** Description changed:
Valgrind reports still reachable leaks in dlopen()/dlclose() only when
linked with -lpthread with the following code:
- $ cat /tmp/valgrind-dlopen-pthread-leak.c
+ $ cat /tmp/valgrind-dlopen-pthread-leak.c
#include <stdio.h>
#include <dlfcn.h>
int main() {
- char *error = 0;
+ char *error = 0;
- void *handle = dlopen(NULL, RTLD_NOW | RTLD_GLOBAL);
+ void *handle = dlopen(NULL, RTLD_NOW | RTLD_GLOBAL);
- if((error = dlerror())) {
- printf("dlopen failed: %s\n", error);
- return 1;
- }
- printf("%p\n", handle);
+ if((error = dlerror())) {
+ printf("dlopen failed: %s\n", error);
+ return 1;
+ }
+ printf("%p\n", handle);
- dlclose(handle);
+ dlclose(handle);
- if((error = dlerror())) {
- printf("dlclose failed: %s\n", error);
- return 1;
- }
+ if((error = dlerror())) {
+ printf("dlclose failed: %s\n", error);
+ return 1;
+ }
- return 0;
+ return 0;
}
This code correctly dlopen()s and dlclose()s, so there should be no leak
whatsoever. And this can be confirmed from the result of valgrind
without -lpthread:
$ gcc /tmp/valgrind-dlopen-pthread-leak.c -ldl
$ valgrind ./a.out
...
==31371== All heap blocks were freed -- no leaks are possible
...
But this doesn't hold once I compile the sample code with -lpthread:
$ gcc /tmp/valgrind-dlopen-pthread-leak.c -ldl -lpthread
$ valgrind ./a.out
...
==31363== LEAK SUMMARY:
==31363== definitely lost: 0 bytes in 0 blocks
==31363== indirectly lost: 0 bytes in 0 blocks
==31363== possibly lost: 0 bytes in 0 blocks
==31363== still reachable: 32 bytes in 1 blocks
==31363== suppressed: 0 bytes in 0 blocks
...
I've created a suppresion for this:
- $ valgrind --gen-suppressions=yes --leak-check=full --show-reachable=yes
./a.out
+ $ valgrind --gen-suppressions=all --leak-check=full --show-reachable=yes
./a.out
...
==31414== 32 bytes in 1 blocks are still reachable in loss record 1 of 1
==31414== at 0x4C29DB4: calloc (in
/usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==31414== by 0x4E3359F: _dlerror_run (dlerror.c:142)
==31414== by 0x4E32FC0: dlopen@@GLIBC_2.2.5 (dlopen.c:88)
==31414== by 0x400662: main (in
/home/ryoqun/dev/rubinius/rubinius-master/a.out)
...
{
- Still-reachable leak in dlopen/dlclose when linked to libpthread
- Memcheck:Leak
- fun:calloc
- fun:_dlerror_run
- fun:dlopen@@GLIBC_2.2.5
- fun:main
+ Still-reachable leak in dlopen/dlclose when linked to libpthread
+ Memcheck:Leak
+ fun:calloc
+ fun:_dlerror_run
+ fun:dlopen@@GLIBC_2.2.5
+ fun:main
}
...
I don't know this should rather be fixed at libc...
--
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https://bugs.launchpad.net/bugs/1160352
Title:
Still reachable leak is reported with dlopen and pthread
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