Refactor util_libc

Author: newpavlov

src/backends.rs

@@ -13,11 +13,9 @@ cfg_if! {
         pub use custom::*;
     } else if #[cfg(getrandom_backend = "linux_getrandom")] {
         mod getrandom;
-        mod sanitizer;
         pub use getrandom::*;
     } else if #[cfg(getrandom_backend = "linux_raw")] {
         mod linux_raw;
-        mod sanitizer;
         pub use linux_raw::*;
     } else if #[cfg(getrandom_backend = "rdrand")] {
         mod rdrand;
@@ -49,7 +47,6 @@ cfg_if! {
         pub use unsupported::*;
     } else if #[cfg(all(target_os = "linux", target_env = ""))] {
         mod linux_raw;
-        mod sanitizer;
         pub use linux_raw::*;
     } else if #[cfg(target_os = "espidf")] {
         mod esp_idf;
@@ -117,7 +114,6 @@ cfg_if! {
     ))] {
         mod use_file;
         mod linux_android_with_fallback;
-        mod sanitizer;
         pub use linux_android_with_fallback::*;
     } else if #[cfg(any(
         target_os = "android",
@@ -132,8 +128,6 @@ cfg_if! {
         all(target_os = "horizon", target_arch = "arm"),
     ))] {
         mod getrandom;
-        #[cfg(any(target_os = "android", target_os = "linux"))]
-        mod sanitizer;
         pub use getrandom::*;
     } else if #[cfg(target_os = "solaris")] {
         mod solaris;

src/backends/getentropy.rs

@@ -12,15 +12,16 @@ use core::{ffi::c_void, mem::MaybeUninit};
 
 pub use crate::util::{inner_u32, inner_u64};
 
-#[path = "../util_libc.rs"]
-mod util_libc;
+#[path = "../utils/get_errno.rs"]
+mod utils;
 
 #[inline]
 pub fn fill_inner(dest: &mut [MaybeUninit<u8>]) -> Result<(), Error> {
     for chunk in dest.chunks_mut(256) {
         let ret = unsafe { libc::getentropy(chunk.as_mut_ptr().cast::<c_void>(), chunk.len()) };
         if ret != 0 {
-            return Err(util_libc::last_os_error());
+            let errno = utils::get_errno();
+            return Err(Error::from_errno(errno));
         }
     }
     Ok(())

src/backends/getrandom.rs

@@ -20,19 +20,12 @@ use core::mem::MaybeUninit;
 
 pub use crate::util::{inner_u32, inner_u64};
 
-#[path = "../util_libc.rs"]
-mod util_libc;
+#[path = "../utils/sys_fill_exact.rs"]
+mod utils;
 
 #[inline]
 pub fn fill_inner(dest: &mut [MaybeUninit<u8>]) -> Result<(), Error> {
-    util_libc::sys_fill_exact(dest, |buf| {
-        let ret = unsafe { libc::getrandom(buf.as_mut_ptr().cast(), buf.len(), 0) };
-
-        #[cfg(any(target_os = "android", target_os = "linux"))]
-        unsafe {
-            super::sanitizer::unpoison_linux_getrandom_result(buf, ret);
-        }
-
-        ret
+    utils::sys_fill_exact(dest, |buf| unsafe {
+        libc::getrandom(buf.as_mut_ptr().cast(), buf.len(), 0)
     })
 }

src/backends/linux_android_with_fallback.rs

@@ -1,13 +1,13 @@
 //! Implementation for Linux / Android with `/dev/urandom` fallback
-use super::{sanitizer, use_file};
+use super::use_file;
 use crate::Error;
 use core::{
     ffi::c_void,
     mem::{MaybeUninit, transmute},
     ptr::NonNull,
     sync::atomic::{AtomicPtr, Ordering},
 };
-use use_file::util_libc;
+use use_file::utils;
 
 pub use crate::util::{inner_u32, inner_u64};
 
@@ -44,13 +44,13 @@ fn init() -> NonNull<c_void> {
             if cfg!(getrandom_test_linux_fallback) {
                 NOT_AVAILABLE
             } else if res.is_negative() {
-                match util_libc::last_os_error().raw_os_error() {
-                    Some(libc::ENOSYS) => NOT_AVAILABLE, // No kernel support
+                match utils::get_errno() {
+                    libc::ENOSYS => NOT_AVAILABLE, // No kernel support
                     // The fallback on EPERM is intentionally not done on Android since this workaround
                     // seems to be needed only for specific Linux-based products that aren't based
                     // on Android. See https://github.com/rust-random/getrandom/issues/229.
                     #[cfg(target_os = "linux")]
-                    Some(libc::EPERM) => NOT_AVAILABLE, // Blocked by seccomp
+                    libc::EPERM => NOT_AVAILABLE, // Blocked by seccomp
                     _ => fptr,
                 }
             } else {
@@ -94,10 +94,8 @@ pub fn fill_inner(dest: &mut [MaybeUninit<u8>]) -> Result<(), Error> {
     } else {
         // note: `transmute` is currently the only way to convert a pointer into a function reference
         let getrandom_fn = unsafe { transmute::<NonNull<c_void>, GetRandomFn>(fptr) };
-        util_libc::sys_fill_exact(dest, |buf| unsafe {
-            let ret = getrandom_fn(buf.as_mut_ptr().cast(), buf.len(), 0);
-            sanitizer::unpoison_linux_getrandom_result(buf, ret);
-            ret
+        utils::sys_fill_exact(dest, |buf| unsafe {
+            getrandom_fn(buf.as_mut_ptr().cast(), buf.len(), 0)
         })
     }
 }

src/backends/linux_raw.rs

@@ -6,6 +6,9 @@ use crate::{Error, MaybeUninit};
 #[cfg(not(any(target_os = "android", target_os = "linux")))]
 compile_error!("`linux_raw` backend can be enabled only for Linux/Android targets!");
 
+#[path = "../utils/sanitizer.rs"]
+mod utils;
+
 #[allow(non_upper_case_globals)]
 unsafe fn getrandom_syscall(buf: *mut u8, buflen: usize, flags: u32) -> isize {
     let r0;
@@ -147,11 +150,12 @@ pub fn fill_inner(mut dest: &mut [MaybeUninit<u8>]) -> Result<(), Error> {
 
     loop {
         let ret = unsafe { getrandom_syscall(dest.as_mut_ptr().cast(), dest.len(), 0) };
-        unsafe { sanitizer::unpoison_linux_getrandom_result(dest, ret) };
         match usize::try_from(ret) {
             Ok(0) => return Err(Error::UNEXPECTED),
             Ok(len) => {
-                dest = dest.get_mut(len..).ok_or(Error::UNEXPECTED)?;
+                let (l, r) = dest.split_at_mut_checked(len).ok_or(Error::UNEXPECTED)?;
+                unsafe { utils::unpoison(l) };
+                dest = r;
                 if dest.is_empty() {
                     return Ok(());
                 }

src/backends/netbsd.rs

@@ -14,8 +14,8 @@ use core::{
 
 pub use crate::util::{inner_u32, inner_u64};
 
-#[path = "../util_libc.rs"]
-mod util_libc;
+#[path = "../utils/sys_fill_exact.rs"]
+mod utils;
 
 unsafe extern "C" fn polyfill_using_kern_arand(
     buf: *mut c_void,
@@ -72,7 +72,7 @@ pub fn fill_inner(dest: &mut [MaybeUninit<u8>]) -> Result<(), Error> {
         fptr = init();
     }
     let fptr = unsafe { mem::transmute::<*mut c_void, GetRandomFn>(fptr) };
-    util_libc::sys_fill_exact(dest, |buf| unsafe {
+    utils::sys_fill_exact(dest, |buf| unsafe {
         fptr(buf.as_mut_ptr().cast::<c_void>(), buf.len(), 0)
     })
 }

src/backends/rdrand.rs

@@ -2,7 +2,7 @@
 use crate::{Error, util::slice_as_uninit};
 use core::mem::{MaybeUninit, size_of};
 
-#[path = "../lazy.rs"]
+#[path = "../utils/lazy.rs"]
 mod lazy;
 
 #[cfg(not(any(target_arch = "x86_64", target_arch = "x86")))]

src/backends/rndr.rs

@@ -69,7 +69,7 @@ fn is_rndr_available() -> bool {
 
 #[cfg(not(target_feature = "rand"))]
 fn is_rndr_available() -> bool {
-    #[path = "../lazy.rs"]
+    #[path = "../utils/lazy.rs"]
     mod lazy;
     static RNDR_GOOD: lazy::LazyBool = lazy::LazyBool::new();
 

src/backends/solaris.rs

@@ -14,12 +14,10 @@
 //! which also explains why this crate should not use getentropy(2).
 use crate::Error;
 use core::{ffi::c_void, mem::MaybeUninit};
+use libc::___errno as errno_location;
 
 pub use crate::util::{inner_u32, inner_u64};
 
-#[path = "../util_libc.rs"]
-mod util_libc;
-
 const MAX_BYTES: usize = 1024;
 
 #[inline]
@@ -33,7 +31,10 @@ pub fn fill_inner(dest: &mut [MaybeUninit<u8>]) -> Result<(), Error> {
             // Good. Keep going.
             Ok(ret) if ret == chunk.len() => {}
             // The syscall failed.
-            Ok(0) => return Err(util_libc::last_os_error()),
+            Ok(0) => {
+                let errno = unsafe { core::ptr::read(errno_location()) };
+                return Err(Error::from_errno(errno));
+            }
             // All other cases should be impossible.
             _ => return Err(Error::UNEXPECTED),
         }

src/backends/use_file.rs

@@ -9,8 +9,8 @@ use core::{
 #[cfg(not(any(target_os = "android", target_os = "linux")))]
 pub use crate::util::{inner_u32, inner_u64};
 
-#[path = "../util_libc.rs"]
-pub(super) mod util_libc;
+#[path = "../utils/sys_fill_exact.rs"]
+pub(super) mod utils;
 
 /// For all platforms, we use `/dev/urandom` rather than `/dev/random`.
 /// For more information see the linked man pages in lib.rs.
@@ -46,7 +46,7 @@ pub fn fill_inner(dest: &mut [MaybeUninit<u8>]) -> Result<(), Error> {
     if fd == FD_UNINIT || fd == FD_ONGOING_INIT {
         fd = open_or_wait()?;
     }
-    util_libc::sys_fill_exact(dest, |buf| unsafe {
+    utils::sys_fill_exact(dest, |buf| unsafe {
         libc::read(fd, buf.as_mut_ptr().cast::<c_void>(), buf.len())
     })
 }
@@ -58,10 +58,10 @@ fn open_readonly(path: &CStr) -> Result<libc::c_int, Error> {
         if fd >= 0 {
             return Ok(fd);
         }
-        let err = util_libc::last_os_error();
+        let errno = utils::get_errno();
         // We should try again if open() was interrupted.
-        if err.raw_os_error() != Some(libc::EINTR) {
-            return Err(err);
+        if errno != libc::EINTR {
+            return Err(Error::from_errno(errno));
         }
     }
 }
@@ -136,7 +136,7 @@ mod sync {
 
 #[cfg(any(target_os = "android", target_os = "linux"))]
 mod sync {
-    use super::{Error, FD, FD_ONGOING_INIT, open_readonly, util_libc::last_os_error};
+    use super::{Error, FD, FD_ONGOING_INIT, open_readonly, utils};
 
     /// Wait for atomic `FD` to change value from `FD_ONGOING_INIT` to something else.
     ///
@@ -152,7 +152,7 @@ mod sync {
         debug_assert!({
             match ret {
                 0 => true,
-                -1 => last_os_error().raw_os_error() == Some(libc::EAGAIN),
+                -1 => utils::get_errno() == libc::EAGAIN,
                 _ => false,
             }
         });
@@ -209,12 +209,12 @@ mod sync {
                 debug_assert_eq!(res, 1);
                 break Ok(());
             }
-            let err = last_os_error();
+            let errno = utils::get_errno();
             // Assuming that `poll` is called correctly,
             // on Linux it can return only EINTR and ENOMEM errors.
-            match err.raw_os_error() {
-                Some(libc::EINTR) => continue,
-                _ => break Err(err),
+            match errno {
+                libc::EINTR => continue,
+                _ => break Err(Error::from_errno(errno)),
             }
         };
         unsafe { libc::close(fd) };