asan: flaky memory leak on mh_i32ptr_new

[avtikhon]

Tarantool version:
2.6.0-78-gc1f72aeb7
Target: Linux-x86_64-RelWithDebInfo
Build options: cmake . -DCMAKE_INSTALL_PREFIX=/usr/local -DENABLE_BACKTRACE=ON
Compiler: /usr/bin/clang-8 /usr/bin/clang++-8
C_FLAGS: -Wno-unknown-pragmas -fexceptions -funwind-tables -fno-omit-frame-pointer -fno-stack-protector -fno-common -msse2 -fsanitize=address -fsanitize-blacklist=/source/asan/asan.supp -std=c11 -Wall -Wextra -Wno-strict-aliasing -fsanitize=alignment,bool,bounds,builtin,enum,float-cast-overflow,float-divide-by-zero,function,integer-divide-by-zero,return,shift,unreachable,vla-bound -fno-sanitize-recover=alignment,bool,bounds,builtin,enum,float-cast-overflow,float-divide-by-zero,function,integer-divide-by-zero,return,shift,unreachable,vla-bound -Wno-char-subscripts -Wno-gnu-alignof-expression -Werror
CXX_FLAGS: -Wno-unknown-pragmas -fexceptions -funwind-tables -fno-omit-frame-pointer -fno-stack-protector -fno-common -msse2 -fsanitize=address -fsanitize-blacklist=/source/asan/asan.supp -std=c++11 -Wall -Wextra -Wno-strict-aliasing -fsanitize=alignment,bool,bounds,builtin,enum,float-cast-overflow,float-divide-by-zero,function,integer-divide-by-zero,return,shift,unreachable,vla-bound -fno-sanitize-recover=alignment,bool,bounds,builtin,enum,float-cast-overflow,float-divide-by-zero,function,integer-divide-by-zero,return,shift,unreachable,vla-bound -Wno-char-subscripts -Wno-invalid-offsetof -Wno-gnu-alignof-expression -Werror

OS version:
Debian GNU/Linux buster/sid

Bug description:
In asan/lsan check found memory leaks:

Direct leak of 56 byte(s) in 1 object(s) allocated from:
    #0 0x524dfa in calloc (/tnt/src/tarantool+0x524dfa)
    #1 0xa161d8 in mh_i32ptr_new /source/src/lib/salad/mhash.h:402:39
    #2 0x9d62d3 in cord_create /source/src/lib/core/fiber.c:1375:25
    #3 0x9d776f in cord_thread_func /source/src/lib/core/fiber.c:1454:2
    #4 0x7f5d7a30dfa2 in start_thread (/lib/x86_64-linux-gnu/libpthread.so.0+0x7fa2)

Indirect leak of 56 byte(s) in 1 object(s) allocated from:
    #0 0x524dfa in calloc (/tnt/src/tarantool+0x524dfa)
    #1 0xa161ed in mh_i32ptr_new /source/src/lib/salad/mhash.h:403:32
    #2 0x9d62d3 in cord_create /source/src/lib/core/fiber.c:1375:25
    #3 0x9d776f in cord_thread_func /source/src/lib/core/fiber.c:1454:2
    #4 0x7f5d7a30dfa2 in start_thread (/lib/x86_64-linux-gnu/libpthread.so.0+0x7fa2)

Indirect leak of 48 byte(s) in 1 object(s) allocated from:
    #0 0x524dfa in calloc (/tnt/src/tarantool+0x524dfa)
    #1 0xa16264 in mh_i32ptr_new /source/src/lib/salad/mhash.h:406:23
    #2 0x9d62d3 in cord_create /source/src/lib/core/fiber.c:1375:25
    #3 0x9d776f in cord_thread_func /source/src/lib/core/fiber.c:1454:2
    #4 0x7f5d7a30dfa2 in start_thread (/lib/x86_64-linux-gnu/libpthread.so.0+0x7fa2)

Indirect leak of 4 byte(s) in 1 object(s) allocated from:
    #0 0x524dfa in calloc (/tnt/src/tarantool+0x524dfa)
    #1 0xa1628a in mh_i32ptr_new /source/src/lib/salad/mhash.h:408:22
    #2 0x9d62d3 in cord_create /source/src/lib/core/fiber.c:1375:25
    #3 0x9d776f in cord_thread_func /source/src/lib/core/fiber.c:1454:2
    #4 0x7f5d7a30dfa2 in start_thread (/lib/x86_64-linux-gnu/libpthread.so.0+0x7fa2)

It was disabled in asan suppression file 'asan/lsan.supp' with block:

# test: box-tap/schema_mt.test.lua
# source: src/lib/salad/mhash.h
leak:mh_i32ptr_new

Steps to reproduce:
Login to dev1 test host

Start the docker container:

docker run --network=host -v $PWD:/source -w /source -ti registry.gitlab.com/tarantool/tarantool/testing/debian-buster:latest
Inside the docker container run:

mkdir /tnt ; cd /tnt/ ; rm -rf /tnt/*

CC=clang-8 CXX=clang++-8 cmake /source \
        -DCMAKE_BUILD_TYPE=RelWithDebInfo \
        -DENABLE_WERROR=ON \
        -DENABLE_ASAN=ON \
        -DENABLE_UB_SANITIZER=ON && make -j

cat >asan.patch <<EOF
diff --git a/asan/lsan.supp b/asan/lsan.supp
index 46b3001e9..927dc016f 100644
--- a/asan/lsan.supp
+++ b/asan/lsan.supp
@@ -44,6 +44,6 @@ leak:libc.so*
 
 # test: box-tap/schema_mt.test.lua
 # source: src/lib/salad/mhash.h
-leak:mh_i32ptr_new
+#leak:mh_i32ptr_new
 
 # test: sql-tap/gh2250-trigger-chain-limit.test.lua
 # source: src/lib/core/exception.cc
EOF
patch -p1 -i asan.patch

cd test

Create test 'box-tap/schema_mt_vinyl.test.lua' based on 'box-tap/schema_mt.test.lua':

#!/usr/bin/env tarantool
box.cfg{log="/tmp/tarantool_vinyl.log"}
local sp2 = box.schema.create_space('test2', {engine = 'vinyl'})
local sp2_pk = sp2:create_index('pk')
sp2:drop()
os.exit(0)

And run command:

ASAN_OPTIONS=heap_profile=0:unmap_shadow_on_exit=1:detect_invalid_pointer_pairs=1:symbolize=1:detect_leaks=1:dump_instruction_bytes=1:print_suppressions=0 LSAN_OPTIONS=suppressions=/source/asan/lsan.supp /source/test/test-run.py --builddir /tnt --vardir /tnt/test/var --force box-tap/schema_mt_vinyl.test.lua

It will produce errors:

Direct leak of 56 byte(s) in 1 object(s) allocated from:
    #0 0x524dfa in calloc (/tnt/src/tarantool+0x524dfa)
    #1 0xa161d8 in mh_i32ptr_new /source/src/lib/salad/mhash.h:402:39
    #2 0x9d62d3 in cord_create /source/src/lib/core/fiber.c:1375:25
    #3 0x9d776f in cord_thread_func /source/src/lib/core/fiber.c:1454:2
    #4 0x7fa4399c5fa2 in start_thread (/lib/x86_64-linux-gnu/libpthread.so.0+0x7fa2)

Indirect leak of 56 byte(s) in 1 object(s) allocated from:
    #0 0x524dfa in calloc (/tnt/src/tarantool+0x524dfa)
    #1 0xa161ed in mh_i32ptr_new /source/src/lib/salad/mhash.h:403:32
    #2 0x9d62d3 in cord_create /source/src/lib/core/fiber.c:1375:25
    #3 0x9d776f in cord_thread_func /source/src/lib/core/fiber.c:1454:2
    #4 0x7fa4399c5fa2 in start_thread (/lib/x86_64-linux-gnu/libpthread.so.0+0x7fa2)

Indirect leak of 48 byte(s) in 1 object(s) allocated from:
    #0 0x524dfa in calloc (/tnt/src/tarantool+0x524dfa)
    #1 0xa16264 in mh_i32ptr_new /source/src/lib/salad/mhash.h:406:23
    #2 0x9d62d3 in cord_create /source/src/lib/core/fiber.c:1375:25
    #3 0x9d776f in cord_thread_func /source/src/lib/core/fiber.c:1454:2
    #4 0x7fa4399c5fa2 in start_thread (/lib/x86_64-linux-gnu/libpthread.so.0+0x7fa2)

Indirect leak of 4 byte(s) in 1 object(s) allocated from:
    #0 0x524dfa in calloc (/tnt/src/tarantool+0x524dfa)
    #1 0xa1628a in mh_i32ptr_new /source/src/lib/salad/mhash.h:408:22
    #2 0x9d62d3 in cord_create /source/src/lib/core/fiber.c:1375:25
    #3 0x9d776f in cord_thread_func /source/src/lib/core/fiber.c:1454:2
    #4 0x7fa4399c5fa2 in start_thread (/lib/x86_64-linux-gnu/libpthread.so.0+0x7fa2)

SUMMARY: AddressSanitizer: 1596 byte(s) leaked in 5 allocation(s).

Optional (but very desirable):

• coredump
• backtrace
• netstat