[Bug translator/14013] New: Access to user space thread local variables (errno)

[Bug translator/14013] New: Access to user space thread local variables (errno)

[mjw at redhat dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=14013

             Bug #: 14013
           Summary: Access to user space thread local variables (errno)
           Product: systemtap
           Version: unspecified
            Status: NEW
          Severity: normal
          Priority: P2
         Component: translator
        AssignedTo: systemtap@sourceware.org
        ReportedBy: mjw@redhat.com
    Classification: Unclassified


Trying to access errno in glibc fails:

$ /usr/local/install/systemtap/bin/stap -e 'probe
process("/lib64/libc.so.6").function("*open*").return { printf("%s\n",
errno_str(@var("errno@errno.c"))) }'
semantic error: unrecognized operation in DWARF expression [1] at 9 (0xe0: 0,
0): identifier '@var' at <input>:1:88
        source: probe process("/lib64/libc.so.6").function("*open*").return {
printf("%s\n", errno_str(@var("errno@errno.c"))) }
                                                                               
                       ^

Pass 2: analysis failed.  Try again with another '--vp 01' option.

That is because we don't handle DW_OP_GNU_push_tls_address in the location
expression.

-- 
Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.

[Bug translator/14013] Access to user space thread local variables (errno)

[fche at redhat dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=14013

Frank Ch. Eigler <fche at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |fche at redhat dot com

--- Comment #1 from Frank Ch. Eigler <fche at redhat dot com> 2012-05-28 19:56:50 UTC ---
See also bug #13429, with a related problem of accessing TLS data via fs/gs
registers.

-- 
Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.

[Bug translator/14013] Access to user space thread local variables (errno)

[fweimer at redhat dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=14013

Florian Weimer <fweimer at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |fweimer at redhat dot com

-- 
You are receiving this mail because:
You are the assignee for the bug.

[Bug translator/14013] Access to user space thread local variables (errno)

[fche at redhat dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=14013

Frank Ch. Eigler <fche at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Blocks|                            |25580


Referenced Bugs:

https://sourceware.org/bugzilla/show_bug.cgi?id=25580
[Bug 25580] lp tracker
-- 
You are receiving this mail because:
You are the assignee for the bug.

[Bug translator/14013] Access to user space thread local variables (errno)

[fche at redhat dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=14013

Frank Ch. Eigler <fche at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|systemtap at sourceware dot org    |scox at redhat dot com

--- Comment #2 from Frank Ch. Eigler <fche at redhat dot com> ---
stap 4.3+ translate TLS operation dwarf location-expressions into calls to an
as-yet unimplemented tapset function __push_tls_address().  Let's start
implementing it, to mirror libthread_db's tls lookup entry points that gdb
uses:
td_thr_tls_get_addr / td_thr_tlsbase.  The tapset function would have to
traverse the ld.so data structures (via @cast / maybe a snapshot of glibc's
internal version of thread_db.h).

See also: https://infinitynotes.org/wiki/Glibc
https://akkadia.org/drepper/tls.pdf

-- 
You are receiving this mail because:
You are the assignee for the bug.