On Wednesday 11 October 2017 09:42 AM, Michael Ellerman wrote:
> Kamalesh Babulal <kamal...@linux.vnet.ibm.com> writes:
>
>> Use WARN_ON(), while running out of stubs in stub_for_addr()
>> and abort loading of the module instead of BUG_ON().
>
> Thanks. This looks good in principle. Have you actually tested it to
> make sure we do in fact gracefully fail the module load?
>
Thanks for the review. I tested with little hackish version of this patch:
+ if (!strncmp(me->name, "live", 4))
+ j = 100;
+ for (i = 0; stub_func_addr(stubs[i].funcdata); i+=j) {
+ if (WARN_ON(i >= num_stubs))
+ return 0;
and it fails gracefully.
# modprobe livepatch-sample
modprobe: ERROR: could not insert 'livepatch_sample': Unknown symbol in module,
or unknown parameter (see dmesg)
# echo $?
1
# dmesg
------------[ cut here ]------------
WARNING: CPU: 2 PID: 2836 at arch/powerpc/kernel/module_64.c:526
apply_relocate_add+0x71c/0xb00
--
cheers,
Kamalesh.
