diff --git a/src/unix/bsd/freebsdlike/freebsd/riscv64.rs b/src/unix/bsd/freebsdlike/freebsd/riscv64.rs
index 143393e5c56ae..85afef02975bf 100644
--- a/src/unix/bsd/freebsdlike/freebsd/riscv64.rs
+++ b/src/unix/bsd/freebsdlike/freebsd/riscv64.rs
@@ -21,10 +21,10 @@ s_no_extra_traits! {
     }
 
     pub struct fpregs {
-        pub fp_x: [[::register_t; 2]; 32],
-        pub fp_fcsr: ::register_t,
+        pub fp_x: [[u64; 2]; 32],
+        pub fp_fcsr: u64,
         pub fp_flags: ::c_int,
-        pub fp_pad: ::c_int,
+        pub pad: ::c_int,
     }
 
     pub struct mcontext_t {
@@ -85,7 +85,7 @@ cfg_if! {
                 self.fp_x == other.fp_x
                     && self.fp_fcsr == other.fp_fcsr
                     && self.fp_flags == other.fp_flags
-                    && self.fp_pad == other.fp_pad
+                    && self.pad == other.pad
             }
         }
         impl Eq for fpregs {}
@@ -95,7 +95,7 @@ cfg_if! {
                     .field("fp_x", &self.fp_x)
                     .field("fp_fcsr", &self.fp_fcsr)
                     .field("fp_flags", &self.fp_flags)
-                    .field("fp_pad", &self.fp_pad)
+                    .field("pad", &self.pad)
                     .finish()
             }
         }
@@ -104,7 +104,7 @@ cfg_if! {
                 self.fp_x.hash(state);
                 self.fp_fcsr.hash(state);
                 self.fp_flags.hash(state);
-                self.fp_pad.hash(state);
+                self.pad.hash(state);
             }
         }
         impl PartialEq for mcontext_t {
diff --git a/src/unix/bsd/netbsdlike/netbsd/riscv64.rs b/src/unix/bsd/netbsdlike/netbsd/riscv64.rs
index 643940d03de85..14b1be38041c7 100644
--- a/src/unix/bsd/netbsdlike/netbsd/riscv64.rs
+++ b/src/unix/bsd/netbsdlike/netbsd/riscv64.rs
@@ -3,7 +3,26 @@ use PT_FIRSTMACH;
 pub type c_long = i64;
 pub type c_ulong = u64;
 pub type c_char = u8;
+pub type __greg_t = u64;
 pub type __cpu_simple_lock_nv_t = ::c_int;
+pub type __gregset = [__greg_t; _NGREG];
+pub type __fregset = [__freg; _NFREG];
+
+s! {
+    pub struct mcontext_t {
+        pub __gregs: __gregset,
+        pub __fregs: __fpregset,
+        __spare: [::__greg_t; 7],
+    }
+}
+
+s_no_extra_traits! {
+    #[cfg_attr(feature = "extra_traits", allow(missing_debug_implementations))]
+    pub union __fpreg {
+        pub u_u64: u64,
+        pub u_d: ::c_double,
+    }
+}
 
 pub(crate) const _ALIGNBYTES: usize = ::mem::size_of::<::c_long>() - 1;
 
@@ -11,3 +30,50 @@ pub const PT_GETREGS: ::c_int = PT_FIRSTMACH + 0;
 pub const PT_SETREGS: ::c_int = PT_FIRSTMACH + 1;
 pub const PT_GETFPREGS: ::c_int = PT_FIRSTMACH + 2;
 pub const PT_SETFPREGS: ::c_int = PT_FIRSTMACH + 3;
+
+pub const _NGREG: usize = 32;
+pub const _NFREG: usize = 33;
+
+pub const _REG_X1: ::c_int = 0;
+pub const _REG_X2: ::c_int = 1;
+pub const _REG_X3: ::c_int = 2;
+pub const _REG_X4: ::c_int = 3;
+pub const _REG_X5: ::c_int = 4;
+pub const _REG_X6: ::c_int = 5;
+pub const _REG_X7: ::c_int = 6;
+pub const _REG_X8: ::c_int = 7;
+pub const _REG_X9: ::c_int = 8;
+pub const _REG_X10: ::c_int = 9;
+pub const _REG_X11: ::c_int = 10;
+pub const _REG_X12: ::c_int = 11;
+pub const _REG_X13: ::c_int = 12;
+pub const _REG_X14: ::c_int = 13;
+pub const _REG_X15: ::c_int = 14;
+pub const _REG_X16: ::c_int = 15;
+pub const _REG_X17: ::c_int = 16;
+pub const _REG_X18: ::c_int = 17;
+pub const _REG_X19: ::c_int = 18;
+pub const _REG_X20: ::c_int = 19;
+pub const _REG_X21: ::c_int = 20;
+pub const _REG_X22: ::c_int = 21;
+pub const _REG_X23: ::c_int = 22;
+pub const _REG_X24: ::c_int = 23;
+pub const _REG_X25: ::c_int = 24;
+pub const _REG_X26: ::c_int = 25;
+pub const _REG_X27: ::c_int = 26;
+pub const _REG_X28: ::c_int = 27;
+pub const _REG_X29: ::c_int = 28;
+pub const _REG_X30: ::c_int = 29;
+pub const _REG_X31: ::c_int = 30;
+pub const _REG_PC: ::c_int = 31;
+
+pub const _REG_RA: ::c_int = _REG_X1;
+pub const _REG_SP: ::c_int = _REG_X2;
+pub const _REG_GP: ::c_int = _REG_X3;
+pub const _REG_TP: ::c_int = _REG_X4;
+pub const _REG_S0: ::c_int = _REG_X8;
+pub const _REG_RV: ::c_int = _REG_X10;
+pub const _REG_A0: ::c_int = _REG_X10;
+
+pub const _REG_F0: ::c_int = 0;
+pub const _REG_FPCSR: ::c_int = 32;
diff --git a/src/unix/hurd/mod.rs b/src/unix/hurd/mod.rs
index 72e5bf76087b4..f9410317a8bfa 100644
--- a/src/unix/hurd/mod.rs
+++ b/src/unix/hurd/mod.rs
@@ -2732,8 +2732,10 @@ pub const MAP_SHARED: ::c_int = 16;
 pub const MAP_PRIVATE: ::c_int = 0;
 pub const MAP_FIXED: ::c_int = 256;
 pub const MAP_NOEXTEND: ::c_int = 512;
-pub const MAP_HASSEMPHORE: ::c_int = 1024;
+pub const MAP_HASSEMAPHORE: ::c_int = 1024;
 pub const MAP_INHERIT: ::c_int = 2048;
+pub const MAP_32BIT: ::c_int = 4096;
+pub const MAP_EXCL: ::c_int = 16384;
 pub const MAP_FAILED: *mut ::c_void = !0 as *mut ::c_void;
 pub const MADV_NORMAL: ::c_int = 0;
 pub const MADV_RANDOM: ::c_int = 1;
diff --git a/src/unix/linux_like/linux/uclibc/mips/mod.rs b/src/unix/linux_like/linux/uclibc/mips/mod.rs
index 56bfcc5d355a7..d51d73f2944fe 100644
--- a/src/unix/linux_like/linux/uclibc/mips/mod.rs
+++ b/src/unix/linux_like/linux/uclibc/mips/mod.rs
@@ -23,10 +23,10 @@ pub const ECOMM: ::c_int = 70;
 pub const EPROTO: ::c_int = 71;
 pub const EDOTDOT: ::c_int = 73;
 
-pub const SA_NODEFER: ::c_int = 0x40000000;
-pub const SA_RESETHAND: ::c_int = 0x80000000;
-pub const SA_RESTART: ::c_int = 0x10000000;
-pub const SA_NOCLDSTOP: ::c_int = 0x00000001;
+pub const SA_NODEFER: ::c_uint = 0x40000000;
+pub const SA_RESETHAND: ::c_uint = 0x80000000;
+pub const SA_RESTART: ::c_uint = 0x10000000;
+pub const SA_NOCLDSTOP: ::c_uint = 0x00000001;
 
 pub const EPOLL_CLOEXEC: ::c_int = 0x80000;