s390: fix br_r1_trampoline for machines without exrl
authorMartin Schwidefsky <schwidefsky@de.ibm.com>
Mon, 6 Aug 2018 12:26:39 +0000 (14:26 +0200)
committerMartin Schwidefsky <schwidefsky@de.ibm.com>
Tue, 7 Aug 2018 11:38:16 +0000 (13:38 +0200)
commit26f843848bae973817b3587780ce6b7b0200d3e4
tree99617d15709b26b2906ab6f661b7bdd20bd8c597
parent5eda25b10297684c1f46a14199ec00210f3c346e
s390: fix br_r1_trampoline for machines without exrl

For machines without the exrl instruction the BFP jit generates
code that uses an "br %r1" instruction located in the lowcore page.
Unfortunately there is a cut & paste error that puts an additional
"larl %r1,.+14" instruction in the code that clobbers the branch
target address in %r1. Remove the larl instruction.

Cc: <stable@vger.kernel.org> # v4.17+
Fixes: de5cb6eb51 ("s390: use expoline thunks in the BPF JIT")
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
arch/s390/net/bpf_jit_comp.c