Merge branch 'use-symloopmax' into 'master'

use SYMLOOP_MAX in resolve_sym_links in redox path

See merge request redox-os/relibc!1477

src/header/limits/mod.rs

@@ -101,6 +101,7 @@ pub const _POSIX_SIGQUEUE_MAX: c_long = 32;
 pub const _POSIX_SSIZE_MAX: c_long = 32767;
 pub const _POSIX_STREAM_MAX: c_long = 8;
 pub const _POSIX_SYMLINK_MAX: c_long = 255;
+/// Minimum required value for `SYMLOOP_MAX`.
 pub const _POSIX_SYMLOOP_MAX: c_long = 8;
 pub const _POSIX_THREAD_DESTRUCTOR_ITERATIONS: c_long = 4;
 pub const _POSIX_THREAD_KEYS_MAX: c_long = 128;
@@ -145,5 +146,7 @@ pub const PTHREAD_DESTRUCTOR_ITERATIONS: c_long = _POSIX_THREAD_DESTRUCTOR_ITERA
 // TODO: What should this limit be? Both glibc and musl have it as 1024
 pub const PTHREAD_KEYS_MAX: c_long = 4096 * 32;
 pub const PTHREAD_STACK_MIN: c_long = 65536;
+/// Maximum number of symbolic links that can be reliably traversed in the
+/// resolution of a pathname in the absence of a loop.
 pub const SYMLOOP_MAX: c_long = 64;
 pub const TTY_NAME_MAX: c_long = 32; // "/scheme/pty/".len() + size of usize::MAX as string + 1

src/platform/redox/path.rs

@@ -272,10 +272,8 @@ fn calc_next_abs_path(current_abs: &str, link_target: &str) -> Result<String> {
 }
 
 fn resolve_sym_links(mut current_path_string: String, flags: usize) -> Result<usize> {
-    // TODO: SYMLOOP_MAX
-    const MAX_LEVEL: usize = 64;
     // Sym reolve loop
-    for _ in 0..(MAX_LEVEL - 1) {
+    for _ in 0..limits::SYMLOOP_MAX {
         match open_absolute(&current_path_string, flags) {
             Ok(fd) => return Ok(fd),
             Err(e) if e == Error::new(EXDEV) => {