| Message ID | 20100602053308.GA24509@drongo (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
On Mit, 2010-06-02 at 15:33 +1000, Paul Mackerras wrote: > This fixes a sporadic oops at boot on G5 Power Macs. The table_end > variable has the address of the last byte of the table. Adding on > PAGE_SIZE means we flush too much, and if the page after the table > is not mapped for any reason, the kernel will oops. Instead we add > on 1 because flush_dcache_range() interprets its second argument as > the first byte past the range to be flushed. > > Signed-off-by: Paul Mackerras <paulus@samba.org> Reviewed-by: Michel Dänzer <michel@daenzer.net> Tested-by: Michel Dänzer <michel@daenzer.net> Thanks for the good catch, Paul. > --- > > diff --git a/drivers/char/agp/uninorth-agp.c b/drivers/char/agp/uninorth-agp.c > index 6f48931..9aaa0eb 100644 > --- a/drivers/char/agp/uninorth-agp.c > +++ b/drivers/char/agp/uninorth-agp.c > @@ -413,7 +413,7 @@ static int uninorth_create_gatt_table(struct agp_bridge_data *bridge) > bridge->gatt_table_real = (u32 *) table; > /* Need to clear out any dirty data still sitting in caches */ > flush_dcache_range((unsigned long)table, > - (unsigned long)(table_end + PAGE_SIZE)); > + (unsigned long)table_end + 1); > bridge->gatt_table = vmap(pages, (1 << page_order), 0, PAGE_KERNEL_NCG); > > if (bridge->gatt_table == NULL)
diff --git a/drivers/char/agp/uninorth-agp.c b/drivers/char/agp/uninorth-agp.c index 6f48931..9aaa0eb 100644 --- a/drivers/char/agp/uninorth-agp.c +++ b/drivers/char/agp/uninorth-agp.c @@ -413,7 +413,7 @@ static int uninorth_create_gatt_table(struct agp_bridge_data *bridge) bridge->gatt_table_real = (u32 *) table; /* Need to clear out any dirty data still sitting in caches */ flush_dcache_range((unsigned long)table, - (unsigned long)(table_end + PAGE_SIZE)); + (unsigned long)table_end + 1); bridge->gatt_table = vmap(pages, (1 << page_order), 0, PAGE_KERNEL_NCG); if (bridge->gatt_table == NULL)
This fixes a sporadic oops at boot on G5 Power Macs. The table_end variable has the address of the last byte of the table. Adding on PAGE_SIZE means we flush too much, and if the page after the table is not mapped for any reason, the kernel will oops. Instead we add on 1 because flush_dcache_range() interprets its second argument as the first byte past the range to be flushed. Signed-off-by: Paul Mackerras <paulus@samba.org> ---