On 01/29/2015 05:14 AM, Stefano Borini wrote: > Good morning, > > I am encountering what seems to be a spinlock with the chcon utility > trying the following operation > > chcon -t texrel_shlib_t /tmp/subdir/withheldpath > > where withheld path is a .so that is going to be accessed with dlopen. > I am not invoking the chcon command directly nor performing the dlopen, > a closed-source library does that, apparently to prepare the .so for > dlopening. > > Note that if I try the same operation from the command line, even while > the spinlock is in progress, no lock occurs. > > I am unable to understand the details of what may cause this spinlock. > This is the backtrace of chcon, apparently involving some thread local > storage > > #0 0x0000003e3ea00b64 in rtld_lock_default_lock_recursive () from > /lib64/ld-linux-x86-64.so.2 > #1 0x0000003e3ea11257 in tls_get_addr_tail () from > /lib64/ld-linux-x86-64.so.2 > #2 0x0000003e3ea11660 in __tls_get_addr () from > /lib64/ld-linux-x86-64.so.2 > #3 0x0000003e40a14334 in selinux_raw_to_trans_context () from > /lib64/libselinux.so.1 > #4 0x0000003e40a0ca7a in getfilecon () from /lib64/libselinux.so.1 > > Checking the tls_get_addr_tail function, it is apparently stuck in the > again: loop > > http://code.woboq.org/userspace/glibc/elf/dl-tls.c.html#742 > > I have only access to the centos 6.4 and can run additional > non-destructive tests if needed. It's a customer machine so I am unable > to say if modifications have been done to it when it comes to security, > although I suspect it's a standard centos6.4 installation with selinux > enabled. > > The current ls -Z of /tmp gives > > system_u:object_r:tmp_t:s0 > > of subdir and of the so file is > > unconfined_u:object_r:user_tmp_t:s0 > > Thank you for your help. libselinux version? _______________________________________________ Selinux mailing list Selinux@xxxxxxxxxxxxx To unsubscribe, send email to Selinux-leave@xxxxxxxxxxxxx. To get help, send an email containing "help" to Selinux-request@xxxxxxxxxxxxx.
