From d0405298b24db0e2a6b2abfdc8c7e5ebbe49d1a0 Mon Sep 17 00:00:00 2001 From: Hrutvik Kanabar Date: Tue, 25 Oct 2022 10:13:51 +0000 Subject: prog, pkg/compiler: add `BufferCompressed` buffer type & `compressed_image` builtin Create the `BufferCompressed` kind of `BufferType`, which will be used to represent compressed data. Create the corresponding `compressed_image` syzlang builtin, which is backed by `BufferCompressed`. For now, no syscalls use this feature - this will be introduced in future commits. We have to be careful to decompress the data before mutating, and re-compress before storing. We make sure that any deserialised `BufferCompressed` data is valid too. `BufferCompressed` arguments are mutated using a generic heatmap. In future, we could add variants of `BufferCompressed` or populate the `BufferType` sub-kind, using it to choose different kinds of heatmap for different uncompressed data formats. Various operations on compressed data must be forbidden, so we check for `BufferCompressed` in key places. We also have to ensure `compressed_image` can only be used in syscalls that are marked `no_{generate,minimize}`. Therefore, we add a generic compiler check which allows type descriptions to require attributes on the syscalls which use them. --- prog/analysis.go | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'prog/analysis.go') diff --git a/prog/analysis.go b/prog/analysis.go index 04f0b270a..b4a30dbe8 100644 --- a/prog/analysis.go +++ b/prog/analysis.go @@ -76,7 +76,8 @@ func (s *state) analyzeImpl(c *Call, resources bool) { } case *BufferType: a := arg.(*DataArg) - if a.Dir() != DirOut && len(a.Data()) != 0 { + if a.Dir() != DirOut && len(a.Data()) != 0 && + (typ.Kind == BufferString || typ.Kind == BufferFilename) { val := string(a.Data()) // Remove trailing zero padding. for len(val) >= 2 && val[len(val)-1] == 0 && val[len(val)-2] == 0 { -- cgit mrf-deployment