Tweak our symbol resolution again#336
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I've found another case where the libpython gets mmap'ed by a process and breaks pystack's ability to find `_PyRuntime`. This time, I noticed it happening when Memray is symbolizing native stacks, which can trigger elfutils to mmap the text section of libpython if one of those native stack frames resolves to an address inside libpython. When this happened, the symbol resolution callback was finding an address for the symbol, and discovering that that address was mapped, but not noticing that it fell within a different module entirely, since only a small part of libpython was mapped at that first mapping. Address this by preferring matches which fall within the module we searched in over mappings which don't, while continuing to prefer a match in an earlier module over one in a later one. Signed-off-by: Matt Wozniski <mwozniski@bloomberg.net>
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The 3.15 CI failures can be ignored. Those failures currently exist on main, and will be fixed by rebasing after #337 is merged. |
Codecov Report❌ Patch coverage is
Additional details and impacted files@@ Coverage Diff @@
## main #336 +/- ##
==========================================
- Coverage 77.63% 77.55% -0.09%
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Files 57 57
Lines 6601 6612 +11
Branches 628 630 +2
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+ Hits 5125 5128 +3
- Misses 1476 1484 +8
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I've found another case where the libpython gets mmap'ed by a process and breaks pystack's ability to find
_PyRuntime. This time, I noticed it happening when Memray is symbolizing native stacks, which can trigger elfutils to mmap the text section of libpython if one of those native stack frames resolves to an address inside libpython.When this happened, the symbol resolution callback was finding an address for the symbol, and discovering that that address was mapped, but not noticing that it fell within a different module entirely, since only a small part of libpython was mapped at that first mapping.
Address this by preferring matches which fall within the module we searched in over mappings which don't, while continuing to prefer a match in an earlier module over one in a later one.