Messages in this thread | | | Date | Fri, 27 Jan 2006 12:28:07 -0700 | From | "Jeff V. Merkey" <> | Subject | Re: 2.6.14 kernels and above copy_to_user stupidity with IRQ disabled check |
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Phillip Susi wrote:
> jmerkey@ns1.utah-nac.org wrote: > >> OK. Got it. I guess I need to restructure. And BTW, This was a >> code fragment >> only, the spinlock gets released when -EFAULT is called -- was just >> an example. >> >> Jeff > > > Unless you have redefined EFAULT in some strange and hideous way, it > is not "called" and doesn't free the spinlock. EFAULT is defined as a > literal integer, so you're just returning a number without freeing the > spinlock. > > If you have redefined EFAULT to a macro function call or whatever, > then don't do that, it's REALLY horrible coding practice. > > No. I posted a code fragment as an example. Here's the actual code:
int dump_regen(VIRTUAL_SETUP *s, ULONG count) { register int i = 0; VIRTUAL_SETUP *v;
spin_lock_irqsave(®en_lock, regen_flags); v = regen_head; while (v) { if (i >= count) { spin_unlock_irqrestore(®en_lock, regen_flags); return -EFAULT; }
err = copy_to_user(&s[i++], v, sizeof(VIRTUAL_SETUP)); if (err) { spin_unlock_irqrestore(®en_lock, regen_flags); return err; }
v = v->next; } spin_unlock_irqrestore(®en_lock, regen_flags); return 0; }
Needless to say, this has been restructured to this:
int dump_regen(VIRTUAL_SETUP *s, ULONG count) { register int i = 0; VIRTUAL_SETUP *v;
spin_lock_irqsave(®en_lock, regen_flags); v = regen_head; while (v) { if (i >= count) { spin_unlock_irqrestore(®en_lock, regen_flags); return 0; }
P_Copy(&s[i++], v, sizeof(VIRTUAL_SETUP)); v = v->next; } spin_unlock_irqrestore(®en_lock, regen_flags); return 0; }
Jeff
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