OpenCloudOS-Kernel/kernel/bpf
Alexei Starovoitov 4923ec0b10 bpf: simplify verifier register state assignments
verifier is using the following structure to track the state of registers:
struct reg_state {
    enum bpf_reg_type type;
    union {
        int imm;
        struct bpf_map *map_ptr;
    };
};
and later on in states_equal() does memcmp(&old->regs[i], &cur->regs[i],..)
to find equivalent states.
Throughout the code of verifier there are assignements to 'imm' and 'map_ptr'
fields and it's not obvious that most of the assignments into 'imm' don't
need to clear extra 4 bytes (like mark_reg_unknown_value() does) to make sure
that memcmp doesn't go over junk left from 'map_ptr' assignment.

Simplify the code by converting 'int' into 'long'

Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-10 22:43:18 -04:00
..
Makefile bpf: introduce percpu_freelist 2016-03-08 15:28:31 -05:00
arraymap.c bpf: check for reserved flag bits in array and stack maps 2016-03-08 15:28:31 -05:00
core.c bpf: Mark __bpf_prog_run() stack frame as non-standard 2016-02-29 08:35:11 +01:00
hashtab.c bpf: pre-allocate hash map elements 2016-03-08 15:28:31 -05:00
helpers.c bpf: avoid copying junk bytes in bpf_get_current_comm() 2016-03-09 23:27:30 -05:00
inode.c bpf, inode: allow for rename and link ops 2015-12-12 18:44:23 -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: support bpf_get_stackid() and bpf_perf_event_output() in tracepoint programs 2016-04-07 21:04:26 -04:00
syscall.c bpf: add missing map_flags to bpf_map_show_fdinfo 2016-03-25 11:36:41 -04:00
verifier.c bpf: simplify verifier register state assignments 2016-04-10 22:43:18 -04:00