Force shutdown fsmonitor daemon if the worktree root directory
is moved, renamed, or deleted.
Use Windows low-level GetFileInformationByHandle() to get and
compare the Windows system unique ID for the directory with a
cached version when we started up. This lets us detect the
case where someone renames the directory that we are watching
and then creates a new directory with the original pathname.
This is important because we are listening to a named pipe for
requests and they are stored in the Named Pipe File System (NPFS)
which a kernel-resident pseudo filesystem not associated with
the actual NTFS directory.
For example, if the daemon was watching "~/foo/", it would have
a directory-watch handle on that directory and a named-pipe
handle for "//./pipe/...foo". Moving the directory to "~/bar/"
does not invalidate the directory handle. (So the daemon would
actually be watching "~/bar" but listening on "//./pipe/...foo".
If the user then does "git init ~/foo" and causes another daemon
to start, the first daemon will still have ownership of the pipe
and the second daemon instance will fail to start. "git status"
clients in "~/foo" will ask "//./pipe/...foo" about changes and
the first daemon instance will tell them about "~/bar".
This commit causes the first daemon to shutdown if the system unique
ID for "~/foo" changes (changes from what it was when the daemon
started). Shutdown occurs after a periodic poll. After the
first daemon exits and releases the lock on the named pipe,
subsequent Git commands may cause another daemon to be started
on "~/foo". Similarly, a subsequent Git command may cause another
daemon to be started on "~/bar".
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Extend the Windows version of the "health" thread to periodically
inspect the system and shutdown if warranted.
This commit updates the thread's wait loop to use a timeout and
defines a (currently empty) table of functions to poll the system.
A later commit will add functions to the table to actually
inspect the system.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Create another thread to watch over the daemon process and
automatically shut it down if necessary.
This commit creates the basic framework for a "health" thread
to monitor the daemon and/or the file system. Later commits
will add platform-specific code to do the actual work.
The "health" thread is intended to monitor conditions that
would be difficult to track inside the IPC thread pool and/or
the file system listener threads. For example, when there are
file system events outside of the watched worktree root or if
we want to have an idle-timeout auto-shutdown feature.
This commit creates the health thread itself, defines the thread-proc
and sets up the thread's event loop. It integrates this new thread
into the existing IPC and Listener thread models.
This commit defines the API to the platform-specific code where all of
the monitoring will actually happen.
The platform-specific code for MacOS is just stubs. Meaning that the
health thread will immediately exit on MacOS, but that is OK and
expected. Future work can define MacOS-specific monitoring.
The platform-specific code for Windows sets up enough of the
WaitForMultipleObjects() machinery to watch for system and/or custom
events. Currently, the set of wait handles only includes our custom
shutdown event (sent from our other theads). Later commits in this
series will extend the set of wait handles to monitor other
conditions.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rename platform-specific listener thread related variables
and data types as we prepare to add another backend thread
type.
[] `struct fsmonitor_daemon_backend_data` becomes `struct fsm_listen_data`
[] `state->backend_data` becomes `state->listen_data`
[] `state->error_code` becomes `state->listen_error_code`
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach the fsmonitor--daemon to CD outside of the worktree
before starting up.
The common Git startup mechanism causes the CWD of the daemon process
to be in the root of the worktree. On Windows, this causes the daemon
process to hold a locked handle on the CWD and prevents other
processes from moving or deleting the worktree while the daemon is
running.
CD to HOME before entering main event loops.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Ignore FSEvents resulting from `xattr` changes. Git does not care about
xattr's or changes to xattr's, so don't waste time collecting these
events in the daemon nor transmitting them to clients.
Various security tools add xattrs to files and/or directories, such as
to mark them as having been downloaded. We should ignore these events
since it doesn't affect the content of the file/directory or the normal
meta-data that Git cares about.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
On MacOS mark repos on NTFS or FAT32 volumes as incompatible.
The builtin FSMonitor used Unix domain sockets on MacOS for IPC
with clients. These sockets are kept in the .git directory.
Unix sockets are not supported by NTFS and FAT32, so the daemon
cannot start up.
Test for this during our compatibility checking so that client
commands do not keep trying to start the daemon.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach Git to detect remote working directories on Windows and mark them as
incompatible with FSMonitor.
With this `git fsmonitor--daemon run` will error out with a message like it
does for bare repos.
Client commands, such as `git status`, will not attempt to start the daemon.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach Git to detect remote working directories on macOS and mark them as
incompatible with FSMonitor.
With this, `git fsmonitor--daemon run` will error out with a message
like it does for bare repos.
Client commands, like `git status`, will not attempt to start the daemon.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
VFS for Git virtual repositories are incompatible with FSMonitor.
VFS for Git is a downstream fork of Git. It contains its own custom
file system watcher that is aware of the virtualization. If a working
directory is being managed by VFS for Git, we should not try to watch
it because we may get incomplete results.
We do not know anything about how VFS for Git works, but we do
know that VFS for Git working directories contain a well-defined
config setting. If it is set, mark the working directory as
incompatible.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Extend generic incompatibility checkout with platform-specific
mechanism. Stub in Win32 version.
In the existing fsmonitor-settings code we have a way to mark
types of repos as incompatible with fsmonitor (whether via the
hook and IPC APIs). For example, we do this for bare repos,
since there are no files to watch.
Extend this exclusion mechanism for platform-specific reasons.
This commit just creates the framework and adds a stub for Win32.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach FSMonitor daemon on Windows to recognize shortname paths as
aliases of normal longname paths. FSMonitor clients, such as `git
status`, should receive the longname spelling of changed files (when
possible).
Sometimes we receive FS events using the shortname, such as when a CMD
shell runs "RENAME GIT~1 FOO" or "RMDIR GIT~1". The FS notification
arrives using whatever combination of long and shortnames were used by
the other process. (Shortnames do seem to be case normalized,
however.)
Use Windows GetLongPathNameW() to try to map the pathname spelling in
the notification event into the normalized longname spelling. (This
can fail if the file/directory is deleted, moved, or renamed, because
we are asking the FS for the mapping in response to the event and
after it has already happened, but we try.)
Special case the shortname spelling of ".git" to avoid under-reporting
these events.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Implement file system event listener on MacOS using FSEvent,
CoreFoundation, and CoreServices.
Co-authored-by: Kevin Willford <Kevin.Willford@microsoft.com>
Co-authored-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Include MacOS system declarations to allow us to use FSEvent and
CoreFoundation APIs. We need different versions of the declarations
for GCC vs. clang because of compiler and header file conflicts.
While it is quite possible to #include Apple's CoreServices.h when
compiling C source code with clang, trying to build it with GCC
currently fails with this error:
In file included
from /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/...
...Library/Frameworks/Security.framework/Headers/AuthSession.h:32,
from /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/...
...Library/Frameworks/Security.framework/Headers/Security.h:42,
from /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/...
...Library/Frameworks/CoreServices.framework/Frameworks/...
...OSServices.framework/Headers/CSIdentity.h:43,
from /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/...
...Library/Frameworks/CoreServices.framework/Frameworks/...
...OSServices.framework/Headers/OSServices.h:29,
from /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/...
...Library/Frameworks/CoreServices.framework/Frameworks/...
...LaunchServices.framework/Headers/IconsCore.h:23,
from /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/...
...Library/Frameworks/CoreServices.framework/Frameworks/...
...LaunchServices.framework/Headers/LaunchServices.h:23,
from /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/...
...Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:45,
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/...
...Library/Frameworks/Security.framework/Headers/Authorization.h:193:7:
error: variably modified 'bytes' at file scope
193 | char bytes[kAuthorizationExternalFormLength];
| ^~~~~
The underlying reason is that GCC (rightfully) objects that an `enum`
value such as `kAuthorizationExternalFormLength` is not a constant
(because it is not, the preprocessor has no knowledge of it, only the
actual C compiler does) and can therefore not be used to define the size
of a C array.
This is a known problem and tracked in GCC's bug tracker:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93082
In the meantime, let's not block things and go the slightly ugly route
of declaring/defining the FSEvents constants, data structures and
functions that we need, so that we can avoid above-mentioned issue.
Let's do this _only_ for GCC, though, so that the CI/PR builds (which
build both with clang and with GCC) can guarantee that we _are_ using
the correct data types.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach the win32 backend to register a watch on the working tree
root directory (recursively). Also watch the <gitdir> if it is
not inside the working tree. And to collect path change notifications
into batches and publish.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Stub in empty implementation of fsmonitor--daemon
backend for Darwin (aka MacOS).
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Stub in empty filesystem listener backend for fsmonitor--daemon on Windows.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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
Fix a hand-rolled alloca() imitation that may have violated
alignment requirement of data being sorted in compatibility
implementation of qsort_s() and stable qsort().
* jc/qsort-s-alignment-fix:
stable-qsort: avoid using potentially unaligned access
compat/qsort_s.c: avoid using potentially unaligned access
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>
A recent upstream topic introduced checks for certain Git commands that
prevent them from deleting the current working directory, introducing
also a regression test that ensures that commands such as `git version`
_can_ run without a current working directory.
While technically not possible on Windows via the regular Win32 API, we
do run the regression tests in an MSYS2 Bash which uses a POSIX
emulation layer (the MSYS2/Cygwin runtime) where a really evil hack
_does_ allow to delete a directory even if it is the current working
directory.
Therefore, Git needs to be prepared for a missing working directory,
even on Windows.
This issue was not noticed in upstream Git because there was no caller
that tried to discover a Git directory with a deleted current working
directory in the test suite. But in the microsoft/git fork, we do want
to run `pre-command`/`post-command` hooks for every command, even for
`git version`, which means that we make precisely such a call. The bug
is not in that `pre-command`/`post-command` feature, though, but in
`mingw_getcwd()` and needs to be addressed there.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
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>
Christoph Reiter reported on the Git for Windows issue tracker[1], that
mingw_strftime() imports strftime() from ucrtbase.dll with the wrong
calling convention. It should be __cdecl instead of WINAPI, which we
always use in DECLARE_PROC_ADDR().
The MSYS2 project encountered cmake sefaults on x86 Windows caused by
the same issue in the cmake source. [2] There are no known git crashes
that where caused by this, yet, but we should try to prevent them.
We import two other non-WINAPI functions via DECLARE_PROC_ADDR(), too.
* NtSetSystemInformation() (NTAPI)
* GetUserNameExW() (SEC_ENTRY)
NTAPI, SEC_ENTRY and WINAPI are all ususally defined as __stdcall,
but there are circumstances where they're defined differently.
Teach DECLARE_PROC_ADDR() about calling conventions and be explicit
about when we want to use which calling convention.
Import winnt.h for the definition of NTAPI and sspi.h for SEC_ENTRY
near their respective only users.
[1] https://github.com/git-for-windows/git/issues/3560
[2] https://github.com/msys2/MINGW-packages/issues/10152
Reported-By: Christoph Reiter <reiter.christoph@gmail.com>
Signed-off-by: Matthias Aßhauer <mha1993@live.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The compatibility definition for qsort_s() uses "char buffer[1024]"
on the stack to avoid making malloc() calls for small temporary
space, which essentially hand-rolls alloca().
But the elements of the array being sorted may have alignment needs
more strict than what an array of bytes may have. &buf[0] may be
word aligned, but using the address as if it stores the first
element of an array of a struct, whose first member may need to be
aligned on double-word boundary, would be a no-no.
We could use xalloca() from git-compat-util.h, or alloca() directly
on platforms with HAVE_ALLOCA_H, but let's try using unconditionally
xmalloc() before we know the performance characteristics of the
callers.
It may not make much of an argument to inspect the current callers
and say "it shouldn't matter to any of them", but anyway:
* The one in object-name.c is used to sort potential matches to a
given ambiguous object name prefix in the error path;
* The one in pack-write.c is done once per a pack .idx file being
written to create the reverse index, so (1) the cost of malloc()
overhead is dwarfed by the cost of the packing operation, and (2)
the number of entries being sorted is the number of objects in a
pack;
* The one in ref-filter.c is used by "branch --list", "tag --list",
and "for-each-ref", only once per operation. We sort an array of
pointers with entries, each corresponding to a ref that is shown.
* The one in string-list.c is used by sort_string_list(), which is
way too generic to assume any access patterns, so it may or may
not matter, but I do not care too much ;-)
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "reftable" backend for the refs API, without integrating into
the refs subsystem, has been added.
* hn/reftable:
Add "test-tool dump-reftable" command.
reftable: add dump utility
reftable: implement stack, a mutable database of reftable files.
reftable: implement refname validation
reftable: add merged table view
reftable: add a heap-based priority queue for reftable records
reftable: reftable file level tests
reftable: read reftable files
reftable: generic interface to tables
reftable: write reftable files
reftable: a generic binary tree implementation
reftable: reading/writing blocks
Provide zlib's uncompress2 from compat/zlib-compat.c
reftable: (de)serialization for the polymorphic record type.
reftable: add blocksource, an abstraction for random access reads
reftable: utility functions
reftable: add error related functionality
reftable: add LICENSE
hash.h: provide constants for the hash IDs
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>
Cygwin emulates Unix sockets by writing files with custom contents and
then marking them as system files.
The tricky problem is that while the file is written and its `system`
bit is set, it is still identified as a file. This caused test failures
when Git is too fast looking for the Unix sockets and then complains
that there is a plain file in the way.
Let's work around this by adding a delayed retry loop, specifically for
Cygwin.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Tested-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
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>
An editor session launched during a Git operation (e.g. during 'git
commit') can leave the terminal in a funny state. The code path
has updated to save the terminal state before, and restore it
after, it spawns an editor.
* cm/save-restore-terminal:
editor: save and reset terminal after calling EDITOR
terminal: teach git how to save/restore its terminal settings
Built-in fsmonitor (part 1).
* jh/builtin-fsmonitor-part1:
t/helper/simple-ipc: convert test-simple-ipc to use start_bg_command
run-command: create start_bg_command
simple-ipc/ipc-win32: add Windows ACL to named pipe
simple-ipc/ipc-win32: add trace2 debugging
simple-ipc: move definition of ipc_active_state outside of ifdef
simple-ipc: preparations for supporting binary messages.
trace2: add trace2_child_ready() to report on background children
Mostly preliminary clean-up in the hook API.
* ab/config-based-hooks-1:
hook-list.h: add a generated list of hooks, like config-list.h
hook.c users: use "hook_exists()" instead of "find_hook()"
hook.c: add a hook_exists() wrapper and use it in bugreport.c
hook.[ch]: move find_hook() from run-command.c to hook.c
Makefile: remove an out-of-date comment
Makefile: don't perform "mv $@+ $@" dance for $(GENERATED_H)
Makefile: stop hardcoding {command,config}-list.h
Makefile: mark "check" target as .PHONY
mmap() imitation used to call xmalloc() that dies upon malloc()
failure, which has been corrected to just return an error to the
caller to be handled.
* rs/git-mmap-uses-malloc:
compat: let git_mmap use malloc(3) directly
This will be needed for reading reflog blocks in reftable.
Helped-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, git will share its console with all its children (unless
they create their own), and is therefore possible that any of them
that might change the settings for it could affect its operations once
completed.
Refactor the platform specific functionality to save the terminal
settings and expand it to also do so for the output handler.
This will allow for the state of the terminal to be saved and
restored around a child that might misbehave (ex vi) which will
be implemented next.
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
gcc will helpfully raise a -Wcast-function-type warning when casting
between functions that might have incompatible return types
(ex: GetUserNameExW returns bool which is only half the size of the
return type from FARPROC which is long long), so create a new type that
could be used as a completely generic function pointer and cast through
it instead.
Additionaly remove the -Wno-incompatible-pointer-types temporary
flag added in 27e0c3c (win32: allow building with pedantic mode
enabled, 2021-09-03), as it will be no longer needed.
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Here, GCC warns about every use of the INIT_PROC_ADDR macro, for example:
In file included from compat/mingw.c:8:
compat/mingw.c: In function 'mingw_strftime':
compat/win32/lazyload.h:38:12: warning: assignment to
'size_t (*)(char *, size_t, const char *, const struct tm *)'
{aka 'long long unsigned int (*)(char *, long long unsigned int,
const char *, const struct tm *)'} from incompatible pointer type
'FARPROC' {aka 'long long int (*)()'} [-Wincompatible-pointer-types]
38 | (function = get_proc_addr(&proc_addr_##function))
| ^
compat/mingw.c:1014:6: note: in expansion of macro 'INIT_PROC_ADDR'
1014 | if (INIT_PROC_ADDR(strftime))
| ^~~~~~~~~~~~~~
(message wrapped for convenience). Insert a cast to keep the compiler
happy. A cast is fine in these cases because they are generic function
pointer values that have been looked up in a DLL.
Helped-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change various places that hardcode the names of these two files to
refer to either $(GENERATED_H), or to a new generated-hdrs
target. That target is consistent with the *-objs targets I recently
added in 029bac01a8 (Makefile: add {program,xdiff,test,git,fuzz}-objs
& objects targets, 2021-02-23).
A subsequent commit will add a new generated hook-list.h. By doing
this refactoring we'll only need to add the new file to the
GENERATED_H variable, not EXCEPT_HDRS, the vcbuild/README etc.
Hardcoding command-list.h there seems to have been a case of
copy/paste programming in 976aaedca0 (msvc: add a Makefile target to
pre-generate the Visual Studio solution, 2019-07-29). The
config-list.h was added later in 709df95b78 (help: move
list_config_help to builtin/help, 2020-04-16).
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Update the build procedure to use the "-pedantic" build when
DEVELOPER makefile macro is in effect.
* cb/pedantic-build-for-developers:
developer: enable pedantic by default
win32: allow building with pedantic mode enabled
gettext: remove optional non-standard parens in N_() definition
The tracing of process ancestry information has been enhanced.
* ab/tr2-leaks-and-fixes:
tr2: log N parent process names on Linux
tr2: do compiler enum check in trace2_collect_process_info()
tr2: leave the parent list empty upon failure & don't leak memory
tr2: stop leaking "thread_name" memory
tr2: clarify TRACE2_PROCESS_INFO_EXIT comment under Linux
tr2: remove NEEDSWORK comment for "non-procfs" implementations
Set an ACL on the named pipe to allow the well-known group EVERYONE
to read and write to the IPC server's named pipe. In the event that
the daemon was started with elevation, allow non-elevated clients
to communicate with the daemon.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Create "ipc-debug" category events to log unexpected errors
when creating Simple-IPC connections.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add `command_len` argument to the Simple IPC API.
In my original Simple IPC API, I assumed that the request would always
be a null-terminated string of text characters. The `command`
argument was just a `const char *`.
I found a caller that would like to pass a binary command to the
daemon, so I am amending the Simple IPC API to receive `const char
*command, size_t command_len` arguments.
I considered changing the `command` argument to be a `void *`, but the
IPC layer simply passes it to the pkt-line layer which takes a `const
char *`, so to avoid confusion I left it as is.
Note, the response side has always been a `struct strbuf` which
includes the buffer and length, so we already support returning a
binary answer. (Yes, it feels a little weird returning a binary
buffer in a `strbuf`, but it works.)
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
mmap() imitation used to call xmalloc() that dies upon malloc()
failure, which has been corrected to just return an error to the
caller to be handled.
* rs/git-mmap-uses-malloc:
compat: let git_mmap use malloc(3) directly
In 2f732bf15e (tr2: log parent process name, 2021-07-21) we started
logging parent process names, but only logged all parents on Windows.
on Linux only the name of the immediate parent process was logged.
Extend the functionality added there to also log full parent chain on
Linux.
This requires us to lookup "/proc/<getppid()>/stat" instead of
"/proc/<getppid()>/comm". The "comm" file just contains the name of the
process, but the "stat" file has both that information, and the parent
PID of that process, see procfs(5). We parse out the parent PID of our
own parent, and recursively walk the chain of "/proc/*/stat" files all
the way up the chain. A parent PID of 0 indicates the end of the
chain.
It's possible given the semantics of Linux's PID files that we end up
getting an entirely nonsensical chain of processes. It could happen if
e.g. we have a chain of processes like:
1 (init) => 321 (bash) => 123 (git)
Let's assume that "bash" was started a while ago, and that as shown
the OS has already cycled back to using a lower PID for us than our
parent process. In the time it takes us to start up and get to
trace2_collect_process_info(TRACE2_PROCESS_INFO_STARTUP) our parent
process might exit, and be replaced by an entirely different process!
We'd racily look up our own getppid(), but in the meantime our parent
would exit, and Linux would have cycled all the way back to starting
an entirely unrelated process as PID 321.
If that happens we'll just silently log incorrect data in our ancestry
chain. Luckily we don't need to worry about this except in this
specific cycling scenario, as Linux does not have PID
randomization. It appears it once did through a third-party feature,
but that it was removed around 2006[1]. For anyone worried about this
edge case raising PID_MAX via "/proc/sys/kernel/pid_max" will mitigate
it, but not eliminate it.
One thing we don't need to worry about is getting into an infinite
loop when walking "/proc/*/stat". See 353d3d77f4 (trace2: collect
Windows-specific process information, 2019-02-22) for the related
Windows code that needs to deal with that, and [2] for an explanation
of that edge case.
Aside from potential race conditions it's also a bit painful to
correctly parse the process name out of "/proc/*/stat". A simpler
approach is to use fscanf(), see [3] for an implementation of that,
but as noted in the comment being added here it would fail in the face
of some weird process names, so we need our own parse_proc_stat() to
parse it out.
With this patch the "ancestry" chain for a trace2 event might look
like this:
$ GIT_TRACE2_EVENT=/dev/stdout ~/g/git/git version | grep ancestry | jq -r .ancestry
[
"bash",
"screen",
"systemd"
]
And in the case of naughty process names like the following. This uses
perl's ability to use prctl(PR_SET_NAME, ...). See
Perl/perl5@7636ea95c5 (Set the legacy process name with prctl() on
assignment to $0 on Linux, 2010-04-15)[4]:
$ perl -e '$0 = "(naughty\nname)"; system "GIT_TRACE2_EVENT=/dev/stdout ~/g/git/git version"' | grep ancestry | jq -r .ancestry
[
"sh",
"(naughty\nname)",
"bash",
"screen",
"systemd"
]
1. https://grsecurity.net/news#grsec2110
2. https://lore.kernel.org/git/48a62d5e-28e2-7103-a5bb-5db7e197a4b9@jeffhostetler.com/
3. https://lore.kernel.org/git/87o8agp29o.fsf@evledraar.gmail.com/
4. 7636ea95c5
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change code added in 2f732bf15e (tr2: log parent process name,
2021-07-21) to use a switch statement without a "default" branch to
have the compiler error if this code ever drifts out of sync with the
members of the "enum trace2_process_info_reason".
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
