Fix ignore_noninstrumented_modules on Linux
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@swift-ci Please test |
My initial implementation of `ignore_noninstrumented_modules` for Linux (landed in 6159242) did not consider that the GNU symbol table could be present but empty. "Empty" means: void of real symbol entries, but potential "terminator/placeholder" symbols that are skipped via `header->symoffset`. In this case `last_symbol` is zero and we should avoid computing `chains[last_symbol - header->symoffset]`. This bug seems to only manifest in combination with `LD_PRELOAD` (counterpart of `DYLD_INSERT_LIBRARIES` for Linux) and for small binaries, (e.g., the "not" utility from the llvm test suite) that have segments without any real symbols. This should fix the remaining failing ASan tests on the Swift Linux CI. rdar://57566645 (cherry picked from commit 988adcc)
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@swift-ci Please test and merge |
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@swift-ci Please test |
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@swift-ci Please test Linux |
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Fixes the following tests: |
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My initial implementation of
ignore_noninstrumented_modulesfor Linux(landed in 6159242) did not consider
that the GNU symbol table could be present but empty. "Empty" means:
void of real symbol entries, but potential "terminator/placeholder"
symbols that are skipped via
header->symoffset. In this caselast_symbolis zero and we should avoid computingchains[last_symbol - header->symoffset].This bug seems to only manifest in combination with
LD_PRELOAD(counterpart of
DYLD_INSERT_LIBRARIESfor Linux) and for smallbinaries, (e.g., the "not" utility from the llvm test suite) that have
segments without any real symbols.
This should fix the remaining failing ASan tests on the Swift Linux CI.
rdar://57566645
(cherry picked from commit 19739fe327b3db6bbe4d6a22a5201c013018e032)