Bug 666660
| Summary: | inadequate parenthesization in systemtap probe macros | ||
|---|---|---|---|
| Product: | [Fedora] Fedora | Reporter: | Tom Lane <tgl> |
| Component: | systemtap | Assignee: | Frank Ch. Eigler <fche> |
| Status: | CLOSED CURRENTRELEASE | QA Contact: | Fedora Extras Quality Assurance <extras-qa> |
| Severity: | medium | Docs Contact: | |
| Priority: | low | ||
| Version: | 13 | CC: | fche, hhorak, jistone, roland, scox |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2011-04-24 15:09:10 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
Can you check whether changing /usr/include/sys/sdt.h by adding parentheses in these two places works for you? 67: #define STAP_CAST(t) (t) 83: #define STAP_CAST(t) (size_t)(t) Stan, can you audit git systemtap's sdt.h also, to make sure that incoming parameter expressions are parenthesized? The _SDT_PROBE() calls in #define STAP_PROBE... near line 200+ appear to lack this. I confirm those changes silence the warning in Postgres. Personally I'd spell the latter macro as "((size_t) (t))", but maybe I'm just overly paranoid. systemtap-1.4 corrects this. |
Description of problem: Source code like this: TRACE_POSTGRESQL_SORT_DONE(state->tapeset != NULL, spaceUsed); produces this warning: tuplesort.c:843: warning: comparison between pointer and integer Investigation shows that the macro is expanding to do { size_t arg1 = (size_t)state->tapeset != ((void *)0); ... so obviously the problem is failure to parenthesize the macro argument. In this particular case it manages to give the right runtime behavior anyway, but in other cases it would yield an outright wrong value for the probe argument. Version-Release number of selected component (if applicable): systemtap-sdt-devel-1.3-3.fc13.x86_64 Additional info: The probe definition is probe sort__done(bool, long); though I'm not sure that matters.