Add implementation of PTRACE_{GET,SET}REGSET

Also added `PTRACE_{GET,SET}REGS` for most platforms other than x86
using aforementioned implementation.

CHANGELOG.md

@@ -5,6 +5,11 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 
 ## [0.27.1] - 2023-08-28
 
+### Added
+
+- Added implementation of `PTRACE_{GET,SET}REGSET`, and `PTRACE_{GET,SET}REGS` on aarch64/riscv64 Linux.
+  ([#2044](https://github.com/nix-rust/nix/pull/2044))
+
 ### Fixed
 
 - Fixed generating the documentation on docs.rs.

src/sys/ptrace/linux.rs

@@ -17,8 +17,10 @@ pub type AddressType = *mut ::libc::c_void;
             target_arch = "x86_64",
             any(target_env = "gnu", target_env = "musl")
         ),
-        all(target_arch = "x86", target_env = "gnu")
-    )
+        all(target_arch = "x86", target_env = "gnu"),
+        all(target_arch = "aarch64", target_env = "gnu"),
+        all(target_arch = "riscv64", target_env = "gnu"),
+    ),
 ))]
 use libc::user_regs_struct;
 
@@ -152,6 +154,29 @@ libc_enum! {
     }
 }
 
+libc_enum! {
+    #[cfg(all(
+        target_os = "linux",
+        target_env = "gnu",
+        any(
+            target_arch = "x86_64",
+            target_arch = "x86",
+            target_arch = "aarch64",
+            target_arch = "riscv64",
+        )
+    ))]
+    #[repr(i32)]
+    /// Defining a specific register set, as used in [`getregset`] and [`setregset`].
+    #[non_exhaustive]
+    pub enum RegisterSet {
+        NT_PRSTATUS,
+        NT_PRFPREG,
+        NT_PRPSINFO,
+        NT_TASKSTRUCT,
+        NT_AUXV,
+    }
+}
+
 libc_bitflags! {
     /// Ptrace options used in conjunction with the PTRACE_SETOPTIONS request.
     /// See `man ptrace` for more details.
@@ -213,6 +238,48 @@ pub fn getregs(pid: Pid) -> Result<user_regs_struct> {
     ptrace_get_data::<user_regs_struct>(Request::PTRACE_GETREGS, pid)
 }
 
+/// Get user registers, as with `ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, ...)`
+#[cfg(all(
+    target_os = "linux",
+    target_env = "gnu",
+    any(
+        target_arch = "aarch64",
+        target_arch = "riscv64",
+    )
+))]
+pub fn getregs(pid: Pid) -> Result<user_regs_struct> {
+    getregset(pid, RegisterSet::NT_PRSTATUS)
+}
+
+/// Get a particular set of user registers, as with `ptrace(PTRACE_GETREGSET, ...)`
+#[cfg(all(
+    target_os = "linux",
+    target_env = "gnu",
+    any(
+        target_arch = "x86_64",
+        target_arch = "x86",
+        target_arch = "aarch64",
+        target_arch = "riscv64",
+    )
+))]
+pub fn getregset(pid: Pid, set: RegisterSet) -> Result<user_regs_struct> {
+    let request = Request::PTRACE_GETREGSET;
+    let mut data = mem::MaybeUninit::<user_regs_struct>::uninit();
+    let mut iov = libc::iovec {
+        iov_base: data.as_mut_ptr() as *mut _,
+        iov_len: mem::size_of::<user_regs_struct>(),
+    };
+    unsafe {
+        ptrace_other(
+            request,
+            pid,
+            set as i32 as AddressType,
+            &mut iov as *mut _ as *mut c_void,
+        )?;
+    };
+    Ok(unsafe { data.assume_init() })
+}
+
 /// Set user registers, as with `ptrace(PTRACE_SETREGS, ...)`
 #[cfg(all(
     target_os = "linux",
@@ -236,6 +303,50 @@ pub fn setregs(pid: Pid, regs: user_regs_struct) -> Result<()> {
     Errno::result(res).map(drop)
 }
 
+/// Set user registers, as with `ptrace(PTRACE_SETREGSET, pid, NT_PRSTATUS, ...)`
+#[cfg(all(
+    target_os = "linux",
+    target_env = "gnu",
+    any(
+        target_arch = "aarch64",
+        target_arch = "riscv64",
+    )
+))]
+pub fn setregs(pid: Pid, regs: user_regs_struct) -> Result<()> {
+    setregset(pid, RegisterSet::NT_PRSTATUS, regs)
+}
+
+/// Set a particular set of user registers, as with `ptrace(PTRACE_SETREGSET, ...)`
+#[cfg(all(
+    target_os = "linux",
+    target_env = "gnu",
+    any(
+        target_arch = "x86_64",
+        target_arch = "x86",
+        target_arch = "aarch64",
+        target_arch = "riscv64",
+    )
+))]
+pub fn setregset(
+    pid: Pid,
+    set: RegisterSet,
+    regs: user_regs_struct,
+) -> Result<()> {
+    let iov = libc::iovec {
+        iov_base: &regs as *const _ as *mut c_void,
+        iov_len: mem::size_of::<user_regs_struct>(),
+    };
+    unsafe {
+        ptrace_other(
+            Request::PTRACE_SETREGSET,
+            pid,
+            set as i32 as AddressType,
+            &iov as *const _ as *mut c_void,
+        )?;
+    }
+    Ok(())
+}
+
 /// Function for ptrace requests that return values from the data field.
 /// Some ptrace get requests populate structs or larger elements than `c_long`
 /// and therefore use the data field to return values. This function handles these

test/sys/test_ptrace.rs

@@ -1,7 +1,12 @@
 #[cfg(all(
     target_os = "linux",
-    any(target_arch = "x86_64", target_arch = "x86"),
-    target_env = "gnu"
+    target_env = "gnu",
+    any(
+        target_arch = "x86_64",
+        target_arch = "x86",
+        target_arch = "aarch64",
+        target_arch = "riscv64",
+    )
 ))]
 use memoffset::offset_of;
 use nix::errno::Errno;
@@ -179,8 +184,13 @@ fn test_ptrace_interrupt() {
 // ptrace::{setoptions, getregs} are only available in these platforms
 #[cfg(all(
     target_os = "linux",
-    any(target_arch = "x86_64", target_arch = "x86"),
-    target_env = "gnu"
+    target_env = "gnu",
+    any(
+        target_arch = "x86_64",
+        target_arch = "x86",
+        target_arch = "aarch64",
+        target_arch = "riscv64",
+    )
 ))]
 #[test]
 fn test_ptrace_syscall() {
@@ -226,14 +236,28 @@ fn test_ptrace_syscall() {
             let get_syscall_id =
                 || ptrace::getregs(child).unwrap().orig_eax as libc::c_long;
 
+            #[cfg(target_arch = "aarch64")]
+            let get_syscall_id =
+                || ptrace::getregs(child).unwrap().regs[8] as libc::c_long;
+
+            #[cfg(target_arch = "riscv64")]
+            let get_syscall_id =
+                || ptrace::getregs(child).unwrap().a7 as libc::c_long;
+
             // this duplicates `get_syscall_id` for the purpose of testing `ptrace::read_user`.
             #[cfg(target_arch = "x86_64")]
             let rax_offset = offset_of!(libc::user_regs_struct, orig_rax);
             #[cfg(target_arch = "x86")]
             let rax_offset = offset_of!(libc::user_regs_struct, orig_eax);
+            #[cfg(target_arch = "aarch64")]
+            let rax_offset = offset_of!(libc::user_regs_struct, regs)
+                + 8 * mem::size_of::<libc::c_ulonglong>();
+            #[cfg(target_arch = "riscv64")]
+            let rax_offset = offset_of!(libc::user_regs_struct, a7);
 
             let get_syscall_from_user_area = || {
                 // Find the offset of `user.regs.rax` (or `user.regs.eax` for x86)
+                #[cfg(any(target_arch = "x86_64", target_arch = "x86"))]
                 let rax_offset = offset_of!(libc::user, regs) + rax_offset;
                 ptrace::read_user(child, rax_offset as _).unwrap()
                     as libc::c_long