LeRoy on 10 Mar 2013 10:06:37 -0700 |
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Re: [PLUG] File ownership under Linux |
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 On 03/10/2013 11:04 AM, Eric H. Johnson wrote: > Hi all, > > I am running into a problem running an executable cross compiled on > Ubuntu for X86 and targeting an Arm7. I suspect the problem may > have to do with ownership. I am using Ubuntu 12.04 on an X86 to > target to an Arm7. I have successfully compiled a patched kernel > which successfully boots to it and a Debian Wheezy image. I am now > trying to port some utilities which I have successfully compiled on > the x86 with the same tool chain. There is no packaging system in > place so I am just copying files. > > The file I want to run is an executable, so if I try the fully > qualified path, running as root on arm7: /usr/bin/xenomai/latency > > I get an error to the effect that there is no file or directory by > that name. > > Here is what I need clarification on. Everything on the Arm7 runs > on an SD card, so at the moment I just plug the SD into the x86 > computer and copy the files I need. When I copy I am running as > root on the x86. After I boot to the SD from the Arm7 and check the > file ownership and attributes they are: > > root:root and -xrw-xr-xr respectively. What file system are you running on the SD chip? If the SD chip is using a Windows file system then all files are automatically root:root ownership. Also how is the SD chip mounted? You can see this by issuing a mount command. There are some distributions that mount FAT and NTFS file systems as ro (read only) and noexec (non executable). > > But even so I have used chmod and chown to force the ownership and > attributes, but see no discernible difference. As stated above FAT and NTFS file systems cannot have ownership and permissions changed. When I mount /windows on my dual boot laptop mount shows: /dev/sda1 on /windows type fuseblk (ro,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other,blksize=4096) On my Debian system a NTFS file system mounts with setting the user_id and group_id which cannot be changed with chown. Also if the file system is mounted with noexec then you cannot run even a script. To change this you need to run mount -o remount,etc Read the man page for mount to check on all of the options available. ls -lh /windows drwxrwxrwx 1 root root 4.0K May 22 2009 Temp drwxrwxrwx 1 root root 4.0K Oct 10 2008 Users - -rwxrwxrwx 1 root root 1.4M Nov 7 2007 VC_RED.cab - -rwxrwxrwx 1 root root 5.6K Nov 7 2007 vcredist.bmp - -rwxrwxrwx 1 root root 228K Nov 7 2007 VC_RED.MSI drwxrwxrwx 1 root root 28K Mar 3 10:06 Windows If you are putting linux on a SD chip first I would make the filesystem either ext3 or ext4 or any other UNIX type filesystem. Personally I create SD chips as encrypted chips which require cryptsetup LuksOpen /dev/sdc1 sandisk Then I can mount /dev/mapper/sandisk /mnt/sandisk I hope that this helps :-) - -- Rev. LeRoy D. Cressy mailto:leroy@lrcressy.com /\_/\ http://lrcressy.com ( o.o ) > ^ < Cell Phone: 267-307-3527 Open PGP Key: C34B77CC gpg fingerprint: 8AD5 35EF 1FDF F1A7 E483 8CCE A50D 4E81 C34B 77CC For info on enigmail: http://enigmail.mozdev.org/ For info on gpg: http://www.gnupg.org/ Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me. (John 14:6) -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQIcBAEBCgAGBQJRPL19AAoJEI9ujBCAoueI04sP/1qftpOz/RDJOkkE6DXoOnIE F+M1THopohJ1AI12bZ1IQ+7u6lL8MNB030sNP8j+RF4X/iv5bP5CPzlyDLarPjMS eosRZ29sNb9txMI6JbNenpHV5bHmXStbBJX3GJfP/sSYFKVcMToXITj4jAP/17ty BD3JBrZ/rf9JA7X/ziQUptnZzyiTwIPR94a5sG7460qIx63LYlmP/snTKQbg4uUr NmQj6gfUc054ZzbK+LyZ8+stgUz3diTDEgTiqCdOanebIJYDltgF3kiUgEtyQe3Y umkeUCsu4SUUDYIAMeG09sTZ8vbiqMeyt2Rxv0nls1Qbg/qA+n3m2sILcWkddcis dLIRKCXCmdRicvlPtILLO+y4J9pa5HDlifWYBILjtY8jDleaZgC1gHqAMSf1DqMl j6UFd+OrYgY/F/2bCt1amcmf/BuikZcWY1yDW/dsp2brF3wBiGwWCPEg+VTkqSKg on3Pklm0KDBqO3hDeOAVqNLn63qvfwy58Vg/odQjcgmaYp0qBESZL+OFVJnV+zKQ Je5J8GunIgeszMwU6jlXQIgLxDwAsIWUFNJ+AiBcG8refJqyjW1IULRW2PciAd9c wHknfDUSSAn+k8wrHI1tYLs9T635rGBDvDq1XG2VrjgTNhTzZbQ09ROwPc42/e95 xi2It3vfO2TvpvNXCb81 =+1Ji -----END PGP SIGNATURE----- ___________________________________________________________________________ Philadelphia Linux Users Group -- http://www.phillylinux.org Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce General Discussion -- http://lists.phillylinux.org/mailman/listinfo/plug