tech-userlevel archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Re: RFC: setjmp/longjmp (and friends) for a new port

On Sep 1, 2009, at 1:11 PM, Christos Zoulas wrote:

In article <>,
Joerg Sonnenberger  <> wrote:
On Tue, Sep 01, 2009 at 02:53:36PM +0200, Joerg Sonnenberger wrote:
On Tue, Sep 01, 2009 at 12:54:14AM -0700, Matt Thomas wrote:
So I'm thinking that in MIPS64, setjmp/longjmp can just be versions of
longjmp need to be able to set the return value, but that's a minor

Can anyone think of valid reasons not do that?

getcontext/setcontext modify the signal mask, setjmp/longjmp don't.

OK, let me partially take that back. setjmp/longjmp may restore the
signal mask, SUS leaves that as undefined behavior. As such it is valid to use getcontext/setcontext for that. Depending on the ABI patching the output of getcontext should be good enough for longjmp, e.g. set the IP
to a ret and the return value register to the expected data.

Well, you could clear the uc_flags for signal mask and fpu before calling
setcontext to implement this, no?

Exactly what I thinking.  (well, not FP).

Home | Main Index | Thread Index | Old Index