Only key difference that calloc(), in contrast to rellocarray(),
is zero-initializing. The overhead is hard to measure on today's
machines, and it's safer programming practise to always allocate
zero-initialized, so one can't forget to do it explicitly.
Cocci rule:
@@
expression COUNT;
expression LEN;
@@
- xallocarray(COUNT,LEN)
+ calloc(COUNT,LEN)
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Using calloc() instead of malloc() as preventive measure, so there
never can be any hidden bugs or leaks due uninitialized memory.
The extra cost of using this compiler intrinsic should be practically
impossible to measure - in many cases a good compiler can even deduce
if certain areas really don't need to be zero'd (because they're written
to right after allocation) and create more efficient machine code.
The code pathes in question are pretty cold anyways, so it's probably
not worth even thinking about potential extra runtime costs.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Wrapping ScreenRec's function pointers is problematic for many reasons,
so use the new screen close notify hook instead.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
The ‘RRCrtcNotify() and RRCrtcSet() functions are exported, so there's chance
that a buggy driver could call them with NULL parameter, leading to segfault.
Those are hard to trace, so it's better having a BUG_* check here.
| ../randr/rrcrtc.c: In function ‘RRCrtcNotify’:
| ../randr/rrcrtc.c:187:5: warning: use of NULL ‘outputs’ where non-null expected [CWE-476] [-Wanalyzer-null-argument]
| 187 | memcpy(crtc->outputs, outputs, numOutputs * sizeof(RROutputPtr));
| | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| ../randr/rrcrtc.c: In function ‘RRCrtcSet’:
| ../randr/rrcrtc.c:742:20: warning: dereference of NULL ‘outputs’ [CWE-476] [-Wanalyzer-null-dereference]
| 742 | if (outputs[o]) {
| | ~~~~~~~^~~
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
If there's no data to send, the whole reply payload can be skipped entirely.
This can also ease the whole code flow, and we don't need to rely on the
individual copy loops never trying to dereference a NULL pointer.
(what the analyzer can't proof). Also scoping several some variables that
are only used when there actually is data to send.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
If there's no data to send, the whole reply payload can be skipped entirely.
This can also ease the whole code flow, and we don't need to rely on the
individual copy loops never trying to dereference a NULL pointer.
(what the analyzer can't proof). Also scoping several some variables that
are only used when there actually is data to send.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Moving payload buffer assembly right into the same branch where the buffer is
allocated, so making the whole code flow easier to understand. Also moving the
byteswap there (when the fields should still be in CPU cache), instead of having
some callback doing it much later, so even more simplication.
As a nice by-product, that's also reducing some analyzer noise.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
The code can be much simpler by just using CopySwap32Write().
And we also don't need the callback in WriteSwappedDataToClient(),
just call the corresponding write function directly.
This also makes some analyzer warnings go away.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Make it a bit easier to understand how exactly the name string is copied into
the reply payload: just do the little memcpy() right where the target position
is decided any the rest of the payload is filled.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Instead of relying on memcpy() coping with NULL buffer when size == 0,
move the call to the branch where we actually have things to copy.
This also silences yet another analyzer warning.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Instead of relying on memcpy() coping with NULL buffer when size == 0,
move the call to the branch where we actually have things to copy.
This also silences yet another analyzer warning.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Instead of relying on memcpy() coping with NULL buffer when size == 0,
move the call to the branch where we actually have things to copy.
This also silences yet another analyzer warning.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Simplifying the code flow allocating/checking/copying some buffers in
RRConfigureOutputProperty() and RRConfigureProviderProperty() so it's
easier to understand for both the human reader as well as the analyzer.
Depending on whether we have elements to process, a temporary buffer needs
to be allocated, checked for successful allocation and copy over data. The
way it's currently done is technically correct, but unnecessarily complex to
understand: instead of just branching on whether there are elements and doing
all the buffer-related things only then, the branching is done just somewhere
in the middle, only on checking for allocation failure, and relying on both
calloc() and memcpy() not doing weird things when size is zero.
It's easy to simplify by putting it all behind one if statement and so make
things easier for both human reader as well as the analyzer (so it's not
spilling out false alarms here anymore) and also drops unnecessary calls
in the zero-size case.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Enrico Weigelt, metux IT consult