1307381 - dump_syms should support compressed debug symbols

Status: RESOLVED FIXED

(Toolkit :: Crash Reporting, enhancement)

Description

[Julien Cristau [:jcristau] (back April 22)]

Debian packages ship detached debug symbols built with GNU objcopy --compress-debug-sections, which dump_syms doesn't understand.  This results in an assertion failure or no info depending on -DNDEBUG when interpreting the zlib data as a debug section.

Upstream added an ElfReader class where this looks like it'd be easier to add as it handles sections individually, but linux/dump_symbols.cc doesn't seem to use that code :/

Comment 1

[Julien Cristau [:jcristau] (back April 22)]

Attachment: prototype patch to support SHF_COMPRESSED sections

This patch (based on breakpad git c53ed143108948eb7e2d7ee77dc8c0d92050ce7c) lets dump_syms understand sections with the SHF_COMPRESSED flag set.

Comment 2

[Gabriele Svelto [:gsvelto] (PTO)]

You might want to have a look at bug 1264367. I'm upgrading Breakpad there and dump_syms will be picking up the ElfReader class. Looking at the code upstream Breakpad doesn't seem to support compressed symbols yet but I'll be glad to help you to add support and upstream it too.

Comment 3

[Julien Cristau [:jcristau] (back April 22)]

Thanks for the advice Gabriele.  I've pushed a WIP to the shf-compressed branch on https://github.com/jcristau/breakpad where I added support for compressed symbols in ElfReader and ported linux dump_symbols to use that.  Unfortunately it doesn't look like ElfReader comes with any tests, so I'll have to figure out how to update the dump_symbols tests.

Comment 4

[Gabriele Svelto [:gsvelto] (PTO)]

The new dump_syms fully supports compressed sections so closing this.