firmware: use the cslice crate to get rid of unsafe code in ksupport.

artiq/firmware/Cargo.lock

@@ -29,6 +29,11 @@ name = "byteorder"
 version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "cslice"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "fringe"
 version = "1.1.0"
@@ -54,6 +59,7 @@ dependencies = [
  "board 0.0.0",
  "build_artiq 0.0.0",
  "byteorder 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cslice 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "std_artiq 0.0.0",
 ]
 
@@ -144,6 +150,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [metadata]
 "checksum byteorder 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c40977b0ee6b9885c9013cd41d9feffdd22deb3bb4dc3a71d901cc7a77de18c8"
+"checksum cslice 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "0f8cb7306107e4b10e64994de6d3274bd08996a7c1322a27b86482392f96be0a"
 "checksum fringe 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "987689dcfad85eee8d76b477865641ec483e63fb86d52966bfc350c4a647d78a"
 "checksum kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7507624b29483431c0ba2d82aece8ca6cdba9382bff4ddd0f7490560c056098d"
 "checksum libc 0.2.18 (registry+https://github.com/rust-lang/crates.io-index)" = "a51822fc847e7a8101514d1d44e354ba2ffa7d4c194dcab48870740e327cac70"

artiq/firmware/ksupport/Cargo.toml

@@ -17,3 +17,4 @@ alloc_none = { path = "../liballoc_none" }
 std_artiq = { path = "../libstd_artiq" }
 board = { path = "../libboard" }
 byteorder = { version = "1.0", default-features = false }
+cslice = { version = "0.3" }

artiq/firmware/ksupport/lib.rs

@@ -7,6 +7,7 @@ extern crate std_artiq as std;
 extern crate libc;
 extern crate byteorder;
 extern crate board;
+extern crate cslice;
 
 #[path = "../runtime/mailbox.rs"]
 mod mailbox;
@@ -50,6 +51,7 @@ macro_rules! artiq_raise {
 use core::{mem, ptr, slice, str};
 use std::io::Cursor;
 use libc::{c_char, size_t};
+use cslice::{CSlice, CMutSlice, AsCSlice};
 use kernel_proto::*;
 use dyld::Library;
 
@@ -99,34 +101,22 @@ pub extern fn panic_fmt(args: core::fmt::Arguments, file: &'static str, line: u3
     loop {}
 }
 
-#[repr(C)]
-pub struct ArtiqList<T> {
-    ptr: *const T,
-    len: usize
-}
-
-impl<T> ArtiqList<T> {
-    pub fn from_slice(slice: &'static [T]) -> ArtiqList<T> {
-        ArtiqList { ptr: slice.as_ptr(), len: slice.len() }
-    }
-
-    pub unsafe fn as_slice(&self) -> &[T] {
-        slice::from_raw_parts(self.ptr, self.len)
-    }
-}
-
 static mut NOW: u64 = 0;
 
 #[no_mangle]
-pub extern fn send_to_core_log(ptr: *const u8, len: usize) {
+pub extern fn send_to_core_log(text: CSlice<u8>) {
-    send(&LogSlice(unsafe {
+    match str::from_utf8(text.as_ref()) {
-        str::from_utf8_unchecked(slice::from_raw_parts(ptr, len))
+        Ok(s) => send(&LogSlice(s)),
-    }))
+        Err(e) => {
+            send(&LogSlice(str::from_utf8(&text.as_ref()[..e.valid_up_to()]).unwrap()));
+            send(&LogSlice("(invalid utf-8)\n"));
+        }
+    }
 }
 
 #[no_mangle]
-pub extern fn send_to_rtio_log(timestamp: i64, ptr: *const u8, len: usize) {
+pub extern fn send_to_rtio_log(timestamp: i64, text: CSlice<u8>) {
-    rtio::log(timestamp, unsafe { slice::from_raw_parts(ptr, len) })
+    rtio::log(timestamp, text.as_ref())
 }
 
 extern fn abort() -> ! {
@@ -185,9 +175,7 @@ extern fn recv_rpc(slot: *mut ()) -> usize {
 
 #[no_mangle]
 pub extern fn __artiq_terminate(exception: *const kernel_proto::Exception,
-                            backtrace_data: *mut usize,
+                                mut backtrace: CMutSlice<usize>) -> ! {
-                            backtrace_size: usize) -> ! {
-    let backtrace = unsafe { slice::from_raw_parts_mut(backtrace_data, backtrace_size) };
     let mut cursor = 0;
     for index in 0..backtrace.len() {
         if backtrace[index] > kernel_proto::KERNELCPU_PAYLOAD_ADDRESS {
@@ -195,7 +183,7 @@ pub extern fn __artiq_terminate(exception: *const kernel_proto::Exception,
             cursor += 1;
         }
     }
-    let backtrace = &mut backtrace[0..cursor];
+    let backtrace = &mut backtrace.as_mut()[0..cursor];
 
     send(&NowSave(unsafe { NOW }));
     send(&RunException {
@@ -218,21 +206,21 @@ extern fn watchdog_clear(id: i32) {
     send(&WatchdogClear { id: id as usize })
 }
 
-extern fn cache_get(key: *const u8) -> ArtiqList<i32> {
+extern fn cache_get(key: *const u8) -> CSlice<'static, i32> {
     extern { fn strlen(s: *const c_char) -> size_t; }
     let key = unsafe { slice::from_raw_parts(key, strlen(key as *const c_char)) };
     let key = unsafe { str::from_utf8_unchecked(key) };
 
     send(&CacheGetRequest { key: key });
-    recv!(&CacheGetReply { value } => ArtiqList::from_slice(value))
+    recv!(&CacheGetReply { value } => value.as_c_slice())
 }
 
-extern fn cache_put(key: *const u8, list: ArtiqList<i32>) {
+extern fn cache_put(key: *const u8, list: CSlice<i32>) {
     extern { fn strlen(s: *const c_char) -> size_t; }
     let key = unsafe { slice::from_raw_parts(key, strlen(key as *const c_char)) };
     let key = unsafe { str::from_utf8_unchecked(key) };
 
-    send(&CachePutRequest { key: key, value: unsafe { list.as_slice() } });
+    send(&CachePutRequest { key: key, value: list.as_ref() });
     recv!(&CachePutReply { succeeded } => {
         if !succeeded {
             artiq_raise!("CacheError", "cannot put into a busy cache row")

artiq/firmware/ksupport/rtio.rs

@@ -1,9 +1,9 @@
 #[path = "../runtime/kernel_proto.rs"]
 mod kernel_proto;
 
-use board::csr;
 use core::ptr::{read_volatile, write_volatile};
-use ::ArtiqList;
+use cslice::CSlice;
+use board::csr;
 use ::send;
 use kernel_proto::*;
 
@@ -84,12 +84,11 @@ pub extern fn output(timestamp: i64, channel: i32, addr: i32, data: i32) {
     }
 }
 
-pub extern fn output_wide(timestamp: i64, channel: i32, addr: i32, list: ArtiqList<i32>) {
+pub extern fn output_wide(timestamp: i64, channel: i32, addr: i32, data: CSlice<i32>) {
     unsafe {
         csr::rtio::chan_sel_write(channel as u32);
         csr::rtio::o_timestamp_write(timestamp as u64);
         csr::rtio::o_address_write(addr as u32);
-        let data = list.as_slice();
         for i in 0..data.len() {
             rtio_o_data_write(i, data[i] as u32)
         }

artiq/runtime/artiq_personality.c

@@ -308,7 +308,8 @@ static _Unwind_Reason_Code __artiq_uncaught_exception(
 
   if(actions & _UA_END_OF_STACK) {
     EH_LOG0("end of stack");
-    __artiq_terminate(&inflight->artiq, inflight->backtrace, inflight->backtrace_size);
+    struct slice backtrace = { inflight->backtrace, inflight->backtrace_size };
+    __artiq_terminate(&inflight->artiq, backtrace);
   } else {
     EH_LOG0("continue");
     return _URC_NO_REASON;

artiq/runtime/artiq_personality.h

@@ -4,6 +4,11 @@
 #include <stdint.h>
 #include <stddef.h>
 
+struct slice {
+    void   *ptr;
+    size_t  len;
+};
+
 struct artiq_exception {
   union {
     uintptr_t typeinfo;
@@ -43,8 +48,7 @@ void __artiq_reraise(void)
 
 /* Called by the runtime */
 void __artiq_terminate(struct artiq_exception *artiq_exn,
-                       uintptr_t *backtrace,
+                       struct slice backtrace)
-                       size_t backtrace_size)
         __attribute__((noreturn));
 
 #ifdef __cplusplus

artiq/runtime/ksupport_glue.c

@@ -6,8 +6,13 @@
 #include <link.h>
 #include <dlfcn.h>
 
-void send_to_core_log(const char *ptr, size_t length);
+struct slice {
-void send_to_rtio_log(long long int timestamp, const char *ptr, size_t length);
+    void   *ptr;
+    size_t  len;
+};
+
+void send_to_core_log(struct slice str);
+void send_to_rtio_log(long long int timestamp, struct slice data);
 
 #define KERNELCPU_EXEC_ADDRESS    0x40800000
 #define KERNELCPU_PAYLOAD_ADDRESS 0x40840000
@@ -28,7 +33,8 @@ int fprintf(FILE *stream, const char *fmt, ...)
     vsnprintf(buf, size + 1, fmt, args);
     va_end(args);
 
-    send_to_core_log(buf, size);
+    struct slice str = { buf, size };
+    send_to_core_log(str);
     return 0;
 }
 
@@ -113,7 +119,8 @@ int core_log(const char *fmt, ...)
     vsnprintf(buf, size + 1, fmt, args);
     va_end(args);
 
-    send_to_core_log(buf, size);
+    struct slice str = { buf, size };
+    send_to_core_log(str);
     return 0;
 }
 
@@ -132,5 +139,6 @@ void rtio_log(long long int timestamp, const char *fmt, ...)
     vsnprintf(buf, size + 1, fmt, args);
     va_end(args);
 
-    send_to_rtio_log(timestamp, buf, size);
+    struct slice str = { buf, size };
+    send_to_rtio_log(timestamp, str);
 }