tree c3d235118128190cc10f6b05bc9923ca76f5ccd5
parent cabc70cc795b2392201cabfc3cc5f384a74f850d
author Malte Isberner <malte.isberner@gmail.com> 1664541647 +0000
committer Jonathan Amsterdam <jba@google.com> 1664564958 +0000

vulncheck: cache executable symbols in a map

Currently, `lookupSymbol` for the various executable formats is implemented in terms of a linear search. This is inefficient and makes `govulncheck` not scale on larger binaries.

You can test this with a large binary. I took the main binary from StackRox Scanner:
```sh
$ docker export "$(docker create quay.io/stackrox-io/scanner:3.72.0)" | tar -C /tmp -x scanner
```

On my machine (MacOS, Intel Core i9 8x2.4GHz), the results are the following:
```sh
$ time /tmp/govulncheck-orig /tmp/scanner
govulncheck is an experimental tool. Share feedback at https://go.dev/s/govulncheck-feedback.
[...]
real    19m7.105s
user    21m4.712s
sys     1m50.733s
```

With this patch, it looks vastly different:
```sh
$ time /tmp/govulncheck-patched /tmp/scanner
govulncheck is an experimental tool. Share feedback at https://go.dev/s/govulncheck-feedback.
[...]
real    0m2.315s
user    0m0.307s
sys     0m0.126s
```

Note: I ran experiments only for ELF binaries; however, I do not see a reason why PE and Mach-O executables should have substantially fewer symbols, so it should have a similar effect there.

Change-Id: Ibd58a53a4718ce668b46add0a8f5e1d6f75952cd
GitHub-Last-Rev: 13c85caa6f35289e38d6696a8864c940814ffd10
GitHub-Pull-Request: golang/vuln#2
Reviewed-on: https://go-review.googlesource.com/c/vuln/+/435123
Reviewed-by: Julie Qiu <julieqiu@google.com>
Reviewed-by: Zvonimir Pavlinovic <zpavlinovic@google.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>