* Stefan Liebler:
if the specified needle crosses a page-boundary, the s390-z15 ifunc
variant of strstr truncates the needle which results in invalid
results.
This is fixed by loading the needle beyond the page boundary to v18
instead of v16. The bug is sometimes observable in test-strstr.c in
check1() and check2() as the haystack and needle is stored on
stack. Thus the needle can be on a page boundary.
(GNU style is “check1 and check2”, no parentheses.)
check2 is now extended to test haystack / needles located on stack, at
end of page and on two pages.
The test change looks okay to me. I haven't reviewed the assembler
change. I think you can commit that as the architecture maintainer.
We will need help from your team with testing the downstream fix. Do
you think we should fix this proactively in Red Hat Enterprise Linux 8.1
as well? It received the backport of the new strstr implementation,
too.
Thanks,
Florian