Commit Graph

17138 Commits

Author SHA1 Message Date
Yaakov Selkowitz 04f288851a Feature test macros overhaul: sys/time.h
The inclusion of <sys/select.h> is required also by POSIX.1-2001.
setitimer is XSI, and futimesat is GNU.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:09:18 -05:00
Yaakov Selkowitz 069e400c91 Feature test macros overhaul: sys/stat.h
Replace all !_POSIX_SOURCE with BSD.  All *at functions depend on
ATFILE; futimens is POSIX.1-2008.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:09:16 -05:00
Yaakov Selkowitz 03c4ef1c51 Feature test macros overhaul: sys/select.h
Remove !_POSIX_SOURCE conditional; pselect is POSIX.1-2001.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:09:15 -05:00
Yaakov Selkowitz 73e2f46419 Feature test macros overhaul: wchar.h
open_wmemstream is POSIX.1-2008.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:09:13 -05:00
Yaakov Selkowitz be657151f1 Feature test macros overhaul: unistd.h
Throughout, use proper internal macros for functions, including those
marked as target-specific.  Use ATFILE for all *at functions.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:09:12 -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 6fe6a822ee Feature test macros overhaul: strings.h
Replace __STRICT_ANSI__ with the proper internal macros for bcmp etc.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:09:09 -05:00
Yaakov Selkowitz 615d63599b Feature test macros overhaul: string.h
Throughout, remove __STRICT_ANSI__ and use the proper internal macros.

bcmp, bcopy, bzero, index, and rindex were in POSIX prior to 2008.

memrchr is GNU.

strdup and strndup are POSIX.1-2008.

The int-returning form of strerror_r is POSIX.1-2001.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:09:07 -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 feec81e571 Feature test macros overhaul: stdio.h
Throughout, remove references to __STRICT_ANSI__ and use the proper
internal macros and versions for C99, POSIX, ATFILE for the various *at
functions, or LARGEFILE for fseeko and ftello.

[v]asprintf are GNU extensions, but the *iprintf, *iscanf, and
*asnprintf functions are unique to newlib.

getw and putw were removed from POSIX.1-2001. funopen is BSD, and
fopencookie is GNU.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:09:04 -05:00
Yaakov Selkowitz 5c78499ae2 Feature test macros overhaul: signal.h
Use proper internal macros for BSD sig_t and GNU sighandler_t.

sigaltstack and friends are XSI even in SUSv4 but in glibc are
nonetheless handled as POSIX.1-2008 (not 2001).

The requirement for the ucontext_t typedef in signal.h was XSI prior to
POSIX.1-2008.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:09:03 -05:00
Yaakov Selkowitz 25507f80a2 Feature test macros overhaul: pwd.h
getpw*_r dates back to POSIX.1c, and *pwent to XPG4v2.  Both are also BSD.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:09:01 -05:00
Yaakov Selkowitz 96972e7198 Feature test macros overhaul: pthread.h
Use internal macros for GNU extensions.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:09:00 -05:00
Yaakov Selkowitz 4e8291b8b0 Feature test macros overhaul: math.h
Simplify the C99 conditionals.  Mark the drem and gamma functions as
BSD|SVID, the Bessel double functions also XSI and the floats also SUSv3.
signgam is BSD|SVID|XSI, and matherr is SVID.  Finally, use the internal
macros to control the symbolic constants.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:08:59 -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 ec4fe40b23 Feature test macros overhaul: grp.h
_PATH_GROUP is a BSDism. getgr*_r are BSD|SVID|POSIX, and the *grent
functions are BSD|SVID|XPG4v2.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:08:56 -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 d2df6d381b Feature test macros overhaul: fcntl.h
Most of the !_POSIX_SOURCE code is BSD, although ironically some were
added to POSIX.1-2001.

Use the ATFILE conditional for most of the *at functions, except
futimesat which is GNU.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:08:53 -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
Yaakov Selkowitz 575608b202 Feature test macros overhaul: ctype.h
Simplify C99 test for isblank.  isascii and toascii are BSD|SVID|XSI.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:08:50 -05:00
Yaakov Selkowitz 6ba26630e0 Feature test macros overhaul: sys/features.h
This is the complete rework of the feature tests macros for better
compatibility with GNU libc, primarily based on the Linux man pages
documentation:

http://man7.org/linux/man-pages/man7/feature_test_macros.7.html

The previous implementation was flawed in its approach that macros were
often used to hide symbols if defined (e.g. !defined __STRICT_ANSI__ or
!defined _POSIX_SOURCE), whereas the approach of glibc is that these macros
make symbols available when defined (e.g. defined _BSD_SOURCE, or as used
internally, #if __BSD_VISIBLE).  As much open-source software is written
with glibc in mind, this necessitated patching numerous packages just to
compile.

In particular, __STRICT_ANSI__ (which is defined by gcc -ansi or -std=c*)
was given too much importance.  This implementation limits the influence
of __STRICT_ANSI__ to controlling the default when no other feature test
macros are defined, and to the inclusion of <alloca.h> in <stdlib.h> as
documented.  These are the only places where __STRICT_ANSI__ should be
tested.

The following macros are now accepted: _ATFILE_SOURCE, _BSD_SOURCE,
_DEFAULT_SOURCE, _ISOC99_SOURCE, _ISOC11_SOURCE, _LARGEFILE_SOURCE,
_SVID_SOURCE, _XOPEN_SOURCE_EXTENDED.

The existing __*_VISIBLE internal macros have been kept mostly
compatible with the original BSD implementation, with some changes to
the criteria which controls them.  Several more macros in this style
have been added where needed for concision or accuracy.

Enabling C++11 or newer in the compiler also enables C99 and C11
functions.  Doing so should help move away from the need to define
_GNU_SOURCE in g++ for _GLIBCXX_USE_C99 support as on Linux:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51749

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
2016-03-17 21:06:40 -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
Jon Turney e8e379ff1d Attempt to fix Coverity issues in ssp
* ssp.c (lookup_thread_id): Consistently check if tix is a null
	pointer.
	(run_program): Annotate that STATUS_BREAKPOINT falls-through to
	STATUS_SINGLE_STEP case.
	(main): Guard against high_pc-low_pc overflow and malloc failure.

Signed-off-by: Jon Turney <jon.turney@dronecode.org.uk>
2016-03-15 13:25:57 +00:00
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
Stefan Roesch 414c8adc8b or1k: properly restore timer
Consider the function parameter for restoring the timer
2016-03-13 12:50:23 +01:00
Stefan Roesch 81ad4e656a or1k: Fix multicore stack calculation
Change the type of the stack pointers to enable pointer calculations at byte
granularity, which is needed for the calculation of _or1k_stack_core[c] and
_or1k_exception_stack_core[c] with _or1k_stack_size and
_or1k_exception_stack_size. (util.c:53-54)
2016-03-13 12:50:05 +01:00
Corinna Vinschen 8c5911b37c setvbuf: Drop setting reent->__cleanup
The __sinit call added with 1eb6db6 already sets reent->__cleanup.

	* libc/stdio/setvbuf.c (setvbuf): Drop setting reent->__cleanup.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-13 12:03:03 +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 1eb6db6efb Update setvbuf to latest OpenBSD implementation
Newlib's setvbuf function is very old and has two bugs:
- It sets the SRD/SWR flags incorrectly in case of files opened for
  reading and writing.
  See https://cygwin.com/ml/cygwin/2016-03/msg00180.html
  for a desription of the effect.
- It always sets the buffer size to BUFSIZ if it's not provided by
  the application, independent of the optimal blocksize for the
  underlying IO device.

Update setvbuf to latest code from OpenBSD to fix both problems.

	* libc/stdio/setvbuf.c (setvbuf): Import latest OpenBSD
	implementation.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-12 23:41:21 +01:00
Corinna Vinschen 99d0e2341d Add __swhatbuf function from OpenBSD
To fix a long-standing setvbuf bug, import __swhatbuf function from
OpenBSD and only slightly rearrange for newlib.

	* libc/stdio/local.h (__swhatbuf_r): Declare.
	* libc/stdio/makebuf (__smakebuf_r): New function.
	(__smakebuf_r): Drop file handling code and call __smakebuf_r.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-12 23:37:01 +01:00
Corinna Vinschen 6b97fabf1b Use __sputc_r inline code when building with gcc
Per the preceeding comment this inline code is disabled since 1993(!)
because of a bug in GCC at the time.  This is long gone and the equivalent
inline code is used in the BSDs for quite some time.  Enable this code for
newlib as well.

	* libc/include/stdio.h (__sputc_r): Enable GCC inline code.  Add
	handling for targets defining __SCLE.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-12 23:25:11 +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
Mark Geisert d0cf3b7c02 Documentation covering profiling Cygwin programs. 2016-03-11 11:08:01 +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 2b174636e5 Add commit 5807ba83e release message to documentation
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-10 20:47:33 +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
Nick Clifton c86b2f8e93 Remove bogus LONG(0) directives from MSP430 linker scripts. 2016-03-10 10:41:13 +00:00
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