Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

FS#4222 - valgrind: does not detect memory leaks depite unstripped libraries #9203

Open
openwrt-bot opened this issue Jan 9, 2022 · 1 comment
Labels

Comments

@openwrt-bot
Copy link

@openwrt-bot openwrt-bot commented Jan 9, 2022

MikePetullo:

I am using valgrind 3.18.1-1 on x86_64 r18400-f9782f5bcd. This build uses musl 1.2.2-3. My libraries, to include libc, are not stripped.

According to the upstream bug at https://bugs.kde.org/show_bug.cgi?id=435441, changes to musl left valgrind unable to detect memory leaks. The workaround proposed in that bug report, namely passing "--soname-synonyms=somalloc=NONE" to valgrind, seems to fix the problem on OpenWrt.

Here is an example program:

#include #include

int f(void) {
char *buf = malloc(BUFSIZ);
if (buf == NULL) {
return -1;
}
return 0;
}

int main(void)
{
f();
}

I compiled this with "gcc -O0 -o test test.c", and I ran the following to demonstrate the problem and workaround:

$ valgrind --leak-check=full ./test
==31728== Memcheck, a memory error detector
==31728== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==31728== Using Valgrind-3.18.1 and LibVEX; rerun with -h for copyright info
==31728== Command: ./test
==31728==
==31728==
==31728== HEAP SUMMARY:
==31728== in use at exit: 0 bytes in 0 blocks
==31728== total heap usage: 0 allocs, 0 frees, 0 bytes allocated
==31728==
==31728== All heap blocks were freed -- no leaks are possible
==31728==
==31728== For lists of detected and suppressed errors, rerun with: -s
==31728== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
$ valgrind --leak-check=full --soname-synonyms=somalloc=NONE ./test
==31732== Memcheck, a memory error detector
==31732== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==31732== Using Valgrind-3.18.1 and LibVEX; rerun with -h for copyright info
==31732== Command: ./test
==31732==
==31732==
==31732== HEAP SUMMARY:
==31732== in use at exit: 1,024 bytes in 1 blocks
==31732== total heap usage: 1 allocs, 0 frees, 1,024 bytes allocated
==31732==
==31732== 1,024 bytes in 1 blocks are definitely lost in loss record 1 of 1
==31732== at 0x48806B6: malloc (vg_replace_malloc.c:381)
==31732== by 0x40111B: f (in /home/mike@flyn.org/valgrindC/test)
==31732== by 0x40113D: main (in /home/mike@flyn.org/valgrindC/test)
==31732==
==31732== LEAK SUMMARY:
==31732== definitely lost: 1,024 bytes in 1 blocks
==31732== indirectly lost: 0 bytes in 0 blocks
==31732== possibly lost: 0 bytes in 0 blocks
==31732== still reachable: 0 bytes in 0 blocks
==31732== suppressed: 0 bytes in 0 blocks
==31732==
==31732== For lists of detected and suppressed errors, rerun with: -s
==31732== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)

@openwrt-bot
Copy link
Author

@openwrt-bot openwrt-bot commented Jan 9, 2022

jow-:

Shouldn't that be reported to musl libc then? What are we supposed to do about this?

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
Projects
None yet
Development

No branches or pull requests

1 participant