VirtualCPU::cmd: Take descriptive arguments

hermit-os · Jan 3, 2022 · 1affe92 · 1affe92
1 parent 40b9e08
commit 1affe92
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Showing 3 changed files with 20 additions and 11 deletions.
diff --git a/src/linux/vcpu.rs b/src/linux/vcpu.rs
@@ -2,6 +2,8 @@ use crate::consts::*;
 use crate::linux::virtio::*;
 use crate::linux::KVM;
 use crate::vm::HypervisorResult;
+use crate::vm::SysCmdsize;
+use crate::vm::SysCmdval;
 use crate::vm::VcpuStopReason;
 use crate::vm::VirtualCPU;
 use kvm_bindings::*;
@@ -348,12 +350,16 @@ impl VirtualCPU for UhyveCPU {
 							UHYVE_PORT_CMDSIZE => {
 								let data_addr: usize =
 									unsafe { (*(addr.as_ptr() as *const u32)) as usize };
-								self.cmdsize(self.host_address(data_addr));
+								let args_ptr = self.host_address(data_addr);
+								let syssize = unsafe { &mut *(args_ptr as *mut SysCmdsize) };
+								self.cmdsize(syssize);
 							}
 							UHYVE_PORT_CMDVAL => {
 								let data_addr: usize =
 									unsafe { (*(addr.as_ptr() as *const u32)) as usize };
-								self.cmdval(self.host_address(data_addr));
+								let args_ptr = self.host_address(data_addr);
+								let syscmdval = unsafe { &*(args_ptr as *const SysCmdval) };
+								self.cmdval(syscmdval);
 							}
 							UHYVE_PORT_NETWRITE => {
 								match &self.tx {

diff --git a/src/macos/x86_64/vcpu.rs b/src/macos/x86_64/vcpu.rs
@@ -3,6 +3,8 @@
 use crate::consts::*;
 use crate::macos::x86_64::ioapic::IoApic;
 use crate::vm::HypervisorResult;
+use crate::vm::SysCmdsize;
+use crate::vm::SysCmdval;
 use crate::vm::VcpuStopReason;
 use crate::vm::VirtualCPU;
 use burst::x86::{disassemble_64, InstructionOperation, OperandType};
@@ -743,13 +745,17 @@ impl VirtualCPU for UhyveCPU {
 						UHYVE_PORT_CMDSIZE => {
 							let data_addr: u64 =
 								self.vcpu.read_register(&Register::RAX)? & 0xFFFFFFFF;
-							self.cmdsize(self.host_address(data_addr as usize));
+							let args_ptr = self.host_address(data_addr as usize);
+							let syssize = unsafe { &mut *(args_ptr as *mut SysCmdsize) };
+							self.cmdsize(syssize);
 							self.vcpu.write_register(&Register::RIP, rip + len)?;
 						}
 						UHYVE_PORT_CMDVAL => {
 							let data_addr: u64 =
 								self.vcpu.read_register(&Register::RAX)? & 0xFFFFFFFF;
-							self.cmdval(self.host_address(data_addr as usize));
+							let args_ptr = self.host_address(data_addr as usize);
+							let syscmdval = unsafe { &*(args_ptr as *const SysCmdval) };
+							self.cmdval(syscmdval);
 							self.vcpu.write_register(&Register::RIP, rip + len)?;
 						}
 						UHYVE_PORT_EXIT => {

diff --git a/src/vm.rs b/src/vm.rs
@@ -73,15 +73,15 @@ const MAX_ARGC: usize = 128;
 const MAX_ENVC: usize = 128;
 
 #[repr(C, packed)]
-struct SysCmdsize {
+pub struct SysCmdsize {
 	argc: i32,
 	argsz: [i32; MAX_ARGC],
 	envc: i32,
 	envsz: [i32; MAX_ENVC],
 }
 
 #[repr(C, packed)]
-struct SysCmdval {
+pub struct SysCmdval {
 	argv: *const u8,
 	envp: *const u8,
 }
@@ -140,8 +140,7 @@ pub trait VirtualCPU {
 	/// Returns the (host) path of the kernel binary.
 	fn kernel_path(&self) -> &Path;
 
-	fn cmdsize(&self, args_ptr: usize) {
-		let syssize = unsafe { &mut *(args_ptr as *mut SysCmdsize) };
+	fn cmdsize(&self, syssize: &mut SysCmdsize) {
 		syssize.argc = 0;
 		syssize.envc = 0;
 
@@ -185,9 +184,7 @@ pub trait VirtualCPU {
 	}
 
 	/// Copies the arguments end environment of the application into the VM's memory.
-	fn cmdval(&self, args_ptr: usize) {
-		let syscmdval = unsafe { &*(args_ptr as *const SysCmdval) };
-
+	fn cmdval(&self, syscmdval: &SysCmdval) {
 		let mut counter: i32 = 0;
 		let argv = self.host_address(syscmdval.argv as usize);
 		let mut found_separator = false;