[Bug translator/31028] New: Systemtap doesn't find probe points for process.function("*").callee("*")' in code with DWARF5 debuginfo

["wcohen at redhat dot com" <sourceware-bugzilla@sourceware.org>]

https://sourceware.org/bugzilla/show_bug.cgi?id=31028

            Bug ID: 31028
           Summary: Systemtap doesn't find probe points for
                    process.function("*").callee("*")' in code with DWARF5
                    debuginfo
           Product: systemtap
           Version: unspecified
            Status: NEW
          Severity: normal
          Priority: P2
         Component: translator
          Assignee: systemtap at sourceware dot org
          Reporter: wcohen at redhat dot com
  Target Milestone: ---

When reviewing the systemtap "make install" test results there were and
excessive number of failures for the systemtap.base/listing_mode.exp on RHEL9,
Fedora 38, and rawhide, about 200 failure on x86_64 machines.  this can be
reproduced with:

sudo make installcheck RUNTESTFLAGS="-debug systemtap.base/listing_mode.exp"

The issues are with the .callee()

There are fewer failures on RHEL8 machine.  When comparing the code being
instrumented I found that RHEL 8 is using DWARF4 and the tests with the high
failure rate are using DWARF5. Can narrow the reproducer down to following:

 gcc  /usr/share/systemtap/testsuite/systemtap.base/listing_mode.c  
-isystem/usr/share/systemtap/testsuite -isystem/usr/include -g -O -fPIC -shared
-DLISTING_MODE_LIB  -lm  -o liblisting_mode.so
 gcc  /usr/share/systemtap/testsuite/systemtap.base/listing_mode.c  
-isystem/usr/share/systemtap/testsuite -isystem/usr/include -g -O
-llisting_mode -Wl,-rpath,/usr/share/systemtap/testsuite -L.
-DLISTING_MODE_MAIN  -lm  -o listing_mode  

 stap -l 'process.function("foo").callee("bar")'  -c listing_mode

On RHEL8 get the expected output:

process("/home/wcohen/systemtap_write/systemtap/listing_mode").function("foo@/usr/share/systemtap/testsuite/systemtap.base/listing_mode.c:23").callee("bar@/usr/share/systemtap/testsuite/systemtap.base/listing_mode.c:16")

On RHEL9/fedora38/rawhide get nothing.

Comparing the llvm-dwarfdump output for listing_mode on RHEL8 see:

0x000003f6:     DW_TAG_GNU_call_site
                  DW_AT_low_pc  (0x0000000000400711)
                  DW_AT_abstract_origin (0x0000040c "bar")

0x00000403:       DW_TAG_GNU_call_site_parameter
                    DW_AT_location      (DW_OP_reg5 RDI)
                    DW_AT_GNU_call_site_value  
(DW_OP_GNU_entry_value(DW_OP_reg5 RDI))

On Fedora 38 the dwarf 5 call site information is a little different:

0x00000188:     DW_TAG_call_site
                  DW_AT_call_return_pc  (0x0000000000401182)
                  DW_AT_call_origin     (0x0000019e)

0x00000195:       DW_TAG_call_site_parameter
                    DW_AT_location      (DW_OP_reg5 RDI)
                    DW_AT_call_value    (DW_OP_entry_value(DW_OP_reg5 RDI))

Appears:
DWARF4 -> DWARF5
DW_AT_low_pc -> DW_AT_call_return_pc
DW_AT_abstract_origin -> DW_AT_call_origin

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