Project

General

Profile

Actions

Bug #17810

open

addr2line.c: Some symbol names missing in C backtrace with Clang/LLVM

Added by xtkoba (Tee KOBAYASHI) 5 months ago. Updated 5 months ago.

Status:
Open
Priority:
Normal
Assignee:
-
Target version:
-
[ruby-core:103491]

Description

When Clang/LLVM is used for compilation, some symbol names are missing in C level backtrace information. An example:

-- C level backtrace information -------------------------------------------
(...snip...)
/var/tmp/ruby.debug/lib/libruby.so.3.1(vm_call_method_each_type+0x6a) [0x7f73856ac33f] ../vm_insnhelper.c:3438
/var/tmp/ruby.debug/lib/libruby.so.3.1(0x7f73856ac29a) [0x7f73856ac29a]
/var/tmp/ruby.debug/lib/libruby.so.3.1(0x7f73856aadf6) [0x7f73856aadf6]
/var/tmp/ruby.debug/lib/libruby.so.3.1(vm_exec_core+0xff7) [0x7f738569c3cd] ../insns.def:792
/var/tmp/ruby.debug/lib/libruby.so.3.1(rb_vm_exec+0x5c9) [0x7f73856a78d4]
/var/tmp/ruby.debug/lib/libruby.so.3.1(rb_ec_exec_node+0xe5) [0x7f73855a1bec] ../eval.c:320
/var/tmp/ruby.debug/lib/libruby.so.3.1(ruby_run_node+0x5a) [0x7f73855a1acf] ../eval.c:379
/var/tmp/ruby.debug/bin/ruby(main+0x73) [0x55c15877ac4b] ../main.c:47

This seems to happen because dladdr(3) sometimes fills NULL in dli_sname which is then overwritten to lines[i].sname regardless of its previous value.

A patch is attached to fix this issue. It modifies addr2line.c so that it does not use dli_sname (and also dli_fname) when the value is NULL.

I also attach another patch that makes addr2line.c print source filename even when source lineno is not available (which is the case for rb_vm_exec in the above example).

When these two patches are applied, C level backtrace information is printed as follows.

-- C level backtrace information -------------------------------------------
(...snip...)
/var/tmp/ruby.debug/lib/libruby.so.3.1(vm_call_method_each_type+0x6a) [0x7fb08928231f] ../vm_insnhelper.c:3438
/var/tmp/ruby.debug/lib/libruby.so.3.1(vm_call_method+0xf6) [0x7fb08928227a] ../vm_insnhelper.c:0
/var/tmp/ruby.debug/lib/libruby.so.3.1(vm_sendish+0x334) [0x7fb089280dd6] ../vm_insnhelper.c:0
/var/tmp/ruby.debug/lib/libruby.so.3.1(vm_exec_core+0xff7) [0x7fb0892723ad] ../insns.def:792
/var/tmp/ruby.debug/lib/libruby.so.3.1(rb_vm_exec+0x5c9) [0x7fb08927d8b4] ../vm.c:0
/var/tmp/ruby.debug/lib/libruby.so.3.1(rb_ec_exec_node+0xe5) [0x7fb089177bcc] ../eval.c:320
/var/tmp/ruby.debug/lib/libruby.so.3.1(ruby_run_node+0x5a) [0x7fb089177aaf] ../eval.c:379
/var/tmp/ruby.debug/bin/ruby(main+0x73) [0x557ed1e0bc4b] ../main.c:47

Files

ruby-addr2line-do-not-overwrite-sname-with-null.patch (1.07 KB) ruby-addr2line-do-not-overwrite-sname-with-null.patch Do not overwrite sname with NULL xtkoba (Tee KOBAYASHI), 04/17/2021 06:36 AM
ruby-addr2line-print-filename-without-lineno.patch (574 Bytes) ruby-addr2line-print-filename-without-lineno.patch Print filename without lineno xtkoba (Tee KOBAYASHI), 04/17/2021 06:37 AM
Actions

Also available in: Atom PDF