- Fix an old bug of possible lock against oneself (uao_detach_locked() is
called from uao_swap_off() with uao_list_lock acquired). Also removes
the try-lock dance in uao_swap_off(), since the lock order changes.
This consists of two parts:
- for NetBSD/i386 and NetBSD/AMD64 with -m32, use a default stack
alignment of 23bit as specified by the ABI
- ensure that double and long long variables on the stack are by default
only aligned to 32bit, if there is nothing else in the function
needing a larger stack alignment
The combination ensures that SSE variables on the stack trigger the
realignment logic, but just using double or long long doesn't.
While there, don't pretend to support the Permedia2 non-V - I don't have the
hardware and it has never been tested in the first place. The only hardware
this has been tested on is a TechSource Raptor GFX 8P / Sun PGX32 which
happens to be a Permedia2V with Sun firmware.
while there, fix pm2fb_bitblt() packed mode, for real this time
TODO:
- use packed mode when uploading glyphs
- let the hardware do the alpha blending if possible
- mode setting
the TLS pointer, therefore wrecking the pthread environement.
Some ports had _UC_TLSBASE flag or equivalent (_UC_UNIQUE on alpha)
that controlled whether setcontext() would change the TLS pointer.
This change let libpthread override setcontext() with its own version
that unsets _UC_TLSBASE, enabling safe usage of setcontext() with
-lpthread.
We also have the following required changes here:
- rename alpha's _UC_UNIQUE into _UC_TLSBASE
- add _UC_TLSBASE definition in header file for all ports
(powerpc, sh3, sparc and sparc64 lack the implementation for now)
- introduce a libc stub that can be overriden for setcontext()
- modify MD libcs swapcontext() implementations so that they use the
setcontext() libc stub instead of doing a plain system call.
While we are there:
- document various MD _UC_* flags in header file
- add libc and libpthread tests for swapcontext() behavior
(hopefully helpful to spot MD problems introduced with this change)
Future work:
- Deciding whether kernel support or _UC_TLSBASE should be added for
powerpc, sh3, sparc and sparc64 is left to portmasters
sparc64
Approved by core@
