diff options
Diffstat (limited to 'winsup/cygwin/path.cc')
| -rw-r--r-- | winsup/cygwin/path.cc | 59 |
1 files changed, 36 insertions, 23 deletions
diff --git a/winsup/cygwin/path.cc b/winsup/cygwin/path.cc index deefc7791..f0cdbee1c 100644 --- a/winsup/cygwin/path.cc +++ b/winsup/cygwin/path.cc @@ -3286,36 +3286,48 @@ cwdstuff::init () int cwdstuff::set (path_conv *nat_cwd, const char *posix_cwd) { + NTSTATUS status; UNICODE_STRING upath; bool virtual_path = false; bool unc_path = false; bool inaccessible_path = false; - /* Here are the problems with using SetCurrentDirectory: + /* Here are the problems with using SetCurrentDirectory. Just skip this + comment if you don't like whining. - SetCurrentDirectory only supports paths of up to MAX_PATH - 1 chars, including a trailing backslash. That's an absolute restriction, even in the UNICODE API. - - SetCurrentDirectory fails for directories with strict - permissions even for processes with the SE_BACKUP_NAME - privilege enabled. The reason is apparently that - SetCurrentDirectory calls NtOpenFile without the + - SetCurrentDirectory fails for directories with strict permissions even + for processes with the SE_BACKUP_NAME privilege enabled. The reason + is apparently that SetCurrentDirectory calls NtOpenFile without the FILE_OPEN_FOR_BACKUP_INTENT flag set. - SetCurrentDirectory does not support case-sensitivity. - - Unlinking a cwd fails because SetCurrentDirectory seems to - open directories so that deleting the directory is disallowed. + - Unlinking a cwd fails because SetCurrentDirectory seems to open + directories so that deleting the directory is disallowed. - SetCurrentDirectory can naturally not work on virtual Cygwin paths like /proc or /cygdrive. - Therefore, we do without SetCurrentDirectory and handle the CWD all - by ourselves. To avoid surprising behaviour in the Win32 API which - would stem from the fact that the Win32 CWD is different from the - POSIX CWD, we move the Win32 CWD to an invalid directory in which - typical relative Win32 path handling fails. */ + Unfortunately, even though we have access to the Win32 process parameter + block, we can't just replace the directory handle. Starting with Vista, + the handle is used elsewhere, and just replacing the handle in the process + parameter block shows quite surprising results. + FIXME: If we ever find a *safe* way to replace the directory handle in + the process parameter block, we're back in business. + + Nevertheless, doing entirely without SetCurrentDirectory is not really + feasible, because it breaks too many mixed applications using the Win32 + API. + + Therefore we handle the CWD all by ourselves and just keep the Win32 + CWD in sync. However, to avoid surprising behaviour in the Win32 API + when we are in a CWD which is inaccessible as Win32 CWD, we set the + Win32 CWD to a "weird" directory in which all relative filesystem-related + calls fail. */ cwd_lock.acquire (); @@ -3332,7 +3344,6 @@ cwdstuff::set (path_conv *nat_cwd, const char *posix_cwd) HANDLE h = NULL; if (!virtual_path) { - NTSTATUS status; IO_STATUS_BLOCK io; OBJECT_ATTRIBUTES attr; @@ -3351,7 +3362,9 @@ cwdstuff::set (path_conv *nat_cwd, const char *posix_cwd) nat_cwd->objcaseinsensitive () | OBJ_INHERIT, NULL, NULL); /* First try without FILE_OPEN_FOR_BACKUP_INTENT, to find out if the - directory is valid for Win32 apps. */ + directory is valid for Win32 apps. And, no, we can't just call + SetCurrentDirectory here, since that would potentially break + case-sensitivity. */ status = NtOpenFile (&h, SYNCHRONIZE | FILE_TRAVERSE, &attr, &io, FILE_SHARE_VALID_FLAGS, FILE_DIRECTORY_FILE @@ -3397,15 +3410,6 @@ cwdstuff::set (path_conv *nat_cwd, const char *posix_cwd) unc_path = true; posix_cwd = NULL; - - /* When inited move the actual Win32 CWD out of the way, as explained - above. Surprisingly, the PIPE filesystem seems to be usable as CWD - on all Windows systems. */ - if (!SetCurrentDirectoryW (L"\\\\?\\PIPE\\")) - system_printf ( -"WARNING: Couldn't set Win32 CWD to //?/PIPE (error %E). This will\n" -"probably not affect normal POSIX path operations. However, please report\n" -"this problem to the mailing list mailto:cygwin@cygwin.com. Thank you."); } else { @@ -3468,6 +3472,15 @@ cwdstuff::set (path_conv *nat_cwd, const char *posix_cwd) else error = 0; } + /* Keep the Win32 CWD in sync. Don't check for error, other than for + strace output. Try to keep overhead low. */ + if (nat_cwd) + { + status = RtlSetCurrentDirectory_U (error ? &ro_u_pipedir : &win32); + if (!NT_SUCCESS (status)) + debug_printf ("RtlSetCurrentDirectory_U(%S) failed, %p", + error ? &ro_u_pipedir : &win32, status); + } /* Eventually, create POSIX path if it's not set on entry. */ tmp_pathbuf tp; |