symbolic links of libblas.so.3 - linux

I messed up the symbolic links of my libblas.so.3
I get the error message:
sudo update-alternatives --list libblas.so.3
update-alternatives: error: cannot stat file '/usr/lib/libblas/libblas.so.3': Too many levels of symbolic links
When I do:
ls -l /usr/lib/libblas/libblas.so.3:
lrwxrwxrwx 1 root root 30 Nov 23 15:15 /usr/lib/libblas/libblas.so.3 -> /etc/alternatives/libblas.so.3
Then, again:
ls -l /etc/alternatives/libblas.so.3
lrwxrwxrwx 1 root root 29 Nov 25 14:36 /etc/alternatives/libblas.so.3 -> /usr/lib/libblas/libblas.so.3
Any help to get ot of this situation would be very much appreciated. I do not know if it is enough information. If not, let me know and I try to provide more. Thanks.
I guess the problem is that /usr/lib/libblas/libblas.so.3 links back to etc/.., however it should point to the actual file. How can I do that?

I had to remove the link in the alternatives directory:
sudo rm /etc/alternatives/libblas.so.3
Then, I recreated the link, but pointnig to a real library file. For that I chose the corresponding one from the atlas package:
sudo ln -s /usr/lib/atlas/atlas-base/libblas.so.3 /etc/alternatives/libblas.so.3

Related

Unable to write to a file with group permissions

We are getting the error "permission denied" when trying to write to a file that is owned by a service user and a shared group. In particular that is www-data:www-data and the user trying to write to it is in the group www-data.
There is no acl on none of the parent folders and the permissions to the file and folders are correct.
Here some details:
$ sudo -u deploy id -Gn
www-data
$ ls -lah /tmp
drwxrwxrwt 17 root root 4.0K Jul 11 11:22 .
drwxr-xr-x 23 root root 4.0K Jul 8 10:08 ..
...
-rw-rw-r-- 1 www-data www-data 0 Jul 11 10:50 test
...
$ echo 'hello world' | sudo -u deploy tee -a /tmp/test
tee: /tmp/test: Permission denied
hello world
we tried that on different folders and made sure there is no acl on any of the folders or parents or files...
Unfortunately that is not described in the link stark posted in the comment. And also not in any other page I found until I found an answer here on stackoverflow that clarified it.
2018 two new filesystem configurations got added to sysctl that should prevent regular files and fifos from beeing opened with the O_CREAT flag (as append mode is doing) in directories with the sticky bit set unless the user is the owner of the file. This commit added the settings: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=30aba6656f61ed44cba445a3c0d38b296fa9e8f5
To change that behaviour you have to set fs.protected_regular to 0:
sudo sysctl fs.protected_regular=0
Or to persist the change add fs.protected_regular=0 to your sysctl.conf.
side node: since O_CREAT is not deleting or renaming the file I'm wondered why it is connected to the sticky bit. It really is possible to create a file in directories with the stick bit set.

Using a compiled from source library that is a newer version of a preexisting library

I'm unsure about some small obscure details that I worry will have large effects. On my Raspbian Debian 11 running on a Raspberry Pi, sudo apt update && sudo apt full-upgrade only updates my libxml2 library to version 2.9.10, no further. However, I need version 2.9.14 for the security patches contained within. With help from this question (thank you Esther!), I decided to compile version 2.9.14 from source. Everything went well, and the library was placed into /usr/local/lib. I then updated ldconfig by following this answer. However, although that should have made Debian use the new 2.9.14 version, apt-cache policy libxml2 still shows:
libxml2:
Installed: 2.9.10+dfsg-6.7+deb11u2
Candidate: 2.9.10+dfsg-6.7+deb11u2
Version table:
*** 2.9.10+dfsg-6.7+deb11u2 500
500 http://raspbian.raspberrypi.org/raspbian stable/main armhf Packages
100 /var/lib/dpkg/status
I think I know why this is. If I was installing a never-before-seen library, everything might have worked properly. However, since I now have a second libxml2 library without removing the 1st, any time the system needs to use libxml2, the search first reaches /usr/lib/arm-linux-gnueabihf where the old libxml2 is, so the system finds the old version, is satisfied, and so stops searching before finding the new version.
For context before I continue:
(link to below but in color: https://i.stack.imgur.com/OJLJW.png)
pi#fuelightcontrol:~ $ cd /usr/lib/arm-linux-gnueabihf/
pi#fuelightcontrol:/usr/lib/arm-linux-gnueabihf $ ls -l | grep libxml2
lrwxrwxrwx 1 root root 17 May 15 14:58 libxml2.so.2 -> libxml2.so.2.9.10
-rw-r--r-- 1 root root 1510312 May 15 14:58 libxml2.so.2.9.10
pi#fuelightcontrol:/usr/lib/arm-linux-gnueabihf $ cd /usr/local/lib
pi#fuelightcontrol:/usr/local/lib $ ls -l
total 12120
drwxr-xr-x 3 root root 4096 Jun 14 18:17 cmake
-rw-r--r-- 1 root root 7145994 Jun 14 18:17 libxml2.a
-rwxr-xr-x 1 root root 944 Jun 14 18:17 libxml2.la
lrwxrwxrwx 1 root root 17 Jun 14 18:17 libxml2.so -> libxml2.so.2.9.14
lrwxrwxrwx 1 root root 17 Jun 14 18:17 libxml2.so.2 -> libxml2.so.2.9.14
-rwxr-xr-x 1 root root 5242072 Jun 14 18:17 libxml2.so.2.9.14
drwxr-xr-x 2 root root 4096 Jun 14 18:17 pkgconfig
drwxr-xr-x 3 root root 4096 Jun 13 21:43 python3.9
-rw-r--r-- 1 root root 205 Jun 14 18:17 xml2Conf.sh
pi#fuelightcontrol:/usr/local/lib $
The question is, what would be the best way to go about fixing the problem of the old version still being used by apt-cache policy libxml2 and other programs? I could:
Just delete /usr/lib/arm-linux-gnueabihf/libxml2.so.2.9.10 (the old one) and its symbolic link, so the system keeps searching past that point and eventually finds /usr/local/lib/libxml2.so.2.9.14 (the new one). However, something feels... off about having my libraries scattered around in different directories. My gut tells me to keep them in one place. Also, see paragraph below the next list item.
I could delete /usr/lib/arm-linux-gnueabihf/libxml2.so.2.9.10 (the old one) and its symbolic link, then move the new version into /usr/lib/arm-linux-gnueabihf to replace the old version. However, there's more libxml2 related files and 1 more symbolic link in /usr/local/lib that are not present in /usr/lib/arm-linux-gnueabihf. Do I need to move those too, or should I just move libxml2.so.2.9.14 and one (both?) of the symbolic links? If only 1 link, which?
Should I delete the files left behind after I move the required ones over? Also, see paragraph below.
What concerns me about deleting anything is if some other script comes looking for libxml2.2.9.10, can't find it, and fails. I don't know how to tell the rest of the programs that libxml2's filename is different now. I suppose both options 1 and 2 might work, but is one option a cleaner, smarter idea? I'm trying to save myself some work in the future.
Sorry this is such a small silly question. Thank you for your help!
Edit: After making backups of both directories, I tried option 1 first, then option 2. Neither changed the output of apt-cache policy libxml2 - it still says I have libxml2 2.9.10 installed, even though I deleted /usr/lib/arm-linux-gnueabihf/libxml2.so.2.9.10 and its symbolic link, rebooted, and ran sudo apt update
Here's how I updated ldconfig (same as the second link), to clear up loose ends. The link to /usr/local/lib was done for me already, which was nice.
Link to screenshot of below but in color: https://i.stack.imgur.com/7w6XR.png
pi#fuelightcontrol:/etc $ ls -l ld.so.conf
ld.so.conf ld.so.conf.d/
pi#fuelightcontrol:/etc $ cat ld.so.conf
include /etc/ld.so.conf.d/*.conf
pi#fuelightcontrol:/etc $ ls -l ld.so.conf.d
total 16
-rw-r--r-- 1 root root 12 Dec 1 2021 00-vmcs.conf
-rw-r--r-- 1 root root 109 May 14 2019 arm-linux-gnueabihf.conf
-rw-r--r-- 1 root root 41 Jun 25 2018 fakeroot-arm-linux-gnueabihf.conf
-rw-r--r-- 1 root root 44 Jun 14 19:08 libc.conf
pi#fuelightcontrol:/etc $ cat ld.so.conf.d/libc.conf
# libc default configuration
/usr/local/lib
pi#fuelightcontrol:/etc $ sudo ldconfig
pi#fuelightcontrol:/etc $ sudo ldconfig /usr/local/lib
pi#fuelightcontrol:/etc $ sudo ldconfig -n /usr/local/lib
pi#fuelightcontrol:/etc $ cat ld.so.conf.d/00-vmcs.conf
/opt/vc/lib
pi#fuelightcontrol:/etc $ cat ld.so.conf.d/arm-linux-gnueabihf.conf clear
# Multiarch support
/usr/local/lib/arm-linux-gnueabihf
/lib/arm-linux-gnueabihf
/usr/lib/arm-linux-gnueabihf
cat: clear: No such file or directory
pi#fuelightcontrol:/etc $ cat ld.so.conf.d/fakeroot-arm-linux-gnueabihf.conf
/usr/lib/arm-linux-gnueabihf/libfakeroot
pi#fuelightcontrol:/etc $

Executing script with musl-built tclsh8.6 gives `No such file or directory`

I am trying to run a simple tcl script with tclsh8.6 that I compiled from source using a musl toolchain on x86_64 Debian.
The script, hello.tcl, looks like this:
puts hello
and when I try to run it I get the following error:
$ /usr/local/x86_64-linux-musl/bin/tclsh8.6 hello.tcl
-bash: /usr/local/x86_64-linux-musl/bin/tclsh8.6: No such file or directory
The necessary tcl libraries and include files are all installed to the prefix /usr/local/x86_64-linux-musl. The binary also exists:
$ ls -l /usr/local/x86_64-linux-musl/bin/tclsh8.6
-rwxr-xr-x 1 root root 8328 Nov 15 12:18 /usr/local/x86_64-linux-musl/bin/tclsh8.6
$ ldd /usr/local/x86_64-linux-musl/bin/tclsh8.6
linux-vdso.so.1 (0x00007ffd04718000)
libtcl8.6.so => /usr/local/x86_64-linux-musl/lib/libtcl8.6.so (0x00007f005981e000)
libc.so => /usr/local/x86_64-linux-musl/lib/libc.so (0x00007f0059587000)
I would like to keep things musl based, so I am trying to avoid a potential solution I found elsewhere, which is to reinstall tcl or tcl-dev with apt-get.
What is causing this error? Any guidance/help is greatly appreciated. Thanks :)
EDIT
As requested by some of the comments here is some additional information.
The output of the file command:
$ file /usr/local/x86_64-linux-musl/bin/tclsh8.6
/usr/local/x86_64-linux-musl/bin/tclsh8.6: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib/ld-musl-x86_64.so.1, not stripped
The output of the strace command:
strace /usr/local/x86_64-linux-musl/bin/tclsh8.6 hello.tcl
execve("/usr/local/x86_64-linux-musl/bin/tclsh8.6", ["/usr/local/x86_64-linux-musl/bin"..., "hello.tcl"], 0x7fffb8c5b278 /* 19 vars */) = -1 ENOENT (No such file or directory)
strace: exec: No such file or directory
+++ exited with 1 +++
After seeing this output, I checked to see if the loader/interpreter existed at /lib and it didn't. To fix this, I ran:
$ sudo ln -s /usr/local/x86_64-linux-musl/lib/ld-musl-x86_64.so.1 /lib/ld-musl-x86_64.so.1
That gave me a different error when I ran tclsh8.6:
$ /usr/local/x86_64-linux-musl/bin/tclsh8.6 hello.tcl
-bash: /usr/local/x86_64-linux-musl/bin/tclsh8.6: Permission denied
Running it with sudo gives the same thing:
$ sudo /usr/local/x86_64-linux-musl/bin/tclsh8.6 hello.tcl
sudo: unable to execute /usr/local/x86_64-linux-musl/bin/tclsh8.6: Permission denied
The permissions on the interpreter and script are as follows:
$ ls -l /usr/local/x86_64-linux-musl/bin/tclsh8.6
-rwxr-xr-x 1 root root 8328 Nov 15 13:34 /usr/local/x86_64-linux-musl/bin/tclsh8.6
$ ls -l hello.tcl
-rwxr-xr-x 1 user user 11 Nov 15 12:44 hello.tcl
Hopefully this new information helps a bit more.
EDIT 2
More permission information :)
$ ls -l /lib/ld-musl-x86_64.so.1
lrwxrwxrwx 1 root root 52 Nov 16 10:04 /lib/ld-musl-x86_64.so.1 -> /usr/local/x86_64-linux-musl/lib/ld-musl-x86_64.so.1
$ ls -l /usr/local/x86_64-linux-musl/lib/ld-musl-x86_64.so.1
lrwxrwxrwx 1 root root 12 Nov 15 12:02 /usr/local/x86_64-linux-musl/lib/ld-musl-x86_64.so.1 -> /lib/libc.so
$ $ ls -l /lib/libc.so
-rw-r--r-- 1 root root 246 Nov 14 15:15 /lib/libc.so
And here is the contents of /lib/libc.so:
/* GNU ld script
Use the shared library, but some functions are only in
the static library, so try that secondarily. */
OUTPUT_FORMAT(elf64-x86-64)
GROUP ( //lib/libc.so.6 //lib/libc_nonshared.a AS_NEEDED ( //lib/ld-linux-x86-64.so.2 ) )
It is a linker script, which if you make executable fails and says the library is corrupted.
With the help of #Shawn I was able to figure out my problem.
tclsh8.6 was looking for the program interpreter at /lib/ld-musl-x86_64.so.1 which didn't exist - I guess when I was installing musl-cross-make it didn't set this up. To fix this problem, I simply symlinked from where ld-musl-x86_64.so.1 was located to lib:
$ sudo ln -s /usr/local/x86_64-linux-musl/lib/ld-musl-x86_64.so.1 /lib/ld-musl-x86_64.so.1
However, I still was getting an error, but this time it was a permissions error:
$ /usr/local/x86_64-linux-musl/bin/tclsh8.6 hello.tcl
-bash: /usr/local/x86_64-linux-musl/bin/tclsh8.6: Permission denied
It turns out that ld-musl-x86_64.so.1 ended up being a symlink that resolved to /lib/libc.so which is a linker script and not the executable DSO that we want. I changed this symlink accordingly:
sudo ln -fs /usr/local/x86_64-linux-musl/lib/libc.so /usr/local/x86_64-linux-musl/lib/ld-musl-x86_64.so.1
After that, I could execute my script and everything worked like a charm! :)

library not found although I use ldconfig and /etc/ld.so.conf.d/lib.conf

I'm using Fedora 25.
I have a binary that needs multiple libraries. The binary can't find libRblas.so:
$ ldd XPore-Engine | less | grep not
libvtkRenderingAnnotation.so.1 => /usr/lib64/vtk/libvtkRenderingAnnotation.so.1 (0x00007fac12563000)
libRblas.so => not found
libRblas.so => not found
libRblas.so => not found
The library path is properly configured with a .conf file:
$ cat /etc/ld.so.conf.d/R-x86_64.conf
/usr/lib64/R/lib
$ ll /usr/lib64/R/lib
lrwxrwxrwx. 1 root root 11 dic 16 20:46 libopenblas.so.0 -> libRblas.so
lrwxrwxrwx. 1 root root 27 oct 31 21:16 libRblas.so -> /usr/lib64/libopenblas.so.0
-rwxr-xr-x. 1 root root 1989312 oct 31 21:16 libRlapack.so
-rwxr-xr-x. 1 root root 178856 oct 31 21:16 libRrefblas.so
-rwxr-xr-x. 1 root root 2911536 oct 31 21:16 libR.so
And I load the configuration with ldconfig:
$ ldconfig -v | grep libRblas
libopenblas.so.0 -> libRblas.so
However, after executing ldd again it returns the same output saying that libRblas.so wasn't found.
How can I fix this?
I've found a workaround provided by Tom in the Read Hat Bugzilla bug-tracking system at https://bugzilla.redhat.com/show_bug.cgi?id=1404662.
Yeah, so it looks like while R is perfectly happy using libRblas.so as a > symlink to libopenblas.so.0, externally, nothing else is.
The speedup from using openblas is significant, so the fix is to build a copy of openblas that has the libRblas.so filename and soname, and use that instead of the symlink. I have a new build of openblas going which adds this, then I'll do a new round of R builds that depend on it.
As a temporary workaround, you can run (as root):
rm -f /usr/lib64/R/lib/libRblas.so
mv /usr/lib64/R/lib/libRrefblas.so /usr/lib64/R/lib/libRblas.so
That will restore the unoptimized libRblas.so that R provides.
Oh, and run /sbin/ldconfig (as root) after moving libRrefblas.so so that the ldcache is updated.

sudo: effective uid is not 0, is sudo installed setuid root? (on mac os x 10.12)

So I'm a bit of a terminal noob so bear with me but I was trying to update brew to install something, so I ran: brew update and got Error: /usr/local must be writable!
Wasn't really sure what that was about so I tried running sudo brew update and got sudo: effective uid is not 0, is sudo installed setuid root?
Not sure if this helps but running ls -l $(which sudo) gave me:
ls: is: No such file or directory
ls: is: No such file or directory
ls: is: No such file or directory
ls: is: No such file or directory
ls: sudo: No such file or directory
ls: sudo: No such file or directory
ls: sudo: No such file or directory
ls: sudo: No such file or directory
-r-s--x--x 1 root wheel 369136 Sep 13 20:56 /usr/bin/sudo
-r-s--x--x 1 my_profile admin 168448 Jan 13 2016 /usr/local/bin/sudo
-r-s--x--x 1 my_profile admin 168448 Jan 13 2016 /usr/local/bin/sudo
-r-s--x--x 1 my_profile admin 168448 Jan 13 2016 /usr/local/bin/sudo
I tried the suggestion here (using Disk Utility and running First Aid) but it didn't seem to have any effect....
Can anyone tell me what's going on and what I need to do?
If you run ls -la /usr, the result most likely will be something like below:
total 0
drwxr-xr-x# 11 root wheel 374 Oct 14 14:35 .
drwxr-xr-x 32 root wheel 1156 Oct 26 09:49 ..
drwxr-xr-x 19 root wheel 646 Oct 10 18:51 local
... (some other files and directories)
Now it's obvious from the above that unless you are logged in as a root or your user is in the wheel group (which is most likely not), any command you issue with your user which needs write permission (such as brew update) will fail.
One of the possible solutions (and I am not claiming is the best one) would be to change permissions of /usr/local.
Like so:
sudo chown -R $(whoami) /usr/local
Interestingly enough, if you then run
brew update
all goes well and you get the following message:
=> Migrating HOMEBREW_REPOSITORY (please wait)...
==> Migrated HOMEBREW_REPOSITORY to /usr/local/Homebrew!
Homebrew no longer needs to have ownership of /usr/local. If you wish you can
return /usr/local to its default ownership with:
sudo chown root:wheel /usr/local
Which I guess explains what happened in the first place.
Hope that helps.

Resources