| Summary: | leak on fedora 33 and higher in getaddrinfo | ||
|---|---|---|---|
| Product: | [Developer tools] valgrind | Reporter: | Alex <alex> |
| Component: | memcheck | Assignee: | Julian Seward <jseward> |
| Status: | RESOLVED NOT A BUG | ||
| Severity: | normal | CC: | tom |
| Priority: | NOR | ||
| Version First Reported In: | 3.18.1 | ||
| Target Milestone: | --- | ||
| Platform: | Other | ||
| OS: | Linux | ||
| Latest Commit: | Version Fixed/Implemented In: | ||
| Sentry Crash Report: | |||
That's not a leak - as valgrind says that memory is still reachable. A leak is memory is unreachable because there are no pointers to it but it hasn't been freed. What you're looking at is some sort of cache inside the dynamic linker. Possibly it's a glibc bug, in that we deliberately call __libc_freeres to ask glibc to free it's internal resources at exit (which doesn't happen normally) but it's not a valgrind bug. (In reply to Tom Hughes from comment #1) > That's not a leak - as valgrind says that memory is still reachable. A leak > is memory is unreachable because there are no pointers to it but it hasn't > been freed. > > What you're looking at is some sort of cache inside the dynamic linker. > > Possibly it's a glibc bug, in that we deliberately call __libc_freeres to > ask glibc to free it's internal resources at exit (which doesn't happen > normally) but it's not a valgrind bug. Thanks I'll try to open a bug with glibc... |
SUMMARY Starting with Fedora 33 glibc-2.32-10.fc33.x86_64 NAME=Fedora VERSION="33 (Container Image)" Valgrind on Fedora 32 doesn't report the memory leak valgrind reports (See complete stack trace below ) ... ==18== by 0x401DE9F: strdup (strdup.c:42) ==18== by 0x40184F4: _dl_load_cache_lookup (dl-cache.c:312) ... on program exit It looks to be related to: getaddrinfo STEPS TO REPRODUCE ``` #include <netdb.h> #include <stdio.h> #include <stdlib.h> #include <string.h> int main(int argc, char *argv[]) { struct addrinfo hints; struct addrinfo *result; if (argc < 2) { fprintf(stderr, "Usage: %s host port...\n", argv[0]); exit(EXIT_FAILURE); } memset(&hints, '\0', sizeof(struct addrinfo)); hints.ai_family = AF_UNSPEC; /* Allow IPv4 or IPv6 */ hints.ai_socktype = SOCK_DGRAM; /* Datagram socket */ getaddrinfo(argv[1], argv[2], &hints, &result); freeaddrinfo(result); exit(EXIT_SUCCESS); ``` compile with: ``` clang -g -o leak leak.c valgrind --leak-check=full --trace-children=yes --show-leak-kinds=all ./leak archlinux.org 80 ``` OBSERVED RESULT leak EXPECTED RESULT no leaks as in fedora 32 SOFTWARE/OS VERSIONS Windows: macOS: Linux/KDE Plasma: (available in About System) KDE Plasma Version: KDE Frameworks Version: Qt Version: ADDITIONAL INFORMATION ==18== Using Valgrind-3.16.1 and LibVEX; rerun with -h for copyright info ==18== Command: /usr/bin/api --debug ==18== ==18== ==18== HEAP SUMMARY: ==18== in use at exit: 5,061 bytes in 12 blocks ==18== total heap usage: 121,783 allocs, 121,771 frees, 171,928,544 bytes allocated ==18== ==18== 21 bytes in 1 blocks are still reachable in loss record 1 of 7 ==18== at 0x4839809: malloc (vg_replace_malloc.c:307) ==18== by 0x401DE9F: malloc (rtld-malloc.h:56) ==18== by 0x401DE9F: strdup (strdup.c:42) ==18== by 0x40184F4: _dl_load_cache_lookup (dl-cache.c:312) ==18== by 0x400A046: _dl_map_object (dl-load.c:2185) ==18== by 0x400E694: openaux (dl-deps.c:64) ==18== by 0x5139BB7: _dl_catch_exception (in /usr/lib64/libc-2.32.so) ==18== by 0x400EADA: _dl_map_object_deps (dl-deps.c:248) ==18== by 0x4014B09: dl_open_worker (dl-open.c:584) ==18== by 0x5139BB7: _dl_catch_exception (in /usr/lib64/libc-2.32.so) ==18== by 0x401460D: _dl_open (dl-open.c:864) ==18== by 0x5138FE0: do_dlopen (in /usr/lib64/libc-2.32.so) ==18== by 0x5139BB7: _dl_catch_exception (in /usr/lib64/libc-2.32.so) ==18== ==18== 21 bytes in 1 blocks are still reachable in loss record 2 of 7 ==18== at 0x4839809: malloc (vg_replace_malloc.c:307) ==18== by 0x400C8B8: UnknownInlinedFun (rtld-malloc.h:56) ==18== by 0x400C8B8: _dl_new_object (dl-object.c:196) ==18== by 0x400841A: _dl_map_object_from_fd (dl-load.c:1073) ==18== by 0x4009B3A: _dl_map_object (dl-load.c:2319) ==18== by 0x400E694: openaux (dl-deps.c:64) ==18== by 0x5139BB7: _dl_catch_exception (in /usr/lib64/libc-2.32.so) ==18== by 0x400EADA: _dl_map_object_deps (dl-deps.c:248) ==18== by 0x4014B09: dl_open_worker (dl-open.c:584) ==18== by 0x5139BB7: _dl_catch_exception (in /usr/lib64/libc-2.32.so) ==18== by 0x401460D: _dl_open (dl-open.c:864) ==18== by 0x5138FE0: do_dlopen (in /usr/lib64/libc-2.32.so) ==18== by 0x5139BB7: _dl_catch_exception (in /usr/lib64/libc-2.32.so