From a599c7f95e8916600ce092da1a5486bd62edef0f Mon Sep 17 00:00:00 2001
From: Matheus <matheusuky@gmail.com>
Date: Fri, 12 Sep 2025 23:03:30 -0300
Subject: [PATCH] syscalls: getcpu

---
 kernel-src/arch/x86-64/syscall.asm     |  4 +++-
 kernel-src/arch/x86-64/syscalllog.c    |  8 +++++---
 kernel-src/sys/syscalls/getcpu.c       | 14 +++++++++++++
 patches/mlibc/jinx-working-patch.patch | 28 +++++++++++---------------
 4 files changed, 34 insertions(+), 20 deletions(-)
 create mode 100644 kernel-src/sys/syscalls/getcpu.c

diff --git a/kernel-src/arch/x86-64/syscall.asm b/kernel-src/arch/x86-64/syscall.asm
index 97a93354..ff7c651b 100644
--- a/kernel-src/arch/x86-64/syscall.asm
+++ b/kernel-src/arch/x86-64/syscall.asm
@@ -94,6 +94,7 @@ extern syscall_killthread
 extern syscall_shutdown
 extern syscall_nice
 extern syscall_flock
+extern syscall_getcpu
 syscalltab:
 dq syscall_print
 dq syscall_mmap
@@ -190,7 +191,8 @@ dq syscall_killthread
 dq syscall_shutdown
 dq syscall_nice
 dq syscall_flock
-syscallcount equ 95
+dq syscall_getcpu
+syscallcount equ 96
 section .text
 global arch_syscall_entry
 ; on entry:
diff --git a/kernel-src/arch/x86-64/syscalllog.c b/kernel-src/arch/x86-64/syscalllog.c
index 8855e3d1..453e95c5 100644
--- a/kernel-src/arch/x86-64/syscalllog.c
+++ b/kernel-src/arch/x86-64/syscalllog.c
@@ -5,7 +5,7 @@
 
 #ifdef SYSCALL_LOGGING
 
-#define SYSCALL_COUNT 95
+#define SYSCALL_COUNT 96
 #define LOGSTR(x) arch_e9_puts(x)
 
 static char *name[] = {
@@ -103,7 +103,8 @@ static char *name[] = {
 	"killthread",
 	"shutdown",
 	"nice",
-	"flock"
+	"flock",
+	"getcpu"
 };
 
 static char *args[] = {
@@ -201,7 +202,8 @@ static char *args[] = {
 	"pid %d tid %d signal %d", // killthread
 	"how %d", // shutdown
 	"off %d", // nice
-	"fd %d op %d" // flock
+	"fd %d op %d", // flock
+	"N/A" // getcpu
 };
 
 #endif
diff --git a/kernel-src/sys/syscalls/getcpu.c b/kernel-src/sys/syscalls/getcpu.c
new file mode 100644
index 00000000..272e85a7
--- /dev/null
+++ b/kernel-src/sys/syscalls/getcpu.c
@@ -0,0 +1,14 @@
+#include <kernel/syscalls.h>
+#include <arch/cpu.h>
+
+syscallret_t syscall_getcpu(context_t *) {
+	syscallret_t ret = {
+		.errno = 0
+	};
+
+
+	uint32_t cpu_id = current_cpu_internal_id();
+
+	ret.ret = cpu_id;
+	return ret;
+}
diff --git a/patches/mlibc/jinx-working-patch.patch b/patches/mlibc/jinx-working-patch.patch
index ec650797..bb51cd07 100644
--- a/patches/mlibc/jinx-working-patch.patch
+++ b/patches/mlibc/jinx-working-patch.patch
@@ -84,26 +84,21 @@ index d5ba7b2..a86353f 100644
  	long error = syscall(SYSCALL_ARCHCTL, &ret, func, (uint64_t)arg);
  	if(error)
 diff --git mlibc-clean/sysdeps/astral/generic/generic.cpp mlibc-workdir/sysdeps/astral/generic/generic.cpp
-index bb85dba..5e9e21a 100644
+index bb85dba..5f12e17 100644
 --- mlibc-clean/sysdeps/astral/generic/generic.cpp
 +++ mlibc-workdir/sysdeps/astral/generic/generic.cpp
-@@ -31,6 +31,12 @@ namespace mlibc {
+@@ -40,6 +40,31 @@ namespace mlibc {
  		return 0;
  	}
  
 +	int sys_getcpu(int *cpu) {
-+		*cpu = 0;
-+		// TODO unstub
++		long ret;
++		// can never fail
++		syscall(SYSCALL_GETCPU, &ret);
++		*cpu = ret;
 +		return 0;
 +	}
 +
- 	int sys_getsockopt(int fd, int layer, int number,
- 		void *__restrict buffer, socklen_t *__restrict size) {
- 		(void)size;
-@@ -40,6 +46,23 @@ namespace mlibc {
- 		return 0;
- 	}
- 
 +	int sys_flock(int fd, int options) {
 +		long r;
 +		return syscall(SYSCALL_FLOCK, &r, fd, options);
@@ -124,7 +119,7 @@ index bb85dba..5e9e21a 100644
  	int sys_tgkill(int pid, int tid, int sig) {
  		long ret;
  		return syscall(SYSCALL_KILLTHREAD, &ret, pid, tid, sig);
-@@ -161,7 +184,18 @@ namespace mlibc {
+@@ -161,7 +186,18 @@ namespace mlibc {
  		*bytes_written = writec;
  		return error;
  	}
@@ -144,7 +139,7 @@ index bb85dba..5e9e21a 100644
  	#ifndef MLIBC_BUILDING_RTLD
  
  	typedef struct {
-@@ -376,6 +410,12 @@ namespace mlibc {
+@@ -376,6 +412,12 @@ namespace mlibc {
  		return ret;
  	}
  
@@ -157,7 +152,7 @@ index bb85dba..5e9e21a 100644
  	#ifndef MLIBC_BUILDING_RTLD
  
  	[[noreturn]] void sys_thread_exit() {
-@@ -771,7 +811,7 @@ namespace mlibc {
+@@ -771,7 +813,7 @@ namespace mlibc {
  
  	int sys_tcb_set(void *pointer) {
  		long r;
@@ -184,16 +179,17 @@ index d738e02..7e4f2a1 100644
  #ifdef __cplusplus
  extern "C" {
 diff --git mlibc-clean/sysdeps/astral/include/astral/syscall.h mlibc-workdir/sysdeps/astral/include/astral/syscall.h
-index 5f42d62..6fbb253 100644
+index 5f42d62..8414286 100644
 --- mlibc-clean/sysdeps/astral/include/astral/syscall.h
 +++ mlibc-workdir/sysdeps/astral/include/astral/syscall.h
-@@ -96,6 +96,9 @@
+@@ -96,6 +96,10 @@
  #define SYSCALL_SIGTIMEDWAIT 89
  #define SYSCALL_SIGPENDING 90
  #define SYSCALL_KILLTHREAD 91
 +#define SYSCALL_SHUTDOWN 92
 +#define SYSCALL_NICE 93
 +#define SYSCALL_FLOCK 94
++#define SYSCALL_GETCPU 95
  
  #ifndef __MLIBC_ABI_ONLY