| Summary: | low-mem files processed in multifile mode | ||
|---|---|---|---|
| Product: | dwz | Reporter: | Tom de Vries <vries> |
| Component: | default | Assignee: | Nobody <nobody> |
| Status: | NEW --- | ||
| Severity: | enhancement | CC: | dwz, jakub, mark |
| Priority: | P2 | ||
| Version: | unspecified | ||
| Target Milestone: | --- | ||
| Host: | Target: | ||
| Build: | Last reconfirmed: | ||
AFAIU, there is code intended to prevent this scenario from happening at the end of dwz:
...
free (dso);
if (ret == 0 && !low_mem)
res->res = 0;
return ret;
...
But the low_mem condition is never true here, because cleanup is run before arriving there, which sets multifile_mode to 0.
posted patch: https://sourceware.org/ml/dwz/2019-q1/msg00058.html Reclassifying as enhancement. Has an unreviewed patch, see Comment #2 |
Consider four executables, a.out and b.out a hello world example, and c.out and d.out copied from the dwz executable itself: ... $ gcc hello.c -g ; cp a.out b.out $ cp dwz c.out ; cp c.out d.out ... This gives us two executables with 130 DIEs, and two executables with 5356 DIEs: ... $ readelf -w a.out | grep '(DW_TAG' | wc -l 130 $ readelf -w b.out | grep '(DW_TAG' | wc -l 130 $ readelf -w c.out | grep '(DW_TAG' | wc -l 5356 $ readelf -w d.out | grep '(DW_TAG' | wc -l 5356 ... Now consider a gdb script that traces the dwz invocations: ... $ cat gdb.script b dwz commands continue end run ... We run in multifile mode, with a low-mem limit of 1000 dies, and trace into LOG: ... $ gdb \ -batch \ -x gdb.script \ --args dwz -m3 -l1000 a.out b.out c.out d.out \ > LOG 2>&1 ... which we then summarize as follows: ... $ grep 'dwz (' LOG | awk '{print $5}' "a.out", "b.out", "c.out", "c.out", "d.out", "d.out", "a.out", "b.out", "c.out", "d.out", ... The first 6 invocations are according to plan: - a.out and b.out have fewer DIEs than 1000, and are processed. - c.out and d.out have more DIEs than 1000, and are each processed twice: - once in regular mode (where dwz stops at a 1000 processed DIEs and returns 2), and - once in low-mem mode. However, then all 4 files are once more processed in fi_multifile mode, while the intention is that c.out and d.out (being bigger than the low-mem limit) are not processed anymore.