cmd/cgo/internal/testsanitizers: ASAN symbolization problems for LUCI's older gcc versionswith DWARF 5

[thanm]

In the LUCI infrastucture used for Golang testing, we use system images that have baked-in versions of GCC. At the moment for linux-amd64 this means version 10 of GCC, including corresponding versions of various runtime libraries needed to support GCC (e.g. libcc.a, libgcc_s.so, and so on).

In the process of migrating the Go compiler+linker to generate DWARF version 5, we discovered that the asan tests in cmd/cgo/internal/testsanitizers were failing on linux/amd64 LUCI builders with symbolization problems. Here is an example failure:

    asan_test.go:74: `/home/swarming/.swarming/w/ir/x/t/TestASANasan_unsafe_fail3190432212/001/asan_unsafe_fail3` exited without expected location of the error
        asan_unsafe_fail3.go:18; got failure
        =================================================================
        ==40747==ERROR: AddressSanitizer: use-after-poison on address 0x10c000122068 at pc 0x00000053df85 bp 0x000000000000 sp 0x10c000070ef8
        WRITE of size 8 at 0x10c000122068 thread T0
            #0 0x53df84 in fmt.Println <autogenerated>:18
            #1 0x53df84 in main.main <autogenerated>:20
            #2 0x46ebec in asancall ?:89

Asan is correctly reporting a problem, but getting the file/line wrong when DWARF 5 is used (DWARF 4 has no such issue). Later versions of the runtime (e.g. libasan.so.8 as opposed to libasan.so.6) don't seem to have this problem.

Filing this issue to describe the prolem, and to make a note of the fact that it would be nice to get the GCC version baked into our LUCI images updated to something more modern (GCC 10 is a 2020-vintage release that is no longer supported/updated).

[gopherbot]

Change https://go.dev/cl/656175 mentions this issue: cmd/cgo/internal/testsanitizers: bump GCC version for asan location checking

[gabyhelp]

Related Issues

• cmd/cgo/internal/testsanitizers,x/build: upstream clang does not build against zlib, so checking for ASAN symbolization is disabled during the ASAN tests #65606

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