[Toybox] top -H segfault

[enh]

On Tue, May 24, 2016 at 2:23 PM, Rob Landley <rob at landley.net> wrote:
> On 05/23/2016 07:59 PM, enh wrote:
>> just running home, so no time to debug further, but in case you
>> haven't seen this yet... plain "top -H" is segfaulting for me before
>> displaying anything.
>
> Hmmm, no I hadn't seen that. But I do see that ./toybox top -H isn't
> displaying anything when I do that...
>
> Ah. The active node logic changed and I missed updating a spot. (I
> tested it, but nothing I tested used "collate". Oops. I need to work out
> how to add this sort of stuff to the test suite. Probably have to use
> archival snapshots of "ps" contents to get consistent reproducible test
> output...)
>
>> Program received signal SIGSEGV, Segmentation fault.
>>                                                     0x00000000004219c1
>> in top_common (filter=filter at entry=0x41f738 <merge_deltas>) at
>> toys/posix/ps.c:1349
>> 1349      if (old.count && (!new.count || *otb->slot < *ntb->slot)) {
>
> Null dereference on *otb and *ntb because now you traverse the tree in
> order and keep each node that has a non-null ->extra field.
>
> Try now?

(sorry, was too busy to get back to this until now...)

yes, works for me now, and i probably wouldn't have found that myself
in a reasonable amount of time anyway!

"toybox top -b -n 1 -o
pid,tid,user,pr,ni,%cpu,s,vsz,rss,pcy,command,name -s 6" now looks
close enough to what dumpstate wants for bug reports that i can give
it a go...

> Rob



-- 
Elliott Hughes - http://who/enh - http://jessies.org/~enh/
Android native code/tools questions? Mail me/drop by/add me as a reviewer.