diff --git a/src/imp/libc/fs/syscalls.rs b/src/imp/libc/fs/syscalls.rs
index 77d75ef1..5ec08208 100644
--- a/src/imp/libc/fs/syscalls.rs
+++ b/src/imp/libc/fs/syscalls.rs
@@ -304,11 +304,14 @@ pub(crate) fn chmodat(dirfd: BorrowedFd<'_>, path: &ZStr, mode: Mode) -> io::Res
 pub(crate) fn chmodat(dirfd: BorrowedFd<'_>, path: &ZStr, mode: Mode) -> io::Result<()> {
     // Note that Linux's `fchmodat` does not have a flags argument.
     unsafe {
+        // Pass `mode` as a `c_uint` even if `mode_t` is narrower, since
+        // `libc_openat` is declared as a variadic function and narrrower
+        // arguments are promoted.
         syscall_ret(c::syscall(
             c::SYS_fchmodat,
             borrowed_fd(dirfd),
             c_str(path),
-            mode.bits(),
+            c::c_uint::from(mode.bits()),
         ))
     }
 }
@@ -503,7 +506,13 @@ pub(crate) fn fchmod(fd: BorrowedFd<'_>, mode: Mode) -> io::Result<()> {
     // implementations, such as musl, add extra logic to `fchmod` to emulate
     // support for `O_PATH`, which uses `/proc` outside our control and
     // interferes with our own use of `O_PATH`.
-    unsafe { syscall_ret(c::syscall(c::SYS_fchmod, borrowed_fd(fd), mode.bits())) }
+    unsafe {
+        syscall_ret(c::syscall(
+            c::SYS_fchmod,
+            borrowed_fd(fd),
+            c::c_uint::from(mode.bits()),
+        ))
+    }
 }
 
 #[cfg(not(target_os = "wasi"))]
@@ -617,11 +626,11 @@ pub(crate) fn ftruncate(fd: BorrowedFd<'_>, length: u64) -> io::Result<()> {
     // Use `ftruncate64` when available, in Android 12 and later.
     #[cfg(all(target_os = "android", target_pointer_width = "32"))]
     {
-        weak!(fn ftruncate64(c_int, i64) -> c_int);
+        weak!(fn ftruncate64(c::c_int, i64) -> c::c_int);
 
         unsafe {
             match ftruncate64.get() {
-                Some(f) => return ret(f(fd, size as i64)),
+                Some(f) => return ret(f(borrowed_fd(fd), length as i64)),
                 None => {}
             }
         }
diff --git a/src/imp/libc/io/syscalls.rs b/src/imp/libc/io/syscalls.rs
index 562c3958..c437d63c 100644
--- a/src/imp/libc/io/syscalls.rs
+++ b/src/imp/libc/io/syscalls.rs
@@ -58,23 +58,22 @@ pub(crate) fn write(fd: BorrowedFd<'_>, buf: &[u8]) -> io::Result<usize> {
 pub(crate) fn pread(fd: BorrowedFd<'_>, buf: &mut [u8], offset: u64) -> io::Result<usize> {
     let len = min(buf.len(), READ_LIMIT);
 
+    // Silently cast; we'll get `EINVAL` if the value is negative.
+    let offset = offset as i64;
+
     #[cfg(not(all(target_os = "android", target_pointer_width = "32")))]
-    let nread = {
-        // Silently cast; we'll get `EINVAL` if the value is negative.
-        let offset = offset as i64;
-        unsafe {
-            ret_ssize_t(libc_pread(
-                borrowed_fd(fd),
-                buf.as_mut_ptr().cast(),
-                len,
-                offset,
-            ))?
-        }
+    let nread = unsafe {
+        ret_ssize_t(libc_pread(
+            borrowed_fd(fd),
+            buf.as_mut_ptr().cast(),
+            len,
+            offset,
+        ))?
     };
 
     #[cfg(all(target_os = "android", target_pointer_width = "32"))]
-    let nread = {
-        weak!(fn pread64(c_int, *mut c_void, size_t, i64) -> ssize_t);
+    let nread = unsafe {
+        weak!(fn pread64(c::c_int, *mut c::c_void, c::size_t, i64) -> c::ssize_t);
         pread64
             .get()
             .map(|f| ret_ssize_t(f(borrowed_fd(fd), buf.as_mut_ptr().cast(), len, offset)))
@@ -89,38 +88,36 @@ pub(crate) fn pread(fd: BorrowedFd<'_>, buf: &mut [u8], offset: u64) -> io::Resu
                 } else {
                     return Err(io::Error::FBIG);
                 }
-            })
+            })?
     };
 
     Ok(nread as usize)
 }
 
-#[cfg(not(all(target_os = "android", target_pointer_width = "32")))]
 pub(crate) fn pwrite(fd: BorrowedFd<'_>, buf: &[u8], offset: u64) -> io::Result<usize> {
     let len = min(buf.len(), READ_LIMIT);
 
+    // Silently cast; we'll get `EINVAL` if the value is negative.
+    let offset = offset as i64;
+
     #[cfg(not(all(target_os = "android", target_pointer_width = "32")))]
-    let nwritten = {
-        // Silently cast; we'll get `EINVAL` if the value is negative.
-        let offset = offset as i64;
-        unsafe {
-            ret_ssize_t(libc_pwrite(
-                borrowed_fd(fd),
-                buf.as_ptr().cast(),
-                len,
-                offset,
-            ))?
-        }
+    let nwritten = unsafe {
+        ret_ssize_t(libc_pwrite(
+            borrowed_fd(fd),
+            buf.as_ptr().cast(),
+            len,
+            offset,
+        ))?
     };
 
     #[cfg(all(target_os = "android", target_pointer_width = "32"))]
-    {
-        weak!(fn pwrite64(c_int, *const c_void, size_t, i64) -> ssize_t);
+    let nwritten = unsafe {
+        weak!(fn pwrite64(c::c_int, *const c::c_void, c::size_t, i64) -> c::ssize_t);
         pwrite64
             .get()
-            .map(|f| ret_ssize_t(f(borrowed_fd(fd), buf.as_mut_ptr.cast(), len, offset)))
+            .map(|f| ret_ssize_t(f(borrowed_fd(fd), buf.as_ptr().cast(), len, offset)))
             .unwrap_or_else(|| {
-                if let Ok(o) = offset.try_into() {
+                if let Ok(offset) = offset.try_into() {
                     ret_ssize_t(libc_pwrite(
                         borrowed_fd(fd),
                         buf.as_ptr().cast(),
@@ -130,8 +127,8 @@ pub(crate) fn pwrite(fd: BorrowedFd<'_>, buf: &[u8], offset: u64) -> io::Result<
                 } else {
                     return Err(io::Error::FBIG);
                 }
-            })
-    }
+            })?
+    };
 
     Ok(nwritten as usize)
 }
diff --git a/src/imp/libc/net/syscalls.rs b/src/imp/libc/net/syscalls.rs
index db412262..ba1c4984 100644
--- a/src/imp/libc/net/syscalls.rs
+++ b/src/imp/libc/net/syscalls.rs
@@ -128,7 +128,7 @@ pub(crate) fn sendto_unix(
             send_recv_len(buf.len()),
             flags.bits(),
             as_ptr(&encode_sockaddr_unix(addr)).cast::<c::sockaddr>(),
-            size_of::<SocketAddrUnix>() as u32,
+            size_of::<SocketAddrUnix>() as _,
         ))?
     };
     Ok(nwritten as usize)
diff --git a/src/imp/libc/process/auxv.rs b/src/imp/libc/process/auxv.rs
index 9cf2627b..eb096f94 100644
--- a/src/imp/libc/process/auxv.rs
+++ b/src/imp/libc/process/auxv.rs
@@ -1,5 +1,8 @@
 use super::super::c;
-#[cfg(any(target_os = "android", target_os = "linux"))]
+#[cfg(any(
+    all(target_os = "android", target_pointer_width = "64"),
+    target_os = "linux"
+))]
 use crate::ffi::ZStr;
 
 #[inline]
@@ -7,7 +10,10 @@ pub(crate) fn page_size() -> usize {
     unsafe { c::sysconf(c::_SC_PAGESIZE) as usize }
 }
 
-#[cfg(any(target_os = "android", target_os = "linux"))]
+#[cfg(any(
+    all(target_os = "android", target_pointer_width = "64"),
+    target_os = "linux"
+))]
 #[inline]
 pub(crate) fn linux_hwcap() -> (usize, usize) {
     unsafe {
@@ -17,7 +23,10 @@ pub(crate) fn linux_hwcap() -> (usize, usize) {
     }
 }
 
-#[cfg(any(target_os = "android", target_os = "linux"))]
+#[cfg(any(
+    all(target_os = "android", target_pointer_width = "64"),
+    target_os = "linux"
+))]
 #[inline]
 pub(crate) fn linux_execfn() -> &'static ZStr {
     unsafe { ZStr::from_ptr(c::getauxval(c::AT_EXECFN) as *const _) }
diff --git a/src/imp/libc/process/mod.rs b/src/imp/libc/process/mod.rs
index 2cf2471e..4e5f9c5f 100644
--- a/src/imp/libc/process/mod.rs
+++ b/src/imp/libc/process/mod.rs
@@ -6,7 +6,10 @@ use super::c;
 #[cfg(not(windows))]
 pub(crate) mod syscalls;
 pub(crate) use auxv::page_size;
-#[cfg(any(target_os = "android", target_os = "linux"))]
+#[cfg(any(
+    all(target_os = "android", target_pointer_width = "64"),
+    target_os = "linux"
+))]
 pub(crate) use auxv::{linux_execfn, linux_hwcap};
 #[cfg(not(target_os = "wasi"))]
 pub(crate) use c::{
diff --git a/src/process/auxv.rs b/src/process/auxv.rs
index 85758342..1b8d4774 100644
--- a/src/process/auxv.rs
+++ b/src/process/auxv.rs
@@ -2,7 +2,16 @@
 //! pointers.
 #![cfg_attr(target_vendor = "mustang", allow(unsafe_code))]
 
-#[cfg(any(linux_raw, all(libc, any(target_os = "android", target_os = "linux"))))]
+#[cfg(any(
+    linux_raw,
+    all(
+        libc,
+        any(
+            all(target_os = "android", target_pointer_width = "64"),
+            target_os = "linux"
+        )
+    )
+))]
 use crate::ffi::ZStr;
 use crate::imp;
 
@@ -23,7 +32,16 @@ pub fn page_size() -> usize {
 ///  - [Linux]
 ///
 /// [Linux]: https://man7.org/linux/man-pages/man3/getauxval.3.html
-#[cfg(any(linux_raw, all(libc, any(target_os = "android", target_os = "linux"))))]
+#[cfg(any(
+    linux_raw,
+    all(
+        libc,
+        any(
+            all(target_os = "android", target_pointer_width = "64"),
+            target_os = "linux"
+        )
+    )
+))]
 #[inline]
 pub fn linux_hwcap() -> (usize, usize) {
     imp::process::linux_hwcap()
@@ -38,7 +56,16 @@ pub fn linux_hwcap() -> (usize, usize) {
 ///  - [Linux]
 ///
 /// [Linux]: https://man7.org/linux/man-pages/man3/getauxval.3.html
-#[cfg(any(linux_raw, all(libc, any(target_os = "android", target_os = "linux"))))]
+#[cfg(any(
+    linux_raw,
+    all(
+        libc,
+        any(
+            all(target_os = "android", target_pointer_width = "64"),
+            target_os = "linux"
+        )
+    )
+))]
 #[inline]
 pub fn linux_execfn() -> &'static ZStr {
     imp::process::linux_execfn()
diff --git a/src/process/mod.rs b/src/process/mod.rs
index 91df6d24..6244ce60 100644
--- a/src/process/mod.rs
+++ b/src/process/mod.rs
@@ -29,7 +29,16 @@ mod wait;
 #[cfg(target_vendor = "mustang")]
 pub use auxv::init;
 pub use auxv::page_size;
-#[cfg(any(linux_raw, all(libc, any(target_os = "android", target_os = "linux"))))]
+#[cfg(any(
+    linux_raw,
+    all(
+        libc,
+        any(
+            all(target_os = "android", target_pointer_width = "64"),
+            target_os = "linux"
+        )
+    )
+))]
 pub use auxv::{linux_execfn, linux_hwcap};
 #[cfg(not(target_os = "wasi"))]
 pub use chdir::chdir;