[BUG?] semantic error: failed to retrieve location attribute for local

[Jan Blunck <jblunck at suse dot de>]

I have the following simple probe:

probe kernel.inline("real_lookup")
{
        printf("%s - %s(%s): %s\n", thread_indent(0), probefunc(),
                   kernel_string($parent->d_name->name),
                   kernel_string($name->name))
}

The full error message is as follows:

jblunck:~/systemtap$ stap -vvvv -p2 real_lookup.stp
Created temporary directory "/tmp/stapABdKKf"
Searched '/usr/share/systemtap/tapset/2.6.18.2-34-default/i686/*.stp', match
count 0
Searched '/usr/share/systemtap/tapset/2.6.18.2-34-default/*.stp', match count
0
Searched '/usr/share/systemtap/tapset/2.6.18.2/i686/*.stp', match count 0
Searched '/usr/share/systemtap/tapset/2.6.18.2/*.stp', match count 0
Searched '/usr/share/systemtap/tapset/2.6.18/i686/*.stp', match count 0
Searched '/usr/share/systemtap/tapset/2.6.18/*.stp', match count 0
Searched '/usr/share/systemtap/tapset/2.6/i686/*.stp', match count 0
Searched '/usr/share/systemtap/tapset/2.6/*.stp', match count 0
Searched '/usr/share/systemtap/tapset/i686/*.stp', match count 1
Searched '/usr/share/systemtap/tapset/*.stp', match count 33
Searched '/usr/share/systemtap/tapset/LKET/2.6.18.2-34-default/i686/*.stp',
match count 0
Searched '/usr/share/systemtap/tapset/LKET/2.6.18.2-34-default/*.stp', match
count 0
Searched '/usr/share/systemtap/tapset/LKET/2.6.18.2/i686/*.stp', match count 0
Searched '/usr/share/systemtap/tapset/LKET/2.6.18.2/*.stp', match count 0
Searched '/usr/share/systemtap/tapset/LKET/2.6.18/i686/*.stp', match count 0
Searched '/usr/share/systemtap/tapset/LKET/2.6.18/*.stp', match count 0
Searched '/usr/share/systemtap/tapset/LKET/2.6/i686/*.stp', match count 0
Searched '/usr/share/systemtap/tapset/LKET/2.6/*.stp', match count 0
Searched '/usr/share/systemtap/tapset/LKET/i686/*.stp', match count 0
Searched '/usr/share/systemtap/tapset/LKET/*.stp', match count 19
Pass 1: parsed user script and 53 library script(s) in 420usr/0sys/426real ms.
parsed 'real_lookup' -> func 'real_lookup'
pattern 'kernel' matches module 'kernel'
focused on module 'kernel = [c0100000-c042ae14, bias 0] file
/usr/lib/debug/boot/vmlinux-2.6.18.2-34-default.debug ELF machine i686 (code
3)
pattern 'real_lookup' matches function 'real_lookup'
checking instances of inline real_lookup
examining inline instance of real_lookup
selected inline instance of real_lookup
querying entrypc c0170197 of instance of inline 'real_lookup'
probe real_lookup@fs/namei.c:447 kernel section=.text pc=0xc0170197
finding location for local 'parent' near address c0170197, module bias 0
finding location for local 'name' near address c0170197, module bias 0
pattern 'kernel' matches module 'kernel'
Eliding unused function print_regs
Eliding unused function print_backtrace
Eliding unused function backtrace
Eliding unused function pid
Eliding unused function ppid
Eliding unused function pexecname
Eliding unused function gid
Eliding unused function egid
Eliding unused function uid
Eliding unused function euid
Eliding unused function cpuid
Eliding unused function cpu
Eliding unused function print_stack
Eliding unused function pp
Eliding unused function probemod
Eliding unused function is_return
Eliding unused function target
Eliding unused function stp_pid
Eliding unused function stack_size
Eliding unused function stack_used
Eliding unused function stack_unused
Eliding unused function caller_addr
Eliding unused function caller
Eliding unused function user_string
Eliding unused function user_string2
Eliding unused function user_string_warn
Eliding unused function user_string_quoted
Eliding unused function get_cycles
Eliding unused function gettimeofday_ms
Eliding unused function gettimeofday_s
keeping expression identifier 'printf' at real_lookup.stp:7:2 because it
writes: _indent_counters _indent_timestamps and/or embedded: 1
keeping expression operator '=' at /usr/share/systemtap/tapset/indent.stp:5:6
because it writes: ts and/or embedded: 0
keeping expression operator '=' at /usr/share/systemtap/tapset/indent.stp:6:56
because it writes: _indent_timestamps and/or embedded: 0
keeping expression operator '=' at /usr/share/systemtap/tapset/indent.stp:9:5
because it writes: x and/or embedded: 0
keeping expression operator '+=' at
/usr/share/systemtap/tapset/indent.stp:10:25 because it writes:
_indent_counters and/or embedded: 0
keeping expression operator '=' at /usr/share/systemtap/tapset/indent.stp:12:5
because it writes: r and/or embedded: 0
keeping expression operator '=' at /usr/share/systemtap/tapset/indent.stp:14:9
because it writes: i and/or embedded: 0
keeping expression operator '++' at
/usr/share/systemtap/tapset/indent.stp:14:19 because it writes: i and/or
embedded: 0
keeping expression operator '.=' at
/usr/share/systemtap/tapset/indent.stp:14:25 because it writes: r and/or
embedded: 0
keeping expression identifier 'printf' at real_lookup.stp:7:2 because it
writes: _indent_counters _indent_timestamps and/or embedded: 1
keeping expression operator '=' at /usr/share/systemtap/tapset/indent.stp:5:6
because it writes: ts and/or embedded: 0
keeping expression operator '=' at /usr/share/systemtap/tapset/indent.stp:6:56
because it writes: _indent_timestamps and/or embedded: 0
keeping expression operator '=' at /usr/share/systemtap/tapset/indent.stp:9:5
because it writes: x and/or embedded: 0
keeping expression operator '+=' at
/usr/share/systemtap/tapset/indent.stp:10:25 because it writes:
_indent_counters and/or embedded: 0
keeping expression operator '=' at /usr/share/systemtap/tapset/indent.stp:12:5
because it writes: r and/or embedded: 0
keeping expression operator '=' at /usr/share/systemtap/tapset/indent.stp:14:9
because it writes: i and/or embedded: 0
keeping expression operator '++' at
/usr/share/systemtap/tapset/indent.stp:14:19 because it writes: i and/or
embedded: 0
keeping expression operator '.=' at
/usr/share/systemtap/tapset/indent.stp:14:25 because it writes: r and/or
embedded: 0
semantic error: failed to retrieve location attribute for local 'name'
(dieoffset: 85127198053): identifier '$name' at real_lookup.stp:9:20
semantic error: failed to retrieve location attribute for local 'name'
(dieoffset: 85127198053): identifier '$name' at real_lookup.stp:9:20
semantic error: failed to retrieve location attribute for local 'name'
(dieoffset: 85127198053): identifier '$name' at real_lookup.stp:9:20
semantic error: failed to retrieve location attribute for local 'name'
(dieoffset: 85127198053): identifier '$name' at real_lookup.stp:9:20
Pass 2: analyzed script: 1 probe(s), 10 function(s), 1 embed(s), 2 global(s)
in 610usr/430sys/3166real ms.
Pass 2: analysis failed.  Try again with more '-v' (verbose) options.
Running rm -rf /tmp/stapABdKKf

So it seems that 'name' local is found but somehow it isn't able to handle
it. Besides that it is really strange that '$name' is of the same type than
'$parent->d_name' and which is actually found. 

Is this a bug?

Cheers,
Jan