Merge pull request #216 from tatref/iomem

Add /proc/iomem

Author: eminence

examples/iomem.rs

@@ -0,0 +1,22 @@
+//
+// Print physical location of system RAM
+// This requires CAP_SYS_ADMIN privilege, or root, otherwise physical memory addresses will be zero
+//
+
+fn main() {
+    if !rustix::process::geteuid().is_root() {
+        println!("WARNING: Access to /proc/iomem requires root, re-run with sudo");
+    }
+
+    let iomem = procfs::iomem().expect("Can't read /proc/iomem");
+
+    for (indent, map) in iomem.iter() {
+        if map.name == "System RAM" {
+            println!("Found RAM here: 0x{:x}-0x{:x}", map.address.0, map.address.1);
+        }
+    }
+
+    if !rustix::process::geteuid().is_root() {
+        println!("\n\nWARNING: Access to /proc/iomem requires root, re-run with sudo");
+    }
+}

src/iomem.rs

@@ -0,0 +1,53 @@
+#[cfg(feature = "serde1")]
+use serde::{Deserialize, Serialize};
+use std::io::{BufRead, BufReader};
+
+use super::{FileWrapper, ProcResult};
+use crate::split_into_num;
+
+/// Reads and parses the `/proc/iomem`, returning an error if there are problems.
+///
+/// Requires root, otherwise every memory address will be zero
+pub fn iomem() -> ProcResult<Vec<(usize, PhysicalMemoryMap)>> {
+    let f = FileWrapper::open("/proc/iomem")?;
+
+    let reader = BufReader::new(f);
+    let mut vec = Vec::new();
+
+    for line in reader.lines() {
+        let line = expect!(line);
+
+        let (indent, map) = PhysicalMemoryMap::from_line(&line)?;
+
+        vec.push((indent, map));
+    }
+
+    Ok(vec)
+}
+
+/// To construct this structure, see [crate::iomem()].
+#[derive(Debug, PartialEq, Eq, Clone, Hash)]
+#[cfg_attr(feature = "serde1", derive(Serialize, Deserialize))]
+pub struct PhysicalMemoryMap {
+    /// The address space in the process that the mapping occupies.
+    pub address: (u64, u64),
+    pub name: String,
+}
+
+impl PhysicalMemoryMap {
+    fn from_line(line: &str) -> ProcResult<(usize, PhysicalMemoryMap)> {
+        let indent = line.chars().take_while(|c| *c == ' ').count() / 2;
+        let line = line.trim();
+        let mut s = line.split(" : ");
+        let address = expect!(s.next());
+        let name = expect!(s.next());
+
+        Ok((
+            indent,
+            PhysicalMemoryMap {
+                address: split_into_num(address, '-', 16)?,
+                name: String::from(name),
+            },
+        ))
+    }
+}

src/lib.rs

@@ -288,6 +288,9 @@ pub mod keyring;
 mod uptime;
 pub use uptime::*;
 
+mod iomem;
+pub use iomem::*;
+
 lazy_static! {
     /// The number of clock ticks per second.
     ///

support.md

@@ -81,7 +81,7 @@ This is an approximate list of all the files under the `/proc` mount, and an ind
 * [ ] `/proc/fs`
 * [ ] `/proc/ide`
 * [ ] `/proc/interrupts`
-* [ ] `/proc/iomem`
+* [x] `/proc/iomem`
 * [ ] `/proc/ioports`
 * [ ] `/proc/kallsyms`
 * [ ] `/proc/kcore`