diff --git a/libc-test/semver/freebsd-x86_64.txt b/libc-test/semver/freebsd-x86_64.txt
index be73d1f7290fe..14ddc25a1b254 100644
--- a/libc-test/semver/freebsd-x86_64.txt
+++ b/libc-test/semver/freebsd-x86_64.txt
@@ -13,8 +13,6 @@ _MC_HASSEGS
 fpreg
 fpreg32
 max_align_t
-mcontext_t
 reg
 reg32
-ucontext_t
 xmmreg
diff --git a/libc-test/semver/freebsd.txt b/libc-test/semver/freebsd.txt
index d4b53860b5a53..eb598483a3bf4 100644
--- a/libc-test/semver/freebsd.txt
+++ b/libc-test/semver/freebsd.txt
@@ -2020,6 +2020,7 @@ mallctl
 mallctlbymib
 mallctlnametomib
 mallocx
+mcontext_t
 memmem
 memrchr
 memset_s
@@ -2350,13 +2351,14 @@ timer_t
 timex
 truncate
 ttyname_r
-uuidgen
+ucontext_t
 unmount
 useconds_t
 uselocale
 utimensat
 utmpx
 utrace
+uuidgen
 vm_size_t
 vmtotal
 wait4
diff --git a/src/unix/bsd/freebsdlike/freebsd/arm.rs b/src/unix/bsd/freebsdlike/freebsd/arm.rs
index 8ff500c65981c..965abd33f0a48 100644
--- a/src/unix/bsd/freebsdlike/freebsd/arm.rs
+++ b/src/unix/bsd/freebsdlike/freebsd/arm.rs
@@ -5,6 +5,49 @@ pub type wchar_t = u32;
 pub type time_t = i64;
 pub type suseconds_t = i32;
 pub type register_t = i32;
+pub type __greg_t = ::c_uint;
+pub type __gregset_t = [::__greg_t; 17];
+
+s_no_extra_traits! {
+    pub struct mcontext_t {
+        pub __gregs: ::__gregset_t,
+        pub mc_vfp_size: ::__size_t,
+        pub mc_vfp_ptr: *mut ::c_void,
+        pub mc_spare: [::c_uint; 33],
+    }
+}
+
+cfg_if! {
+    if #[cfg(feature = "extra_traits")] {
+        impl PartialEq for mcontext_t {
+            fn eq(&self, other: &mcontext_t) -> bool {
+                self.__gregs == other.__gregs &&
+                self.mc_vfp_size == other.mc_vfp_size &&
+                self.mc_vfp_ptr == other.mc_vfp_ptr &&
+                self.mc_spare.iter().zip(other.mc_spare.iter()).all(|(a, b)| a == b)
+            }
+        }
+        impl Eq for mcontext_t {}
+        impl ::fmt::Debug for mcontext_t {
+            fn fmt(&self, f: &mut ::fmt::Formatter) -> ::fmt::Result {
+                f.debug_struct("mcontext_t")
+                    .field("__gregs", &self.__gregs)
+                    .field("mc_vfp_size", &self.mc_vfp_size)
+                    .field("mc_vfp_ptr", &self.mc_vfp_ptr)
+                    .field("mc_spare", &self.mc_spare)
+                    .finish()
+            }
+        }
+        impl ::hash::Hash for mcontext_t {
+            fn hash<H: ::hash::Hasher>(&self, state: &mut H) {
+                self.__gregs.hash(state);
+                self.mc_vfp_size.hash(state);
+                self.mc_vfp_ptr.hash(state);
+                self.mc_spare.hash(state);
+            }
+        }
+    }
+}
 
 // should be pub(crate), but that requires Rust 1.18.0
 cfg_if! {
@@ -16,5 +59,6 @@ cfg_if! {
         pub const _ALIGNBYTES: usize = 4 - 1;
     }
 }
+
 pub const MAP_32BIT: ::c_int = 0x00080000;
 pub const MINSIGSTKSZ: ::size_t = 4096; // 1024 * 4
diff --git a/src/unix/bsd/freebsdlike/freebsd/mod.rs b/src/unix/bsd/freebsdlike/freebsd/mod.rs
index a15987df10775..dda108e8c0ef2 100644
--- a/src/unix/bsd/freebsdlike/freebsd/mod.rs
+++ b/src/unix/bsd/freebsdlike/freebsd/mod.rs
@@ -1654,6 +1654,15 @@ s_no_extra_traits! {
         _kf_cap_spare: u64,
         pub kf_path: [::c_char; ::PATH_MAX as usize],
     }
+
+    pub struct ucontext_t {
+        pub uc_sigmask: ::sigset_t,
+        pub uc_mcontext: ::mcontext_t,
+        pub uc_link: *mut ::ucontext_t,
+        pub uc_stack: ::stack_t,
+        pub uc_flags: ::c_int,
+        __spare__: [::c_int; 4],
+    }
 }
 
 cfg_if! {
@@ -2656,6 +2665,18 @@ cfg_if! {
                 self.kf_path.hash(state);
             }
         }
+
+        impl ::fmt::Debug for ucontext_t {
+            fn fmt(&self, f: &mut ::fmt::Formatter) -> ::fmt::Result {
+                f.debug_struct("ucontext_t")
+                    .field("uc_sigmask", &self.uc_sigmask)
+                    .field("uc_mcontext", &self.uc_mcontext)
+                    .field("uc_link", &self.uc_link)
+                    .field("uc_stack", &self.uc_stack)
+                    .field("uc_flags", &self.uc_flags)
+                    .finish()
+            }
+        }
     }
 }
 
diff --git a/src/unix/bsd/freebsdlike/freebsd/powerpc.rs b/src/unix/bsd/freebsdlike/freebsd/powerpc.rs
index f84062ba34b93..d856e80226746 100644
--- a/src/unix/bsd/freebsdlike/freebsd/powerpc.rs
+++ b/src/unix/bsd/freebsdlike/freebsd/powerpc.rs
@@ -6,6 +6,72 @@ pub type time_t = i64;
 pub type suseconds_t = i32;
 pub type register_t = i32;
 
+cfg_if! {
+    if #[cfg(libc_align)] {
+        s_no_extra_traits! {
+            #[repr(align(16))]
+            pub struct mcontext_t {
+                pub mc_vers: ::c_int,
+                pub mc_flags: ::c_int,
+                pub mc_onstack: ::c_int,
+                pub mc_len: ::c_int,
+                pub mc_avec: [u64; 64],
+                pub mc_av: [u32; 2],
+                pub mc_frame: [::register_t; 42],
+                pub mc_fpreg: [u64; 33],
+                pub mc_vsxfpreg: [u64; 32],
+            }
+        }
+    }
+}
+
+cfg_if! {
+    if #[cfg(all(libc_align, feature = "extra_traits"))] {
+        impl PartialEq for mcontext_t {
+            fn eq(&self, other: &mcontext_t) -> bool {
+                self.mc_vers == other.mc_vers &&
+                self.mc_flags == other.mc_flags &&
+                self.mc_onstack == other.mc_onstack &&
+                self.mc_len == other.mc_len &&
+                self.mc_avec == other.mc_avec &&
+                self.mc_av == other.mc_av &&
+                self.mc_frame == other.mc_frame &&
+                self.mc_fpreg == other.mc_fpreg &&
+                self.mc_vsxfpreg == other.mc_vsxfpreg
+            }
+        }
+        impl Eq for mcontext_t {}
+        impl ::fmt::Debug for mcontext_t {
+            fn fmt(&self, f: &mut ::fmt::Formatter) -> ::fmt::Result {
+                f.debug_struct("mcontext_t")
+                    .field("mc_vers", &self.mc_vers)
+                    .field("mc_flags", &self.mc_flags)
+                    .field("mc_onstack", &self.mc_onstack)
+                    .field("mc_len", &self.mc_len)
+                    .field("mc_avec", &self.mc_avec)
+                    .field("mc_av", &self.mc_av)
+                    .field("mc_frame", &self.mc_frame)
+                    .field("mc_fpreg", &self.mc_fpreg)
+                    .field("mc_vsxfpreg", &self.mc_vsxfpreg)
+                    .finish()
+            }
+        }
+        impl ::hash::Hash for mcontext_t {
+            fn hash<H: ::hash::Hasher>(&self, state: &mut H) {
+                self.mc_vers.hash(state);
+                self.mc_flags.hash(state);
+                self.mc_onstack.hash(state);
+                self.mc_len.hash(state);
+                self.mc_avec.hash(state);
+                self.mc_av.hash(state);
+                self.mc_frame.hash(state);
+                self.mc_fpreg.hash(state);
+                self.mc_vsxfpreg.hash(state);
+            }
+        }
+    }
+}
+
 // should be pub(crate), but that requires Rust 1.18.0
 cfg_if! {
     if #[cfg(libc_const_size_of)] {
diff --git a/src/unix/bsd/freebsdlike/freebsd/powerpc64.rs b/src/unix/bsd/freebsdlike/freebsd/powerpc64.rs
index 69cf4c5fc88c7..ec1c17e32db3f 100644
--- a/src/unix/bsd/freebsdlike/freebsd/powerpc64.rs
+++ b/src/unix/bsd/freebsdlike/freebsd/powerpc64.rs
@@ -6,6 +6,72 @@ pub type time_t = i64;
 pub type suseconds_t = i64;
 pub type register_t = i64;
 
+cfg_if! {
+    if #[cfg(libc_align)] {
+        s_no_extra_traits! {
+            #[repr(align(16))]
+            pub struct mcontext_t {
+                pub mc_vers: ::c_int,
+                pub mc_flags: ::c_int,
+                pub mc_onstack: ::c_int,
+                pub mc_len: ::c_int,
+                pub mc_avec: [u64; 64],
+                pub mc_av: [u32; 2],
+                pub mc_frame: [::register_t; 42],
+                pub mc_fpreg: [u64; 33],
+                pub mc_vsxfpreg: [u64; 32],
+            }
+        }
+    }
+}
+
+cfg_if! {
+    if #[cfg(all(libc_align, feature = "extra_traits"))] {
+        impl PartialEq for mcontext_t {
+            fn eq(&self, other: &mcontext_t) -> bool {
+                self.mc_vers == other.mc_vers &&
+                self.mc_flags == other.mc_flags &&
+                self.mc_onstack == other.mc_onstack &&
+                self.mc_len == other.mc_len &&
+                self.mc_avec == other.mc_avec &&
+                self.mc_av == other.mc_av &&
+                self.mc_frame == other.mc_frame &&
+                self.mc_fpreg == other.mc_fpreg &&
+                self.mc_vsxfpreg == other.mc_vsxfpreg
+            }
+        }
+        impl Eq for mcontext_t {}
+        impl ::fmt::Debug for mcontext_t {
+            fn fmt(&self, f: &mut ::fmt::Formatter) -> ::fmt::Result {
+                f.debug_struct("mcontext_t")
+                    .field("mc_vers", &self.mc_vers)
+                    .field("mc_flags", &self.mc_flags)
+                    .field("mc_onstack", &self.mc_onstack)
+                    .field("mc_len", &self.mc_len)
+                    .field("mc_avec", &self.mc_avec)
+                    .field("mc_av", &self.mc_av)
+                    .field("mc_frame", &self.mc_frame)
+                    .field("mc_fpreg", &self.mc_fpreg)
+                    .field("mc_vsxfpreg", &self.mc_vsxfpreg)
+                    .finish()
+            }
+        }
+        impl ::hash::Hash for mcontext_t {
+            fn hash<H: ::hash::Hasher>(&self, state: &mut H) {
+                self.mc_vers.hash(state);
+                self.mc_flags.hash(state);
+                self.mc_onstack.hash(state);
+                self.mc_len.hash(state);
+                self.mc_avec.hash(state);
+                self.mc_av.hash(state);
+                self.mc_frame.hash(state);
+                self.mc_fpreg.hash(state);
+                self.mc_vsxfpreg.hash(state);
+            }
+        }
+    }
+}
+
 // should be pub(crate), but that requires Rust 1.18.0
 cfg_if! {
     if #[cfg(libc_const_size_of)] {
diff --git a/src/unix/bsd/freebsdlike/freebsd/x86.rs b/src/unix/bsd/freebsdlike/freebsd/x86.rs
index 31a660e7d0a22..43545044e6793 100644
--- a/src/unix/bsd/freebsdlike/freebsd/x86.rs
+++ b/src/unix/bsd/freebsdlike/freebsd/x86.rs
@@ -41,17 +41,6 @@ s_no_extra_traits! {
     }
 }
 
-s! {
-    pub struct ucontext_t {
-        pub uc_sigmask: ::sigset_t,
-        pub uc_mcontext: ::mcontext_t,
-        pub uc_link: *mut ::ucontext_t,
-        pub uc_stack: ::stack_t,
-        pub uc_flags: ::c_int,
-        __spare__: [::c_int; 4],
-    }
-}
-
 // should be pub(crate), but that requires Rust 1.18.0
 cfg_if! {
     if #[cfg(libc_const_size_of)] {
diff --git a/src/unix/bsd/freebsdlike/freebsd/x86_64/align.rs b/src/unix/bsd/freebsdlike/freebsd/x86_64/align.rs
index 3a016a0519852..208e7f2c90c0a 100644
--- a/src/unix/bsd/freebsdlike/freebsd/x86_64/align.rs
+++ b/src/unix/bsd/freebsdlike/freebsd/x86_64/align.rs
@@ -184,14 +184,3 @@ cfg_if! {
         }
     }
 }
-
-s! {
-    pub struct ucontext_t {
-        pub uc_sigmask: ::sigset_t,
-        pub uc_mcontext: ::mcontext_t,
-        pub uc_link: *mut ::ucontext_t,
-        pub uc_stack: ::stack_t,
-        pub uc_flags: ::c_int,
-        __spare__: [::c_int; 4],
-    }
-}