Always use the internal "use_weak" random seed when initializing
the "mimalloc" heap when statically linked on Windows.
The imported "mimalloc" routines support several random sources
to seed the heap data structures, including BCrypt.dll and
RtlGenRandom. Crashes have been reported when using BCrypt.dll
if it initialized during an `atexit()` handler function. Granted,
such DLL initialization should not happen in an atexit handler,
but yet the crashes remain.
It should be noted that on Windows when statically linked, the
mimalloc startup code (called by the GCC CRT to initialize static
data prior to calling `main()`) always uses the internal "weak"
random seed. "mimalloc" does not try to load an alternate
random source until after the OS initialization has completed.
Heap data is stored in `__declspec(thread)` TLS data and in theory
each Git thread will have its own heap data. However, testing
shows that the "mimalloc" library doesn't actually call
`os_random_buf()` (to load a new random source) when creating these
new per-thread heap structures.
However, if an atexit handler is forced to run on a non-main
thread, the "mimalloc" library *WILL* try to create a new heap
and seed it with `os_random_buf()`. (The reason for this is still
a mystery to this author.) The `os_random_buf()` call can cause
the (previously uninitialized BCrypt.dll library) to be dynamically
loaded and a call made into it. Crashes have been reported in
v2.40.1.vfs.0.0 while in this call.
As a workaround, the fix here forces the use of the internal
"use_weak" random code for the subsequent `os_random_buf()` calls.
Since we have been using that random generator for the majority
of the program, it seems safe to use it for the final few mallocs
in the atexit handler (of which there really shouldn't be that many.
Signed-off-by: Jeff Hostetler <jeffhostetler@github.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
By defining `USE_MIMALLOC`, Git can now be compiled with that
nicely-fast and small allocator.
Note that we have to disable a couple `DEVELOPER` options to build
mimalloc's source code, as it makes heavy use of declarations after
statements, among other things that disagree with Git's conventions.
We even have to silence some GCC warnings in non-DEVELOPER mode. For
example, the `-Wno-array-bounds` flag is needed because in `-O2` builds,
trying to call `NtCurrentTeb()` (which `_mi_thread_id()` does on
Windows) causes the bogus warning about a system header, likely related
to https://sourceforge.net/p/mingw-w64/mailman/message/37674519/ and to
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99578:
C:/git-sdk-64-minimal/mingw64/include/psdk_inc/intrin-impl.h:838:1:
error: array subscript 0 is outside array bounds of 'long long unsigned int[0]' [-Werror=array-bounds]
838 | __buildreadseg(__readgsqword, unsigned __int64, "gs", "q")
| ^~~~~~~~~~~~~~
Also: The `mimalloc` library uses C11-style atomics, therefore we must
require that standard when compiling with GCC if we want to use
`mimalloc` (instead of requiring "only" C99). This is what we do in the
CMake definition already, therefore this commit does not need to touch
`contrib/buildsystems/`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
We want to compile mimalloc's source code as part of Git, rather than
requiring the code to be built as an external library: mimalloc uses a
CMake-based build, which is not necessarily easy to integrate into the
flavors of Git for Windows (which will be the main benefitting port).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This commit imports mimalloc's source code as per v2.1.2, fetched from
the tag at https://github.com/microsoft/mimalloc.
The .c files are from the src/ subdirectory, and the .h files from the
include/ and include/mimalloc/ subdirectories. We will subsequently
modify the source code to accommodate building within Git's context.
Since we plan on using the `mi_*()` family of functions, we skip the
C++-specific source code, some POSIX compliant functions to interact
with mimalloc, and the code that wants to support auto-magic overriding
of the `malloc()` function (mimalloc-new-delete.h, alloc-posix.c,
mimalloc-override.h, alloc-override.c, alloc-override-osx.c,
alloc-override-win.c and static.c).
To appease the `check-whitespace` job of Git's Continuous Integration,
this commit was washed one time via `git rebase --whitespace=fix`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
We are about to vendor in `mimalloc`'s source code which we will want to
include `git-compat-util.h` after defining that constant.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The mingw-w64 GCC seems to link implicitly to libwinpthread, which does
implement a pthread emulation (that is more complete than Git's). Let's
keep preferring Git's.
To avoid linker errors where it thinks that the `pthread_self` and the
`pthread_create` symbols are defined twice, let's give our version a
`win32_` prefix, just like we already do for `pthread_join()`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
While Git for Windows does not _ship_ Python (in order to save on
bandwidth), MSYS2 provides very fine Python interpreters that users can
easily take advantage of, by using Git for Windows within its SDK.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This topic branch extends the protections introduced for Git GUI's
CVE-2022-41953 to cover `gitk`, too.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Just like CVE-2022-41953 for Git GUI, there exists a vulnerability of
`gitk` where it looks for `taskkill.exe` in the current directory before
searching `PATH`.
Note that the many `exec git` calls are unaffected, due to an obscure
quirk in Tcl's `exec` function. Typically, `git.exe` lives next to
`wish.exe` (i.e. the program that is run to execute `gitk` or Git GUI)
in Git for Windows, and that is the saving grace for `git.exe because
`exec` searches the directory where `wish.exe` lives even before the
current directory, according to
https://www.tcl-lang.org/man/tcl/TclCmd/exec.htm#M24:
If a directory name was not specified as part of the application
name, the following directories are automatically searched in
order when attempting to locate the application:
The directory from which the Tcl executable was loaded.
The current directory.
The Windows 32-bit system directory.
The Windows home directory.
The directories listed in the path.
The same is not true, however, for `taskkill.exe`: it lives in the
Windows system directory (never mind the 32-bit, Tcl's documentation is
outdated on that point, it really means `C:\Windows\system32`).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Leakfix.
* rj/add-i-leak-fix:
add: plug a leak on interactive_add
add-patch: plug a leak handling the '/' command
add-interactive: plug a leak in get_untracked_files
apply: plug a leak in apply_data
Demote a BUG() to an die() when the failure from vsnprintf() may
not be due to a programmer error.
* rs/vsnprintf-failure-is-not-a-bug:
don't report vsnprintf(3) error as bug
Originally introduced as `core.useBuiltinFSMonitor` in Git for Windows
and developed, improved and stabilized there, the built-in FSMonitor
only made it into upstream Git (after unnecessarily long hemming and
hawing and throwing overly perfectionist style review sticks into the
spokes) as `core.fsmonitor = true`.
In Git for Windows, with this topic branch, we re-introduce the
now-obsolete config setting, with warnings suggesting to existing users
how to switch to the new config setting, with the intention to
ultimately drop the patch at some stage.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This topic branch re-adds the deprecated --stdin/-z options to `git
reset`. Those patches were overridden by a different set of options in
the upstream Git project before we could propose `--stdin`.
We offered this in MinGit to applications that wanted a safer way to
pass lots of pathspecs to Git, and these applications will need to be
adjusted.
Instead of `--stdin`, `--pathspec-from-file=-` should be used, and
instead of `-z`, `--pathspec-file-nul`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
A fix for calling `vim` in Windows Terminal caused a regression and was
reverted. We partially un-revert this, to get the fix again.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This patch introduces support to set special NTFS attributes that are
interpreted by the Windows Subsystem for Linux as file mode bits, UID
and GID.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
With this patch, Git for Windows works as intended on mounted APFS
volumes (where renaming read-only files would fail).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This is the recommended way on GitHub to describe policies revolving around
security issues and about supported versions.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
