[lkml]   [2001]   [May]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] x86 page fault handler not interrupt safe
Nigel Gamble wrote:
> On Mon, 7 May 2001, Linus Torvalds wrote:
> > On Mon, 7 May 2001, Brian Gerst wrote:
> > > This patch will still cause the user process to seg fault: The error
> > > code on the stack will not match the address in %cr2.
> >
> > You've convinced me. Good thinking. Let's do the irq thing.
> I've actually seen user processes seg faulting because of this with the
> fully preemptible kernel patch applied. The fix we used in that patch
> was to use an interrupt gate for the fault handler, then to simply
> restore the interrupt state:

Keep in mind that regs->eflags could be from user space, and could have
some undesirable flags set. That's why I did a test/sti instead of
reloading eflags. Plus my patch leaves interrupts disabled for the
minimum time possible.


Brian Gerst
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 12:52    [W:0.050 / U:0.528 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site