* struct sigacts gets a new sigact_sigdesc structure, which has the
sigaction and the trampoline/version. Version 0 means "legacy kernel
provided trampoline". Other versions are coordinated with machine-
dependent code in libc.
* sigaction1() grows two more arguments -- the trampoline pointer and
the trampoline version.
* A new __sigaction_sigtramp() system call is provided to register a
trampoline along with a signal handler.
* The handler is no longer passed to sensig() functions. Instead,
sendsig() looks up the handler by peeking in the sigacts for the
process getting the signal (since it has to look in there for the
trampoline anyway).
* Native sendsig() functions now select the appropriate trampoline and
its arguments based on the trampoline version in the sigacts.
Changes to libc to use the new facility will be checked in later. Kernel
version not bumped; we will ride the 1.6C bump made recently.
- the signal trampoline address is given to the kernel by a sigaction()
fourth argument
- we introduce an irix_emuldata structure to keep track of the signal
trampoline address
- we don't support per-sigaction signal trampolines, we only do per-process
- now that we use the IRIX libc signal trampoline, we do not have to handle
the errno update from the signal trampoline
- it is possible that IRIX 5 signal delivery works too, since theses binaries
will come with their own signal trampoline
when SA_SIGINFO is used. The IRIX process will hence find the expected
information using the third argument of the signal handler.
We do not provide code and siginfo yet.
- do not save/and restore registers that should not be saved and restore
- do give an accurate sigcontext pointer to the signal handler
- do use the struct sigreturna from IRIX.
This eliminates panics and hangs in certain circonstances
Also some cosmetic changes with tabs usage
perry