Re: [patch] edac i5000: fix pointer math in i5000_get_mc_regs()

Dan Carpenter
2012-03-02T19:09:32Z

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On Fri, Mar 02, 2012 at 10:00:06AM +0100, walter harms wrote:
> > diff --git a/drivers/edac/i5000_edac.c b/drivers/edac/i5000_edac.c
> > index 4dc3ac2..fcdc4ab 100644
> > --- a/drivers/edac/i5000_edac.c
> > +++ b/drivers/edac/i5000_edac.c
> > @@ -1130,7 +1130,7 @@ static void i5000_get_mc_regs(struct mem_ctl_info *mci)
> > pci_read_config_dword(pvt->system_address, AMBASE,
> > (u32 *) & pvt->ambase);
> > pci_read_config_dword(pvt->system_address, AMBASE + sizeof(u32),
> > - ((u32 *) & pvt->ambase) + sizeof(u32));
> > + (u32 *)((char *) &pvt->ambase + sizeof(u32)));
> >
> > maxdimmperch = pvt->maxdimmperch;
> > maxch = pvt->maxch;
>
> i think this is hard to understand. personally i would prefer a union or other
> more obvious solutions. my suggestion would be to get rid of this.
>
> u32 bottom,top;
> pci_read_config_dword(pvt->system_address, AMBASE,
> &bottom);
> pci_read_config_dword(pvt->system_address, AMBASE+ sizeof(u32),
> &top);
> maxdimmperch=(u64)top<<32|bottom;
>
> you can find this pattern in other parts of the kernel also.
>

Sure. I want to do this again anyway because I see I've missed some
other parts which have the same bug. I'll resend a patch later.

regards,
dan carpenter

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