ch04: rust_proc WIP

/ # insmod share/rust_proc.ko
[    7.457539] rust_proc: module verification failed: signature and/or required key missing - tainting kernel
[    7.459266] rust_proc: rust_proc is loaded
/ # ls /proc
1              27             7              iomem          pressure
10             28             8              ioports        rust_proc
11             29             9              irq            schedstat
111            3              bootconfig     kallsyms       self
12             30             buddyinfo      kcore          slabinfo
120            31             bus            key-users      softirqs
13             32             cgroups        keys           stat
14             33             cmdline        kmsg           swaps
15             34             consoles       kpagecgroup    sys
16             35             cpuinfo        kpagecount     sysrq-trigger
17             36             crypto         kpageflags     sysvipc
18             39             devices        loadavg        thread-self
19             4              diskstats      locks          timer_list
2              40             dma            meminfo        tty
20             41             driver         misc           uptime
21             42             dynamic_debug  modules        version
22             5              execdomains    mounts         vmallocinfo
23             53             fb             mtrr           vmstat
24             6              filesystems    net            zoneinfo
25             61             fs             pagetypeinfo
26             62             interrupts     partitions
/ # ls /proc/rust_proc/
/ #

Author: Gioh Kim

rust/bindings/bindings_helper.h

@@ -20,6 +20,7 @@
 #include <linux/uaccess.h>
 #include <linux/delay.h>
 #include <linux/miscdevice.h>
+#include <linux/proc_fs.h>
 
 /* `bindgen` gets confused at certain things. */
 const size_t BINDINGS_ARCH_SLAB_MINALIGN = ARCH_SLAB_MINALIGN;

samples/rust/Kconfig

@@ -57,4 +57,11 @@ config SAMPLE_RUST_LDD03
 	help
 	  This option builds the Rust Linux Device Drivers examples
 
+config SAMPLE_RUST_LDD_CH04
+	tristate "Linux Device Driver proc in Rust"
+	help
+	  This option builds the Linux Device Driver examples in Rust.
+
+	  If unsure, say N.
+
 endif # SAMPLES_RUST

samples/rust/Makefile

@@ -5,5 +5,6 @@ obj-$(CONFIG_SAMPLE_RUST_PRINT)			+= rust_print.o
 obj-$(CONFIG_SAMPLE_RUST_FS)			+= rust_fs.o
 obj-$(CONFIG_SAMPLE_RUST_LDD02)			+= rust_ldd02.o
 obj-$(CONFIG_SAMPLE_RUST_LDD03)			+= rust_ldd03.o
+obj-$(CONFIG_SAMPLE_RUST_LDD04)			+= rust_proc.o
 
 subdir-$(CONFIG_SAMPLE_RUST_HOSTPROGS)		+= hostprogs

samples/rust/rust_proc.rs

@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Rust LDD
+//! reference: https://github.com/d0u9/Linux-Device-Driver/tree/master/
+//!
+//! How to build only modules:
+//! make LLVM=1 M=samples/rust
+
+// core is from Rust compiler, not from kernel
+use core::ptr;
+
+use kernel::bindings;
+use kernel::prelude::*;
+use kernel::{
+    file::{self, File},
+    io_buffer::{IoBufferReader, IoBufferWriter},
+    str::CString,
+    sync::{Arc, ArcBorrow, Mutex, UniqueArc},
+};
+
+module! {
+    type: RustProc,
+    name: "rust_proc",
+    author: "Rust for Linux Contributors",
+    description: "Rust LDD ch04 proc_fs_basic",
+    license: "GPL",
+}
+
+struct RustProc {}
+
+impl kernel::Module for RustProc {
+    fn init(name: &'static CStr, _module: &'static ThisModule) -> Result<Self> {
+        pr_info!("{} is loaded\n", name.to_str()?);
+
+        unsafe {
+            let parent_dir = CString::try_from_fmt(fmt!("rust_proc"))?;
+            let proc_dir = bindings::proc_mkdir(parent_dir.as_char_ptr(), ptr::null_mut());
+        }
+
+        Ok(RustProc {})
+    }
+}
+
+impl Drop for RustProc {
+    fn drop(&mut self) {
+        pr_info!("rust_proc is unloaded\n");
+    }
+}