C：glib.h`pkg-config --cflags --libs glib-2.0` valgrind仍然可以访问

Question

main.c as only ...

int main(void) 
{
    return 0;
}

Executing ...

gcc `pkg-config --cflags --libs glib-2.0` -W -Wall -Wextra main.c -o out

Compiles into an executable ...

out

Executing ...

valgrind --show-leak-kinds=all --leak-check=full -v ./out

Gives me ...

==6404== Memcheck, a memory error detector
==6404== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==6404== Using Valgrind-3.14.0-3a3000290b-20181009X and LibVEX; rerun with -h for copyright info
==6404== Command: ./out
==6404== 
--6404-- Valgrind options:
--6404--    --show-leak-kinds=all
--6404--    --leak-check=full
--6404--    -v
--6404-- Contents of /proc/version:
--6404--   Linux version 4.19.28-1-MANJARO (builduser@development) (gcc version 8.2.1 20181127 (GCC)) #1 SMP PREEMPT Sun Mar 10 08:32:42 UTC 2019
--6404-- 
--6404-- Arch and hwcaps: AMD64, LittleEndian, amd64-cx16-lzcnt-rdtscp-sse3-avx-avx2-bmi
--6404-- Page sizes: currently 4096, max supported 4096
--6404-- Valgrind library directory: /usr/lib/valgrind
--6404-- Reading syms from /home/killbyte/Documents/Curso/LI3/tester-project-li3/out
--6404-- Reading syms from /usr/lib/ld-2.28.so
--6404-- Reading syms from /usr/lib/valgrind/memcheck-amd64-linux
--6404--    object doesn't have a dynamic symbol table
--6404-- Scheduler: using generic scheduler lock implementation.
--6404-- Reading suppressions file: /usr/lib/valgrind/default.supp
==6404== embedded gdbserver: reading from /tmp/vgdb-pipe-from-vgdb-to-6404-by-killbyte-on-???
==6404== embedded gdbserver: writing to   /tmp/vgdb-pipe-to-vgdb-from-6404-by-killbyte-on-???
==6404== embedded gdbserver: shared mem   /tmp/vgdb-pipe-shared-mem-vgdb-6404-by-killbyte-on-???
==6404== 
==6404== TO CONTROL THIS PROCESS USING vgdb (which you probably
==6404== don't want to do, unless you know exactly what you're doing,
==6404== or are doing some strange experiment):
==6404==   /usr/lib/valgrind/../../bin/vgdb --pid=6404 ...command...
==6404== 
==6404== TO DEBUG THIS PROCESS USING GDB: start GDB like this
==6404==   /path/to/gdb ./out
==6404== and then give GDB the following command
==6404==   target remote | /usr/lib/valgrind/../../bin/vgdb --pid=6404
==6404== --pid is optional if only one valgrind process is running
==6404== 
--6404-- REDIR: 0x401ff20 (ld-linux-x86-64.so.2:strlen) redirected to 0x580c9742 (vgPlain_amd64_linux_REDIR_FOR_strlen)
--6404-- REDIR: 0x401fcf0 (ld-linux-x86-64.so.2:index) redirected to 0x580c975c (vgPlain_amd64_linux_REDIR_FOR_index)
--6404-- Reading syms from /usr/lib/valgrind/vgpreload_core-amd64-linux.so
--6404-- Reading syms from /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so
==6404== WARNING: new redirection conflicts with existing -- ignoring it
--6404--     old: 0x0401ff20 (strlen              ) R-> (0000.0) 0x580c9742 vgPlain_amd64_linux_REDIR_FOR_strlen
--6404--     new: 0x0401ff20 (strlen              ) R-> (2007.0) 0x0483ad80 strlen
--6404-- REDIR: 0x401c700 (ld-linux-x86-64.so.2:strcmp) redirected to 0x483be40 (strcmp)
--6404-- REDIR: 0x4020480 (ld-linux-x86-64.so.2:mempcpy) redirected to 0x483f860 (mempcpy)
--6404-- Reading syms from /usr/lib/libglib-2.0.so.0.5800.3
--6404--    object doesn't have a symbol table
--6404-- Reading syms from /usr/lib/libc-2.28.so
--6404-- Reading syms from /usr/lib/libpthread-2.28.so
--6404-- Reading syms from /usr/lib/libpcre.so.1.2.11
--6404--    object doesn't have a symbol table
--6404-- REDIR: 0x4a23060 (libc.so.6:strchrnul) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a3b800 (libc.so.6:wcslen) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a27b10 (libc.so.6:memrchr) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a3cf90 (libc.so.6:wcsnlen) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a21b70 (libc.so.6:memcpy@@GLIBC_2.14) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a21a20 (libc.so.6:strncasecmp) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a216c0 (libc.so.6:memmove) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
==6404== Preferring higher priority redirection:
--6404--     old: 0x04af6c60 (__memcpy_avx_unalign) R-> (2018.0) 0x0483c300 memcpy@@GLIBC_2.14
--6404--     new: 0x04af6c60 (__memcpy_avx_unalign) R-> (2018.1) 0x0483e8a0 memmove
--6404-- REDIR: 0x4a20840 (libc.so.6:strncpy) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a219d0 (libc.so.6:strcasecmp) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a20210 (libc.so.6:strcat) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a20880 (libc.so.6:rindex) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a23030 (libc.so.6:rawmemchr) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a3bca0 (libc.so.6:wmemchr) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a3b700 (libc.so.6:wcscmp) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a21830 (libc.so.6:mempcpy) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a21650 (libc.so.6:bcmp) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a207e0 (libc.so.6:strncmp) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a20290 (libc.so.6:strcmp) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a21790 (libc.so.6:memset) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a3b6d0 (libc.so.6:wcschr) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a20770 (libc.so.6:strnlen) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a20340 (libc.so.6:strcspn) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a20300 (libc.so.6:strcpy) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a208b0 (libc.so.6:strpbrk) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a20250 (libc.so.6:index) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a20740 (libc.so.6:strlen) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a21a70 (libc.so.6:strcasecmp_l) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a21620 (libc.so.6:memchr) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a20b70 (libc.so.6:strspn) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a21990 (libc.so.6:stpncpy) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a21950 (libc.so.6:stpcpy) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a21ac0 (libc.so.6:strncasecmp_l) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4aa1380 (libc.so.6:__memcpy_chk) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4a21540 (libc.so.6:strstr) redirected to 0x482d1c0 (_vgnU_ifunc_wrapper)
--6404-- REDIR: 0x4af6530 (libc.so.6:__strrchr_avx2) redirected to 0x483a790 (rindex)
--6404-- REDIR: 0x4af6700 (libc.so.6:__strlen_avx2) redirected to 0x483ac60 (strlen)
--6404-- REDIR: 0x4a1c8d0 (libc.so.6:malloc) redirected to 0x4837710 (malloc)
--6404-- REDIR: 0x4a1d6b0 (libc.so.6:calloc) redirected to 0x4839ab0 (calloc)
--6404-- REDIR: 0x4a1cf20 (libc.so.6:free) redirected to 0x4838940 (free)
==6404== 
==6404== HEAP SUMMARY:
==6404==     in use at exit: 18,604 bytes in 6 blocks
==6404==   total heap usage: 6 allocs, 0 frees, 18,604 bytes allocated
==6404== 
==6404== Searching for pointers to 6 not-freed blocks
==6404== Checked 101,040 bytes
==6404== 
==6404== 4 bytes in 1 blocks are still reachable in loss record 1 of 6
==6404==    at 0x483777F: malloc (vg_replace_malloc.c:299)
==6404==    by 0x488F5C3: ??? (in /usr/lib/libglib-2.0.so.0.5800.3)
==6404==    by 0x488F6BB: g_private_get (in /usr/lib/libglib-2.0.so.0.5800.3)
==6404==    by 0x48B906D: g_slice_alloc (in /usr/lib/libglib-2.0.so.0.5800.3)
==6404==    by 0x48F4CDE: g_hash_table_new_full (in /usr/lib/libglib-2.0.so.0.5800.3)
==6404==    by 0x48CE533: ??? (in /usr/lib/libglib-2.0.so.0.5800.3)
==6404==    by 0x4010549: call_init.part.0 (in /usr/lib/ld-2.28.so)
==6404==    by 0x4010649: _dl_init (in /usr/lib/ld-2.28.so)
==6404==    by 0x4002039: ??? (in /usr/lib/ld-2.28.so)
==6404== 
==6404== 32 bytes in 1 blocks are still reachable in loss record 2 of 6
==6404==    at 0x4839B65: calloc (vg_replace_malloc.c:752)
==6404==    by 0x48D8839: g_malloc0 (in /usr/lib/libglib-2.0.so.0.5800.3)
==6404==    by 0x48F4D47: g_hash_table_new_full (in /usr/lib/libglib-2.0.so.0.5800.3)
==6404==    by 0x48CE533: ??? (in /usr/lib/libglib-2.0.so.0.5800.3)
==6404==    by 0x4010549: call_init.part.0 (in /usr/lib/ld-2.28.so)
==6404==    by 0x4010649: _dl_init (in /usr/lib/ld-2.28.so)
==6404==    by 0x4002039: ??? (in /usr/lib/ld-2.28.so)
==6404== 
==6404== 64 bytes in 1 blocks are still reachable in loss record 3 of 6
==6404==    at 0x4839B65: calloc (vg_replace_malloc.c:752)
==6404==    by 0x48D8839: g_malloc0 (in /usr/lib/libglib-2.0.so.0.5800.3)
==6404==    by 0x48F4D31: g_hash_table_new_full (in /usr/lib/libglib-2.0.so.0.5800.3)
==6404==    by 0x48CE533: ??? (in /usr/lib/libglib-2.0.so.0.5800.3)
==6404==    by 0x4010549: call_init.part.0 (in /usr/lib/ld-2.28.so)
==6404==    by 0x4010649: _dl_init (in /usr/lib/ld-2.28.so)
==6404==    by 0x4002039: ??? (in /usr/lib/ld-2.28.so)
==6404== 
==6404== 88 bytes in 1 blocks are still reachable in loss record 4 of 6
==6404==    at 0x483777F: malloc (vg_replace_malloc.c:299)
==6404==    by 0x48D88D1: g_malloc (in /usr/lib/libglib-2.0.so.0.5800.3)
==6404==    by 0x48B9094: g_slice_alloc (in /usr/lib/libglib-2.0.so.0.5800.3)
==6404==    by 0x48F4CDE: g_hash_table_new_full (in /usr/lib/libglib-2.0.so.0.5800.3)
==6404==    by 0x48CE533: ??? (in /usr/lib/libglib-2.0.so.0.5800.3)
==6404==    by 0x4010549: call_init.part.0 (in /usr/lib/ld-2.28.so)
==6404==    by 0x4010649: _dl_init (in /usr/lib/ld-2.28.so)
==6404==    by 0x4002039: ??? (in /usr/lib/ld-2.28.so)
==6404== 
==6404== 2,032 bytes in 1 blocks are still reachable in loss record 5 of 6
==6404==    at 0x4839B65: calloc (vg_replace_malloc.c:752)
==6404==    by 0x48D8839: g_malloc0 (in /usr/lib/libglib-2.0.so.0.5800.3)
==6404==    by 0x48B92EE: g_slice_alloc (in /usr/lib/libglib-2.0.so.0.5800.3)
==6404==    by 0x48F4CDE: g_hash_table_new_full (in /usr/lib/libglib-2.0.so.0.5800.3)
==6404==    by 0x48CE533: ??? (in /usr/lib/libglib-2.0.so.0.5800.3)
==6404==    by 0x4010549: call_init.part.0 (in /usr/lib/ld-2.28.so)
==6404==    by 0x4010649: _dl_init (in /usr/lib/ld-2.28.so)
==6404==    by 0x4002039: ??? (in /usr/lib/ld-2.28.so)
==6404== 
==6404== 16,384 bytes in 1 blocks are still reachable in loss record 6 of 6
==6404==    at 0x483777F: malloc (vg_replace_malloc.c:299)
==6404==    by 0x48D88D1: g_malloc (in /usr/lib/libglib-2.0.so.0.5800.3)
==6404==    by 0x48CE545: ??? (in /usr/lib/libglib-2.0.so.0.5800.3)
==6404==    by 0x4010549: call_init.part.0 (in /usr/lib/ld-2.28.so)
==6404==    by 0x4010649: _dl_init (in /usr/lib/ld-2.28.so)
==6404==    by 0x4002039: ??? (in /usr/lib/ld-2.28.so)
==6404== 
==6404== LEAK SUMMARY:
==6404==    definitely lost: 0 bytes in 0 blocks
==6404==    indirectly lost: 0 bytes in 0 blocks
==6404==      possibly lost: 0 bytes in 0 blocks
==6404==    still reachable: 18,604 bytes in 6 blocks
==6404==         suppressed: 0 bytes in 0 blocks
==6404== 
==6404== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
==6404== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)

The problem is that valgrind tells me in leak summary still reachable: 18,604 bytes in 6 blocks And i don't even have any code ... Not even the #include

Answer 1

As Ctx said in a comment, these allocations are done in a library constructor function for GLib, which is called automatically before your main() function is entered. They are done once in the process' lifetime to allocate various internal structures and caches.

If you use the glib.supp suppression file installed by GLib in /usr/share/glib-2.0/valgrind/glib.supp , they should be suppressed. If any of them aren't, please file a bug against GLib .