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| author | Ilya Leoshkevich <iii@linux.ibm.com> | 2020-07-17 18:53:23 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-07-21 13:26:24 -0700 |
| commit | 7477d43be5b1448bc0d4c85cb185a0144cc080e1 (patch) | |
| tree | b793d3f549d3590bd3df11bd09d276c22c94c62c /tools/perf/scripts/python/futex-contention.py | |
| parent | 2ea485980734500d41e4530f038d94a21e2b3b34 (diff) | |
s390/bpf: Fix sign extension in branch_ku
Both signed and unsigned variants of BPF_JMP | BPF_K require
sign-extending the immediate. JIT emits cgfi for the signed case,
which is correct, and clgfi for the unsigned case, which is not
correct: clgfi zero-extends the immediate.
s390 does not provide an instruction that does sign-extension and
unsigned comparison at the same time. Therefore, fix by first loading
the sign-extended immediate into work register REG_1 and proceeding
as if it's BPF_X.
Fixes: 4e9b4a6883dd ("s390/bpf: Use relative long branches")
Reported-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Seth Forshee <seth.forshee@canonical.com>
Link: https://lore.kernel.org/bpf/20200717165326.6786-3-iii@linux.ibm.com
Diffstat (limited to 'tools/perf/scripts/python/futex-contention.py')
0 files changed, 0 insertions, 0 deletions