Commit Graph

7510 Commits

Author SHA1 Message Date
Peter Foley 3ba2c39fb2 Add nonnull annotation to posix_memalign.
GCC 6.0+ asserts that the memptr argument to the builtin function
posix_memalign is nonnull.
Add the necessary annotation to the prototype and
remove the now unnecessary check to fix a warning.

newlib/Changelog
newlib/libc/include/stdlib.h: Annotate arg to posix_memalign as
non-null.

winsup/cygwin/ChangeLog
malloc_wrapper.cc (posix_memalign): Remove always true nonnull check.

Signed-off-by: Peter Foley <pefoley2@pefoley.com>
2016-03-21 20:27:16 +01:00
Sebastian Huber 08537d88f6 Move arc4random Cygwin only code to Cygwin
Keep the Newlib arc4random.c identical to the OpenBSD upstream version.

Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>.
2016-03-21 11:12:19 +01:00
Corinna Vinschen 2519f0ef0c srandom: Replace accessing /dev/random by equivalent getentropy call
/dev/random calls getentropy.  So there's no good reason to go out of
our way to open /dev/random just to call getentropy anyway.

	* random.cc (srandomdev): Drop opening /dev/random in favor of
	calling getentropy.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-20 22:29:03 +01:00
Corinna Vinschen 58988463cc Revert "Use high-resolution timebases for select()."
This reverts commit 6e70fd315a.

Revert accidental push
2016-03-20 21:59:47 +01:00
Corinna Vinschen bf0f4baf95 Revert "Debug printfs."
This reverts commit 9f82de59a0.

Revert accidental push
2016-03-20 21:59:43 +01:00
Corinna Vinschen 66dc7d731a Revert "Improve and simplify select()."
This reverts commit 472d0a228c.

Revert accidental push
2016-03-20 21:59:27 +01:00
Corinna Vinschen 1cca343e47 Drop redundant arc4random prototypes from cygwin/stdlib.h
Newlib's default stdlib.h now defines these functions so we can
drop them from the Cygwin-specific header.  Remove the arc4random_stir
and arc4random_uniform prototypes entirely.  They shouldn't be used
by applications anymore.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-20 21:30:58 +01:00
Corinna Vinschen f7f26f65ab Allow machine-dependent arc4 locking
newlib:
	* libc/stdlib/arc4random.h: Remove Cygwin-specific locking code.
	Conditionalize arc4 locking.  Check for _ARC4_LOCK_INIT being
	undefined to fall back to default implementation.

cygwin:
	* include/machine/_arc4random.h: New file.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-20 21:30:08 +01:00
John Hood 472d0a228c Improve and simplify select().
* cygwait.h (cygwait_us) Remove; this reverts previous changes.
	* select.h: Eliminate redundant select_stuff::select_loop state.
	* select.cc (select): Eliminate redundant
	select_stuff::select_loop state.  Eliminate redundant code for
	zero timeout.  Do not return early on early timer return.
	(select_stuff::wait): Eliminate redundant
	select_stuff::select_loop state.
2016-03-20 15:26:32 +01:00
John Hood 9f82de59a0 Debug printfs.
* fhandler.cc (fhandler_base::get_readahead): Add debug code.
	* fhandler_console.cc (fhandler_console::read): Add debug code.
	* select.cc (pselect): Add debug code.
	(peek_console): Add debug code.
2016-03-20 15:26:31 +01:00
John Hood 6e70fd315a Use high-resolution timebases for select().
* cygwait.h: Add cygwait_us() methods.
	* select.h: Change prototype for select_stuff::wait() for larger
	microsecond timeouts.
	* select.cc (pselect): Convert from old cygwin_select().
	Implement microsecond timeouts.
	(cygwin_select): Rewrite as a wrapper on pselect().
	(select): Implement microsecond timeouts.
	(select_stuff::wait): Implement microsecond timeouts with a timer
	object.
2016-03-20 15:26:31 +01:00
John Hood b92b47b7bc Move get_nonascii_key into fhandler_console.
* fhandler.h (fhandler_console): Move get_nonascii_key() from
	select.c into this class.
	* select.cc (peek_console): Move get_nonascii_key() into
	fhandler_console class.
2016-03-20 14:14:27 +01:00
Peter Foley 5bc753c5a2 Fix strict aliasing
Fix a strict aliasing error detected by gcc 6.0+

winsup/cygwin/ChangeLog
* pinfo.cc (winpids::enum_process): Fix strict aliasing.

Signed-off-by: Peter Foley <pefoley2@pefoley.com>
2016-03-20 12:31:42 +01:00
Peter Foley 0611132f04 Fix typoed comparison
winsup/cygwin/ChangeLog
* thread.cc (semaphore::open): Fix mistaken conditional.

Signed-off-by: Peter Foley <pefoley2@pefoley.com>
2016-03-20 12:19:35 +01:00
Peter Foley 1eb7cb2553 The address of an class always evaluates to true
winsup/cygwin/pinfo.cc:465:14: error: the compiler can assume that the
address of 'tc' will always evaluate to 'true' [-Werror=address]

winsup/cygwin/ChangeLog
* pinfo.cc (_pinfo::set_ctty): remove always true check.

Signed-off-by: Peter Foley <pefoley2@pefoley.com>
2016-03-20 12:16:42 +01:00
Peter Foley 2f310e44c4 Remove misleading indentation
* syscalls.cc (getpriority): Fix misleading indentation.

Signed-off-by: Peter Foley <pefoley2@pefoley.com>
2016-03-20 11:58:57 +01:00
Peter Foley dc85a189a4 Add necessary braces to if statements
The missing braces cause only the first expression to be guarded by the
else clause.

winsup/cygwin/ChangeLog
* fhandler_disk_file.cc (facl): Add missing braces to if statement.
* mount.cc (dos_drive_mappings): Add missing braces to if statement.

Signed-off-by: Peter Foley <pefoley2@pefoley.com>
2016-03-20 11:55:08 +01:00
Peter Foley 922e21a3ea Remove dead code from fhandler_console.
This if is unconditionally false, so remove it.

winsup/cygwin/fhandler_console.cc: In member function 'bool dev_console::fillin(HANDLE)':
winsup/cygwin/fhandler_console.cc:740:22: error: self-comparison always evaluates to false [-Werror=tautological-compare]
       if (b.dwSize.Y != b.dwSize.Y || b.dwSize.X != b.dwSize.X)
           ~~~~~~~~~~~^~~~~~~~~~~~~
winsup/cygwin/fhandler_console.cc:740:50: error: self-comparison always evaluates to false [-Werror=tautological-compare]
       if (b.dwSize.Y != b.dwSize.Y || b.dwSize.X != b.dwSize.X)
                                       ~~~~~~~~~~~^~~~~~~~~~~~~

winsup/cygwin/ChangeLog
* fhandle_console.cc (fillin): remove dead code

Signed-off-by: Peter Foley <pefoley2@pefoley.com>
2016-03-20 11:54:49 +01:00
Peter Foley c0b6fc54b1 Remove unused and unsafe call to __builtin_frame_address
initial_sp has been unused since commit fbf23e3 back in 2000.
Keep the value, so as to avoid changing the offset of magic_biscuit.

winsup/cygwin/lib/_cygwin_crt0_common.cc:140:52:
error: calling 'void* __builtin_frame_address(unsigned int)' with a
nonzero argument is unsafe [-Werror=frame-address]
   u->initial_sp = (char *) __builtin_frame_address (1);

winsup/cygwin/ChangeLog
lib/_cygwin_crt0_common.cc (_cygwin_crt0_common): Initialize initial_sp
with nullptr.

Signed-off-by: Peter Foley <pefoley2@pefoley.com>
2016-03-20 11:51:43 +01:00
Corinna Vinschen 3df400dc83 winsup: Move all old CVS Changelogs into CVSChangeLogs.old dir 2016-03-19 13:59:52 +01:00
Corinna Vinschen e42f66d00f Remove ill-advised cygwin_props
Cygwin_props have been invented to allow switching off the unique
installation keys in the first place, supposedly for debugging.
This never really was a good idea, after all we *want* the installations
to be independent and there's no good reason to break that, not even
for debugging purposes.

Other than that, cygwin_props were meant to be used for some other global
settings which never took place.  There's just no good reason to tweak
the DLL binary invisibly where a setting could be done in a file or the
environment.

This patch removes the cygwin_props entirely, including the related
settings in cygcheck.

cygwin:
	* cygprops.h: Remove file.
	* globals.cc (cygwin_props): Remove.
	* cygheap.cc (init_cygheap::init_installation_root): Drop removing
	installation key.

utils:
	* cygcheck.cc: Drop including cygprops.h.  Remove now unused option
	values.
	(unique_object_name_opt): Remove.
	(handle_unique_object_name): Remove function.
	(usage): Remove text for unique-object-names options.
	(longopts): Remove unique-object-names options.
	(main): Drop handling unique-object-names options.

doc:
	* utils.xml (cygcheck): Remove text for unique-object-names options.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-19 13:21:18 +01:00
Corinna Vinschen dcf31cdc99 Implement getentropy for Cygwin
* miscfuncs.cc (getentropy): Move fhandler_dev_random::crypt_gen_random
	here and rename to getentropy.  Fix type and return values to match
	getentropy requirements.
	* miscfuncs.h (getentropy): Add prototype.
	* fhandler.h (fhandler_dev_random::crypt_gen_random): Remove prototype.
	* fhandler_random.cc (fhandler_dev_random::crypt_gen_random): Drop.
	(fhandler_dev_random::write): Use getentropy instead.
	(fhandler_dev_random::read): Ditto.
	* fhandler_socket.cc (fhandler_socket::af_local_set_secret): Ditto.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-18 14:46:20 +01:00
Corinna Vinschen e0fc33322d Delete Cygwin's arc4random in favor of new Newlib implementation
* Makefile.in (DLL_OFILES): Remove arc4random.o.
	* libc/arc4random.c: Remove file.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-18 14:41:33 +01:00
Yaakov Selkowitz 00d2fe1959 Cygwin: define byteswap.h inlines as macros
The bswap_* "functions" are macros in glibc, so they may be tested for
by the preprocessor (e.g. #ifdef bswap_16).

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:09:23 -05:00
Yaakov Selkowitz 3237fb31b3 Feature test macros overhaul: Cygwin headers
Use proper internal macros for BSD and GNU.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:09:22 -05:00
Yaakov Selkowitz 43e5ee83fe Feature test macros overhaul: time.h
Throughout, replace __STRICT_ANSI__ with the proper internal macros.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:09:10 -05:00
Yaakov Selkowitz 84ba25226c Feature test macros overhaul: stdlib.h
Throughout, simplify the C99/C11 conditionals, and replace
__STRICT_ANSI__ with the proper internal POSIX macros.  The _*_r
reentrant functions need not be guarded (and most haven't been) because
such names in the global scope are reserved to the implementation.

atoff is unique to newlib.

dtoa is not actually exported (_dtoa_r is used internally), is
nonstandard, and the declaration conflicts with the code included in
MySQL, NSPR, and SpiderMonkey.

mktemp was removed in POSIX.1-2001.

The qsort_r declarations are reordered so that the GNU version retains
precedence.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:09:06 -05:00
Yaakov Selkowitz 86a724b8c0 Feature test macros overhaul: limits.h
Simplify the C99 conditional, and use the internal macro for GNU extensions.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:08:57 -05:00
Yaakov Selkowitz d94d983d1b Feature test macros overhaul: fnmatch.h
Use the proper internal macro for GNU extensions.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:08:54 -05:00
Yaakov Selkowitz d2937299fa Feature test macros overhaul: dirent.h
MAXNAMLEN is a BSDism.

Use the proper internal macros instead of !_POSIX_SOURCE.  telldir and
seekdir are XSI, scandir and alphasort are POSIX.1-2008, and scandirat
is GNU.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:08:51 -05:00
Corinna Vinschen 446d0d355f add release message for commit 4c9bb3e
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-17 17:58:43 +01:00
Corinna Vinschen 4c9bb3e0f9 Propagate correct Windows error if executable can't be opened
* spawn.cc (av::setup): Set last Win32 error if NtOpenFile fails.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-17 17:46:11 +01:00
Thomas Wolff aa2d448093 Add release message for commit 7346568 2016-03-17 08:59:17 +01:00
Thomas Wolff 734656818a Make requested console reports work
cf https://cygwin.com/ml/cygwin-patches/2012-q3/msg00019.html

This enables the following ESC sequences:
ESC[c sends primary device attributes
ESC[>c sends secondary device attributes
ESC[6n sends cursor position report

    * fhandler.h (class dev_console): Add console read-ahead buffer.
    (class fhandler_console): Add peek function for it (for select).
    * fhandler_console.cc (fhandler_console::setup): Init buffer.
    (fhandler_console::read): Check console read-aheader buffer.
    (fhandler_console::char_command): Put responses to terminal
    requests (device status and cursor position reports) into
    common console buffer (shared between CONOUT/CONIN)
    instead of fhandler buffer (separated).
    * select.cc (peek_console): Check console read-ahead buffer.
2016-03-16 10:25:34 +01:00
Corinna Vinschen 7176a85cd4 cygwin_getaddrinfo: workaround Winsock getaddrinfo issue with broken DNS
Add experimental code to workaround the issue described in the thread
starting at

  https://cygwin.com/ml/cygwin/2015-07/msg00350.html

There's a hint in https://communities.vmware.com/message/2577858#2577858
that this problem is related to using the AI_ALL flag.

This patch checks if GetAddrInfoW returned with WSANO_RECOVERY and if
the AI_ALL flag was set, it retries GetAddrInfo without the AI_ALL flag.

	* net.cc (cygwin_getaddrinfo): Add experimental code to retry
	GetAddrInfoW without AI_ALL flag if it returned with WSANO_RECOVERY.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-14 17:57:22 +01:00
Corinna Vinschen f75114fc59 Don't write NULL SID ACE if it's not necessary.
If the ACL is supposed to reflect only standard POSIX permissions,
and if the permissions are so that user has more perms than group
and group has more perms than other, we don't really need the NULL
SID ACE.  If the permissions are that simple, get_posix_access will
not call AuthZ.

	* sec_acl.cc (set_posix_perms): Don't write NULL SID ACE if it's
	not required.  Explain why.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-13 16:02:55 +01:00
Corinna Vinschen ddc91e5b2b Update Cygwin release message text with latest bugfixes.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-13 00:20:39 +01:00
Corinna Vinschen fcd8a0d4f4 Fix typo which might break permission evaluation
* sec_acl.cc (get_posix_access): Fix a typo checking for a_id
	rather than a_type.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-12 17:57:34 +01:00
Corinna Vinschen fc180edcf4 Fix reading/writing Samba ACLs using RFC2307 mapping
When using RFC2307 uid/gid-mapping on Samba shares, the POSIX ACL contains
the Windows SIDs.  When writing back such an ACL we have to map the
Windows SIDs back to the corresponding Samba SIDs representing the UNIX
uid/gid value.  When reading Samba SIDs, make sure never to evaluate a
UNIX user account as group.

	* sec_acl.cc (set_posix_access): Convert Windows SIDs to
	RFC2307-mapped Sambe UNIX SIDs.
	* sec_helper.cc (cygpsid::get_id): Skip UNIX user accounts when
	trying to evaluate a SID as group.  Skip UNIX group accounts when
	trying to evaluate a SID as user.
	* cygheap.h (cygheap_ugid_cache::reverse_get): New method to
	get nfs id from cygwin id.
	(cygheap_ugid_cache::reverse_get_uid): Wrapper for uids.
	(cygheap_ugid_cache::reverse_get_gid): Wrapper for gids.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-12 17:56:21 +01:00
Corinna Vinschen 018fa93e2b Add cygsid methods to create SIDs from scratch
So far creating cygsids requires to generate an "S-1-..." string
which is then converted to a SID by cygsid::getfromstr.

Add two new methods:

- cygsid::create (DWORD auth, DWORD subauth_count, ...)

    ... is a variable length list of subauth_count DWORD values being
    the actual subauths.

- cygsid::append (DWORD rid)

    allows to append a single RID to an alreaday constituted SID.

	* security.h (cygsid::create): Declare public.
	(cygsid::append): Ditto.
	* sec_helper.cc (cygsid::create): Implement.
	(cygsid::append): Implement.
	* uinfo.cc (pwdgrp::fetch_account_from_windows): Use both new
	methods as appropriate.  Drop setting csid from string.  Create
	SID strings for printing SIDs only.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-12 16:39:19 +01:00
Corinna Vinschen 5b972d5b29 gmon.h: Fix type of gmonparam state member
gmonparam::state is used in calls to Win32 Interlocked functions.
Having this defined as int breaks the build on i686.  Redefine as
LONG (same size and correct type on all platforms) to make gcc happy.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-11 22:50:24 +01:00
Václav Haisman b5476c81d2 Spinlock spin with pause instruction
Hi.

I have noticed that Cygwin's spinlock goes into heavy sleeping code
for each spin. It seems it would be a good idea to actually try to
spin a bit first. There is this 'pause' instruction which let's the
CPU make such busy loops be less busy. Here is a patch to do this.

--
VH
2016-03-11 14:01:25 +01:00
Corinna Vinschen bf81f082cd Add release message for commit 8b1ede3ce1
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-10 20:48:04 +01:00
Corinna Vinschen 60fd26a4df Add release message for commit 5807ba83e4
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-10 20:42:42 +01:00
Mark Geisert 5807ba83e4 Support profiling of multi-threaded apps.
This patch set modifies Cygwin's profiling support to sample PC values
of all an app's threads, not just the main thread. There is no change
to how profiling is requested: just compile and link the app with "-pg"
as usual. The profiling info is dumped into file gmon.out as always.

A new facility enabled via the environment variable GMON_OUT_PREFIX.
This facility is intended to match an undocumented Linux glibc feature.
Exporting the variable with a non-empty value such as "foo" causes the
profiling info to go to a file named foo.$pid instead of the default.
With that, both resulting processes of a fork() can have their profiling
data captured in separate files. gprof already knows how to accumulate
data from multiple files if they all pertain to the same app.

There is no change to the normal Cygwin execution paths if profiling is
not enabled. And when it is enabled, only the one profiling thread per
profiled app is doing more work than it used to.

	* include/sys/cygwin.h: Add CW_CYGHEAP_PROFTHR_ALL.
	* cygheap.cc (cygheap_profthr_all): New C-callable function that
	runs cygheap's threadlist handing each pthread's thread handle in
	turn to profthr_byhandle().
	* external.cc (cygwin_internal): Add case CW_CYGHEAP_PROFTHR_ALL.
	* gmon.c (_mcleanup): Add support for multiple simultaneous
	gmon.out* files named via environment variable GMON_OUT_PREFIX.
	* gmon.h (struct gmonparam): Make state decl volatile.
	* mcount.c (_MCOUNT_DECL): Change stores into gmonparam.state to use
	Interlocked operations. Add #include "winsup.h", update commentary.
	* profil.c (profthr_byhandle): New function abstracting out the
	updating of profile counters based on a thread handle.
	(profthr_func): Update to call profthr_byhandle() to sample the main
	thread then call cygheap_profthr_all() indirectly through
	cygwin_internal(CW_CYGHEAP_PROFTHR_ALL) to sample all other threads.
	(profile_off): Zero targthr to indicate profiling was turned off.
	(profile_on): Fix handle leak on failure path.
	(profile_child): New callback func to restart profiling in child
	process after a fork if the parent was being profiled.
	(profile_ctl): Call pthread_atfork() to set profile_child callback.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-10 20:39:46 +01:00
Corinna Vinschen 65231f415a getifaddrs: Return pointer to extended interface info in ifa_data member
According to https://cygwin.com/ml/cygwin/2016-03/msg00124.html it's a
problem to collect friendlyname info using AF_INET6 sockets.  Fix problem
by exposing additional hardware info for all collected interfaces via the
pointer in the ifaddrs::ifa_data member.

	* include/ifaddrs.h (struct ifaddrs_hwdata): Define as struct of
	not yet exposed members of struct ifall, defined in net.cc.
	* net.cc (struct ifall): Replace hardware dta members with struct
	ifaddrs_hwdata.  Accommodate throughout.
	(get_ifs): Let ifaddrs ifa_data member point to ifall::ifa_hwdata
	member.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-10 18:00:00 +01:00
Corinna Vinschen f368589492 Revamp acl_extended_fd/acl_extended_file to avoid open(2) call
Calling open from acl_extended_file{_nofollow} indiscriminately may hang
if the file is a FIFO.  Ultimately the FIFO implementation needs a thorough
rewrite, but for the time being we better do what stat(2) and friends do:
Just create an fhandler directly.

	* sec_posixacl.cc (__acl_extended_fh): New static function calling
	fhandler::facl.
	(acl_extended_fd): Just call __acl_extended_fh.
	(__acl_extended_file): Take just a path_conv as parameter and
	create temporary fhandler to call __acl_extended_fh.
	(acl_extended_file): Create path_conv from incoming path and
	call __acl_extended_file on it.
	(acl_extended_file_nofollow): Ditto.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-10 10:36:00 +01:00
Corinna Vinschen 48511f3d38 Overwite potentially faked kernel version with correct values
* ntdll.h (RtlGetNtVersionNumbers): Declare.
	* wincap.cc (wincapc::init): Overwrite kernel version info
	returned by RtlGetVersion with correct info returnd by
	RtlGetNtVersionNumbers.  Add comment.

Originally, using RtlGetVersion instead of GetVersionEx was supposed to
fix the fact that GetVersionInfo returns the wrong kernel version if the
executable has been built with an old manifest (or none at all), starting
with Windows 8.1.  Either this never really worked as desired and our
testing was flawed, or this has been changed again with Windows 10, so
that RtlGetVersion does the kernel faking twist as well.  Since we're
only reading the value in the first process in a process tree. the entire
process tree is running with a wrong OS version information in that case.

Fortunately, the (undocumented) RtlGetNtVersionNumbers function is not
affected by this nonsense, so we simply override the OS version info
fields with the correct values now.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-09 23:10:17 +01:00
Corinna Vinschen 264b5e137e Move definition of wsadata into wsock_init
The problem this patch fixes showed up after updating to gcc-5.3.0.  The
cuplrit is a change in gcc when emitting section attributes.  It only
shows up when building without optimization.  Effect in Cygwin: ws2_32
functions failed to load.

In the original code the definition of "NO_COPY wsadata" was preceeding
an __asm__ block (the definition of the _wsock_init wrapper), while the
definition of "NO_COPY here" immediately follows the same assembler
block.  When gcc-5.3.0 emits assembler code for the wsadata definition,
it emits the .data_cygwin_nocopy section attribute.

Next it emits the assembler output for the __asm_ block, entirely ignoring
its content.  The __asm__ block adds a .text section definition.

Eventually gcc emits assembler code for the here definition.  However,
apparently gcc still "knows" that it just emitted the .data_cygwin_nocopy
section attribute and so doesn't redefine it.  Remember the __asm__?  It
changed the section to .text.

So with gcc-4.9.3 we got:

    .section .data_cygwin_nocopy,"w"
  wsadata:

  __asm__ block:
    .text

    .section .data_cygwin_nocopy,"w"
  here:

With gcc 5.3.0 we now get:

    .section .data_cygwin_nocopy,"w"
  wsadata:

  __asm__ block:
    .text

  here:

So "here" is now in the .text segment which is read-only.  Hilarity ensues.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-09 22:55:28 +01:00
Corinna Vinschen c09e96fda0 Cygwin: Document new POSIX ACL API
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-08 17:33:08 +01:00