core/syscall.c

@@ -1,6 +1,8 @@
 #include "syscall.h"
+#include "kernel.h"
 #include "keyboard.h"
 #include "klibc.h"
+#include "paging.h"
 #include "process.h"
 #include "stdarg.h"
 #include "thread.h"
@@ -43,17 +45,17 @@ int syscallExecute(int syscallId, const struct cpu_state *userCtx)
             printf("Got 5args from userspace %d %d %d %d %d\n", arg1, arg2, arg3, arg4, arg5);
             break;
         }
-        case SYSCALL_ID_BRK:{
+        case SYSCALL_ID_BRK: {
 
             struct uAddrSpace *as;
             uaddr_t newHeapTop;
 
-            as = processGetAddrSpace(getCurrentThread()->process);
+            as  = processGetAddrSpace(getCurrentThread()->process);
             ret = syscallGet1arg(userCtx, (unsigned int *)&newHeapTop);
             if (ret != 0)
                 break;
             threadChangeCurrentContext(uAddrSpaceGetMMUContext(as));
-            //TODO : what if *newHeapTop raise page fault?
+            // TODO : what if *newHeapTop raise page fault?
             ret = sysBrk(as, newHeapTop);
             threadChangeCurrentContext(NULL);
             break;
@@ -110,6 +112,40 @@ int syscallExecute(int syscallId, const struct cpu_state *userCtx)
             ret = uAddrSpaceUnmap(as, uaddr, size);
             break;
         }
+        case SYSCALL_ID_NEW_THREAD: {
+            struct uAddrSpace *as;
+            uaddr_t funcAddr;
+            uint32_t arg1, arg2;
+            size_t stackSize;
+
+            ret = syscallGet4args(userCtx, (unsigned int *)&funcAddr, (unsigned int *)&arg1,
+                                  (unsigned int *)&arg2, (unsigned int *)&stackSize);
+            if (ret)
+                break;
+            if (stackSize <= 0) {
+                ret = -EINVAL;
+                break;
+            }
+
+            as        = processGetAddrSpace(getCurrentThread()->process);
+            stackSize = ALIGN(stackSize, PAGE_SIZE);
+
+            uaddr_t stackAddr = 0;
+            ret = zeroMmap(as, &stackAddr, stackSize, PAGING_MEM_READ | PAGING_MEM_WRITE, 0);
+
+            if (ret)
+                break;
+
+            struct thread *th = threadCreateUser(NULL, getCurrentThread()->process, funcAddr,
+                                                 arg1, arg2, stackAddr + stackSize);
+
+            if (th == NULL) {
+                ret = -ENOMEM;
+                uAddrSpaceUnmap(as, stackAddr, stackSize);
+            }
+
+            break;
+        }
         default:
             printf("Unknon syscall id %d\n", syscallId);
             ret = -ENOENT;

core/syscall.h

@@ -11,6 +11,7 @@
 #define SYSCALL_ID_BRK 6
 #define SYSCALL_ID_MMAP 7
 #define SYSCALL_ID_MUNMAP 8
+#define SYSCALL_ID_NEW_THREAD 9
 
 #ifdef __KERNEL__
 int syscallExecute(int syscallId, const struct cpu_state *user_ctx);

userspace/kernel/syscall.h

@@ -11,6 +11,7 @@
 #define SYSCALL_ID_BRK 6
 #define SYSCALL_ID_MMAP 7
 #define SYSCALL_ID_MUNMAP 8
+#define SYSCALL_ID_NEW_THREAD 9
 
 #ifdef __KERNEL__
 int syscallExecute(int syscallId, const struct cpu_state *user_ctx);

userspace/libc.c

@@ -745,3 +745,23 @@ int munmap(void *addr, size_t len)
 
     return syscall2(SYSCALL_ID_MUNMAP, (unsigned int)addr, len);
 }
+
+/* As when a new thread is run, the params are passed by register (See cpu_ustate_init), use
+ * this function to simplify new thread usage*/
+static void thread_runner()
+{
+    register unsigned long int reg_arg1 asm("%eax");
+    register unsigned long int reg_arg2 asm("%ebx");
+
+    start_routine *func = (start_routine *)reg_arg1;
+    void *arg           = (void *)reg_arg2;
+
+    func(arg);
+    _exit(0);
+}
+
+int new_thread(start_routine *func, void *arg, size_t stackSize)
+{
+    return syscall4(SYSCALL_ID_NEW_THREAD, (unsigned int)thread_runner, (unsigned int)func,
+                    (unsigned int)arg, stackSize);
+}

userspace/libc.h

@@ -63,3 +63,6 @@ void *malloc(size_t size);
 void *calloc(size_t nmemb, size_t size);
 void *realloc(void *ptr, size_t size);
 void free(void *ptr);
+
+typedef void *(start_routine)(void *);
+int new_thread(start_routine *func, void *arg, size_t stackSize);

userspace/main_user.c

@@ -15,6 +15,7 @@ int func_help()
         printf("        tiny: a tiny C-like interpreter\n");
         printf("        mmap: test mmap \n");
         printf("        munmap: test munmap \n");
+        printf("        thread: run a user thread\n");
         return 0;
 }
 
@@ -118,8 +119,20 @@ int func_munmap()
         return ret;
 }
 
-int main(int argc, char *argv[])
-{
+static void *print_hello(void *arg) {
+        (void)arg;
+        printf("Hello World from thread\n");
+
+        return NULL;
+}
+
+int func_thread() {
+        new_thread(print_hello, NULL, 4096);
+
+        return 0;
+}
+
+int main(int argc, char *argv[]) {
         (void)argc;
         (void)argv;
         char buf[64];
@@ -156,6 +169,10 @@ int main(int argc, char *argv[])
                         func_munmap();
                         continue;
                 }
+                if (strcmp(buf, "thread") == 0) {
+                        func_thread();
+                        continue;
+                }
         }
         return 0;
 }