| [tcf-dev] Continue if invalid public symbol object offset |
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Hi, I investigate a debugging problem where it seems that some entries in .debug_pubnames have faulty offsets. Not sure why, but it seems that the debug information (C++, the compiler is Clang 3.5.2) is broken The current code for handling this throws an exception (dwarfcache.c): if (obj_offs >= unit_size) str_fmt_exception(ERR_INV_DWARF, "Invalid object offset in %s section", pub_names->name); For other errors, however the iteration of pubnames simply continues, and the current pubname is ignored. In my binary, the pubname string is valid (and non-empty). I wonder if it would be possible to continue (and ignore the pubname) here as well, if the name was read first. Reading the name I assume would be necessary to keep iteration in sync? See diff below. This would allow some debugging even though some .debug_pubnames entries would not be found if offsets are broken. Perhaps this is a bad workaround for broken debug information? --- a/src/extensions/tcf-agent.mirror/tcf_agent/agent/tcf/services/dwarfcache.c +++ b/src/extensions/tcf-agent.mirror/tcf_agent/agent/tcf/services/dwarfcache.c @@ -1281,9 +1281,14 @@ static void load_pub_names(ELF_Section * debug_info, ELF_Section * pub_names) { ObjectInfo * info = NULL; U8_T obj_offs = dwarf64 ? dio_ReadU8() : (U8_T)dio_ReadU4(); if (obj_offs == 0) break; - if (obj_offs >= unit_size) str_fmt_exception(ERR_INV_DWARF, - "Invalid object offset in %s section", pub_names->name); name = dio_ReadString(); + if (obj_offs >= unit_size) { + trace(LOG_ALWAYS, "Invalid public name offset 0x%x for" + " '%s' in section '%s', CU 0x%x with size 0x%x", + obj_offs, name, pub_names->name, unit_addr, + unit_size); + continue; + } ---------------------------------------------------------------------- This e-mail and any attachments may contain confidential material for |