From 0995ecadaff56d2ff44c965763800ec892490bad Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Matthias=20A=C3=9Fhauer?= Date: Sat, 4 Jan 2025 19:27:47 +0100 Subject: [PATCH 1/4] mingw_open_existing: handle directories better MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit CreateFileW() requires FILE_FLAG_BACKUP_SEMANTICS to create a directory handle [1] and errors out with ERROR_ACCESS_DENIED without this flag. Fall back to accessing Directory handles this way. [1] https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilew#directories This fixes https://github.com/git-for-windows/git/issues/5068 Signed-off-by: Matthias Aßhauer --- compat/mingw.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index 5d69ae32f4b946..2dd5cbcaee0d5a 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -588,13 +588,24 @@ static int mingw_open_existing(const wchar_t *filename, int oflags, ...) &security_attributes, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL); if (handle == INVALID_HANDLE_VALUE) { DWORD err = GetLastError(); + if (err == ERROR_ACCESS_DENIED) { + DWORD attrs = GetFileAttributesW(filename); + if (attrs != INVALID_FILE_ATTRIBUTES && (attrs & FILE_ATTRIBUTE_DIRECTORY)) + handle = CreateFileW(filename, access, + FILE_SHARE_WRITE | FILE_SHARE_READ | FILE_SHARE_DELETE, + &security_attributes, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL| FILE_FLAG_BACKUP_SEMANTICS, NULL); + } - /* See `mingw_open_append()` for why we have this conversion. */ - if (err == ERROR_INVALID_PARAMETER) - err = ERROR_PATH_NOT_FOUND; + if (handle == INVALID_HANDLE_VALUE) { + err = GetLastError(); - errno = err_win_to_posix(err); - return -1; + /* See `mingw_open_append()` for why we have this conversion. */ + if (err == ERROR_INVALID_PARAMETER) + err = ERROR_PATH_NOT_FOUND; + + errno = err_win_to_posix(err); + return -1; + } } fd = _open_osfhandle((intptr_t)handle, oflags | O_BINARY); From 6b4f062d82a80d82eb927cda7304d053b2984aba Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Tue, 4 Mar 2025 11:51:35 +0100 Subject: [PATCH 2/4] mingw: drop Windows 7-specific work-around In ac33519ddfa8 (mingw: restrict file handle inheritance only on Windows 7 and later, 2019-11-22), I introduced code to safe-guard the defense-in-depth handling that restricts handles' inheritance so that it would work with Windows 7, too. Let's revert this patch: Git for Windows dropped supporting Windows 7 (and Windows 8) directly after Git for Windows v2.46.2. For full details, see https://gitforwindows.org/requirements#windows-version. Actually, on second thought: revert only the part that makes this handle inheritance restriction logic optional and that suggests to open a bug report if it fails, but keep the fall-back to try again without said logic: There have been a few false positives over the past few years (where the warning was triggered e.g. because Defender was still accessing a file that Git wanted to overwrite), and the fall-back logic seems to have helped occasionally in such situations. Signed-off-by: Johannes Schindelin --- Documentation/config/core.adoc | 6 --- compat/mingw.c | 68 ++-------------------------------- 2 files changed, 4 insertions(+), 70 deletions(-) diff --git a/Documentation/config/core.adoc b/Documentation/config/core.adoc index 9fde1ab63a70ea..3fbe83eef1612c 100644 --- a/Documentation/config/core.adoc +++ b/Documentation/config/core.adoc @@ -696,12 +696,6 @@ core.unsetenvvars:: Defaults to `PERL5LIB` to account for the fact that Git for Windows insists on using its own Perl interpreter. -core.restrictinheritedhandles:: - Windows-only: override whether spawned processes inherit only standard - file handles (`stdin`, `stdout` and `stderr`) or all handles. Can be - `auto`, `true` or `false`. Defaults to `auto`, which means `true` on - Windows 7 and later, and `false` on older Windows versions. - core.createObject:: You can set this to 'link', in which case a hardlink followed by a delete of the source are used to make sure that object creation diff --git a/compat/mingw.c b/compat/mingw.c index 2dd5cbcaee0d5a..c331c3ac32a8f9 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -244,7 +244,6 @@ enum hide_dotfiles_type { HIDE_DOTFILES_DOTGITONLY }; -static int core_restrict_inherited_handles = -1; static enum hide_dotfiles_type hide_dotfiles = HIDE_DOTFILES_DOTGITONLY; static char *unset_environment_variables; @@ -268,15 +267,6 @@ int mingw_core_config(const char *var, const char *value, return 0; } - if (!strcmp(var, "core.restrictinheritedhandles")) { - if (value && !strcasecmp(value, "auto")) - core_restrict_inherited_handles = -1; - else - core_restrict_inherited_handles = - git_config_bool(var, value); - return 0; - } - return 0; } @@ -1667,7 +1657,6 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **deltaen const char *dir, int prepend_cmd, int fhin, int fhout, int fherr) { - static int restrict_handle_inheritance = -1; STARTUPINFOEXW si; PROCESS_INFORMATION pi; LPPROC_THREAD_ATTRIBUTE_LIST attr_list = NULL; @@ -1687,16 +1676,6 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **deltaen /* Make sure to override previous errors, if any */ errno = 0; - if (restrict_handle_inheritance < 0) - restrict_handle_inheritance = core_restrict_inherited_handles; - /* - * The following code to restrict which handles are inherited seems - * to work properly only on Windows 7 and later, so let's disable it - * on Windows Vista and 2008. - */ - if (restrict_handle_inheritance < 0) - restrict_handle_inheritance = GetVersion() >> 16 >= 7601; - do_unset_environment_variables(); /* Determine whether or not we are associated to a console */ @@ -1798,7 +1777,7 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **deltaen wenvblk = make_environment_block(deltaenv); memset(&pi, 0, sizeof(pi)); - if (restrict_handle_inheritance && stdhandles_count && + if (stdhandles_count && (InitializeProcThreadAttributeList(NULL, 1, 0, &size) || GetLastError() == ERROR_INSUFFICIENT_BUFFER) && (attr_list = (LPPROC_THREAD_ATTRIBUTE_LIST) @@ -1819,52 +1798,13 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **deltaen &si.StartupInfo, &pi); /* - * On Windows 2008 R2, it seems that specifying certain types of handles - * (such as FILE_TYPE_CHAR or FILE_TYPE_PIPE) will always produce an - * error. Rather than playing finicky and fragile games, let's just try - * to detect this situation and simply try again without restricting any - * handle inheritance. This is still better than failing to create - * processes. + * On the off-chance that something with the file handle restriction + * went wrong, silently fall back to trying without it. */ - if (!ret && restrict_handle_inheritance && stdhandles_count) { + if (!ret && stdhandles_count) { DWORD err = GetLastError(); struct strbuf buf = STRBUF_INIT; - if (err != ERROR_NO_SYSTEM_RESOURCES && - /* - * On Windows 7 and earlier, handles on pipes and character - * devices are inherited automatically, and cannot be - * specified in the thread handle list. Rather than trying - * to catch each and every corner case (and running the - * chance of *still* forgetting a few), let's just fall - * back to creating the process without trying to limit the - * handle inheritance. - */ - !(err == ERROR_INVALID_PARAMETER && - GetVersion() >> 16 < 9200) && - !getenv("SUPPRESS_HANDLE_INHERITANCE_WARNING")) { - DWORD fl = 0; - int i; - - setenv("SUPPRESS_HANDLE_INHERITANCE_WARNING", "1", 1); - - for (i = 0; i < stdhandles_count; i++) { - HANDLE h = stdhandles[i]; - strbuf_addf(&buf, "handle #%d: %p (type %lx, " - "handle info (%d) %lx\n", i, h, - GetFileType(h), - GetHandleInformation(h, &fl), - fl); - } - strbuf_addstr(&buf, "\nThis is a bug; please report it " - "at\nhttps://github.com/git-for-windows/" - "git/issues/new\n\n" - "To suppress this warning, please set " - "the environment variable\n\n" - "\tSUPPRESS_HANDLE_INHERITANCE_WARNING=1" - "\n"); - } - restrict_handle_inheritance = 0; flags &= ~EXTENDED_STARTUPINFO_PRESENT; ret = CreateProcessW(*wcmd ? wcmd : NULL, wargs, NULL, NULL, TRUE, flags, wenvblk, dir ? wdir : NULL, From 768a84c8c6ec063717d4a935b86d8110ba0a00c6 Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Wed, 26 Mar 2025 09:01:33 +0100 Subject: [PATCH 3/4] mingw_rename: support ReFS on Windows 2022 ReFS is an alternative filesystem to NTFS. On Windows 2022, it seems not to support the rename operation using POSIX semantics that Git uses on Windows as of 391bceae4350 (compat/mingw: support POSIX semantics for atomic renames, 2024-10-27). However, Windows 2022 reports `ERROR_NOT_SUPPORTED` in this instance. This is in contrast to `ERROR_INVALID_PARAMETER` (as previous Windows versions would report that do not support POSIX semantics in renames at all). Let's handle both errors the same: by falling back to the best-effort option, namely to rename without POSIX semantics. This fixes https://github.com/git-for-windows/git/issues/5427 Signed-off-by: Johannes Schindelin --- compat/mingw.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/compat/mingw.c b/compat/mingw.c index c331c3ac32a8f9..d53ce38b7f829b 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -2277,7 +2277,7 @@ int mingw_rename(const char *pold, const char *pnew) * current system doesn't support FileRenameInfoEx. Keep us * from using it in future calls and retry. */ - if (gle == ERROR_INVALID_PARAMETER) { + if (gle == ERROR_INVALID_PARAMETER || gle == ERROR_NOT_SUPPORTED) { supports_file_rename_info_ex = 0; goto repeat; } From 51113ab9b81555387d5c4083b3c0ec3b0c2d2596 Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Mon, 30 Jun 2025 11:26:00 +0200 Subject: [PATCH 4/4] mingw: support Windows Server 2016 again It was reported to the Git for Windows project that a simple `git init` fails on Windows Server 2016: D:\Dev\test> git init error: could not write config file D:/Dev/test/.git/config: Function not implemented fatal: could not set 'core.repositoryformatversion' to '0' According to https://endoflife.date/windows-server, Windows Server 2016 is officially supported for another one-and-a-half years as of time of writing, so this is not good. The culprit is the `mingw_rename()` changes that try to use POSIX semantics when available, but fail to fall back properly on Windows Server 2016. This fixes https://github.com/git-for-windows/git/issues/5695. Signed-off-by: Johannes Schindelin --- compat/mingw.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/compat/mingw.c b/compat/mingw.c index d53ce38b7f829b..8538e3d1729d25 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -2277,7 +2277,9 @@ int mingw_rename(const char *pold, const char *pnew) * current system doesn't support FileRenameInfoEx. Keep us * from using it in future calls and retry. */ - if (gle == ERROR_INVALID_PARAMETER || gle == ERROR_NOT_SUPPORTED) { + if (gle == ERROR_INVALID_PARAMETER || + gle == ERROR_NOT_SUPPORTED || + gle == ERROR_INVALID_FUNCTION) { supports_file_rename_info_ex = 0; goto repeat; }