Git 2.27.1
  Git 2.26.3
  Git 2.25.5
  Git 2.24.4
  Git 2.23.4
  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
2021-02-12 15:51:12 +01:00
Johannes Schindelin d7bdabe52f Sync with 2.28.1
* maint-2.28:
  Git 2.28.1
  Git 2.27.1
  Git 2.26.3
  Git 2.25.5
  Git 2.24.4
  Git 2.23.4
  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
2021-02-12 15:50:14 +01:00
Johannes Schindelin 3f01e56686 Sync with 2.27.1
* maint-2.27:
  Git 2.27.1
  Git 2.26.3
  Git 2.25.5
  Git 2.24.4
  Git 2.23.4
  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
2021-02-12 15:50:09 +01:00
Johannes Schindelin 2d1142a3e8 Sync with 2.26.3
* maint-2.26:
  Git 2.26.3
  Git 2.25.5
  Git 2.24.4
  Git 2.23.4
  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
2021-02-12 15:50:04 +01:00
Johannes Schindelin 97d1dcb1ef Sync with 2.24.4
* maint-2.24:
  Git 2.24.4
  Git 2.23.4
  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
2021-02-12 15:49:55 +01:00
Johannes Schindelin 92ac04b8ee Sync with 2.23.4
* maint-2.23:
  Git 2.23.4
  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
2021-02-12 15:49:50 +01:00
Johannes Schindelin 4bd06fd490 Sync with 2.22.5
* 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
2021-02-12 15:49:45 +01:00
Johannes Schindelin bcf08f33d8 Sync with 2.21.4
* 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
2021-02-12 15:49:41 +01:00
Johannes Schindelin b1726b1a38 Sync with 2.20.5
* 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
2021-02-12 15:49:35 +01:00
Johannes Schindelin 804963848e Sync with 2.19.6
* 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
2021-02-12 15:49:17 +01:00
Johannes Schindelin fb049fd85b Sync with 2.18.5
* 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
2021-02-12 15:47:47 +01:00
Johannes Schindelin 9b77cec89b Sync with 2.17.6
* 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
2021-02-12 15:47:42 +01:00
Matheus Tavares 684dd4c2b4 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>
2021-02-12 15:47:02 +01:00
Torsten Bögershausen 5c327502db MacOS: precompose_argv_prefix()
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>
2021-02-03 14:09:37 -08:00
Jeff King 765dc16888 git-compat-util: always enable variadic macros
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>
2021-01-27 22:14:37 -08:00