Commit Graph

240603 Commits

Author SHA1 Message Date
Enji Cooper
760b1a815b Standardize -std=c++* as CXXSTD`
CXXSTD was added as the C++ analogue to CSTD.

CXXSTD defaults to `-std=c++11` with supporting compilers; `-std=gnu++98`,
otherwise for older versions of g++.

This change standardizes the CXXSTD variable, originally added to
googletest.test.inc.mk as part of r345203.

As part of this effort, convert all `CXXFLAGS+= -std=*` calls to use `CXXSTD`.

Notes:

This value is not sanity checked in bsd.sys.mk, however, given the two
most used C++ compilers on FreeBSD (clang++ and g++) support both modes, it is
likely to work with both toolchains. This method will be refined in the future
to support more variants of C++, as not all versions of clang++ and g++ (for
instance) support C++14, C++17, etc.

Any manual appending of `-std=*` to `CXXFLAGS` should be replaced with CXXSTD.
Example:

Before this commit:
```
CXXFLAGS+=	-std=c++14
```

After this commit:
```
CXXSTD=	c++14
```

Reviewed by:	asomers
Approved by:	emaste (mentor)
MFC after:	1 month
MFC with:	r345203, r345704, r345705
Relnotes:	yes
Tested with:	make tinderbox
Differential Revision:	https://reviews.freebsd.org/D19732
2019-03-29 18:31:48 +00:00
Enji Cooper
752cabaa1c Revert r345704
I accidentally committed code from two reviews. I will reintroduce the code to
bsd.progs.mk as part of a separate commit from r345704.

Approved by:	emaste (mentor, implicit)
MFC after:	2 months
MFC with:	r345704
2019-03-29 18:16:33 +00:00
Enji Cooper
9a41926bfb CXXSTD is the C++ analogue to CSTD.
CXXSTD defaults to `-std=c++11` with supporting compilers; `-std=gnu++98`,
otherwise for older versions of g++.

This change standardizes the CXXSTD variable, originally added to
googletest.test.inc.mk as part of r345203.

As part of this effort, convert all `CXXFLAGS+= -std=*` calls to use `CXXSTD`.

Notes:

This value is not sanity checked in bsd.sys.mk, however, given the two
most used C++ compilers on FreeBSD (clang++ and g++) support both modes, it is
likely to work with both toolchains. This method will be refined in the future
to support more variants of C++, as not all versions of clang++ and g++ (for
instance) support C++14, C++17, etc.

Any manual appending of `-std=*` to `CXXFLAGS` should be replaced with CXXSTD.
Example:

Before this commit:
```
CXXFLAGS+=	-std=c++14
```

After this commit:
```
CXXSTD=	c++14
```

Reviewed by:	asomers
Approved by:	emaste (mentor)
MFC after:	1 month
Relnotes:	yes
Differential Revision:	https://reviews.freebsd.org/D19732
2019-03-29 18:13:44 +00:00
Konstantin Belousov
5d00c5a657 Fix initial exec TLS mode for dynamically loaded shared objects.
If dso uses initial exec TLS mode, rtld tries to allocate TLS in
static space. If there is no space left, the dlopen(3) fails. If space
if allocated, initial content from PT_TLS segment is distributed to
all threads' pcbs, which was missed and caused un-initialized TLS
segment for such dso after dlopen(3).

The mode is auto-detected either due to the relocation used, or if the
DF_STATIC_TLS dynamic flag is set.  In the later case, the TLS segment
is tried to allocate earlier, which increases chance of the dlopen(3)
to succeed.  LLD was recently fixed to properly emit the flag, ld.bdf
did it always.

Initial test by:	dumbbell
Tested by:	emaste (amd64), ian (arm)
Tested by:	Gerald Aryeetey <aryeeteygerald_rogers.com> (arm64)
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D19072
2019-03-29 17:52:57 +00:00
Konstantin Belousov
9f70117263 Eliminate adj_free field from vm_map_entry.
Drop the adj_free field from vm_map_entry_t. Refine the max_free field
so that p->max_free is the size of the largest gap with one endpoint
in the subtree rooted at p. Change vm_map_findspace so that, first,
the address-based splay is restricted to tree nodes with large-enough
max_free value, to avoid searching for the right starting point in a
subtree where all the gaps are too small. Second, when the address
search leads to a tree search for the first large-enough gap, that gap
is the subject of a splay-search that brings the gap to the top of the
tree, so that an immediate insertion will take constant time.

Break up the splay code into separate components, one for searching
and breaking up the tree and another for reassembling it. Use these
components, and not splay itself, for linking and unlinking. Drop the
after-where parameter to link, as it is computed as a side-effect of
the splay search.

Submitted by:	Doug Moore <dougm@rice.edu>
Reviewed by:	markj
Tested by:	pho
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D17794
2019-03-29 16:53:46 +00:00
Navdeep Parhar
be09e82abb cxgbe/t4_tom: Catch up with r344433, which removed tcb_autorcvbuf_inc.
The declaration in tcp_var.h is still around so t4_tom continued to
compile but wouldn't load.  A separate commit will fix tcp_var.h

Reported By: Dustin Marquess (dmarquess at gmail)

Sponsored by:	Chelsio Communications
2019-03-29 16:43:24 +00:00
Bruce Evans
a32dbad556 Fix restoring to graphics modes in VGLEnd().
Correct restoring was only attempted for mode 258 (800x600x4 P).  (This
was the only useful graphics mode supported in the kernel until 10-15
years ago, and is still the only one explicitly documented in the man
page).  The comment says that it is the geometry (subscreen size) that
is restored, but it seems to only be necessary to restore the font
size, with the geometry only needed since it is set by the same ioctl.
The font size was not restored for this mode, but was forced to 16.

For other graphics modes, the font size was clobbered to 0.  This
confuses but doesn't crash the kernel (font size 0 gives null text).
This confuses and crashes vidcontrol.  The only way to recover was to
use vidcontrol to set the mode to any text mode on the way back to the
original graphics mode.

vidcontrol gets this wrong in the opposite way when backing out of
changes after an error.  It restores the font size correctly, but
forces the geometry to the full screen size.
2019-03-29 16:30:19 +00:00
Edward Tomasz Napierala
f322b7b058 Reduce the precision of "MB/s" by one, making room for displaying
transfer rates larger 99MB/s.

MFC after:	2 weeks
2019-03-29 16:05:30 +00:00
Bruce Evans
cfcc114dcb Fix endless loops for handling SIGBUS and SIGSEGV.
r80270 has the usual wrong fix for unsafe signal handling -- just set
a flag and return to let an event loop check the flag and do safe
handling.  This never works for signals like SIGBUS and SIGSEGV that
repeat and works poorly for others unless the application has an event
loop designed to support this.

For these signals, clean up unsafely as before, except for arranging that
nested signals are fatal and forcing a nested signal if the cleanup doesn't
cause one.
2019-03-29 15:57:08 +00:00
Bruce Evans
0410dc5f5d Fix races in mouse signal handling almost properly using the INTOFF/INTON
method as in /bin/sh.

We still do technically undefined things in the signal handler, but it
is safe in practice to access state that is protected by INTOFF/INTON.

In a recent commit, I sprinkled VGLMouseFrozen++/-- operations in
places that need INTOFF/INTON.  This prevented clobbering of pixels
under the mouse, but left mouse signals deferred for too long.  It is
necessary to call the signal handler when the count goes to 0.  Old
versions did this in the unfreeze function, but didn't block actual
signals, so the signal handler raced itself.  The sprinkled operations
reduced the races, but when then worked to block a race they left
signals deferred for too long.

Use INTOFF/INTON to fix complete loss of mouse signals while reading
the mouse status.  Clobbering of the state was prevented by SIG_IGN'ing
mouse signals, but that has a high overhead and broke more than it
fixed by losing mouse signals completely.  sigprocmask() works to block
signals without losing them completely, but its overhead is also too
high.

libvgl's mouse signal handling is often worse than none.  Applications
can't block waiting for a mouse or keyboard or other event, but have
to busy-wait.  The SIG_IGN's lost about half of all mouse events while
busy-waiting for mouse events.
2019-03-29 15:20:48 +00:00
Ed Maste
650f4477a5 rtld: attempt to fix reloc_non_plt TLS allocation on MIPS
allocate_tls_offset returns true on success.  The same issue existed
on arm and was fixed in r345693.

PR:		236880
MFC after:	1 month
Sponsored by:	The FreeBSD Foundation
2019-03-29 15:07:00 +00:00
Ed Maste
dc412d2d4b rtld: attempt to fix reloc_nonplt_object TLS allocation
allocate_tls_offset returns true on success.  This still needs more
testing and review, but this change is consistent with other archs.

PR:		236880
Reported by:	Andrew Gierth <andrew@tao11.riddles.org.uk>
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
2019-03-29 14:35:23 +00:00
Alan Somers
f220ef0b35 fix the GENERIC-NODEBUG build after r345675
Submitted by:	cy
Reported by:	cy, Michael Butler <imb@protected-networks.net>
MFC after:	2 weeks
X-MFC-With:	345675
2019-03-29 14:07:30 +00:00
Olivier Cochard
08e5c473f1 Skip test if feature security_capabilities is not available
PR:		236863
Approved by:	asomers
MFC after:	1 month
Sponsored by:	Netflix
2019-03-29 08:43:21 +00:00
Kyle Evans
45916554cc NOTES: Use non-default value for BOOT_TAG
Reported by:	jhb
MFC after:	1 week (except non-empty value in stable/11)
2019-03-29 04:00:46 +00:00
Justin Hibbits
484717a4ac powerpc64: Fix kernel ldscript to only emit one PT_LOAD segment
Summary:
kexec-lite cannot currently handle multiple PT_LOAD segments.  In some
cases the compiler generates multiple PT_LOAD segments for an unknown
reason, causing boot to fail from kexec-lite.

Submitted by:	Brandon Bergren (older version)
Differential Revision: https://reviews.freebsd.org/D19574
2019-03-29 03:01:21 +00:00
Alan Somers
b432a7f8cb Add man page for VOP_FDATASYNC(9)
Reviewed by:    kib
MFC after:      2 weeks
Sponsored by:   The FreeBSD Foundation
Differential Revision:  https://reviews.freebsd.org/D19678
2019-03-29 02:44:20 +00:00
Justin Hibbits
0499e9c619 powerpc64: Use medium code model in asm files for TOC references
Summary:
With a sufficiently large TOC, it's possible to index out of range, as
the immediate load instructions only permit 16-bit indices, allowing up
to 64kB range (signed) from the base pointer.  Allow +/- 2GB range, with
the medium code model TOC accesses in asm.

Patch originally by Brandon Bergren.  The issue appears to impact ELFv2
more than ELFv1.

Reviewed by:	luporl
Differential Revision: https://reviews.freebsd.org/D19708
2019-03-29 02:38:30 +00:00
Alan Somers
080518d810 fusefs: convert debug printfs into dtrace probes
fuse(4) was heavily instrumented with debug printf statements that could
only be enabled with compile-time flags. They fell into three basic groups:

1. Totally redundant with dtrace FBT probes. These I deleted.
2. Print textual information, usually error messages. These I converted to
   SDT probes of the form fuse:fuse:FILE:trace. They work just like the old
   printf statements except they can be enabled at runtime with dtrace. They
   can be filtered by FILE and/or by priority.
3. More complicated probes that print detailed information. These I
   converted into ad-hoc SDT probes.

Also, de-inline fuse_internal_cache_attrs.  It's big enough to be a regular
function, and this way it gets a dtrace FBT probe.

This commit is a merge of r345304, r344914, r344703, and r344664 from
projects/fuse2.

Reviewed by:	cem
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D19667
2019-03-29 02:13:06 +00:00
Justin Hibbits
4b4b6f0191 powerpc: Remove now-obsolete P9H MMU name 2019-03-29 02:11:48 +00:00
Edward Tomasz Napierala
09c78d53bf Factor out retrieving the interpreter path from the main ELF
loader routine.

Reviewed by:	kib
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D19715
2019-03-28 21:43:01 +00:00
Navdeep Parhar
dd3b96ecec cxgbe(4): Count and clear interrupts generated at the software's request.
An interrupt can be requested by setting the F_SWINT bit in PL_PF_CTL.

MFC after:	1 week
Sponsored by:	Chelsio Communications
2019-03-28 21:22:28 +00:00
John Baldwin
841613dcdc Use a dedicated malloc type for lagg(4)'s structures.
Reviewed by:	gallatin
MFC after:	1 month
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D19719
2019-03-28 21:00:54 +00:00
Eric Joyner
225eae1bb7 iflib: return ENETDOWN when the network device is down
From Jake:
iflib_if_transmit returns ENOBUFS when the device is down, or when the
link isn't active.

This was changed in r308792 from return (0), so that the function
correctly reports an error that it was unable to transmit.

However, using ENOBUFS can cause some network applications to produce
the following or similar errors:

"ping: sendto: No buffer space available"

This is a bit confusing as the real cause of the issue is that the
network device is down.

Replace the ENOBUFS return with ENETDOWN to indicate more clearly that
the reason for the failure to send is due to the network device is
offline.

This will cause the error message to be reported as

"ping: sendto: Network is down"

Submitted by:	Jacob Keller <jacob.e.keller@intel.com>
Reviewed by:	shurd@, sbruno@, bz@
MFC after:	1 week
Sponsored by:	Intel Corporation
Differential Revision:	https://reviews.freebsd.org/D19652
2019-03-28 20:46:45 +00:00
Eric Joyner
aac9c817af iflib: hold the CTX lock in iflib_pseudo_register
From Jake:
The iflib_device_register function takes the CTX lock before calling
IFDI_ATTACH_PRE, and releases it upon finishing the registration.

Mirror this process in iflib_pseudo_register, so that we always hold the
CTX lock during the attach process when registering a pseudo interface
or a regular interface.

This was caught by code inspection while attempting to analyze where the
CTX lock was held.

Submitted by:	Jacob Keller <jacob.e.keller@intel.com>
Reviewed by:	shurd@, erj@
MFC after:	1 week
Sponsored by:	Intel Corporation
Differential Revision:	https://reviews.freebsd.org/D19604
2019-03-28 20:43:47 +00:00
Alexander Motin
b059686a71 Do not map small IOCTL buffers to KVA, but copy.
CAM IOCTL interfaces traditionally mapped user-space data buffers to KVA.
It was nice originally, but now it takes too much to handle respective
TLB shootdowns, while small kernel memory allocations up to 64KB backed
by UMA and accompanied by copyin()/copyout() can be much cheaper.

For large buffers mapping still may have sense, and unmapped I/O would
be even better, but the last unfortunately is more tricky, since unmapped
I/O API is too specific to struct bio now.

MFC after:	2 weeks
Sponsored by:	iXsystems, Inc.
2019-03-28 20:41:02 +00:00
John Baldwin
2f59b04af1 Remove nested epochs from lagg(4).
lagg_bcast_start appeared to have a bug in that was using the last
lagg port structure after exiting the epoch that was keeping that
structure alive.  However, upon further inspection, the epoch was
already entered by the caller (lagg_transmit), so the epoch enter/exit
in lagg_bcast_start was actually unnecessary.

This commit generally removes uses of the net epoch via LAGG_RLOCK to
protect the list of ports when the list of ports was already protected
by an existing LAGG_RLOCK in a caller, or the LAGG_XLOCK.

It also adds a missing epoch enter/exit in lagg_snd_tag_alloc while
accessing the lagg port structures.  An ifp is still accessed via an
unsafe reference after the epoch is exited, but that is true in the
current code and will be fixed in a future change.

Reviewed by:	gallatin
MFC after:	1 month
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D19718
2019-03-28 20:25:36 +00:00
Edward Tomasz Napierala
100b034530 Make the "KB/s" field one character shorter (by reducing the precision)
and use the space to make the "tps" one character longer.

It makes the iostat(8) output a bit less messed up.

Reviewed by:	allanjude
MFC after:	2 weeks
Sponsored by:	Klara Inc.
Differential Revision:	https://reviews.freebsd.org/D19710
2019-03-28 20:16:19 +00:00
Xin LI
9ace37176e Distinguish between lseek errors and read errores.
MFC after:	2 weeks
2019-03-28 18:20:47 +00:00
Ed Maste
77f552e221 readelf: add newline after dumping dynamic FLAGS / FLAGS_1
All three dump_flags() callers need a newline after printing the flags.

Sponsored by:	The FreeBSD Foundation
2019-03-28 17:30:47 +00:00
Enji Cooper
fb72cf61ac Spam CXXFLAGS with -I${DESTDIR}/usr/include/private, instead of GTEST_CXXFLAGS
This makes it easier for googletest users to leverage googletest, instead of
forcing them to plug GTEST_CXXFLAGS into CXXFLAGS manually (resulting in
unnecessary duplication).

I will be following this up with a more proper fix in src.libnames.mk, as
src.libnames.mk should be automatically adding this directory to
CFLAGS/CXXFLAGS when private libraries are referenced. Not doing so can result
in mismatches between base-provided private library's and ports-provided
library's headers.

While here, tweak the comment to clarify what the intent is behind spamming
CXXFLAGS.

MFC after:	5 weeks
MFC with:	r345203
Reported by:	asomers
Reviewed by:	asomers
Approved by:	emaste (mentor)
Differential Revision: https://reviews.freebsd.org/D19731
2019-03-28 17:22:31 +00:00
Olivier Cochard
7d757b71bf Skip this test if if_tap module is not available
PR:		236842
Approved by:	asomers
MFC after:	1 month
Sponsored by:	Netflix
2019-03-28 16:17:33 +00:00
Bruce Evans
5ee94e9954 Fix VGLLine() in depths > 8.
It started truncating its color arg to 8 bits using plot() in r229415.
The version in r229415 is also more than 3 times slower in segmented
modes, by doing more syscalls to move the window.
2019-03-28 14:21:22 +00:00
Ed Maste
0fd1597549 Revert other accidentally committed part of r345625 2019-03-28 13:27:34 +00:00
Bruce Evans
baca0ce6b3 Fix VGLGetXY(), VGLSetXY() and VGLClear() for MEMBUFs in depths > 8.
This depends on PixelBytes being properly initialized, which it is for
all bitmaps constructed by libvgl except mouse cursor bitmaps.
2019-03-28 12:28:29 +00:00
Ed Maste
5bf271b2f8 Revert change accidentally committed along with r345625
Reported by:	Oliver Pinter <oliver.pinter@hardenedbsd.org>
2019-03-28 10:56:27 +00:00
Bruce Evans
fa68d9b94e Oops, r345496 got the pointer args backwards for bcopy() in VGLClear for
segmented modes.

Also fix some style bugs in the 2 changed lines.  libvgl uses a very non-KNF
style with 2-column indentation with no tabs except for regressions.
2019-03-28 09:51:37 +00:00
Hans Petter Selasky
b55bfda75c Add new USB PCI ID.
Submitted by:		Dmitry Luhtionov <dmitryluhtionov@gmail.com>
MFC after:		1 week
Sponsored by:		Mellanox Technologies
2019-03-28 09:00:56 +00:00
Li-Wen Hsu
dac21b8d14 Fix make in sys/modules
Sponsored by:	The FreeBSD Foundation
2019-03-28 08:59:11 +00:00
Li-Wen Hsu
3cf75dbc4e Add dependent header files
Reported by:	https://ci.freebsd.org/job/FreeBSD-head-mips-build/6702/console
2019-03-28 08:30:45 +00:00
Kyle Evans
d37eb02eb9 dtc(1): Update to 1a79f5f26631
Highlights:
- Bugfix for order in which /delete-node/ and /delete-property/ are
  processed [0]
- /omit-if-no-ref/ support has been added (used only by U-Boot at this
  point, in theory)
- GPL dtc compat version bumped to 1.4.7
- Various small fixes and compatibility improvements

Reported by:	strejda [0]
MFC after:	1 week
2019-03-28 03:48:51 +00:00
Kyle Evans
93c9d31918 if_bridge(4): ensure all traffic passing over the bridge is accounted for
Consider a bridge0 with em0 and em1 members. Traffic rx'd by em0 and
transmitted by bridge0 through em1 gets accounted for in IPACKETS/IBYTES
and bridge0 bpf -- assuming it's not unicast traffic destined for em1.
Unicast traffic destined for em1 traffic is not accounted for by any
mechanism, and isn't pushed through bridge0's bpf machinery as any other
packets that pass over the bridge do.

Fix this and simplify GRAB_OUR_PACKETS by bailing out early if it was rx'd
by the interface that it was addressed for. Everything else there is
relevant for any traffic that came in from one member that's being directed
at another member of the bridge.

Reviewed by:	kp
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D19614
2019-03-28 03:31:51 +00:00
Ed Maste
09b47fc1c2 revert r341429 "disable BIND_NOW in libc, libthr, and rtld"
r345620 by kib@ fixed the rtld issue that caused a crash at startup
during resolution of libc's ifuncs with BIND_NOW.

PR:		233333
Sponsored by:	The FreeBSD Foundation
2019-03-28 02:12:32 +00:00
Konstantin Belousov
ad484b8c53 rtld: disable relro enforcement for irelative relocation processing.
This fixes yet another breakage for relro + bind now.

Reported by:	emaste
Sponsored by:	The FreeBSD Foundation
MFC after:	3 days
2019-03-27 22:35:28 +00:00
Ravi Pokala
ca219866e3 Teach jedec_dimm(4) to be more forgiving of non-fatal errors.
It looks like some DIMMs claim to have a TSOD, but actually don't. Some
claim they weren't able to change the SPD page, but they did. Neither of
those should be fatal errors.

PR:		235944
Submitted by:	Greg V <greg@unrelenting.technology>
Reported by:	Greg V <greg@unrelenting.technology>
Reviewed by:	cem
MFC after:	1 weeks
Sponsored by:	Panasas
Differential Revision:	https://reviews.freebsd.org/D19681
2019-03-27 21:50:01 +00:00
Tycho Nightingale
cec2287b6a Use the BUS_DMA_NOWRITE flag to expose and create the read-only VT-d
IOMMU mappings.

Reviewed by:	kib
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D19729
2019-03-27 20:15:51 +00:00
Mark Johnston
a273e09cb2 Fix pidfile_open(3) to handle relative paths with multiple components.
r322369's use of basename(3) was incorrect and worked by accident so
long as the pidfile path was absolute or consisted of a single
component.  Fix the basename() usage and add a regression test.

Reported by:	0mp
Reviewed by:	cem
MFC after:	3 days
Differential Revision:	https://reviews.freebsd.org/D19728
2019-03-27 19:40:18 +00:00
Mark Johnston
963ae7a63e Stop using -fdebug-prefix-map to map the object directory.
We were doing so as a workaround for the problem addressed by r345593, so
it's no longer necessary.

Reviewed by:	jhb
Discussed with:	emaste
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D19705
2019-03-27 19:34:19 +00:00
Mark Johnston
1fc6236006 Prepend DW_AT_comp_dir to relative line number directory table entries.
Relative directories may appear in the line number program for a CPU if
files were included via a relative path, for instance with "-I.".
Previously, dwarf_srclines(3) and dwarf_srcfiles(3) would return the
relative path, so addr2line, for instance, would do the same.  However,
we can get an absolute path by prepending the compilation directory, so
change libdwarf to do that to improve compatibility with GNU binutils
and since it is more useful in general.

Reviewed by:	jhb
Discussed with:	emaste
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D19705
2019-03-27 19:32:21 +00:00
Bruce Evans
014ddcbce4 Fix accessing pixels under the mouse cursor:
Reading of single pixels didn't look under the cursor.

Copying of 1x1 bitmaps didn't look under the cursor for either reading
or writing.

Copying of larger bitmaps looked under the cursor for at most the
destination.

Copying of larger bitmaps looked under a garbage cursor (for the Display
bitmap) when the destination is a MEMBUF.  The results are not used, so
this only wasted time and flickered the cursor.

Writing of single pixels looked under a garbage cursor for MEMBUF
destinations, as above except this clobbered the current cursor and
didn't update the MEMBUF.  Writing of single pixels is not implemented
yet in depths > 8.  Otherwise, writing of single pixels worked.  It was
the only working case for accessing pixels under the cursor.

Clearing of MEMBUFs wasted time freezing the cursor in the Display bitmap.

The fixes abuse the top bits in the color arg to the cursor freezing
function to control the function.  Also clear the top 8 bits so that
applications can't clobber the control bits or create 256 aliases for
every 24-bit pixel value in depth 32.

Races fixed:

Showing and hiding the cursor only tried to avoid races with the mouse
event signal handler for internal operations.  There are still many
shorter races from not using volatile or sig_atomic_t for the variable
to control this.  This variable also controls freezes, and has more
complicated states than before.

The internal operation of unfreezing the cursor opened a race window
by unsetting the signal/freeze variable before showing the cursor.
2019-03-27 18:03:34 +00:00