Subject: 2.1.126 fp avoidance

From: Philip Blundell <[email-masked]>
Date: Tue, 27 Oct 1998 19:17:32 +0000

Hi Russell (I've posted this to the mailing list in case others are 
interested...),

The FP avoidance code in entry-armv.S has a rather silly bug.  If you 
look at the __und_usr path, it sets up R9 and R14 with return values, loads 
R10 with current and then clobbers R14 while setting `used_math'.  The net 
effect is that you get a branch through zero whenever a real undefined 
instruction is encountered.  Oops.

The fix is hopefully obvious enough that I don't need to send a patch. :-)

Irritatingly both `init' and `bash' on my machine seem to be trying to 
execute RFS instructions now and of course we don't catch them.  Curses.

p.

unsubscribe: body of `unsubscribe linux-arm' to [email-masked]

---

From: Philip Blundell <[email-masked]>
Date: Tue, 27 Oct 1998 21:33:55 +0000

>execute RFS instructions now and of course we don't catch them.  Curses.

I found the source of these (I think).  It turns out that the glibc floating 
point initialisation does an RFS followed by an WFS so that it can preserve 
the state of the "reserved" bits.  So just ignoring RFS in the same way as WFS 
should be OK - I'll try it tomorrow.

p.