[parisc-linux] 2.5 randomly kills applications with page faults

[James Bottomley <James.Bottomley@steeleye.com>]

I find when booting 2.5.51 up on a C380 that applications seem to take random 
page faults and die.  It seems that the more heavily an application does file 
accesses, the more likely it is to suffer from this.

In debugging the problems, so far it has always been stack manipulation 
instructions in the user level code causing this.  Further, on adding a 
register dump to the page fault debugging code, the reason is that the stack 
pointer is way out of where it should be for a user process (around 0x4f000), 
so I surmise it got clobbered on a rare return path from kernel to user.

Does anyone have any additional information and pointers?  I'm trying to audit 
entry.S to see if there is a little used path that can clobber the stack, but 
my parisc assembly isn't the best...

James