With CORE, it is possible that the compiler may produce code like
r1 = 0 // relocation instruction
map_ptr += r1
...
Currently verifier does not allow map_ptr arithmetic, even for adding with 0.
This patch set relaxed the condition so the above code can be accepted.
Patch #1 is the kernel implementation and Patch #2 added selftest tests to
cover the new functionality.
Changelog:
v2 -> v3:
. only change hashmap subtest to use non-inline version of check_default(),
other subtests still used inline version. This will provide coverage for
both inline and non-inline check_default(). (Andrey)
v1 -> v2:
. add comment to clarify smin_val represents the const. (Andrii)
Yonghong Song (2):
bpf: permit map_ptr arithmetic with opcode add and offset 0
selftests/bpf: add test for map_ptr arithmetic
kernel/bpf/verifier.c | 4 +++
.../selftests/bpf/progs/map_ptr_kern.c | 10 +++++-
.../testing/selftests/bpf/verifier/map_ptr.c | 32 +++++++++++++++++++
3 files changed, 45 insertions(+), 1 deletion(-)
--
2.24.1
