Ilya Leoshkevich daf48f68fc s390/bpf: Fix optimizing out zero-extensions ...

commit db7bee653859ef7179be933e7d1384644f795f26 upstream.

Currently the JIT completely removes things like `reg32 += 0`,
however, the BPF_ALU semantics requires the target register to be
zero-extended in such cases.

Fix by optimizing out only the arithmetic operation, but not the
subsequent zero-extension.

Reported-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend")
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2021-09-26 13:37:27 +02:00

..

bpf_jit_comp.c

s390/bpf: Fix optimizing out zero-extensions

2021-09-26 13:37:27 +02:00

bpf_jit.h

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bpf_jit.S

s390: use expoline thunks in the BPF JIT

2018-05-25 16:17:33 +02:00

Makefile

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