问题
I got the following output from the LeakSanitizer tool. What is the difference between a direct and indirect leak, as the tool understands it?
13: ==29107==ERROR: LeakSanitizer: detected memory leaks
13:
13: Direct leak of 288 byte(s) in 6 object(s) allocated from:
13: #0 0x7f2ce0089050 in __interceptor_malloc (/nix/store/zahs1kwq4742f6l6h7yy4mdj44zzc1kd-gcc-7-20170409-lib/lib/libasan.so+0xd9050)
13: #1 0x7f2cdfb974fe in qdr_core_subscribe ../src/router_core/route_tables.c:149
13: #2 0x7f2cdfb47ff0 in IoAdapter_init ../src/python_embedded.c:548
13: #3 0x7f2cde966ecd in type_call (/nix/store/1snk2wkpv97an87pk1842fgskl1vqhkr-python-2.7.14/lib/libpython2.7.so.1.0+0x9fecd)
13:
13: Indirect leak of 2368 byte(s) in 1 object(s) allocated from:
13: #0 0x7f2ce0089b88 in __interceptor_posix_memalign (/nix/store/zahs1kwq4742f6l6h7yy4mdj44zzc1kd-gcc-7-20170409-lib/lib/libasan.so+0xd9b88)
13: #1 0x7f2cdfbcc8ea in qd_alloc ../src/alloc_pool.c:182
13: #2 0x7f2cdfbb6c6b in qd_server_connection ../src/server.c:500
13: #3 0x7f2cdfbbe27d in on_accept ../src/server.c:531
13: #4 0x7f2cdfbbe27d in handle_listener ../src/server.c:701
13: #5 0x7f2cdfbbe27d in handle ../src/server.c:844
13: #6 0x7f2cdfbc2837 in thread_run ../src/server.c:921
13: #7 0x7f2cdf0ba233 in start_thread (/nix/store/zpg78y1mf0di6127q6r51kgx2q8cxsvv-glibc-2.25-49/lib/libpthread.so.0+0x7233)
[...]
回答1:
The LSan wiki design document states:
Another useful feature is being able to distinguish between directly leaked blocks (not reachable from anywhere) and indirectly leaked blocks (reachable from other leaked blocks).
Stated another way, indirect leaks are a result of direct leaks. Fixing direct leaks should make the indirect leaks become either fixed or direct leaks themselves (depending on whether their memory management is implemented correctly or not, respectively).
来源：https://stackoverflow.com/questions/46573427/what-is-the-difference-between-a-direct-and-indirect-leak