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Differential D125716

[lldb] Prevent Overflow (Underflow) error in crashlog.py
ClosedPublic

Authored by JDevlieghere on May 16 2022, 11:47 AM.

Details

Reviewers
mib
Commits
rG9defb3b4b4a3: [lldb] Prevent underflow in crashlog.py
Summary

Avoid a OverflowError when the pc is zero. This can happen for "unknown frames" where the crashlog generator reports a zero pc. We could omit them altogether, but if they're part of the crashlog it seems fair to display them in lldb as well.

rdar://92686666

Diff Detail

Event Timeline

JDevlieghere created this revision.May 16 2022, 11:47 AM
Herald added a project: Restricted Project. · View Herald TranscriptMay 16 2022, 11:47 AM
JDevlieghere requested review of this revision.May 16 2022, 11:47 AM
Harbormaster completed remote builds in B164715: Diff 429801.May 16 2022, 11:49 AM
mib accepted this revision.May 16 2022, 2:42 PM

LGTM

This revision is now accepted and ready to land.May 16 2022, 2:42 PM
Closed by commit rG9defb3b4b4a3: [lldb] Prevent underflow in crashlog.py (authored by JDevlieghere). · Explain WhyMay 16 2022, 3:00 PM
This revision was automatically updated to reflect the committed changes.
JDevlieghere added a commit: rG9defb3b4b4a3: [lldb] Prevent underflow in crashlog.py.
Herald added a project: Restricted Project. · View Herald TranscriptMay 16 2022, 3:00 PM

Revision Contents

PathSize
lldb/
examples/
python/
14 lines

Diff 429870

lldb/examples/python/crashlog.py

Show First 20 Lines • Show All 108 Lines • ▼ Show 20 Lines class Thread:
if options.crashed_only and this_thread_crashed == False: if options.crashed_only and this_thread_crashed == False:
return return
print("%s" % self) print("%s" % self)
display_frame_idx = -1 display_frame_idx = -1
for frame_idx, frame in enumerate(self.frames): for frame_idx, frame in enumerate(self.frames):
disassemble = ( disassemble = (
this_thread_crashed or options.disassemble_all_threads) and frame_idx < options.disassemble_depth this_thread_crashed or options.disassemble_all_threads) and frame_idx < options.disassemble_depth
if frame_idx == 0:
symbolicated_frame_addresses = crash_log.symbolicate(
frame.pc & crash_log.addr_mask, options.verbose)
else:
# Any frame above frame zero and we have to subtract one to # Any frame above frame zero and we have to subtract one to
# get the previous line entry # get the previous line entry.
symbolicated_frame_addresses = crash_log.symbolicate( pc = frame.pc & crash_log.addr_mask
(frame.pc & crash_log.addr_mask) - 1, options.verbose) pc = pc if frame_idx == 0 or pc == 0 else pc - 1
symbolicated_frame_addresses = crash_log.symbolicate(pc, options.verbose)
if symbolicated_frame_addresses: if symbolicated_frame_addresses:
symbolicated_frame_address_idx = 0 symbolicated_frame_address_idx = 0
for symbolicated_frame_address in symbolicated_frame_addresses: for symbolicated_frame_address in symbolicated_frame_addresses:
display_frame_idx += 1 display_frame_idx += 1
print('[%3u] %s' % (frame_idx, symbolicated_frame_address)) print('[%3u] %s' % (frame_idx, symbolicated_frame_address))
if (options.source_all or self.did_crash( if (options.source_all or self.did_crash(
)) and display_frame_idx < options.source_frames and options.source_context: )) and display_frame_idx < options.source_frames and options.source_context:
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