perf srcline: Make sentinel reading for binutils addr2line more robust

The addr2line process is sent an address then multiple function,
filename:line "records" are read. To detect the end of output a ',' is
sent and for llvm-addr2line a ',' is then read back showing the end of
addrline's output.

For binutils addr2line the ',' translates to address 0 and we expect the
bogus filename marker "??:0" (see filename_split) to be sent from
addr2line.

For some kernels address 0 may have a mapping and so a seemingly valid
inline output is given and breaking the sentinel discovery:

  ```
  $ addr2line -e vmlinux -f -i
  ,
  __per_cpu_start
  ./arch/x86/kernel/cpu/common.c:1850
  ```

To avoid this problem enable the address dumping for addr2line (the -a
option). If an address of 0x0000000000000000 is read then this is the
sentinel value working around the problem above.

The filename_split still needs to check for "??:0" as bogus non-zero
addresses also need handling.

Reported-by: Changbin Du <changbin.du@huawei.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Changbin Du <changbin.du@huawei.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tom Rix <trix@redhat.com>
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/r/20230613034817.1356114-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

0 files changed, 0 insertions, 0 deletions