libc: Disable ASAN for certain string functions
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Authored by arichardson on Jul 5 2021, 10:52 AM.

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Reviewers: None
Commits: rG8185be330723: libc: Disable ASAN for certain string functions

Summary

They deliberately read out-of-bounds values to avoid byte-by-byte
loads and check multiple bytes at once. While this will work on x86,
it is flagged as an out-of-bounds read with ASAN, so we have to
disable instrumentation here. This also causes bounds errors for CHERI,
so in CheriBSD we use implementations that avoid OOB reads.

Diff Detail

Repository

rS FreeBSD src repository - subversion

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Lint Passed

Unit

No Test Coverage

Build Status

Buildable 40316
Build 37205: arc lint + arc unit

Event Timeline

arichardson created this revision.Jul 5 2021, 10:52 AM

Herald added a subscriber: imp. · View Herald TranscriptJul 5 2021, 10:52 AM

arichardson requested review of this revision.Jul 5 2021, 10:52 AM

Harbormaster completed remote builds in B40293: Diff 91776.Jul 5 2021, 10:52 AM

arichardson added a parent revision: D31043: Add build system support for ASAN+UBSAN instrumentation.Jul 5 2021, 10:52 AM

remove debug

Harbormaster completed remote builds in B40295: Diff 91778.Jul 5 2021, 10:57 AM

Add memchr

Harbormaster completed remote builds in B40316: Diff 91814.Jul 5 2021, 5:42 PM

arichardson retitled this revision from libc: Disable ASAN for certain str* functions to libc: Disable ASAN for certain string functions.Jul 5 2021, 5:42 PM

This revision was not accepted when it landed; it landed in state Needs Review.Aug 2 2021, 1:35 PM

Closed by commit rG8185be330723: libc: Disable ASAN for certain string functions (authored by arichardson). · Explain Why

This revision was automatically updated to reflect the committed changes.

arichardson added a commit: rG8185be330723: libc: Disable ASAN for certain string functions.