[Bug tapsets/30407] New: Tapset function print_ubacktrace_fileline() no longer works on kernel 6.2

[agentzh at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=30407

            Bug ID: 30407
           Summary: Tapset function print_ubacktrace_fileline() no longer
                    works on kernel 6.2
           Product: systemtap
           Version: unspecified
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: tapsets
          Assignee: systemtap at sourceware dot org
          Reporter: agentzh at gmail dot com
  Target Milestone: ---

I've noted that the standard tapset function `print_ubacktrace_fileline()` no
longer works on the latest 6.2.12 kernel of fedora 36 x86_64.

To reproduce the problem, let's use the following minimal C program as the
target:

```
int main(void) {
    return 0;
}
```

We name it `a.c`.

Then compile it with debug symbols:

```
gcc -g a.c
```

It generates the binary program ./a.out.

Now run the following stap oneliner:

```
$ /opt/stap/bin/stap -c ./a.out --ldd -e 'probe process.function("main") {
print_ubacktrace_fileline() }'
 0x40110a : main+0x4/0xe [/tmp/a.out]
 0x7f896e867510 : __libc_start_call_main+0x80/0xb0 [/usr/lib64/libc.so.6]
 0x7f896e8675c9 : __libc_start_main@GLIBC_2.2.5+0x89/0x150
[/usr/lib64/libc.so.6]
 0x401045 : _start+0x25/0x30 [/tmp/a.out]
```

We can see there are no source file names or line numbers.

For comparison, let's run the same example on an older kernel (5.0.16):

```
$ /opt/stap/bin/stap -c ./a.out --ldd -e 'probe process.function("main") {
print_ubacktrace_fileline() }'
 0x40049a : main+0x4/0x1a at /tmp/a.c:2 [/tmp/a.out]
 0x7fbc6289011b : __libc_start_main+0xeb/0x1c0 [/usr/lib64/libc-2.27.so]
 0x4003da : _start+0x2a/0x30 [/tmp/a.out]
```

It works on this older kernel as expected.

I'm using the latest master branch of the upstream systemtap repo:

```
commit 418f0a45ca4473491385b5c7eef777607bbdb3b7 (HEAD -> master, origin/master,
origin/HEAD)
Author: Frank Ch. Eigler <fche@redhat.com>
Date:   Fri Apr 28 12:07:15 2023 -0400

    NEWS++
```

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