From 5ac84ab421465f8f15ac9350f9f33a4416b4b3b7 Mon Sep 17 00:00:00 2001 From: Alexander Potapenko Date: Tue, 9 Sep 2025 12:09:02 +0200 Subject: prog: pkg/compiler: docs: introduce the `no_squash` attribute The `no_squash` per-syscall attribute prevents the fuzzer from generating squashed arguments to a particular syscall. This is particularly helpful for pseudo-syscalls with elaborate arguments that are hard to reason about when they are squashed - e.g. for syz_kvm_add_vcpu() that takes a SYZOS program as an input. I've considered an alternative solution that prohibits ANY for all pseudo-syscalls. But there is a bunch of existing programs (both the tests and the repros) for syscalls like syz_mount_image() for which the benefit of not passing ANY is not immediately obvious. I therefore decided to go with an explicit attribute that can later be enforced for every pseudo-syscall at compile time. --- pkg/compiler/testdata/all.txt | 1 + 1 file changed, 1 insertion(+) (limited to 'pkg/compiler/testdata') diff --git a/pkg/compiler/testdata/all.txt b/pkg/compiler/testdata/all.txt index 1202e7511..cf6f3594c 100644 --- a/pkg/compiler/testdata/all.txt +++ b/pkg/compiler/testdata/all.txt @@ -339,6 +339,7 @@ flags_with_one_value = 0 # Syscall attributes. fsck_test() (fsck["fsck.test -n"]) +foo_no_squash() (no_squash) # Compressed images. -- cgit mrf-deployment