From 30ed5b1cc6aa0efe6ac099b66d33d46c7c0c6b47 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn-Egil=20Dahlberg?= Date: Tue, 7 Apr 2015 12:58:15 +0200 Subject: erts: Fix deep colliding hash values in maps:from_list/1 Reported-by: Jesper Louis Andersen --- erts/emulator/beam/erl_map.c | 30 +++++++++++++++++++++++++++++- erts/emulator/test/map_SUITE.erl | 10 +++++++++- 2 files changed, 38 insertions(+), 2 deletions(-) (limited to 'erts/emulator') diff --git a/erts/emulator/beam/erl_map.c b/erts/emulator/beam/erl_map.c index 20a17bcd24..3bb3622194 100644 --- a/erts/emulator/beam/erl_map.c +++ b/erts/emulator/beam/erl_map.c @@ -679,7 +679,35 @@ static Eterm hashmap_from_chunked_array(ErtsHeapFactory *factory, hxnode_t *hxns DECLARE_ESTACK(stack); Eterm res = NIL, *hp = NULL, *nhp; - ASSERT(n > 1); + + /* if we get here with only one element then + * we have eight levels of collisions + */ + + if (n == 1) { + res = hxns[0].val; + v = hxns[0].hx; + for (d = 7; d > 0; d--) { + slot = maskval(v,d); + hp = erts_produce_heap(factory, HAMT_NODE_BITMAP_SZ(1), HALLOC_EXTRA); + hp[0] = MAP_HEADER_HAMT_NODE_BITMAP(1 << slot); + hp[1] = res; + res = make_hashmap(hp); + } + + slot = maskval(v,0); + hp = erts_produce_heap(factory, (is_root ? 3 : 2), 0); + + if (is_root) { + hp[0] = MAP_HEADER_HAMT_HEAD_BITMAP(1 << slot); + hp[1] = size; + hp[2] = res; + } else { + hp[0] = MAP_HEADER_HAMT_NODE_BITMAP(1 << slot); + hp[1] = res; + } + return make_hashmap(hp); + } /* push initial nodes on the stack, * this is the starting depth */ diff --git a/erts/emulator/test/map_SUITE.erl b/erts/emulator/test/map_SUITE.erl index dc6286fdb6..f061b177c5 100644 --- a/erts/emulator/test/map_SUITE.erl +++ b/erts/emulator/test/map_SUITE.erl @@ -1888,11 +1888,19 @@ t_bif_map_merge(Config) when is_list(Config) -> M8 = maps:merge(M7,M8), M8 = maps:merge(M8,M8), + %% maps:merge/2 and mixed + + Ks1 = [764492191,2361333849], %% deep collision + Ks2 = lists:seq(1,33), + M9 = maps:from_list([{K,K}||K <- Ks1]), + M10 = maps:from_list([{K,K}||K <- Ks2]), + M11 = maps:merge(M9,M10), + ok = check_keys_exist(Ks1 ++ Ks2, M11), + %% error case {'EXIT',{badarg,[{maps,merge,_,_}|_]}} = (catch maps:merge((1 bsl 65 + 3), <<>>)), {'EXIT',{badarg,[{maps,merge,_,_}|_]}} = (catch maps:merge(<<>>, id(#{ a => 1}))), {'EXIT',{badarg,[{maps,merge,_,_}|_]}} = (catch maps:merge(id(#{ a => 2}), <<>> )), - ok. -- cgit v1.2.3