(Note: names of the binary and binary and library below are obfuscated to protect the innocent. ;-) The app is proprietary under NDA but the behavior may not depend on it.)
I have a Linux binary which prints the following error when run:
binary: error while loading shared libraries: libshared.so: cannot open shared object file: No such file or directory
Which is confusing on its own since libshared.so is in the LD_LIBRARY_PATH. However,
The library is found correctly when running ldd binary (i.e., the ldd output points to the file location)
The library is found correctly when running strace binary, so that the program manages to print its usage information!
I have never seen an application which behaves differently when run on its own vs in strace, but I figure maybe someone else has seen this happen before? Any ideas how to resolve this?
I don't have the source so I can't rebuild. Running the app in production under strace is probably a non-starter. The OS is RHEL 6.2.
(Old question, but hopefully this will help somebody else)
Under new Linux installations, LD_LIBRARY_PATH is not used by the standard system runtime linker for programs with SUID set. It appears that strace, gdb and friends work differently, and do use LD_LIBRARY_PATH.
For suid programs, all libraries must be found in the system library cache. Check (as root) whether your "missing" library is present using
ldconfig -p | grep <my_library_name>
and, if anything's missing, add it to a new file in /etc/ld.so.conf or ld.so.conf.d/ as appropriate, and then rebuild using
ldconfig -v
Or remove the SUID bit if it's not required, of course.
This really helped me a lot!
I was having a similar problem where libraries were not being picked up properly from the LD_LIBRARY_PATH, even when the ldd command showed all libraries were satisfied. However, when troubleshooting using strace, it was working. In my case, however, the problem was that SGID (set group ID sticky bit being on). When the files were installed, the sysadmin did a recursive chmod that set it on all files (including the executables). Once the SGID was removed on the executables, the libraries were now found without strace and everything worked as it should using the LD_LIBRARY_PATH.
Related
i want to install cpanm WWW::Curl::Form on my Synology NAS. But that fails. Here is the output cpanm WWW::Curl::Form WWW::Curl::Easy File::Find::Rule String::CRC32 URI::Escape
--> Working on WWW::Curl::Form
Fetching http://www.cpan.org/authors/id/S/SZ/SZBALINT/WWW-Curl-4.17.tar.gz ... OK
Configuring WWW-Curl-4.17 ... OK
Building and testing WWW-Curl-4.17 ... FAIL
! Installing WWW::Curl::Form failed. See /var/services/homes/fox/.cpanm/work/1541095458.25803/build.log
the log file gives me:
make: i686-linux-gnu-ld: Command not found
But i dont know how to fix it on my Synology NAS (DSM 6.2 and appollolake architecture DS918+)
After reviewing your additional comments, I believe I have potential solution. It looks like you are trying to install some Perl modules via the default Perl shell, cpan. As part of the installation process, the make utility is being executed. This utility is heavily used for compiling and building source from C and C++ source code, along with other languages.
The make utility is trying to call some executable i686-linux-gnu-ld which is a linker, see ld. A linker is a utility used in C programming for linking (combining) multiple compiled object files into a single executable binary. make is calling this utility as some sort of build process. Instead of calling i686-linux-gnu-ld it should probably just be calling ld. The only thing I am not sure about is why it is using the full name of the utility instead of ld.
I can think of two solutions. The first would be to update the make file to use the correct name for the linker. I'm not sure how you would do this when it is being installed via cpan since it is downloading a package and executing the make file before you have a chance to modify it. The other option is to create a symbolic link from the incorrect name and path of ld that the make file is using to the correct path /opt/bin/ld. This will result in ld being called when i686-linux-gnu-ld is called. Also, I forgot to mention it earlier but the which command will tell you where an executable / command is located on your shell's path.
The Stack Overflow post, How to symlink a file in Liunx?, gives a good explanation of how to create a symlink. You need to create a symlink to point to the correct name and path of the linker. To do so run the following command:
ln -s /opt/bin/ld /usr/bin/i686-linux-gnu-ld
Depending on the permissions of these directories you may need to run this command under a account with elevated permissions or via sudo. I apologize for this post being rather long and verbose. I just wanted to explain my solution in detail. I hope this helps. Please let me know if this doesn't resolve the problem.
edit: fixed typo in the command.
I have instaled Cygwin after running MinGW for a while now. But when I try to compile the console gives me:
/usr/lib/gcc/x86_64-pc-cygwin/4.9.2/cc1.exe: error while loading shared libraries: ?: cannot open shared object file: No such file or directory
What does this mean?
I have the same problem and I found the solution.
According to the FAQ of Cygwin
Q: Why is C:\cygwin\usr\bin invisible from windows?
A: Because it does not really exist. In cygwin, /usr/bin is just a link to /bin.
So trying to add "C:\cygwin\usr\bin" to PATH will be in vain.
Add "C:\cygwin64\bin" to PATH instead. Hope this helps :)
You are missing a library, please run cygcheck /usr/lib/gcc/x86_64-pc-cygwin/4.9.2/cc1.exe or ldd /usr/lib/gcc/x86_64-pc-cygwin/4.9.2/cc1.exe to see what is the missing library.
(I'd rather ask a question in the comments first, but I don't have enough reputation yet.)
Your cc1 is unable to load some DLLs it needs to start. Looking at the Cygwin source code, this can be either a library specified in LD_PRELOAD, or -- more probably -- a library the executable depends on. The ? in the error message seems to be the default return value of find_first_notloaded_dll (hookapi.cc), in case the function can't determine what library is missing.
To diagnose the issue, I suggest checking your PATH variable (or even clearing it of any non-Cygwin paths and trying the compilation again) and/or using Dependency Walker to find the missing DLLs (start it from a Cygwin shell, so it can see the same PATH). ldd (included with Cygwin) may also give some clues, but I wouldn't bet on it.
It's possible a clean re-install of Cygwin will be necessary to solve the issue.
Most likely, you are simply missing /usr/bin in the PATH variable.
Adding 'export PATH=/usr/bin:$PATH' to your .bashrc file will solve the issue.
Adding some background info. I had the same problem when building my own program and linking it against graphviz cgraph.dll. Turns out this is related to where windows searches for DLLs (see here: https://msdn.microsoft.com/en-us/library/7d83bc18.aspx) So adding the path of your missing library to PATH should fix the problem.
It is unfortunate that the message doesn't include the name of the library. Luckily cmd.exe DOES give you this name (so it's good for something after all;)
Are you including the path to your lib directory?
Looks like you are not
I'm not very familiar with Cygwin, I mainly use MinGW, but I think the error message speaks for itself
I also came this error on windows machine while executing .exe file generated by scilab2C i.e toolbox for Scilab
For Windows 32 bit Add the environment variable path as follow :
C:\cygwin\usr\i686-pc-cygwin\bin
Hope so this will solve your issue.
Just had this problem trying to compile a package with make and it wanted some cygguile dll file that was just installed along with make.
My solution was I had not only migrated my cygwin64 directory across drives because the sector sizes were mismatched for some reason even though the drivers were both under 2TB and should have been using 512 byte sector sizes.. So I had to install a new system and move files over there, might have had weird permissions on them.
Also had to patch cygwin1.dll end of Jan 2020 because of a recent input problem in ConEmu with Windows 10 1903 build, but just did it again with this working so that doesn't seem to be the issue.
Reinstalling cygwin by deleting that entire directory, taking ownership of it first.., seemed to work now...
I am working in a virtual environment, trying to start open vm tools in a chroot environment.
I tested with bash and it seems to work fine.
I used ./configure --options --prefix=/home/chroot_env to install the program, then using ldd on vmtoolsd, i copied the corresponding libraries to the /lib directory.
Now when I start chroot /home/chroot_env /bin/vmtoolsd, nothing happens, the chroot returns directly. Launching the same binary in the normal environment does work.
Does someone have an idea why it isn't working, the correct libraries are there, and it works with bash.
EDIT : strace showed that vmtoolsd is trying to access /dev/console, I added mount --bind /dev/ /home/chroot_env/dev/ but it is still failing.
EDIT2 : another strace showed it was looking for another plugin loaded dynamically, i added it and it worked, conclusion strace is great for debugging such issue!
When you run a program and nothing happens, you can always run it with strace in order to see which syscalls are made. This is an easy way to obtain the list of the files (regular or not) that are opened. In your case, check that your program doesn't try to access a file that is not in the chroot.
All,
My host supports Perl CGI scripts, how do I use a compiled CGI script on the host?
I tried setting execute permissions via chmod, but when I try and run it via the browser, I get a server error.
Thanks in advance for all help.
It's possible with a few restrictions:
You're compiling statically or don't have any external dependencies
You're using a glibc that's no newer than theirs
If you're compiling under gcc, you might also need to provide libgcc_s.so which might mean you need a LD_LIBRARY_PATH in which case you'd probably run your binary through a shell script.
You can check the dependencies on your binary with ldd. My recommendation is to compile statically with no dependencies on a system with a glibc at least as old as theirs.
NOTE: (1) above isn't strictly a requirement if you can set LD_LIBRARY_PATH and can run everything through a wrapper script, but things get much more complicated if you need such functionality.
perhaps i'm missing something, but the fact that your host supports "perl cgi" doesn't mean that they support "compiled cgi" (which i would presume is a C CGI program).
Some details about what the server error was would be helpful.
I installed the latest busybox to my new embedded project. It runs OK until I try to put dropbear in my application. The busybox shell complains that dropbear is not found although "which dropbear" command gives me the correct answer "/sbin/dropbear". If I change its mode to RW, it complains that dropbear is not executable. I have tried other non-bosybox commands and it complains the same. It must be a setup issue. Can anyone help me out? Thank you very much.
Allan
Perhaps you're missing the necessary libraries? Some environments don't print helpful messages when this happens. Check what libraries it wants to link against.
ldd or objdump -x <file> |grep NEEDED are helpful.
You probably want to do this from your build machine, as it sounds like the embedded shell environment is pretty broken.
Eric Seppanen's answer is true,any missing dynamic library dependency will cause the cryptic "not found" message for the binary in question. Linux will also give this error if it cannot find ld-linux-x86-64.so.2 in the /lib64 directory, or for 32bit binaries, the corresponding 32bit ld-linux*.so in /lib.