Commit 5a0f2c00aa "Cygwin: fork/exec: fix child process permissions"
removed the PROCESS_DUP_HANDLE handle permission of the parent process
handle in the child to avoid a security problem.
It turned out that this broke the following scenario: If a process forks
and then the parent execs, the child loses the ability to register the
parent's death. To wit, after the parent died the child process does
not set its own PPID to 1 anymore.
The current exec mechanism copies required handle values (handles to
keep contact to the child processes) into the child_info for the
about-to-be-exec'ed process. The exec'ed process is supposed to
duplicate these handles. This fails, given that we don't allow the
exec'ed process PROCESS_DUP_HANDLE access to the exec'ing process since
commit 5a0f2c00aa.
The fix is to avoid the DuplicateHandle calls in the exec'ed process.
This patch sets the affected handles to "inheritable" in the exec'ing
process at exec time. The exec'ed process just copies the handle values
and resets handle inheritance to "non-inheritable". The exec'ing
process doesn't have to reset handle inheritance, it exits after setting
up the exec'ed process anyway.
Testcase: $ ssh-agent /bin/sleep 3
ssh-agent forks and the parent exec's sleep. After sleep exits, `ps'
should show ssh-agent to have PPID 1, and eventually ssh-agent exits.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Call find_exec with the FE_NNF flag to enforce a NULL return when the
executable isn't found in $PATH. Convert NULL to "". This aligns
spawnvp and spawnvpe with execvp and execvpe.
If the directory name has the form 'x:' followed by one or more
slashes or backslashes, and if there's at least one backslash, assume
that the user is referring to 'x:\', the root directory of drive x,
and don't strip the backslash.
Previously all trailing slashes and backslashes were stripped, and the
name was treated as a relative file name containing a literal colon.
Addresses https://cygwin.com/ml/cygwin/2019-08/msg00334.html.
On sigwaitinfo or reading from a signalfd, signal processing sets up
signal handling via sigdelayed even if the handler address is NULL.
This doesn't have any impact on sigwaitinfo scenarios (or at least, I
wasn't able to come up with a reproducer) but it breaks signalfd
scenarios, where eventually a call to call_signal_handler from
sigdelayed will try to call the NULL function.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
This patch supplies an implementation of the CPU_SET(3) processor
affinity macros as documented on the relevant Linux man page.
There is a mostly superset implementation of cpusets under newlib's
libc/sys/RTEMS/include/sys that has Linux and FreeBSD compatibility
and is built on top of FreeBSD bitsets. This Cygwin implementation
and the RTEMS one could be combined if desired at some future point.
The sigpending mechanism failed to check if the pending signal was a
process-wide signal, or a signal for the curent thread. Fix that by
adding a matching conditional to wait_sig's __SIGPENDING code.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Add a function timerfd_tracker::enter_critical_section_cancelable,
which is like enter_critical_section but honors a cancel event. Call
this when a timer expires while the timerfd thread is in its inner
loop. This avoids a deadlock if timerfd_tracker::dtor has entered its
critical section and is trying to cancel the thread. See
https://cygwin.com/ml/cygwin/2019-06/msg00096.html.
This patch set implements the Linux syscalls sched_getaffinity,
sched_setaffinity, pthread_getaffinity_np, and pthread_setaffinity_np.
Linux has a straightforward view of the cpu sets used in affinity masks.
They are simply long (1024-bit) bit masks. This code emulates that view
while internally dealing with Windows' distribution of available CPUs among
processor groups.
libX11 provides <X11/Xlocale.h>. The build of libX11 itself adds
include/X11 to the compiler's include path. This results in a name
collision with /usr/include/xlocale.h on case-insensitive filesystems.
Commit 90e35b1eb3 renamed sys/_locale.h to xlocale.h in March 2017 under
the assumption that we should provide the locale_t type in the same file
as on Linux, FreeBSD, and Darwin.
A few weeks later (June 2017), glibc removed the xlocale.h file in favor
of bits/types/locale_t.h, which shouldn't be included directly anyway.
For reference and the reasoning, see
https://sourceware.org/git/?p=glibc.git;a=commit;h=f0be25b6336d
Given the above, revert 90e35b1eb3 and
fix additional usage of xlocale.h.
commit d1be0a59d4,
"Cygwin: winpids: Fix getting process multiple times"
fixed duplicate processes in ps -W output, but it fixed
the symptom, not the cause. It also didn't fix the problem
that the `ps' process itself may show up twice in its own
output.
This patch fixes it. The spawn worker only deleted the
"winpid.PID" symlink of the current process if the child is
a non-Cygwin process, under the assumption that the exec'ing
process exits anyway. However, the Window in which both
winpid.PID symlinks point to the same cygpid.PID area is just
too long. The spawn worker now also deletes its own winpid.PID
symlink if the exec'ed process is a Cygwin process.
Additionally the fix from d1be0a59d4
is now performed on the calling process, too.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
commit c0d7d3e1a2 removed the usage of the
LCMAP_BYTEREV flag in the call to LCMapStringW to workaround a strange
bug in LCMapStringW. This patch didn't take a userspace call of
wcsxfrm{_l} with NULL buffer and 0 size to evaluate the required buffer
size into account. This introduced a crash trying to byte swap the
NULL buffer. This patch fixes that problem.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
3.0.0 changed uname but missed to align /proc/version
which then used the old uname function on the new uname
struct.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The winpid symlinks got created with no query permissions, so
only admins could see all Cygwin processes. Create symlinks
so everyone has query permissions instead.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Canceling the timer thread runs under lock. The thread uses the same
lock to guard its timer_tracker struct access. If the timing is bad,
timer_settime or timer_delete grab the lock at the same time, the timer
expires. In the end, cancel waits for the thread sync while the thread
waits for ther lock to be released.
Fix this by not waiting for the thread sync under lock.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
On setting the timer, the thread is accidentally only canceled when
disarming the timer. This leaks one thread per timer_settimer call.
Move the thread cancellation where it belongs.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Inspecting the content of case-sensitive directories
on remote machines results in lots of errors like
disappearing diretories and files, file not found, etc.
This is not feasible as default behaviour
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
timerfd_tracker::fixup_after_fork_exec always tries to restore
the shared timer region at the same address as in the parent.
This is entirely unnecessary and wasn't intended, rather some
kind of copy/paste thinko. Fix that. Print NtMapViewOfSection
status code in api_fatal on failure for debugging.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The "optimized" condition to recognize an unarmed timer was plain
wrong. Replace it by checking the stored it_value against 0.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
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>
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>
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>
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>
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>
Mark Geisert
Corinna Vinschen
Ken Brown
Corinna Vinschen
Yaakov Selkowitz
Michael Haubenwallner