implement getcpu(2)

etc/syscalls_linux_aarch64.md

@@ -168,7 +168,7 @@
 | 0xa5 (165)  | getrusage               | (int who, struct rusage *ru)                                                                                                               | __arm64_sys_getrusage               | false       |
 | 0xa6 (166)  | umask                   | (int mask)                                                                                                                                 | __arm64_sys_umask                   | true        |
 | 0xa7 (167)  | prctl                   | (int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5)                                               | __arm64_sys_prctl                   | stub        |
-| 0xa8 (168)  | getcpu                  | (unsigned *cpup, unsigned *nodep, struct getcpu_cache *unused)                                                                             | __arm64_sys_getcpu                  | false       |
+| 0xa8 (168)  | getcpu                  | (unsigned *cpup, unsigned *nodep, struct getcpu_cache *unused)                                                                             | __arm64_sys_getcpu                  | true        |
 | 0xa9 (169)  | gettimeofday            | (struct __kernel_old_timeval *tv, struct timezone *tz)                                                                                     | __arm64_sys_gettimeofday            | partial     |
 | 0xaa (170)  | settimeofday            | (struct __kernel_old_timeval *tv, struct timezone *tz)                                                                                     | __arm64_sys_settimeofday            | partial     |
 | 0xab (171)  | adjtimex                | (struct __kernel_timex *txc_p)                                                                                                             | __arm64_sys_adjtimex                | false       |

src/arch/arm64/exceptions/syscall.rs

@@ -47,8 +47,8 @@ use crate::{
         },
     },
     kernel::{
-        hostname::sys_sethostname, power::sys_reboot, rand::sys_getrandom, sysinfo::sys_sysinfo,
-        uname::sys_uname,
+        getcpu::sys_getcpu, hostname::sys_sethostname, power::sys_reboot, rand::sys_getrandom,
+        sysinfo::sys_sysinfo, uname::sys_uname,
     },
     memory::{
         brk::sys_brk,
@@ -561,6 +561,7 @@ pub async fn handle_syscall(mut ctx: ProcessCtx) {
         0xa3 => Err(KernelError::InvalidValue),
         0xa6 => sys_umask(&ctx, arg1 as _).map_err(|e| match e {}),
         0xa7 => sys_prctl(&ctx, arg1 as _, arg2, arg3).await,
+        0xa8 => sys_getcpu(TUA::from_value(arg1 as _), TUA::from_value(arg2 as _)).await,
         0xa9 => sys_gettimeofday(TUA::from_value(arg1 as _), TUA::from_value(arg2 as _)).await,
         0xaa => sys_settimeofday(TUA::from_value(arg1 as _), TUA::from_value(arg2 as _)).await,
         0xac => sys_getpid(&ctx).map_err(|e| match e {}),

src/kernel/getcpu.rs

@@ -0,0 +1,10 @@
+use crate::kernel::cpu_id::CpuId;
+use crate::memory::uaccess::copy_to_user;
+use libkernel::memory::address::TUA;
+
+pub async fn sys_getcpu(cpu_ptr: TUA<u32>, _node_ptr: TUA<u32>) -> libkernel::error::Result<usize> {
+    let cpu_id = CpuId::this().value() as u32;
+    copy_to_user(cpu_ptr, cpu_id).await?;
+    // TODO: implement NUMA and write the node ID to node_ptr
+    Ok(0)
+}

src/kernel/mod.rs

@@ -1,4 +1,5 @@
 pub mod cpu_id;
+pub mod getcpu;
 pub mod hostname;
 pub mod kpipe;
 pub mod power;