linux-stable/kernel/bpf
Edward Cree dc503a8ad9 bpf/verifier: track liveness for pruning
State of a register doesn't matter if it wasn't read in reaching an exit;
 a write screens off all reads downstream of it from all explored_states
 upstream of it.
This allows us to prune many more branches; here are some processed insn
 counts for some Cilium programs:
Program                  before  after
bpf_lb_opt_-DLB_L3.o       6515   3361
bpf_lb_opt_-DLB_L4.o       8976   5176
bpf_lb_opt_-DUNKNOWN.o     2960   1137
bpf_lxc_opt_-DDROP_ALL.o  95412  48537
bpf_lxc_opt_-DUNKNOWN.o  141706  78718
bpf_netdev.o              24251  17995
bpf_overlay.o             10999   9385

The runtime is also improved; here are 'time' results in ms:
Program                  before  after
bpf_lb_opt_-DLB_L3.o         24      6
bpf_lb_opt_-DLB_L4.o         26     11
bpf_lb_opt_-DUNKNOWN.o       11      2
bpf_lxc_opt_-DDROP_ALL.o   1288    139
bpf_lxc_opt_-DUNKNOWN.o    1768    234
bpf_netdev.o                 62     31
bpf_overlay.o                15     13

Signed-off-by: Edward Cree <ecree@solarflare.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-15 16:32:33 -07:00
..
arraymap.c bpf: Add syscall lookup support for fd array and htab 2017-06-29 13:13:25 -04:00
bpf_lru_list.c bpf: lru: Lower the PERCPU_NR_SCANS from 16 to 4 2017-04-17 13:55:52 -04:00
bpf_lru_list.h bpf: Add percpu LRU list 2016-11-15 11:50:20 -05:00
cgroup.c bpf: BPF support for sock_ops 2017-07-01 16:15:13 -07:00
core.c bpf: add BPF_J{LT,LE,SLT,SLE} instructions 2017-08-09 16:53:56 -07:00
devmap.c bpf: devmap fix mutex in rcu critical section 2017-08-07 14:13:04 -07:00
hashtab.c bpf: Add syscall lookup support for fd array and htab 2017-06-29 13:13:25 -04:00
helpers.c bpf: rename ARG_PTR_TO_STACK 2017-01-09 16:56:27 -05:00
inode.c bpf: Implement show_options 2017-07-06 03:31:46 -04:00
lpm_trie.c bpf: fix wrong exposure of map_flags into fdinfo for lpm 2017-05-25 13:44:28 -04:00
Makefile bpf/verifier: rework value tracking 2017-08-08 17:51:34 -07:00
map_in_map.c bpf: Add syscall lookup support for fd array and htab 2017-06-29 13:13:25 -04:00
map_in_map.h bpf: Add syscall lookup support for fd array and htab 2017-06-29 13:13:25 -04:00
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: fix wrong exposure of map_flags into fdinfo for lpm 2017-05-25 13:44:28 -04:00
syscall.c bpf: Extend check_uarg_tail_zero() checks 2017-08-08 18:11:17 -07:00
tnum.c bpf/verifier: track signed and unsigned min/max values 2017-08-08 17:51:34 -07:00
verifier.c bpf/verifier: track liveness for pruning 2017-08-15 16:32:33 -07:00