Commit Graph

2490 Commits

Author SHA1 Message Date
Enrico Weigelt, metux IT consult 08cca901d4 dix: window: use calloc() instead of malloc()
In general safer programming practise to always zero-out newly
allocated chunks.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
2025-06-30 20:39:05 +02:00
Enrico Weigelt, metux IT consult f16d448722 dix: registry: add LookupDixAccessName()
Helper for converting Xace access masks to human-readable text.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
2025-06-30 20:39:05 +02:00
Enrico Weigelt, metux IT consult 154ed75e5c dix: add callback for post root window init
Allow extensions to catch in right after a screen's root window has
been finally initialized

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
2025-06-30 20:39:05 +02:00
Enrico Weigelt, metux IT consult 029f965dd9 (!1867) dix: unexport and rename CreateWindow()
a) an internal function that's not used by any drivers
b) conflicting with function/define of same name on win32

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
2025-06-30 20:39:05 +02:00
Enrico Weigelt, metux IT consult 3b4997b2eb (!1880) Xi: use fixed define for extenion base opcode
Several places outside Xi (eg. dix, security hooks, ...) need to know the
actual XI base opcode. This formerly had been done by a global variable,
which is filled on XI init. This has some drawbacks, eg. requires that
XI really is initialized before anybody else attempting to access this
variable - changes in extension init order could be dangerous.

Since extension opcodes are now (compile-time) fixed for all known
extensions (including XI), this isn't needed anymore. We can really
rely on the XI extension always having the same opcode base. So we
can drop that variable entirely and use the corresponding define instead.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
2025-06-30 20:39:05 +02:00
Enrico Weigelt, metux IT consult bb77b8406d (!1880) dix: reserve fixed extension opcodes for known extensions
Assign fixed opcodes for known (in-tree) extensions and add
defines for them. Other places (eg. security extensions) that
need to know those opcodes now can directly use those defines
not having to look them up at runtime.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
2025-06-30 20:39:05 +02:00
Enrico Weigelt, metux IT consult 8d29cb9f68 (!1880) dix: add support for reserved extension slots
In order to allow extensions being registered at fixed opcodes,
there need to be a reserved slot range. Thus `NumExtensions` needs
to start out with the upper ceiling of the reserved slot space.
Thus it cannot tell whether the array already had been allocated,
and some slots now may be NULL, so we need some extra checks.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
2025-06-30 20:39:05 +02:00
Enrico Weigelt, metux IT consult 13a9436a85 (!1880) dix: AddExtension: simplify error return path
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
2025-06-30 20:39:05 +02:00
Enrico Weigelt, metux IT consult 49faf3ca53 (!1880) dix: simplify extension query
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
2025-06-30 20:39:05 +02:00
Enrico Weigelt, metux IT consult 87492e7608 (!1901) dix: resource: protect FakeClientID() from returning 0
Some callers treating XID = 0 as a sign for non-existing resource.
Practically should not happen, but nevertheless adding extra
protection, just in case.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
2025-06-30 20:39:05 +02:00
Enrico Weigelt, metux IT consult 7e885509bb (!1905) dix: move screen destruction loop into dixFreeAllScreens()
Consolidate the screen destruction code in its own function and
so move it out of the big main loop.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
2025-06-30 20:39:04 +02:00
Enrico Weigelt, metux IT consult 4fafa59389 (!1905) dix: consolidate screen destruction in dixFreeScreen()
Consolidate duplicated screen destruction logic into new function
dixFreeScreen().

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
2025-06-30 20:38:47 +02:00
Enrico Weigelt, metux IT consult 28bf93c2d3 (!1905) dix: replace FreeDefaultStipple()
It's just a one-liner only called once, so no actual need for it.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
2025-06-30 20:38:33 +02:00
Enrico Weigelt, metux IT consult aa2cb56156 (!1905) dix: let FreeGCperDepth() operate on ScreenPtr and NULL protect it
Instead of retrieving the screen index from ScreenRec and passing this,
so the ScreenRec is looked up again, just pass in the ScreenPtr that
already have anyways.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
2025-06-30 20:38:33 +02:00
Enrico Weigelt, metux IT consult 55eb68a017 (!1905) dix: NULL-protect FreeGC()
Make it possible to call FreeGC() w/o prior NULL checks.
In case of NULL, BadMatch is returned.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
2025-06-30 20:38:33 +02:00
Enrico Weigelt, metux IT consult 0f522fa893 dix: unexport and document SetCriticalEvent()
Not used by any external drivers, so no need to keep it exported.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
2025-06-12 16:16:50 +02:00
Enrico Weigelt, metux IT consult 9f0fa773b9 dix: unexport events related request handlers
Request handlers aren't supposed to be called by external drivers directly,
so no need to keep them in the public SDK API.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
2025-06-12 16:16:45 +02:00
Enrico Weigelt, metux IT consult f0fd9f8bf4 dix: fix warning on redefinition of typedefs
| ../dix/input_priv.h:56:29: warning: redefinition of typedef 'InputOption' is a C11 feature [-Wtypedef-redefinition]
|    56 | typedef struct _InputOption InputOption;
|       |                             ^
| ../include/input.h:255:29: note: previous definition is here
|   255 | typedef struct _InputOption InputOption;
|       |                             ^
| In file included from ../hw/xfree86/common/xf86Cursor.c:36:
| ../dix/input_priv.h:57:25: warning: redefinition of typedef 'XI2Mask' is a C11 feature [-Wtypedef-redefinition]
|    57 | typedef struct _XI2Mask XI2Mask;
|       |                         ^
| ../include/input.h:256:25: note: previous definition is here
|   256 | typedef struct _XI2Mask XI2Mask;
|       |                         ^

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1978>
2025-05-18 17:35:31 +00:00
Alan Coopersmith 0fefdc6e29 dix: tables.c should include header that defines InitialVector
Clears warning from clang 19.1.7:

dix/tables.c:59:7: warning: no previous extern declaration for non-static
 variable 'InitialVector' [-Wmissing-variable-declarations]
   59 | int (*InitialVector[3]) (ClientPtr /* client */) = {
      |       ^

Fixes: bae6cbc8c ("include: move private defs to dixstruct_priv.h")
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1910>
2025-04-19 17:02:15 +00:00
Peter Hutterer cab9017485 dix: pick the right keyboard for focus FollowKeyboard
This fixes a crash when we try to send focus events and dereference
FollowKeyboardWin (0x3) as WindowPtr.

A device set to XSetDeviceFocus(FollowKeyboard) is supposed to follow
the focus of the corresponding master device. During ActivateKeyboard
a slave device is detached from the master for the duration for the grab
so we don't actually have a master to follow - leaving our oldWin set to
the FollowKeyboardWin constant. This later crashes when we try to
dereference it.

Fix this by getting the current master (if any), or the saved master (if
temporarily detached due to a grab). And if failing that, use the VCK
as fallback device - that is technically wrong but it's such a niche use
case that it shouldn't matter.

Reproducer:
     window = XCreateSimpleWindow(...)
     deviceid = any device that is IsXExtensionKeyboard device
     XSetDeviceFocus(deviceid, FollowKeyboard, ...)
     XGrabDevice(deviceid, window, ...)

Fixes: f01ee198ff ("dix: don't use inputInfo.keyboard to get the focus window in ActivateKbdGrab")

Found-by: Olivier Fourdan <ofourdan@redhat.com>
Acked-by: Olivier Fourdan <ofourdan@redhat.com>
Tested-by: Olivier Fourdan <ofourdan@redhat.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1870>
2025-04-07 15:45:50 +00:00
Peter Hutterer 2bca68f41b dix: fix erroneous BUG_RETURN check
Check was inverted, we want to complain if evcount exceeds our target
array.

Fixes: 219c54b8a3 ("dix: fix DeviceStateNotify event calculation")
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1868>
2025-03-21 11:42:41 +10:00
Enrico Weigelt, metux IT consult a7401945c4 dix: add prefix to grab state value defines
make it a bit easier to diffenciate from other symbols by
adding a prefix to their names.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1837>
2025-02-26 13:24:41 +00:00
Enrico Weigelt, metux IT consult 5f6cb45ac3 dix: unexport defines for device grab states
These aren't used anywhere in modules or outside DIX & XI, so
no need to keep them in public API any longer.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1837>
2025-02-26 13:24:41 +00:00
Olivier Fourdan 6e0f332ba4 dix: Dequeue pending events on frozen device on removal
When a device is removed while still frozen, the events queued for that
device remain while the device itself is freed.

As a result, replaying the events will cause a use after free.

To avoid the issue, make sure to dequeue and free any pending events on
a frozen device when removed.

CVE-2025-26600, ZDI-CAN-25871

This vulnerability was discovered by:
Jan-Niklas Sohn working with Trend Micro Zero Day Initiative

Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1828>
2025-02-25 11:43:01 +01:00
Peter Hutterer b0a09ba602 dix: keep a ref to the rootCursor
CreateCursor returns a cursor with refcount 1 - that refcount is used by
the resource system, any caller needs to call RefCursor to get their own
reference. That happens correctly for normal cursors but for our
rootCursor we keep a variable to the cursor despite not having a ref for
ourselves.

Fix this by reffing/unreffing the rootCursor to ensure our pointer is
valid.

Related to CVE-2025-26594, ZDI-CAN-25544

Reviewed-by: Olivier Fourdan <ofourdan@redhat.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1828>
2025-02-25 11:43:01 +01:00
Olivier Fourdan 01642f263f Cursor: Refuse to free the root cursor
If a cursor reference count drops to 0, the cursor is freed.

The root cursor however is referenced with a specific global variable,
and when the root cursor is freed, the global variable may still point
to freed memory.

Make sure to prevent the rootCursor from being explicitly freed by a
client.

CVE-2025-26594, ZDI-CAN-25544

This vulnerability was discovered by:
Jan-Niklas Sohn working with Trend Micro Zero Day Initiative

v2: Explicitly forbid XFreeCursor() on the root cursor (Peter Hutterer
<peter.hutterer@who-t.net>)
v3: Return BadCursor instead of BadValue (Michel Dänzer
<michel@daenzer.net>)

Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Suggested-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1828>
2025-02-25 11:43:01 +01:00
Enrico Weigelt, metux IT consult 1fc9a26afd drop not needed includes of geext.h
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1810>
2025-02-24 20:19:55 +00:00
Enrico Weigelt, metux IT consult 90bc995016 Xext: geext: move geeint.h stuff into geext.c
Everything in here only used by geext.c, so no need to keep
a separate header file for that.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1811>
2025-02-23 17:53:25 +00:00
Enrico Weigelt, metux IT consult d973c43810 os: unexport SetCriticalOutputPending()
Not used by any drivers/modules, so no need to keep it exported.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1814>
2025-02-23 17:39:18 +00:00
Enrico Weigelt, metux IT consult 6c88eb0cc4 misc.h: unexport compare_version()
Not used by any external modules, so no need to keep it in public header.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1807>
2025-02-18 11:17:40 +00:00
Enrico Weigelt, metux IT consult 346d5f5c35 os: move BUG_*() macros to own private header
These macros aren't used by any external modules, so no need
to keep them public. Moving them into private header.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1804>
2025-02-17 19:32:48 +00:00
Enrico Weigelt, metux IT consult a6b2eb3780 misc.h: drop LengthRestB() macro
Only used at exactly one place, for trivial size computation, so not worth
having an extra macro in a public header for this.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1805>
2025-02-17 19:25:14 +00:00
Enrico Weigelt, metux IT consult b3ec0bf58a dix: unexport MakePredeclaredAtoms()
Should never be called by modules/drivers.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1802>
2025-02-17 18:13:33 +00:00
Enrico Weigelt, metux IT consult 5b541780c1 dix: use dixDestroyPixmap() instead of direct driver call
Direct calls to ScreenRec->DestroyPixmap() blocks cleaning up the wrapping
jungle, so use the proper dix function instead.

See: https://gitlab.freedesktop.org/xorg/xserver/-/issues/1754

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1711>
2025-02-12 17:48:30 +01:00
Enrico Weigelt, metux IT consult 2e0c19b6d9 dix: add getter for display name
Xrdp needs to know the current display name (for setting up it's
own server sockets accordingly). Instead of exporting an internal
field, adding a little getter for this.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1783>
2025-02-11 19:13:01 +01:00
Enrico Weigelt, metux IT consult f4eb217f11 os: log: replace VErrorF() by LogVMessageVerb()
Since LogVMessageVerb() is now signal safe, we can use this one instead.
Leaving VErrorF() macro for backwards compat with drivers.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1691>
2025-02-06 23:35:27 +00:00
Enrico Weigelt, metux IT consult 2d18c353b4 os: log: replace ErrorFSigSafe() by ErrorF()
Since ErrorF() is now signal safe, we can use this one instead.
Leaving ErrorFSigSafe() macro for backwards compat with drivers.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1691>
2025-02-06 23:35:27 +00:00
Enrico Weigelt, metux IT consult 24d693c5ae dix: make dixDestroyPixmap() NULL-proof
Make dixDestroyPixmap() check for NULL pointer, so callers don't need to
do it anymore. Returning TRUE on NULL pointer - but most callers won't
even look at the retval anyways.

Together with subsequent commits, which will make use of that function,
instead of calling raw ScreenRec->DestroyPixmap vectors, this gives us some
more freedom for architectural changes, eg. get rid of the extremely
complicated and fragile wrapping chains.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1709>
2025-02-06 23:02:06 +00:00
Enrico Weigelt, metux IT consult 4c3ff75772 dix: drop swapping request length fields
The request struct's length fields aren't used anymore - we have the
client->req_len field instead, which also is bigreq-compatible.

Also dropping now obsolete SProcNoOperation().

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1639>
2025-02-06 22:28:51 +00:00
Enrico Weigelt, metux IT consult 216fc6fe83 dix: drop remains of ancient code generator
This script used to generated xproto header as well as a piece of source
for initializing the builtin atoms in the Xserver (MakePredeclaredAtoms()).

At least with R6.6 baseline it didn't seem to be used anymore, and - at least
since the modularization - it's completely broken and useless.

Since we now have a new generator, running directly in the build process,
this ancient script can be dropped.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1670>
2025-02-06 19:29:52 +00:00
Enrico Weigelt, metux IT consult 44e6558934 dix: generate MakePredeclaredAtoms() from BuiltInAtoms file
This function probably been (half?) auto generated somewhere back in the
dark ages (there're still remains of the former generator, which doesn't
work anymore, and hasn't been updated for ages). It's been added to SCM
with R6.6 baseline - and from that on manually maintained.

Adding a little generator to create source from "BuiltInAtoms" file,
directly in the build process.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1670>
2025-02-06 19:29:52 +00:00
Enrico Weigelt, metux IT consult fb696a7d7b rename old symbol PANORAMIX to XINERAMA
PANORAMIX was the original working title of the extension, before it became
official standard. Just nobody cared about fixing the symbols to the official
naming.

For backwards compatibility with drivers, the old PANORAMIX symbol will
still be set.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1258>
2025-02-06 15:51:27 +00:00
Enrico Weigelt, metux IT consult e67f2a5eb5 include: move out private definitions from hotplug.h
Public server module API shouldn't be clobbered with private definitions,
thus move them out to private header.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1360>
2025-02-06 16:24:00 +01:00
Enrico Weigelt, metux IT consult 191cca0905 mi: unexport miSourceValidate()
Not used by any drivers/modules, so no need to keep it public.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1727>
2025-02-06 16:45:20 +02:00
Enrico Weigelt, metux IT consult a54e8f5343 mi: unexport miPaintWindow()
Not used by any drivers/modules, so no need to keep it public.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1727>
2025-02-06 16:45:20 +02:00
Enrico Weigelt, metux IT consult 0f7770bce3 mi: unexport mieqProcessDeviceEvent()
Not used by any drivers/modules, so no need to keep it exported.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1727>
2025-02-06 16:45:20 +02:00
Enrico Weigelt, metux IT consult 9dd280607f mi: unexport mieqEnqueue()
Not used by any (known) drivers, so no need to keep it exported.

Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1727>
2025-02-06 16:45:20 +02:00
Alan Coopersmith b65eea43dd dix: limit checks to MAX_VALUATORS when generating Xi events
Previously, it was looping through sizeof(ev->valuators.mask) * 8
valuators, where valuators.mask is defined as an array of
(MAX_VALUATORS + 7) / 8 entries.  Since MAX_VALUATORS is defined as 36,
this made it actually loop through 40 entries.  The last 4 bits in this
array should never be set, so we should never access memory outside the
bounds of the arrays defined to be exactly MAX_VALUATORS in length, but
we can make the static analyzer happier and not waste time checking bits
that should never be set.

Found by Oracle Parfait 13.3 static analyzer:

   Read outside array bounds [read-outside-array-bounds]:
      In array dereference of ev->valuators.data[i] with index i
      Array size is 36 elements (of 8 bytes each), index >= 0 and index <= 39
        at line 741 of dix/eventconvert.c in function 'eventToDeviceEvent'.

   Read outside array bounds [read-outside-array-bounds]:
      In array dereference of ev->valuators.data[i] with index i
      Array size is 36 elements (of 8 bytes each), index >= 0 and index <= 39
        at line 808 of dix/eventconvert.c in function 'eventToRawEvent'.

   Read outside array bounds [read-outside-array-bounds]:
      In array dereference of ev->valuators.data_raw[i] with index i
      Array size is 36 elements (of 8 bytes each), index >= 0 and index <= 39
        at line 809 of dix/eventconvert.c in function 'eventToRawEvent'.

Fixes: b2ba77bac ("dix: add EventToXI2 and GetXI2Type.")
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1730>
2024-10-28 05:38:25 +00:00
Alan Coopersmith 4b073d65bb dix: fix button offset when generating DeviceButtonStateNotify events
Found by Oracle Parfait 13.3 static analyzer:
   Buffer Overflow in STD C function [buffer-overflow-call-stdc]:
      Buffer overflow in call to memcpy. Buffer &bev->buttons[4] of
       size 24 is written at an offset of 28
      Array size is 28 bytes, index is 32
        at line 743 of dix/enterleave.c in function
	 'DeliverStateNotifyEvent'.

Fixes: a85f0d6b9 ("Xi: fix use of button->down - bitflags instead of int arrays.")
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1730>
2024-10-28 05:38:25 +00:00
Alan Coopersmith 45c485bfdf dix: Use __builtin_popcountl if available to replace Ones()
If the compiler knows of a better algorithm for counting the number of
bits set in a word for the target CPU, let it use that, instead of the
classic algorithm optimized for PDP-6.

Based on xorg/lib/libxext@490a25e6f8a4d2482af4364c700b68ad11a4d10b

v2: make old version static inline, stop exporting after !1695

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1674>
2024-10-26 10:04:13 -07:00