linux-stable/kernel/bpf
Gianluca Borello 3c839744b3 bpf: Preserve const register type on const OR alu ops
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>
2016-12-05 13:40:05 -05:00
..
arraymap.c bpf: Add bpf_current_task_under_cgroup helper 2016-08-12 21:49:41 -07:00
bpf_lru_list.c bpf: Fix compilation warning in __bpf_lru_list_rotate_inactive 2016-11-16 11:30:56 -05:00
bpf_lru_list.h bpf: Add percpu LRU list 2016-11-15 11:50:20 -05:00
cgroup.c bpf: Add new cgroup attach type to enable sock modifications 2016-12-02 13:46:08 -05:00
core.c bpf: add helper for retrieving current numa node id 2016-10-22 17:05:52 -04:00
hashtab.c bpf: Add BPF_MAP_TYPE_LRU_PERCPU_HASH 2016-11-15 11:50:20 -05:00
helpers.c bpf: add helper for retrieving current numa node id 2016-10-22 17:05:52 -04:00
inode.c bpf: allow for mount options to specify permissions 2016-11-27 20:38:47 -05:00
Makefile cgroup: add support for eBPF programs 2016-11-25 16:25:52 -05:00
percpu_freelist.c bpf: introduce percpu_freelist 2016-03-08 15:28:31 -05:00
percpu_freelist.h bpf: introduce percpu_freelist 2016-03-08 15:28:31 -05:00
stackmap.c bpf: add BPF_CALL_x macros for declaring helpers 2016-09-09 19:36:04 -07:00
syscall.c bpf: Add new cgroup attach type to enable sock modifications 2016-12-02 13:46:08 -05:00
verifier.c bpf: Preserve const register type on const OR alu ops 2016-12-05 13:40:05 -05:00