Hi,
On Fri, Aug 09, 2013 at 12:11:15AM +0300, Aaro Koskinen wrote:
> On Thu, Aug 08, 2013 at 12:01:08PM +0100, Russell King - ARM Linux wrote:
> > On Wed, Aug 07, 2013 at 02:26:09AM +0300, Aaro Koskinen wrote:
> > > [ 0.258589] [ffff1224] *pgd=00000000, *pte=11fff0cb000001f1, *ppte=11fff00a00000000
> >
> > BTW, your oops dump is interesting for another reason - the above.
> > You seem to have 64-bit page table entries above.
>
> Yes, this is worrying...
>
> > Now, this is totally legal C:
> >
> > unsigned int val = 0x12345678;
> >
> > printk("%08llx\n", (long long)val);
> >
> > and it should produce "12345678" but I'm willing to bet with your compiler
> > it produces "12345678xxxxxxxx" where xxxxxxxx is just what happens to be
> > sitting in some register. IOW, I think you have a compiler bug here. Can
> > you investigate what's going on with this yourself please?
>
> I made a quick check and added that to the fault handler, and yes,
> the result is crap:
>
> +unsigned int test_bar = 0x12345678;
> void show_pte(struct mm_struct *mm, unsigned long addr)
> {
> pgd_t *pgd;
>
> + printk(KERN_INFO "%d\n", 0);
> + printk(KERN_INFO "%llx\n", (long long)test_bar);
> + printk(KERN_INFO "%d %llx\n", 1, (long long)test_bar);
> [...]
> [ 0.261788] 0
> [ 0.263849] 1234567800000000
> [ 0.267201] 1 0
Still one more thing. Once I apply the FIQ patch and initiate a crash
from userspace, results are as expected:
# echo c > /proc/sysrq-trigger
[ 75.547504] SysRq : Trigger a crash
[ 75.562891] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[ 75.594259] 0
[ 75.607326] 12345678
[ 75.620607] 1 12345678
[ 75.633818] pgd = c10f0000
[ 75.647114] [00000000] *pgd=1195d831, *pte=00000000, *ppte=00000000
A.
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
