chore: update Rust nightly version to 2024-11-20 (1.84) (#148)

* chore: update flake deps and bump rust nightly version

* refactor: add explicit lifetime names

* refactor: replace removed `CARGO_RUSTC_CURRENT_DIR`

ref: rust-lang/cargo#3946

* refactor: switch naked fns to `naked_asm!`

Switch to the newly required `naked_asm!` macro in all naked functions.
ref: rust-lang/rust#90957

* fix: update custom target manifest files to avoid ICE

apparently Rust doesn't like it when the custom target manifest file is missing the `llvm-abiname` field

* silence warning about mutable static

* refactor: elide lifetimes

* fmt

* refactor: apply `clippy::manual_div_ceil` suggestion

* fix: use explicit `ptr.wrapping_byte_add` for conversions from physmem to virtmem references

We previously relied on UB actually doing the wrapping behaviour, but well, that's not ideal is it

flake.nix

@@ -1,48 +1,48 @@
-# forked from https://github.com/tosc-rs/mnemos/blob/main/flake.nix
 {
-    description = "Flake providing a development shell for k23";
+  description = "Flake providing a development shell for k23";
 
-    inputs = {
-        nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
-        flake-utils.url = "github:numtide/flake-utils";
-        rust-overlay = {
-            url = "github:oxalica/rust-overlay";
-            inputs = {
-                nixpkgs.follows = "nixpkgs";
-            };
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+    rust-overlay = {
+        url = "github:oxalica/rust-overlay";
+        inputs = {
+            nixpkgs.follows = "nixpkgs";
         };
     };
+  };
 
-    outputs = { nixpkgs, flake-utils, rust-overlay, ... }:
-        flake-utils.lib.eachDefaultSystem (system:
-            let
-                overlays = [ (import rust-overlay) ];
-                pkgs = import nixpkgs { inherit system overlays; };
-                # use the Rust toolchain specified in the project's rust-toolchain.toml
-                rustToolchain = pkgs.pkgsBuildHost.rust-bin.fromRustupToolchainFile ./rust-toolchain.toml;
-            in
-            {
-                devShell = with pkgs; mkShell rec {
-                    name = "k23-dev";
-                    nativeBuildInputs = [
-                        # compilers
-                        rustToolchain
-                        clang
+  outputs = { self, nixpkgs, rust-overlay, flake-utils, ... }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        overlays = [ (import rust-overlay) ];
+        pkgs = import nixpkgs {
+          inherit system overlays;
+        };
+        rustToolchain = with pkgs; rust-bin.fromRustupToolchainFile ./rust-toolchain.toml;
+      in
+      {
+        devShells.default = with pkgs; mkShell rec {
+          name = "k23-dev";
+          buildInputs = [
+            # compilers
+            rustToolchain
+            clang
 
-                        # devtools
-                        just
-                        mdbook
-                        socat
-                        wabt
+            # devtools
+            just
+            mdbook
+            socat
+            wabt
+            dtc
 
-                        # for testing the kernel
-                        qemu
-                    ];
-                    buildInputs = [];
+            # for testing the kernel
+            qemu
+          ];
 
-                    LIBCLANG_PATH = "${llvmPackages.libclang.lib}/lib";
-                    LD_LIBRARY_PATH = "${lib.makeLibraryPath buildInputs}";
-                };
-            }
-        );
-}
+          LIBCLANG_PATH = "${llvmPackages.libclang.lib}/lib";
+          LD_LIBRARY_PATH = "${lib.makeLibraryPath buildInputs}";
+        };
+      }
+    );
+}

justfile

@@ -50,6 +50,10 @@ Variables can be set using `just VARIABLE=VALUE ...` or
 
 # env var to set the cargo runner for the riscv64 target
 export CARGO_TARGET_RISCV64GC_K23_NONE_KERNEL_RUNNER := "just _run_riscv64"
+# as of recent Rust nightly versions the old `CARGO_RUSTC_CURRENT_DIR` we used to locate the kernel artifact from the
+# loader build script got removed :/ This is a stopgap until they come up with a replacement.
+# https://github.com/rust-lang/cargo/issues/3946
+export __K23_CARGO_RUSTC_CURRENT_DIR := `dirname "$(cargo locate-project --workspace --message-format plain)"`
 
 # default recipe to display help information
 _default:

kernel/riscv64gc-k23-none-kernel.json

@@ -18,6 +18,7 @@
   "position-independent-executables": true,
   "relro-level": "full",
   "supported-sanitizers": [
+    "shadow-call-stack",
     "kernel-address"
   ],
   "target-pointer-width": "64"

kernel/src/arch/riscv64/setjmp_longjmp.rs

@@ -36,7 +36,7 @@
 //! result. In a nested calls scenario (e.g. host->wasm->host->wasm) it is therefore up to each host function
 //! to propagate the trap and each host function therefore gets to clean up all its resources.
 
-use core::arch::asm;
+use core::arch::naked_asm;
 use core::ptr;
 
 /// A store for the register state used by `setjmp` and `longjmp`.
@@ -146,7 +146,7 @@ cfg_if::cfg_if! {
 pub unsafe extern "C" fn setjmp(buf: *mut JumpBuf) -> isize {
     cfg_if::cfg_if! {
         if #[cfg(target_feature = "d")] {
-            asm! {
+            naked_asm! {
                 save_gp!(ra => a0[0]),
                 save_gp!(s0 => a0[1]),
                 save_gp!(s1 => a0[2]),
@@ -177,10 +177,9 @@ pub unsafe extern "C" fn setjmp(buf: *mut JumpBuf) -> isize {
 
                 "mv a0, zero",
                 "ret",
-                options(noreturn)
             }
         } else {
-            asm! {
+            naked_asm! {
                 save_gp!(ra => a0[0]),
                 save_gp!(s0 => a0[1]),
                 save_gp!(s1 => a0[2]),
@@ -197,7 +196,6 @@ pub unsafe extern "C" fn setjmp(buf: *mut JumpBuf) -> isize {
                 save_gp!(sp => a0[13]),
                 "mv a0, zero",
                 "ret",
-                options(noreturn)
             }
         }
     }
@@ -217,7 +215,7 @@ pub unsafe extern "C" fn setjmp(buf: *mut JumpBuf) -> isize {
 pub unsafe extern "C" fn longjmp(buf: *mut JumpBuf, val: isize) -> ! {
     cfg_if::cfg_if! {
         if #[cfg(target_feature = "d")] {
-            asm! {
+            naked_asm! {
                 load_gp!(a0[0] => ra),
                 load_gp!(a0[1] => s0),
                 load_gp!(a0[2] => s1),
@@ -248,10 +246,9 @@ pub unsafe extern "C" fn longjmp(buf: *mut JumpBuf, val: isize) -> ! {
 
                 "add a0, a1, zero",
                 "ret",
-                options(noreturn)
             }
         } else {
-            asm! {
+            naked_asm! {
                 load_gp!(a0[0] => ra),
                 load_gp!(a0[1] => s0),
                 load_gp!(a0[2] => s1),
@@ -269,7 +266,6 @@ pub unsafe extern "C" fn longjmp(buf: *mut JumpBuf, val: isize) -> ! {
 
                 "add a0, a1, zero",
                 "ret",
-                options(noreturn)
             }
         }
     }