shl_load returns errno 22

[ArieMo]

The following line of C-code returns the errno 22:
shl_load(dllname,BIND_DEFERRED|DYNAMIC_PATH, )l);

The dllname is the name of a shared library, which can be found by the program (file permissions are ok). This was working before we converted to a Trusted System (OS = HP-UX 11.00).
What part of the arguments used can be invalid?

Thanks.

[Steve Steel]

Hi

Rebuild with LD_PRELOAD


I can guess that you need the latest linker patch and then use the LD_PRELOAD functionality to avoide this

You can use the LD_PRELOAD environment variable to load a shared library that contains thread-local storage to avoid the following error when loading the library dynamically:

/usr/lib/dld.sl: Can't shl_load() a library containing Thread Local Storage: /usr/lib/libpthread.1

Also error 22

The load order and symbol resolution order may be different in a PA32 program than in the same PA64 program because the dynamic loader uses depth-first search order in PA32 mode and breadth-first search order in PA64 mode.
The dynamic loader uses the LD_PRELOAD environment variable even if you use the +noenvvar in the link line. This insures that LD_PRELOAD is enabled even in a +compat link. The LD_PRELOAD variable is always enabled except for setuid and setgid programs.

Note: Using LD_PRELOAD can cause a core dump when used with applications which mix shared and archived libraries, especially when both the shared library and the application are built with aC++ or use libc.

You can specify multiple libraries as part of the LD_PRELOAD environment variable. Separate the libraries by spaces or colons as in LD_LIBRARY_PATH. (Multi-byte support is not provided as part of parsing the LD_PRELOAD library list). You can specify LD_PRELOAD libraries with absolute paths or relative paths. The LD_PRELOAD libraries can also consist of just the library names, in which case the dynamic loader uses the directory path list in the environment variables LD_LIBRARY_PATH and/or SHLIB_PATH or the embedded path list (if enabled) to search for the libraries.

The dynamic loader does not issue an error or warning message if it cannot find a library specified by LD_PRELOAD. However, if it does not find a dependent of the LD_PRELOAD libraries, the dynamic loader issues the same error message as if the LD_PRELOAD library is specified in the link line.



See man dld.sl when patch is loaded


Steve steel

[ArieMo]

Hi

I don't get the /usr/lib/dld.sl error. I explicit do a printf of errno after the shl_load routine to see why the program doesn't work. I've download the latest ld patch now and will try it again after applying it.

Thanks.

[ArieMo]

Changing the order of the libraries in the make file solved the problem:

Specifying -lc before -lpthread in threaded applications can cause run-time problems because the pthread/cma stubs are resolved instead of the real pthread/cma functions.

Also using LD_PRELOAD='/usr/lib/libpthread.1' worked.

Thanks for the suggestions.