Valgrind reports memory leak in lsslot when listing pci and vio slots

[tyreld]

==2102767== Memcheck, a memory error detector
==2102767== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==2102767== Using Valgrind-3.18.1 and LibVEX; rerun with -h for copyright info
==2102767== Command: src/drmgr/lsslot -c slot
==2102767== 
# Slot                      Description       Linux Name    Device(s)
U9040.MR9.132944X-V16-C0    Virtual I/O Slot  30000000      vty
U9040.MR9.132944X-V16-C11   Virtual I/O Slot  3000000b      l-lan
U9040.MR9.132944X-V16-C101  Virtual I/O Slot  30000065      v-scsi
U9040.MR9.132944X-V16-C312  Virtual I/O Slot  30000138      vfc-client
U9040.MR9.132944X-V16-C313  Virtual I/O Slot  30000139      vfc-client
==2102767== 
==2102767== HEAP SUMMARY:
==2102767==     in use at exit: 64 bytes in 2 blocks
==2102767==   total heap usage: 5,203 allocs, 5,201 frees, 203,943,832 bytes allocated
==2102767== 
==2102767== 26 bytes in 1 blocks are definitely lost in loss record 1 of 2
==2102767==    at 0x40A53B8: malloc (vg_replace_malloc.c:381)
==2102767==    by 0x429F2F3: strdup (in /usr/lib64/libc.so.6)
==2102767==    by 0x1000F3A3: of_to_full_path (common_ofdt.c:456)
==2102767==    by 0x1000F5CF: get_drc_info (common_ofdt.c:499)
==2102767==    by 0x1000BEBF: add_pci_vio_node (common_pci.c:632)
==2102767==    by 0x1000D307: get_dlpar_nodes (common_pci.c:856)
==2102767==    by 0x10003083: lsslot_chrp_pci (lsslot.c:568)
==2102767==    by 0x100047DF: main (lsslot.c:965)
==2102767== 
==2102767== 38 bytes in 1 blocks are definitely lost in loss record 2 of 2
==2102767==    at 0x40A53B8: malloc (vg_replace_malloc.c:381)
==2102767==    by 0x429F2F3: strdup (in /usr/lib64/libc.so.6)
==2102767==    by 0x1000F3A3: of_to_full_path (common_ofdt.c:456)
==2102767==    by 0x1000F5CF: get_drc_info (common_ofdt.c:499)
==2102767==    by 0x1000BEBF: add_pci_vio_node (common_pci.c:632)
==2102767==    by 0x1000D337: get_dlpar_nodes (common_pci.c:859)
==2102767==    by 0x10003083: lsslot_chrp_pci (lsslot.c:568)
==2102767==    by 0x100047DF: main (lsslot.c:965)
==2102767== 
==2102767== LEAK SUMMARY:
==2102767==    definitely lost: 64 bytes in 2 blocks
==2102767==    indirectly lost: 0 bytes in 0 blocks
==2102767==      possibly lost: 0 bytes in 0 blocks
==2102767==    still reachable: 0 bytes in 0 blocks
==2102767==         suppressed: 0 bytes in 0 blocks
==2102767== 
==2102767== For lists of detected and suppressed errors, rerun with: -s
==2102767== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 0 from 0)

[tyreld]

get_drc_info(const char *of_path)                                                
{                                                                                
        struct stat sbuf;                                                        
        char fname[DR_PATH_MAX];                                                 
        char ofdt_path[DR_PATH_MAX];                                             
        char *full_path = NULL;                                                  
        struct dr_connector *list = NULL;                                        
        int rc;                                                                  

        for (list = all_drc_lists; list; list = list->all_next) {                
                if (! strcmp(list->ofdt_path, of_path))                          
                        return list;                                             
        }                                                                        

        full_path = of_to_full_path(of_path);                                    
        if (full_path == NULL)                                                   
                return NULL;                                                     

        /* ibm,drc-info vs the old implementation */                             
        sprintf(fname, "%s/%s", full_path, "ibm,drc-info");                      
        snprintf(ofdt_path, DR_PATH_MAX, "%s", of_path);                         
        rc = stat(fname, &sbuf);                                                 
        if (rc)                                                                  
                rc = drc_info_connectors_v1(full_path, ofdt_path, &list);        
        else                                                                     
                rc = drc_info_connectors_v2(full_path, ofdt_path, &list);        

        if (rc == 0) {                                                           
                list->all_next = all_drc_lists;                                  
                all_drc_lists = list;                                            
        } else {                                                                 
                if (full_path)                                                   
                        free(full_path);                                         
                list = NULL;                                                     
        }                                                                        

        return list;                                                             
}

full_path is only freed if drc_info_connectors_vX() fails. It should be freed regardless. Further, the if (full_path) check is unnecessary as we return immediately if full_path is NULL following of_to_full_path() call.

[tyreld]

This is in src/drmgr common code so I can only assume the same leaks are observed running drmgr.

[tyreld]

Fixed by following commit:

313bb6fdc145 lsslot: fix memory leak when listing IO slots