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// Note: This file is only currently used on targets that call out to the code
// in `mod libs_dl_iterate_phdr` (e.g. linux, freebsd, ...); it may be more
// general purpose, but it hasn't been tested elsewhere.
use super::mystd::fs::File;
use super::mystd::io::Read;
use super::mystd::str::FromStr;
use super::{OsString, String, Vec};
#[derive(PartialEq, Eq, Debug)]
pub(super) struct MapsEntry {
/// start (inclusive) and limit (exclusive) of address range.
address: (usize, usize),
/// The perms field are the permissions for the entry
///
/// r = read
/// w = write
/// x = execute
/// s = shared
/// p = private (copy on write)
perms: [char; 4],
/// Offset into the file (or "whatever").
offset: usize,
/// device (major, minor)
dev: (usize, usize),
/// inode on the device. 0 indicates that no inode is associated with the memory region (e.g. uninitalized data aka BSS).
inode: usize,
/// Usually the file backing the mapping.
///
/// Note: The man page for proc includes a note about "coordination" by
/// using readelf to see the Offset field in ELF program headers. pnkfelix
/// is not yet sure if that is intended to be a comment on pathname, or what
/// form/purpose such coordination is meant to have.
///
/// There are also some pseudo-paths:
/// "[stack]": The initial process's (aka main thread's) stack.
/// "[stack:<tid>]": a specific thread's stack. (This was only present for a limited range of Linux verisons; it was determined to be too expensive to provide.)
/// "[vdso]": Virtual dynamically linked shared object
/// "[heap]": The process's heap
///
/// The pathname can be blank, which means it is an anonymous mapping
/// obtained via mmap.
///
/// Newlines in pathname are replaced with an octal escape sequence.
///
/// The pathname may have "(deleted)" appended onto it if the file-backed
/// path has been deleted.
///
/// Note that modifications like the latter two indicated above imply that
/// in general the pathname may be ambiguous. (I.e. you cannot tell if the
/// denoted filename actually ended with the text "(deleted)", or if that
/// was added by the maps rendering.
pathname: OsString,
}
pub(super) fn parse_maps() -> Result<Vec<MapsEntry>, &'static str> {
let mut v = Vec::new();
let mut proc_self_maps =
File::open("/proc/self/maps").map_err(|_| "Couldn't open /proc/self/maps")?;
let mut buf = String::new();
let _bytes_read = proc_self_maps
.read_to_string(&mut buf)
.map_err(|_| "Couldn't read /proc/self/maps")?;
for line in buf.lines() {
v.push(line.parse()?);
}
Ok(v)
}
impl MapsEntry {
pub(super) fn pathname(&self) -> &OsString {
&self.pathname
}
pub(super) fn ip_matches(&self, ip: usize) -> bool {
self.address.0 <= ip && ip < self.address.1
}
}
impl FromStr for MapsEntry {
type Err = &'static str;
// Format: address perms offset dev inode pathname
// e.g.: "ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0 [vsyscall]"
// e.g.: "7f5985f46000-7f5985f48000 rw-p 00039000 103:06 76021795 /usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2"
// e.g.: "35b1a21000-35b1a22000 rw-p 00000000 00:00 0"
fn from_str(s: &str) -> Result<Self, Self::Err> {
let mut parts = s
.split(' ') // space-separated fields
.filter(|s| s.len() > 0); // multiple spaces implies empty strings that need to be skipped.
let range_str = parts.next().ok_or("Couldn't find address")?;
let perms_str = parts.next().ok_or("Couldn't find permissions")?;
let offset_str = parts.next().ok_or("Couldn't find offset")?;
let dev_str = parts.next().ok_or("Couldn't find dev")?;
let inode_str = parts.next().ok_or("Couldn't find inode")?;
let pathname_str = parts.next().unwrap_or(""); // pathname may be omitted.
let hex = |s| usize::from_str_radix(s, 16).map_err(|_| "Couldn't parse hex number");
let address = {
// This could use `range_str.split_once('-')` once the MSRV passes 1.52.
if let Some(idx) = range_str.find('-') {
let (start, rest) = range_str.split_at(idx);
let (_div, limit) = rest.split_at(1);
(hex(start)?, hex(limit)?)
} else {
return Err("Couldn't parse address range");
}
};
let perms: [char; 4] = {
let mut chars = perms_str.chars();
let mut c = || chars.next().ok_or("insufficient perms");
let perms = [c()?, c()?, c()?, c()?];
if chars.next().is_some() {
return Err("too many perms");
}
perms
};
let offset = hex(offset_str)?;
let dev = {
// This could use `dev_str.split_once(':')` once the MSRV passes 1.52.
if let Some(idx) = dev_str.find(':') {
let (major, rest) = dev_str.split_at(idx);
let (_div, minor) = rest.split_at(1);
(hex(major)?, hex(minor)?)
} else {
return Err("Couldn't parse dev")?;
}
};
let inode = hex(inode_str)?;
let pathname = pathname_str.into();
Ok(MapsEntry {
address,
perms,
offset,
dev,
inode,
pathname,
})
}
}
// Make sure we can parse 64-bit sample output if we're on a 64-bit target.
#[cfg(target_pointer_width = "64")]
#[test]
fn check_maps_entry_parsing_64bit() {
assert_eq!(
"ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0 \
[vsyscall]"
.parse::<MapsEntry>()
.unwrap(),
MapsEntry {
address: (0xffffffffff600000, 0xffffffffff601000),
perms: ['-', '-', 'x', 'p'],
offset: 0x00000000,
dev: (0x00, 0x00),
inode: 0x0,
pathname: "[vsyscall]".into(),
}
);
assert_eq!(
"7f5985f46000-7f5985f48000 rw-p 00039000 103:06 76021795 \
/usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2"
.parse::<MapsEntry>()
.unwrap(),
MapsEntry {
address: (0x7f5985f46000, 0x7f5985f48000),
perms: ['r', 'w', '-', 'p'],
offset: 0x00039000,
dev: (0x103, 0x06),
inode: 0x76021795,
pathname: "/usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2".into(),
}
);
assert_eq!(
"35b1a21000-35b1a22000 rw-p 00000000 00:00 0"
.parse::<MapsEntry>()
.unwrap(),
MapsEntry {
address: (0x35b1a21000, 0x35b1a22000),
perms: ['r', 'w', '-', 'p'],
offset: 0x00000000,
dev: (0x00, 0x00),
inode: 0x0,
pathname: Default::default(),
}
);
}
// (This output was taken from a 32-bit machine, but will work on any target)
#[test]
fn check_maps_entry_parsing_32bit() {
/* Example snippet of output:
08056000-08077000 rw-p 00000000 00:00 0 [heap]
b7c79000-b7e02000 r--p 00000000 08:01 60662705 /usr/lib/locale/locale-archive
b7e02000-b7e03000 rw-p 00000000 00:00 0
*/
assert_eq!(
"08056000-08077000 rw-p 00000000 00:00 0 \
[heap]"
.parse::<MapsEntry>()
.unwrap(),
MapsEntry {
address: (0x08056000, 0x08077000),
perms: ['r', 'w', '-', 'p'],
offset: 0x00000000,
dev: (0x00, 0x00),
inode: 0x0,
pathname: "[heap]".into(),
}
);
assert_eq!(
"b7c79000-b7e02000 r--p 00000000 08:01 60662705 \
/usr/lib/locale/locale-archive"
.parse::<MapsEntry>()
.unwrap(),
MapsEntry {
address: (0xb7c79000, 0xb7e02000),
perms: ['r', '-', '-', 'p'],
offset: 0x00000000,
dev: (0x08, 0x01),
inode: 0x60662705,
pathname: "/usr/lib/locale/locale-archive".into(),
}
);
assert_eq!(
"b7e02000-b7e03000 rw-p 00000000 00:00 0"
.parse::<MapsEntry>()
.unwrap(),
MapsEntry {
address: (0xb7e02000, 0xb7e03000),
perms: ['r', 'w', '-', 'p'],
offset: 0x00000000,
dev: (0x00, 0x00),
inode: 0x0,
pathname: Default::default(),
}
);
}
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