c - Is my valgrind installation broken?

Question

I have this basic Hello World code :

#include <stdio.h>
int main() {printf("Hello World !"); return 0;}

Then valgrind return me this summary :

HEAP SUMMARY:
==17840== in use at exit: 22,114 bytes in 160 blocks
==17840== total heap usage: 176 allocs, 16 frees, 28,258 bytes allocated
==17840==
==17840== LEAK SUMMARY:
==17840== definitely lost: 7,960 bytes in 63 blocks
==17840== indirectly lost: 6,888 bytes in 8 blocks
==17840== possibly lost: 72 bytes in 3 blocks
==17840== still reachable: 32 bytes in 1 blocks
==17840== suppressed: 7,162 bytes in 85 blocks

According to valgrind's documentations, "definitively lost" means fixable leaks, however I don't see any fixable leak, so :
Is my valgrind broken ?

(I'm on OSX Sierra 10.12.4)

Edit: Definitively my OSX version(On my Linux, I go for "no leaks are possible"), I'll update soon, and I'll edit this again when it's done

Answer 1

You have to ask to get the leak information. I am working on macOS Sierra 10.12.6 (you should upgrade; there are key security issues fixed between 10.12.4 and 10.12.6). I'm using Valgrind built from SVN (Subversion — though it is about to switch to using Git instead).

With no extra options

I have a binary search tree program and I just removed the call to the memory free function, and ran it under my version of valgrind:

$ valgrind --suppressions=etc/suppressions-macos-10.12.5 -- ./bst29
==5095== Memcheck, a memory error detector
==5095== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==5095== Using Valgrind-3.13.0.SVN and LibVEX; rerun with -h for copyright info
==5095== Command: ./bst29
==5095== 
1 3 5 7 10 18 20 
==5095== 
==5095== HEAP SUMMARY:
==5095==     in use at exit: 22,476 bytes in 170 blocks
==5095==   total heap usage: 186 allocs, 16 frees, 28,620 bytes allocated
==5095== 
==5095== LEAK SUMMARY:
==5095==    definitely lost: 24 bytes in 1 blocks
==5095==    indirectly lost: 144 bytes in 6 blocks
==5095==      possibly lost: 0 bytes in 0 blocks
==5095==    still reachable: 0 bytes in 0 blocks
==5095==         suppressed: 22,308 bytes in 163 blocks
==5095== Rerun with --leak-check=full to see details of leaked memory
==5095== 
==5095== For counts of detected and suppressed errors, rerun with: -v
==5095== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 5 from 5)
$

Requesting --leak-check=full

Note the Rerun with --leak-check=full to see details of leaked memory message:

$ valgrind --leak-check=full --suppressions=etc/suppressions-macos-10.12.5 -- ./bst29
==5098== Memcheck, a memory error detector
==5098== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==5098== Using Valgrind-3.13.0.SVN and LibVEX; rerun with -h for copyright info
==5098== Command: ./bst29
==5098== 
1 3 5 7 10 18 20 
==5098== 
==5098== HEAP SUMMARY:
==5098==     in use at exit: 22,476 bytes in 170 blocks
==5098==   total heap usage: 186 allocs, 16 frees, 28,620 bytes allocated
==5098== 
==5098== 168 (24 direct, 144 indirect) bytes in 1 blocks are definitely lost in loss record 30 of 45
==5098==    at 0x100096861: malloc (vg_replace_malloc.c:302)
==5098==    by 0x100000C50: main (bst29.c:30)
==5098== 
==5098== LEAK SUMMARY:
==5098==    definitely lost: 24 bytes in 1 blocks
==5098==    indirectly lost: 144 bytes in 6 blocks
==5098==      possibly lost: 0 bytes in 0 blocks
==5098==    still reachable: 0 bytes in 0 blocks
==5098==         suppressed: 22,308 bytes in 163 blocks
==5098== 
==5098== For counts of detected and suppressed errors, rerun with: -v
==5098== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 14 from 14)
$

After fixing the bst29.c program

With the tree freeing code reactivated, the output is:

$ valgrind --leak-check=full --suppressions=etc/suppressions-macos-10.12.5 -- ./bst29
==5124== Memcheck, a memory error detector
==5124== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==5124== Using Valgrind-3.13.0.SVN and LibVEX; rerun with -h for copyright info
==5124== Command: ./bst29
==5124== 
1 3 5 7 10 18 20 
==5124== 
==5124== HEAP SUMMARY:
==5124==     in use at exit: 22,308 bytes in 163 blocks
==5124==   total heap usage: 186 allocs, 23 frees, 28,620 bytes allocated
==5124== 
==5124== LEAK SUMMARY:
==5124==    definitely lost: 0 bytes in 0 blocks
==5124==    indirectly lost: 0 bytes in 0 blocks
==5124==      possibly lost: 0 bytes in 0 blocks
==5124==    still reachable: 0 bytes in 0 blocks
==5124==         suppressed: 22,308 bytes in 163 blocks
==5124== 
==5124== For counts of detected and suppressed errors, rerun with: -v
==5124== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 14 from 14)
$

That's the normal result for me on a Mac — a leak summary with everything suppressed.

Suppressions file

The suppressions file listed contains 10 entries for various forms of system leak:

{
   macOS-Sierra-10.12.5-Leak.1
   Memcheck:Leak
   match-leak-kinds: reachable
   fun:malloc_zone_malloc
   fun:NXCreateMapTableFromZone
   fun:NXCreateMapTableFromZone
   fun:_ZL18__sel_registerNamePKcii
   fun:sel_init
   fun:map_images_nolock
   fun:_ZN11objc_object21sidetable_retainCountEv
   fun:_ZN4dyldL18notifyBatchPartialE17dyld_image_statesbPFPKcS0_jPK15dyld_image_infoEbb
   fun:_ZN4dyld21registerObjCNotifiersEPFvjPKPKcPKPK11mach_headerEPFvS1_S6_ESC_
   fun:_dyld_objc_notify_register
   fun:_objc_init
   fun:_os_object_init
}
{
   macOS-Sierra-10.12.5-Leak.2
   Memcheck:Leak
   match-leak-kinds: reachable
   fun:malloc_zone_malloc
   fun:NXCreateHashTableFromZone
   fun:NXCreateHashTable
   fun:NXCreateMapTableFromZone
   fun:NXCreateMapTableFromZone
   fun:_ZL18__sel_registerNamePKcii
   fun:sel_init
   fun:map_images_nolock
   fun:_ZN11objc_object21sidetable_retainCountEv
   fun:_ZN4dyldL18notifyBatchPartialE17dyld_image_statesbPFPKcS0_jPK15dyld_image_infoEbb
   fun:_ZN4dyld21registerObjCNotifiersEPFvjPKPKcPKPK11mach_headerEPFvS1_S6_ESC_
   fun:_dyld_objc_notify_register
}
{
   macOS-Sierra-10.12.5-Leak.3
   Memcheck:Leak
   match-leak-kinds: reachable
   fun:malloc_zone_malloc
   fun:NXCreateHashTableFromZone
   fun:NXCreateHashTable
   fun:NXCreateMapTableFromZone
   fun:NXCreateMapTableFromZone
   fun:_ZL18__sel_registerNamePKcii
   fun:sel_init
   fun:map_images_nolock
   fun:_ZN11objc_object21sidetable_retainCountEv
   fun:_ZN4dyldL18notifyBatchPartialE17dyld_image_statesbPFPKcS0_jPK15dyld_image_infoEbb
   fun:_ZN4dyld21registerObjCNotifiersEPFvjPKPKcPKPK11mach_headerEPFvS1_S6_ESC_
   fun:_dyld_objc_notify_register
}
{
   macOS-Sierra-10.12.5-Leak.4
   Memcheck:Leak
   match-leak-kinds: reachable
   fun:malloc
   fun:NXCreateHashTableFromZone
   fun:NXCreateHashTable
   fun:NXCreateMapTableFromZone
   fun:NXCreateMapTableFromZone
   fun:_ZL18__sel_registerNamePKcii
   fun:sel_init
   fun:map_images_nolock
   fun:_ZN11objc_object21sidetable_retainCountEv
   fun:_ZN4dyldL18notifyBatchPartialE17dyld_image_statesbPFPKcS0_jPK15dyld_image_infoEbb
   fun:_ZN4dyld21registerObjCNotifiersEPFvjPKPKcPKPK11mach_headerEPFvS1_S6_ESC_
   fun:_dyld_objc_notify_register
}
{
   macOS-Sierra-10.12.5-Leak.5
   Memcheck:Leak
   match-leak-kinds: reachable
   fun:malloc
   fun:NXCreateMapTableFromZone
   fun:NXCreateMapTableFromZone
   fun:_ZL18__sel_registerNamePKcii
   fun:sel_init
   fun:map_images_nolock
   fun:_ZN11objc_object21sidetable_retainCountEv
   fun:_ZN4dyldL18notifyBatchPartialE17dyld_image_statesbPFPKcS0_jPK15dyld_image_infoEbb
   fun:_ZN4dyld21registerObjCNotifiersEPFvjPKPKcPKPK11mach_headerEPFvS1_S6_ESC_
   fun:_dyld_objc_notify_register
   fun:_objc_init
   fun:_os_object_init
}
{
   macOS-Sierra-10.12.5-Leak.6
   Memcheck:Leak
   match-leak-kinds: reachable
   fun:malloc_zone_calloc
   fun:_NXHashRehashToCapacity
   fun:NXHashInsert
   fun:NXCreateHashTableFromZone
   fun:NXCreateHashTable
   fun:NXCreateMapTableFromZone
   fun:NXCreateMapTableFromZone
   fun:_ZL18__sel_registerNamePKcii
   fun:sel_init
   fun:map_images_nolock
   fun:_ZN11objc_object21sidetable_retainCountEv
   fun:_ZN4dyldL18notifyBatchPartialE17dyld_image_statesbPFPKcS0_jPK15dyld_image_infoEbb
}
{
   macOS-Sierra-10.12.5-Leak.7
   Memcheck:Leak
   match-leak-kinds: possible
   fun:calloc
   fun:map_images_nolock
   fun:_ZN11objc_object21sidetable_retainCountEv
   fun:_ZN4dyldL18notifyBatchPartialE17dyld_image_statesbPFPKcS0_jPK15dyld_image_infoEbb
   fun:_ZN4dyld21registerObjCNotifiersEPFvjPKPKcPKPK11mach_headerEPFvS1_S6_ESC_
   fun:_dyld_objc_notify_register
   fun:_objc_init
   fun:_os_object_init
   fun:libdispatch_init
   fun:libSystem_initializer
   fun:_ZN16ImageLoaderMachO18doModInitFunctionsERKN11ImageLoader11LinkContextE
   fun:_ZN16ImageLoaderMachO16doInitializationERKN11ImageLoader11LinkContextE
}

{
   macOS-Sierra-10.12.5-reachable.1
   Memcheck:Leak
   match-leak-kinds: reachable
   fun:malloc_zone_calloc
   fun:_NXHashRehashToCapacity
   fun:NXHashInsert
   fun:NXCreateHashTableFromZone
   fun:NXCreateHashTable
   fun:NXCreateMapTableFromZone
   fun:NXCreateMapTableFromZone
   fun:_ZL18__sel_registerNamePKcii
   fun:sel_init
   fun:map_images_nolock
   fun:_ZN11objc_object21sidetable_retainCountEv
   fun:_ZN4dyldL18notifyBatchPartialE17dyld_image_statesbPFPKcS0_jPK15dyld_image_infoEbb
}

{
   macOS-Sierra-10.12.5-possible.1
   Memcheck:Leak
   match-leak-kinds: possible
   fun:calloc
   fun:map_images_nolock
   fun:_ZN11objc_object21sidetable_retainCountEv
   fun:_ZN4dyldL18notifyBatchPartialE17dyld_image_statesbPFPKcS0_jPK15dyld_image_infoEbb
   fun:_ZN4dyld21registerObjCNotifiersEPFvjPKPKcPKPK11mach_headerEPFvS1_S6_ESC_
   fun:_dyld_objc_notify_register
   fun:_objc_init
   fun:_os_object_init
   fun:libdispatch_init
   fun:libSystem_initializer
   fun:_ZN16ImageLoaderMachO18doModInitFunctionsERKN11ImageLoader11LinkContextE
   fun:_ZN16ImageLoaderMachO16doInitializationERKN11ImageLoader11LinkContextE
}

{
    macOS-Sierra-10.12.5-check.1
    Memcheck:Param
    msg->desc.port.name
    fun:mach_msg_trap
    fun:mach_msg
    fun:task_set_special_port
    fun:_os_trace_create_debug_control_port
    fun:_libtrace_init
    fun:libSystem_initializer
    fun:_ZN16ImageLoaderMachO18doModInitFunctionsERKN11ImageLoader11LinkContextE
    fun:_ZN16ImageLoaderMachO16doInitializationERKN11ImageLoader11LinkContextE
    fun:_ZN11ImageLoader23recursiveInitializationERKNS_11LinkContextEjPKcRNS_21InitializerTimingListERNS_15UninitedUpwardsE
    fun:_ZN11ImageLoader23recursiveInitializationERKNS_11LinkContextEjPKcRNS_21InitializerTimingListERNS_15UninitedUpwardsE
    fun:_ZN11ImageLoader19processInitializersERKNS_11LinkContextEjRNS_21InitializerTimingListERNS_15UninitedUpwardsE
    fun:_ZN11ImageLoader15runInitializersERKNS_11LinkContextERNS_21InitializerTimingListE
}

They all come from the startup code before main() is called; there is nothing I can do about any of them, therefore.