Commit Graph

8377 Commits

Author SHA1 Message Date
Corinna Vinschen dd415f1a8c Cygwin: sys/mount.h: fix comment
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-19 19:34:40 +01:00
Corinna Vinschen 30782f7de4 Cygwin: s4uauth: convert token to primary token
Up to Vista CreateProcessAsUser only worked with primary tokens,
so convert S4U impersonation token to primary token.  MSDN still
documents it that way, but actually an impersonation token is
sufficient since Windows 7.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-18 21:45:34 +01:00
Corinna Vinschen e53373bbdb Cygwin: re-enable create_token for older systems
Under WOW64 on 64 bit Windows 7, MsV1_0S4ULogon appears to be
unimplemented, probably under Vista as well.  Re-enable
create_token method, to allow basic seteuid on W7 WOW64 and
Vista as well.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-18 21:00:59 +01:00
Corinna Vinschen a96d68c5bd Cygwin: s4uauth: make sure to fetch correct package id
for domain accounts we try KerbS4ULogon first, MsV1_0S4ULogon
second.  But we only fetch the package id for the supporting
authentication package (Kerberos/MsV1_0) once at the start.

Duplicate LsaLookupAuthenticationPackage call and move into the
Kerb/MsV1_0 branches so that it fetches the correct package id
for the method we call next.

Curious enough this worked before.  Apparently both methods
work with the MICROSOFT_KERBEROS_NAME_A package id.  However,
requesting and using the right authentication package id is
the prudent thing to do.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-18 17:59:56 +01:00
Corinna Vinschen 959077ac0a CYgwin: bump API minor for MOUNT_BINARY -> MOUNT_TEXT change
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-18 11:04:38 +01:00
Corinna Vinschen 9883959f08 Revert "Cygwin: passwd/group: allow specifying "." as local computername"
This reverts commit 7c34811440.

This potentially allows to circumvent OpenSSHs user/group name matching,
unless the Admin knows to add every local user twice or to use patterns,
e.g.:

  Match user MACHINE+user,.+user
  Match user *+user

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-18 10:38:08 +01:00
Corinna Vinschen 367c1ae161 Cygwin: mount: define binary mount as default
Commit c1023ee353 changed the way
path_conv::binmode() works.  Rather than returning three states,
O_BINARY, O_TEXT, 0, it only returned 2 states, O_BINARY, O_TEXT.  Since
mounts are only binary if they are explicitely mounted binary by setting
the MOUNT_BINARY flag, textmode is default.

This introduced a new bug.  When inheriting stdio HANDLEs from native
Windows processes, the fhandler and its path_conv are created from a
device struct only.  None of the path or mount flags get set this way.
So the mount flags are 0 and path_conv::binmode() returned 0.

After the path_conv::binmode() change it returned O_TEXT since, as
explained above, the default mount mode is textmode.

Rather than just enforcing binary mode for path_conv's created from
device structs, this patch changes the default mount mode to binary:

Replace MOUNT_BINARY flag with MOUNT_TEXT flag with opposite meaning.
Drop all explicit setting of MOUNT_BINARY.  Drop local set_flags
function, it doesn't add any value.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-18 10:26:53 +01:00
Corinna Vinschen f76c8519ac Cygwin: mount: remove unused method mount_info::set_flags_from_win32_path
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-18 10:23:15 +01:00
Corinna Vinschen 5e6ce1cfb2 Cygwin: utils: kill: revert erroneously removed optind correction
When recognizing a negative pid, optind is off by one.  The
code correcting this has been erroneously removed by commit
8de660271f.  Revert that.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-18 10:22:37 +01:00
Corinna Vinschen 7e671e7578 Cygwin: fork: add PROCESS_VM_OPERATION to child process permissions
...on parent process.  This is required for successful mmap propagation.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-18 10:19:44 +01:00
Corinna Vinschen 7c34811440 Cygwin: passwd/group: allow specifying "." as local computername
Convenience only.  The resulting passwd/group antry is still
fully qualified.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-16 18:36:21 +01:00
Corinna Vinschen 538e7abc36 Cygwin: bump version to 3.0.1
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-16 18:11:16 +01:00
Corinna Vinschen 4e34a39b5c Cygwin: passwd/group: store account name case correct, take 2
The solution from commit  9a3cc77b2a
didn't work for foreign domain accounts.  Rather than calling
LookupAccountSid we now use the info when we fetch it anyway
via LDAP or Net*GetInfo.  Only in case of domain groups we have
to add an LDAP call explicitly.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-13 13:16:15 +01:00
Corinna Vinschen 79c4e95fad Cygwin: ldap.cc: fix formatting
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-13 12:43:25 +01:00
Corinna Vinschen 09bbcf8788 Cygwin: passwd/group: rename get_group_name to get_account_name
The function is the same for user and grou accounts.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-13 12:42:56 +01:00
Corinna Vinschen 507982af79 Cygwin: passwd/group: raise local name buffer size
Make sure a domain+username fits into the local name buffer.
The former buffer size didn't take adding a domain name to
a really_really_long_user_name into account.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-13 12:41:55 +01:00
Corinna Vinschen 9a3cc77b2a Cygwin: passwd/group: store account name case correct
When looking up valid accounts by name, LookupAccountName returns
a SID and a case-correct domain name.  However, the name was input
and LookupAccountName is case-insensitive, so the name is not
necessarily written the same way as in SAM or AD.

Fix that by doing a reverse lookup on the just fetched SID.  This
fetches the account name in the correct case.  Override the
incoming name with the case correct name from LookupAccountSid.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-13 11:13:28 +01:00
Corinna Vinschen 43fa1aafa6 Cygwin: uinfo.cc: fix formatting
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-13 11:10:41 +01:00
Michael Haubenwallner f6be530a23 Cygwin: forkables: update doc, add release notes 2019-02-11 14:28:00 +01:00
Corinna Vinschen 52d91f112e Cygwin: disk device: stop using SetFilePointer
This is a really old and crappy API, as the previous commit shows.
Use NtQueryInformationFile(FilePositionInformation) here instead.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-09 18:41:47 +01:00
Corinna Vinschen 0be0b8f033 Cygwin: execve: fix setting O_APPEND file offset for native child
dtable::set_file_pointers_for_exec is called from
child_info_spawn::worker to move the file position of O_APPEND
files to EOF if the child is a native child.

However, this only works correctly for the first O_APPEND
file descriptor:

- set_file_pointers_for_exec calls SetFilePointer.  The higher
  4 bytes of the desired file offset are given to SetFilePointer
  as pointer to a DWORD value.  On return, SetFilePointer returns
  the higher 4 bytes of the new file position in this DWORD.

- So for the second and subsequent descriptors the higher 4 byte
  of the file position depend on what the actual file position
  of the previous file has been set to:

- If the file is > 2 Gigs, the high offset will not be 0 anymore.

- If the desciptor points to a non-seekable file (i.e., a pipe
  or socket), SetFilePosition returns an error and sets the high
  position to -1.

Fix this by calling SetFilePointerEx instead, which does not
modify the incoming position value.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-09 15:36:02 +01:00
Corinna Vinschen 7816cf3636 Cygwin: change CURR_CHILD_INFO_MAGIC according to previous patch
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-08 17:48:34 +01:00
Corinna Vinschen 88605243a1 Cygwin: fix child getting another pid after spawnve
When calling spawnve, in contrast to execve, the parent has
to create the pid for the child.  With the old technique
this was simply the Windows pid, but now we have to inform
the child about its new pid.

Add a cygpid member to class child_info_spawn.  Set it in
child_info_spawn::worker, just prior to calling CreateProcess
rather than afterwards.  Overwrite cygheap->pid in
child_info_spawn::handle_spawn before calling pinfo::thisproc.
Make sure pinfo::thisproc knows the pid is already set by
setting the handle argument to INVALID_HANDLE_VALUE.

Also set procinfo->dwProcessId to myself_initial.dwProcessId
instead of to myself_initial.pid for clarity.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-08 15:49:47 +01:00
Michael Haubenwallner 3956ddd9bf forkables: hardlink without WRITE_ATTRIBUTES first
When the current process has renamed (to bin) a readonly dll, we get
STATUS_TRANSACTION_NOT_ACTIVE for unknown reason when subsequently
creating the forkable hardlink. A workaround is to open the original
file with FILE_WRITE_ATTRIBUTES access, but that fails with permission
denied for users not owning the original file.

* forkable.cc (dll::create_forkable): Retry hardlink creation using the
original file's handle opened with FILE_WRITE_ATTRIBUTES access when the
first attempt fails with STATUS_TRANSACTION_NOT_ACTIVE.
2019-02-07 15:58:02 +01:00
Michael Haubenwallner 22d68bada3 forkables: inline dll_list::forkables_supported
And LONG fits better for shared_info member forkable_hardlink_support.
2019-02-07 15:58:02 +01:00
Michael Haubenwallner 135577f708 forkables: simplify disabling via shm
* Rename cygwin_shared->prefer_forkable_hardlinks to
  forkable_hardlink_support, with values
  0 for Unknown, 1 for Supported, -1 for Unsupported.
  Upon first dll loaded ever, dll_list::forkable_ntnamesize checks the
  /var/run/cygfork directory to both exist and reside on NTFS, setting
  cygwin_shared->forkable_hardlink_support accordingly.
* Replace enum forkables_needs by bool forkables_created: Set
  to True by request_forkables after creating forkable hardlinks.
2019-02-07 15:58:02 +01:00
Michael Haubenwallner 8bbb3d3a23 forkables: use dynloaded dll's IndexNumber as dirname 2019-02-07 15:58:02 +01:00
Michael Haubenwallner 5a41aa6f4d forkables: Keep hardlinks disabled via shared mem.
To avoid the need for each process to check the filesystem to detect
that hardlink creation is impossible or disabled, cache this fact in
shared memory.  Removing cygfork directory while in use does disable
hardlinks creation.  To (re-)enable hardlinks creation, the cygfork
directory has to exist before the first cygwin process does fork.

	* forkable.cc (dll_list::forkable_ntnamesize): Short cut
	forkables needs to impossible when disabled via shared memory.
	(dll_list::update_forkables_needs): When detecting hardlink
	creation as impossible (not on NTFS) while still (we are the
	first one checking) enabled via shared memory, disable the
	shared memory value.
	(dll_list::request_forkables): Disable the shared memory value
	when hardlinks creation became disabled, that is when the
	cygfork directory was removed.
	* include/cygwin/version.h: Bump CYGWIN_VERSION_SHARED_DATA 6.
	* shared_info.h (struct shared_info): Add member
	prefer_forkable_hardlinks.  Update CURR_SHARED_MAGIC.
	* shared.cc (shared_info::initialize): Initialize
	prefer_forkable_hardlinks to 1 (Yes).
2019-02-07 15:58:02 +01:00
Michael Haubenwallner ece7282f32 forkables: On fork failure, retry with hardlinks.
To support in-cygwin package managers, the fork() implementation must
not rely on .exe and .dll files to stay in their original location, as
the package manager's job is to replace these files.  Instead, when the
first fork try fails, and we have NTFS, we use hardlinks to the original
binaries in /var/run/cygfork/ to create the child process during the
second fork try, along the main.exe.local file to enable the "DotLocal
Dll Redirection" feature for the dlls.

The (probably few) users that need an update-safe fork manually have to
create the /var/run/cygfork/ directory for now, using:
mkdir --mode=a=rwxt /var/run/cygfork

	* child_info.h: Bump CURR_CHILD_INFO_MAGIC.
	(enum child_status): Add _CI_SILENTFAIL flag.
	(struct child_info): Add silentfail setter and getter.
	* winsup.h (child_copy): Add bool silentfail parameter.
	* cygheap.cc: Pass silentfail parameter to child_copy.
	* dcrt0.cc: Ditto.
	* dll_init.h (struct dll): Define public inline method forkedntname.
	(struct dll_list): Declare private method find_by_forkedntname.
	* dll_init.cc (struct dll_list): Implement find_by_forkedntname.
	(dll_list::alloc): Use find_by_forkedntname when in load after fork.
	(dll_list::load_after_fork_impl): Load dlls using dll::forkedntname.
	* fork.cc (frok::parent): Set silentfail child info flag.  Pass
	silentfail parameter to child_copy.  Use forkedntname of
	dlls.main_executable.
	(fork): When first dofork run failed and did not use forkables,
	run dofork again with_forkables set to true.
	(child_copy): Use debug_printf if silentfail is true,
	system_printf otherwise.
2019-02-07 15:58:02 +01:00
Michael Haubenwallner 8ddb1f60c8 forkables: Create forkable hardlinks, yet unused.
In preparation to protect fork() against dll- and exe-updates, create
hardlinks to the main executable and each loaded dll in subdirectories
of /var/run/cygfork/, if that one exists on the NTFS file system.

The directory names consist of the user sid, the main executable's NTFS
IndexNumber, and the most recent LastWriteTime of all involved binaries
(dlls and main executable).  Next to the main.exe hardlink we create the
empty file main.exe.local to enable dll redirection.

The name of the mutex to synchronize hardlink creation/cleanup also is
assembled from these directory names, to allow for synchronized cleanup
of even orphaned hardlink directories.

The hardlink to each dynamically loaded dll goes into another directory,
named using the NTFS IndexNumber of the dll's original directory.

	* Makefile.in (DLL_OFILES): Add forkable.o.
	* dll_init.h (struct dll): Declare member variables fbi, fii,
	forkable_ntname.  Declare methods nominate_forkable,
	create_forkable.
	(struct dll_list): Declare enum forkables_needs.  Declare member
	variables forkables_dirx_size, forkables_dirx_ntname,
	forkables_mutex_name, forkables_mutex.  Declare private methods
	forkable_ntnamesize, prepare_forkables_nomination,
	update_forkables_needs, update_forkables, create_forkables,
	denominate_forkables, close_mutex, try_remove_forkables,
	set_forkables_inheritance, request_forkables.  Declare public
	static methods ntopenfile, read_fii, read_fbi.  Declare public
	methods release_forkables, cleanup_forkables.  Define public
	inline method setup_forkables.
	* dll_init.cc (dll_list::alloc): Allocate memory to hold the
	name of the hardlink in struct dll member forkable_ntname.
	Initialize struct dll members fbi, fii.
	(dll_list::load_after_fork): Call release_forkables method.
	* fork.cc: Rename public fork function to static dofork, add
	with_forkables as bool pointer parameter.  Add new fork function
	calling dofork.  (struct frok): Add bool pointer member
	with_forkables, add as constructor parameter.
	(frok::parent): Call dlls.setup_forkables before CreateProcessW,
	dlls.release_forkables afterwards.
	* pinfo.cc (pinfo::exit): Call dlls.cleanup_forkables.
	* syscalls.cc (_unlink_nt): Rename public unlink_nt function to
	static _unlink_nt, with 'shareable' as additional argument.
	(unlink_nt): New, wrap _unlink_nt for original behaviour.
	(unlink_nt_shareable): New, wrap _unlink_nt to keep a binary
	file still loadable while removing one of its hardlinks.
	* forkable.cc: New file.
	Implement static functions mkdirs, rmdirs, rmdirs_synchronized,
	stat_real_file_once, format_IndexNumber, rootname, sidname,
	exename, lwtimename.  Define static array forkable_nameparts.
	(struct dll): Implement nominate_forkable, create_forkable.
	(struct dll_list): Implement static methods ntopenfile,
	read_fii, read_fbi.  Implement forkable_ntnamesize,
2019-02-07 15:58:02 +01:00
Michael Haubenwallner dac0b6826b dll_list: Track main executable and cygwin1.dll.
Even for the main executable and cygwin1.dll store the file name as full
NT path.  Create the child process using the main executable's file name
converted from the full NT path stored before.

	* dll_init.cc (dll_list::alloc): Search for DLL_SELF type entry
	with module name like for DLL_LINK, use full NT path to search
	for DLL_LOAD type only.  For DLL_SELF type do not indicate
	having a destructor to be called.
	(dll_list::find): Ignore DLL_SELF type entries.
	(dll_list::init): Ditto.  Call track_self method.
	(dll_list::track_self): New.
	(dll_list::load_after_fork): Call track_self method.
	* dll_init.h (enum dll_type): Add DLL_SELF, for the main
	executable and cygwin1.dll.
	(struct dll_list): Declare private method track_self.  Declare
	member variable main_executable.
	* fork.cc (frok::parent): Use ntname from dlls.main_executable
	to create child process, converted to short path using
	dll_list::buffered_shortname.
2019-02-07 15:58:02 +01:00
Michael Haubenwallner 2678c4efe1 dll_list: Store dll file name as full NT path.
Store loaded dll's file name as full NT path.

	* dll_init.h (struct dll): Rename member variable name to ntname.
	(struct dll_list): Declare private static member variable
	nt_max_path_buffer.  Declare public static methods form_ntname,
	form_shortname.  Define public static methods nt_max_path_buf,
	buffered_shortname.
	(dll_list::operator []): Use PCWCHAR rather than const PWCHAR.
	(dll_list::find_by_modname): Ditto.
	* dll_init.cc (in_load_after_fork): Define earlier in file.
	(struct dll_list): Rename member variable name to ntname.
	Define nt_max_path_buffer variable.
	Implement static methods form_ntname, form_shortname.
	(dll_list::operator []): Use PCWCHAR rather than const PWCHAR.
	(dll_list::find_by_modname): Ditto.
	(reserve_at): Ditto.
	(release_at): Ditto.
	(dll_list::alloc): Use nt_max_path_buf method instead of local
	buffer.  Store module file name as full NT path, convert using
	the form_ntname static method.
	(dll_list::load_after_fork): Call load_after_fork_impl only when
	reload_on_fork is set.
	* fork.cc (frok::child): Call dlls.load_after_fork even without
	need to dynamically load dlls.
	(frok::parent): Move syscall_printf into the retry loop.
2019-02-07 15:58:02 +01:00
Corinna Vinschen 9fa22dba55 Cygwin: unlink: allow fallback from POSIX to default method
Trying to delete in-use executables and DLLs using
FILE_DISPOSITION_POSIX_SEMANTICS returns STATUS_CANNOT_DELETE.
Fall back to the former method if that error occurs to allow
unlinking these files.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-06 21:17:35 +01:00
Corinna Vinschen 5628399c84 Cygwin: proc fd: fix handling of pipes, sockets, etc
The symlink target of /proc/PID/fd files pointing to pipes and
sockets are just artificial filenames referencing the object using
some internal number.  The pipe open code expects a path specifying
process pid and the internal number so it access the right process
and pipe.

- Set the posix path of the pipe to the simple pipe name only,
  as it shows up in /proc/PID/fd.  A /proc/self prefix is just
  as wrong as a /dev/fd prefix.

- Revert thinko in fhandler_pipe::open expecting the name as
  /proc/self/fd/...  In fact this should never happen.

- Fix up the path before re-opening the pipe instead.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-05 15:32:08 +01:00
Corinna Vinschen b59f5795e6 Cygwin: proc fd: fix a copy/paste bug calling file_pathconv
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-05 15:20:50 +01:00
Corinna Vinschen 1f6340aa8b Cygwin: proc fd: pass along open mode when reopening file
The reopen code neglected to pass along the requested open
mode correctly.  This may end up reopening the file with
incorrect access mask, or duplicating the wrong pipe handle.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-05 15:20:13 +01:00
Corinna Vinschen 7225a82c1a Cygwin: fork: terminate child process unconditionally in error case
Move TerminateProcess call into cleanup code to make sure child
doesn't linger in some border cases.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-05 12:52:13 +01:00
Michael Haubenwallner fb3e8bd88b fork: remove cygpid.N sharedmem on fork failure
When fork finally fails although both CreateProcess and creating the
"cygpid.N" shared memory section succeeded, we have to release that
shared memory section as well - before releasing the process handle.
Otherways we leave an orphan "cygpid.N" shared memory section, and any
subsequent cygwin process receiving the same PID fails to initialize.

* fork.cc (frok::parent): Call child.allow_remove in cleanup code.
2019-02-05 10:20:16 +01:00
Corinna Vinschen 99cd3df6ec Cygwin: timerfd: drop outdated TODO comment
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-04 21:08:03 +01:00
Corinna Vinschen d5d9aac759 Cygwin: tweak Cygwin PID change release note
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-02 21:13:37 +01:00
Corinna Vinschen 658f939003 Cygwin: kill(1): introduce a -W option
Allow to kill processes using Windows PIDs on the command line.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-02 21:02:00 +01:00
Corinna Vinschen 3a3934252c Cygwin: spawn: create and maintain winpid symlinks
- If the execve'ed process is a non-Cygwin process, we have to
  create the matching winpid symlink and remove the old one
  ourselves.

- If we spawn a child, the winpid symlink has to be maintained
  by the child process, otherwise it disappears if the parent
  process exits.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-02 20:01:41 +01:00
Corinna Vinschen d6cf2b781f Cygwin: pinfo: simplify create_winpid_symlink
The arguments are not used anyway, so drop them.  When called,
procinfo->dwProcessId is already set right, so we don't have
to access myself_initial.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-02 18:11:42 +01:00
Corinna Vinschen 2cd6829619 Cygwin: Makefile.in: Fix previous version info generation fix
Commit 231ad6941f looks good...
as long as you never build Cygwin from scratch.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-02 15:27:29 +01:00
Corinna Vinschen 448cf5aa4b Cygwin: processes: fix handling of native Windows processes
Since commit b5e1003722, native
Windows processes not started by Cygwin processes don't have a
Cygwin PID anymore.  This breaks ps -W and kill -f <WINPID>.

Introduce MAX_PID (65536 for now).

Cygwin processes as well as native Windows processes started
from a Cygwin process get a PID < MAX_PID.  All other native
Windows processes get a faked Cygwin PID >= MAX_PID.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-02 12:23:39 +01:00
Corinna Vinschen 231ad6941f Cygwin: Makefile.in: Fix another dependency problem in version info
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-02 11:13:17 +01:00
Corinna Vinschen b5e1003722 Cygwin: processes: use dedicated Cygwin PID rather than Windows PID
Using the Windows PID as Cygwin PID has a few drawbacks:

- the PIDs on Windows get reused quickly.  Some POSIX applications choke
  on that, so we need extra code to avoid too quick PID reuse.

- The code to avoid PID reuse keeps parent process handles and
  (depending on a build option) child processes open unnecessarily.

- After an execve, the process has a split personality:  Its Windows PID
  is a new PID, while its Cygwin PID is the PID of the execve caller
  process.  This requires to keep two procinfo shared sections open, the
  second just to redirect process info requests to the first, correct
  one.

This patch changes the way Cygwin PIDs are generated:

- Cygwin PIDs are generated independently of the Windows PID, in a way
  expected by POSIX processes.  The PIDs are created incrementally in
  the range between 2 and 65535, round-robin.

- On startup of the first Cygwin process, choose a semi-random start PID
  for the first process in the lower PID range to make the PIDs slightly
  unpredictable.  This may not be necessary but it seems kind of inviting
  to know that the first Cygwin process always starts with PID 2.

- Every process not only creates the shared procinfo section, but also a
  symlink in the NT namespace, symlinking the Windows PID to the Cygwin
  PID.  This drops the need for the extra procinfo section after execve.

- Don't keep other process handles around unnecessarily.

- Simplify the code creating/opening the shared procinfo section and
  make a clear distinction between interfaces getting a Cygwin PID and
  interfaces getting a Windows PID.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-01 20:06:47 +01:00
Corinna Vinschen c0b9f600f9 Cygwin: remove outdated vfork doc
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-01 13:37:28 +01:00
Corinna Vinschen 210bd56aa2 Cygwin: /proc: don't exit prematurely from /proc/PID/status
If a process is just exiting, requesting memory info may fail
with STATUS_PROCESS_IS_TERMINATING.  Right now the code just bails
out if fetching mem info fails.  However, the rest of the info is
still valuable for procps, so just carry on.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-01 13:18:15 +01:00
Corinna Vinschen 351b57527d Cygwin: Add pthread exception handling patch to release notes
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2019-02-01 10:45:27 +01:00