[Bug translator/12536] New: sdt v>=2 argument parsing can't parse '4+4(%esp)'

["roland at gnu dot org" <sourceware-bugzilla at sourceware dot org>]

http://sourceware.org/bugzilla/show_bug.cgi?id=12536

           Summary: sdt v>=2 argument parsing can't parse '4+4(%esp)'
           Product: systemtap
           Version: unspecified
            Status: NEW
          Severity: normal
          Priority: P2
         Component: translator
        AssignedTo: scox@redhat.com
        ReportedBy: roland@gnu.org
                CC: systemtap@sources.redhat.com


systemtap-1.4-3.fc15.x86_64

I have the glibc with sdt probes installed, you can get it from
http://koji.fedoraproject.org/scratch/roland/task_2877130/ (though that may
expire in a few days).  Both glibc.x86_64 and glibc.i686 rpms from there are
installed.

I used this script:

probe process("/lib*/libc.so.*").mark("*jmp*") { printf("%s(%p, %d) from PC %p:
%s\n", $$name, $arg1, $arg2, $arg3, sprint_ubacktrace()); }

That was in -e, along with -d .../setjmp --ldd where .../setjmp is an i686
executable (and -c .../setjmp was at the end).

This produced:

WARNING: Downgrading SDT_V2 probe argument to dwarf, can't parse '4+4(%esp)':
identifier '$arg2' at <input>:1:103

That argument appears in /lib/libc.so.6, which is the i686 DSO.

1. It says SDT_V2 when in fact this is v3.
2. I don't understand what "downgrading to dwarf" means anyway, since DWARF is
of no help at all for the $arg2 syntax and what appears to happen is that the
instance of the sdt probe that uses the problematic syntax just doesn't
actually get probed at all.
3. The problem appears to be the 4+4 in the operand syntax.  Having simple
arithmetic expressions in the displacements in operands, or in constant
operands, is common in hand-written assembly (usually resulting from cpp macros
used in the assembly, in fact).
4. The same error occurs when .../setjmp is an x86-64 executable instead, in
which case the script actually works as intended because /lib/libc.so.6 is
never used in the x86-64 process, and the probes in /lib64/libc.so.6 work fine.

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