Occasionally, clang (e.g. version 3.8.1) translates a sum between two constant operands using a BPF_OR instead of a BPF_ADD. The verifier is currently not handling this scenario, and the destination register type becomes UNKNOWN_VALUE even if it's still storing a constant. As a result, the destination register cannot be used as argument to a helper function expecting a ARG_CONST_STACK_*, limiting some use cases. Modify the verifier to handle this case, and add a few tests to make sure all combinations are supported, and stack boundaries are still verified even with BPF_OR. Signed-off-by: Gianluca Borello <g.borello@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net> |
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arraymap.c | ||
bpf_lru_list.c | ||
bpf_lru_list.h | ||
cgroup.c | ||
core.c | ||
hashtab.c | ||
helpers.c | ||
inode.c | ||
Makefile | ||
percpu_freelist.c | ||
percpu_freelist.h | ||
stackmap.c | ||
syscall.c | ||
verifier.c |