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| author | Alexander Potapenko <glider@google.com> | 2024-09-24 15:23:14 +0200 |
|---|---|---|
| committer | Alexander Potapenko <glider@google.com> | 2024-09-25 09:05:57 +0000 |
| commit | 4b1eded1f91812d576538f106b57352d25a6b484 (patch) | |
| tree | 24d63abea11136d185dc9eba0a0ab5eb93f20046 /executor/common_kvm_arm64_syzos.h | |
| parent | 7c9588a40bd882410049d1e772de2452934a7eaf (diff) | |
executor: arm64: sys/linux: implement syz_kvm_setup_syzos_vm and syz_kvm_add_vcpu
The old syz_kvm_setup_cpu() API mixed together VM and VCPU setup, making it
harder to create and fuzz two VCPUs in the same VM.
Introduce two new pseudo-syscalls, syz_kvm_setup_syzos_vm() and syz_kvm_add_vcpu(),
that will simplify this task.
syz_kvm_setup_syzos_vm() takes a VM file descriptor, performs VM setup
(allocates guest memory and installs SYZOS code into it) and returns a
new kvm_syz_vm resource, which is in fact a pointer to `struct kvm_syz_vm`
encapsulating VM-specific data in the C code.
syz_kvm_add_vcpu() takes the VM ID denoted by kvm_syz_vm and creates a
new VCPU within that VM with a proper CPU number. It then stores the
fuzzer-supplied SYZOS API sequence into the corresponding part (indexed by
CPU number) of the VM memory slot, and sets up the CPU registers to interpret
that sequence.
The new pseudo-syscall let the fuzzer create independent CPUs that run different
code sequences without interfering with each other.
Diffstat (limited to 'executor/common_kvm_arm64_syzos.h')
| -rw-r--r-- | executor/common_kvm_arm64_syzos.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/executor/common_kvm_arm64_syzos.h b/executor/common_kvm_arm64_syzos.h index ebfed175c..a22c0651c 100644 --- a/executor/common_kvm_arm64_syzos.h +++ b/executor/common_kvm_arm64_syzos.h @@ -79,7 +79,9 @@ typedef enum { // Main guest function that performs necessary setup and passes the control to the user-provided // payload. -GUEST_CODE static void guest_main(uint64 size, uint64 cpu) +__attribute__((used)) +GUEST_CODE static void +guest_main(uint64 size, uint64 cpu) { uint64 addr = ARM64_ADDR_USER_CODE + cpu * 0x1000; |