Merge branch 'maint'

* maint: erts: Fix crash in ETS compressed tables
erlang · Aug 5, 2024 · 4e9a084 · 4e9a084
2 parents b1f15e2 + 991d2d6
commit 4e9a084
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Showing 2 changed files with 28 additions and 29 deletions.
diff --git a/erts/emulator/beam/external.c b/erts/emulator/beam/external.c
@@ -3853,21 +3853,19 @@ enc_term_int(TTBEncodeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj, byte* ep,
 
                     ASSERT(!use_iov);
 
-                    /* Use [BIT_]BINARY_INTERNAL_REF, copying the actual BinRef
-                     * and/or ErlSubBits whenever that is smaller than the data
-                     * itself. */
-                    if (wire_size >= sizeof(BinRef)) {
-                        if ((encoding == BINARY_EXT) &&
-                            (base == (byte*)refc_binary->orig_bytes) &&
-                            (size == refc_binary->orig_size * 8) &&
-                            (offset == 0)) {
-                            encoding = BINARY_INTERNAL_REF;
-                            copy_payload = 0;
-                        } else if (wire_size >= (sizeof(ErlSubBits) +
-                                                 sizeof(BinRef))) {
-                            encoding = BITSTRING_INTERNAL_REF;
-                            copy_payload = 0;
-                        }
+                    /* Always use [BIT_]BINARY_INTERNAL_REF: this may lead to a
+                     * larger result than copying the payload, but ensures that
+                     * the decoded object is exactly the same as the encoded
+                     * one, simplifying the decompression logic in ETS. */
+                    if ((encoding == BINARY_EXT) &&
+                        (base == (byte*)refc_binary->orig_bytes) &&
+                        (size == refc_binary->orig_size * 8) &&
+                        (offset == 0)) {
+                        encoding = BINARY_INTERNAL_REF;
+                        copy_payload = 0;
+                    } else {
+                        encoding = BITSTRING_INTERNAL_REF;
+                        copy_payload = 0;
                     }
                 }
 
@@ -5606,19 +5604,15 @@ encode_size_struct_int(TTBSizeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj,
 
                 ASSERT(vlen < 0);
 
-                /* Use [BIT_]BINARY_INTERNAL_REF, copying the actual BinRef
-                 * and/or ErlSubBits whenever that is smaller than the data
-                 * itself. */
-                if (wire_size >= sizeof(BinRef)) {
-                    if ((encoding == BINARY_EXT) &&
-                        (base == (byte*)refc_binary->orig_bytes) &&
-                        (size == refc_binary->orig_size * 8) &&
-                        (offset == 0)) {
-                        encoding = BINARY_INTERNAL_REF;
-                    } else if (wire_size >= (sizeof(ErlSubBits) +
-                                             sizeof(BinRef))) {
-                        encoding = BITSTRING_INTERNAL_REF;
-                    }
+                /* Always use [BIT_]BINARY_INTERNAL_REF: see matching comment
+                 * in enc_term_int. */
+                if ((encoding == BINARY_EXT) &&
+                    (base == (byte*)refc_binary->orig_bytes) &&
+                    (size == refc_binary->orig_size * 8) &&
+                    (offset == 0)) {
+                    encoding = BINARY_INTERNAL_REF;
+                } else {
+                    encoding = BITSTRING_INTERNAL_REF;
                 }
             }
 

diff --git a/lib/stdlib/test/ets_SUITE.erl b/lib/stdlib/test/ets_SUITE.erl
@@ -7905,7 +7905,8 @@ maps_sum([L]) ->
 types(Config) when is_list(Config) ->
     init_externals(),
     repeat_for_opts(fun types_do/1, [repeat_for_opts_atom2list(set_types),
-                                     compressed]).
+                                     compressed,
+                                     [ordered_set, compressed]]).
 
 types_do(Opts) ->
     EtsMem = etsmem(),
@@ -9312,9 +9313,12 @@ test_terms(Test_Func, Mode) ->
     Bin2 = list_to_binary(lists:seq(0, ?heap_binary_size+1)),
     Test_Func(Bin2),
     Bin3 = list_to_binary(lists:seq(0, 255)),
+    %% Test an undersized refc binary. GH-8682
+    Bin4 = erts_debug:set_internal_state(binary, 61),
     garbage_collect(),
     Pib = process_info(self(),binary),
     Test_Func(Bin3),
+    Test_Func(Bin4),
     garbage_collect(),
     case Mode of
 	strict -> Pib = process_info(self(),binary);
@@ -9325,6 +9329,7 @@ test_terms(Test_Func, Mode) ->
     Test_Func(make_unaligned_sub_binary(Bin1)),
     Test_Func(make_unaligned_sub_binary(Bin2)),
     Test_Func(make_unaligned_sub_binary(Bin3)),
+    Test_Func(make_unaligned_sub_binary(Bin4)),
 
     Test_Func(make_sub_binary(lists:seq(42, 43))),
     Test_Func(make_sub_binary([42,43,44])),