Before commit 44f73c5a62 ("Cygwin: Fix segfalt when too many command
line args are specified.") we had no actual argument size limit, except
for the fact that the child process created another copy of the argv
array on the stack, which could result in a stack overflow and a
subsequent SEGV. Commit 44f73c5a62 changed that by allocating the
additional argv array via malloc, and it introduced a new SC_ARG_MAX
limit along the lines of the typical Linux limit.
However, this new limit is artificial. Cygwin allocates all argument
and environment data on the cygheap. We only run out of ARG_MAX space
if we're out of memory resources.
Change argument size handling accordingly:
- Drop the args size check from child_info_spawn::worker.
- Return -1 from sysconf (SC_ARG_MAX), i. e., the argument size limit
is undefined.
- Change argv handling in class av, so that a failing cmalloc is not
fatal. This allows the parent process to return E2BIG if it's out
of cygheap resources.
- In the child, add a check around the new malloc call, so that it
doesn't result in a SEGV if the child process gets unexpectedly into
an ENOMEM situation at this point. In this (unlikely) case, proceed
with the original __argv array instead. Add comment to explain why.
Fixes: 44f73c5a62 ("Cygwin: Fix segfalt when too many command line args are specified.")
Tested-by: Takashi Yano <takashi.yano@nifty.ne.jp>
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Bump GPLv2+ to GPLv3+ for some files, clarify BSD 2-clause.
Everything else stays under GPLv3+.
New Linking Exception exempts resulting executables from LGPLv3 section 4.
Add CONTRIBUTORS file to keep track of licensing.
Remove 'Copyright Red Hat Inc' comments.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
* kernel32.cc: Add includes needed for GetCommandLine functions.
(ucmd): New function.
(cygwin_GetCommandLineW): Ditto.
(cygwin_GetCommandLineA): Ditto.
* spawn.cc (child_info_spawn::worker): Rename one_line -> cmd. Use lb_wcs
macro to generate a wide character version of the line buffer. Remove
duplicate printing of command line. Don't access members of linebuf directly.
* winf.h: Use pragma once.
(linebuf): Make storage private.
(linebuf::operator size_t): New operator. Return size of buf.
(linebuf::operator wchar_t): New operator.
(linebuf::wcs): New function.
(lb_wcs): New macro.
* include/cygwin/version.h: Bump API minor number to 268.
* strfuncs.cc: Clarify descriptive file comment.
* fhandler_fifo.cc (fhandler_fifo::open): Rework to cause errno to be set to
ENXIO when opening a fifo write/nonblocking.
* environ.cc (ucreqenv): Rename to ucenv. Move code from old ucenv here and
conditionalize it on create_upcaseenv.
(ucenv): Delete.
(environ_init): Fix compiler warning by moving create_upcaseenv test to ucenv.
Don't bother checking for child_proc_info when calling ucenv since it is
assumed to be NULL at the point where the function is called.
* path.cc (symlink_worker): Turn off MS-DOS path warnings when dealing with
devices since the device handler passes in a translated MS-DOS path.
* sec_auth.cc (lsaprivkeyauth): Avoid variable initialization which causes a
compiler error.
* fhandler_netdrive.cc: Update copyright.
Corinna Vinschen
Christopher Faylor