POC fork()

Author: scopeInfinity

Makefile

@@ -61,8 +61,8 @@ SOURCE_SNAPSHOT="\"$$(git rev-parse --short HEAD)$$(git diff --quiet || echo '_u
 ## Integer is 4 bytes
 
 # Debugging controller
-DEBUG?=
-ifdef DEBUG
+NODEBUG?=
+ifndef NODEBUG
 CC_DEBUG=-g
 NASM_DEBUG=-g
 LD_DEBUG=
@@ -102,7 +102,7 @@ binaries: $(bt_stage1) $(bt_stage2) $(kernel_core) $(rm_static)
 SECTOR_COUNT_BT_STAGE1 = 1
 SECTOR_COUNT_SHARED_LIBRARY = 1
 SECTOR_COUNT_BT_STAGE2 = 12
-SECTOR_COUNT_KERNEL = 54
+SECTOR_COUNT_KERNEL = 55
 
 SECTOR_START_BT_STAGE1 = 0
 SECTOR_START_SHARED_LIBRARY = $(shell expr $(SECTOR_START_BT_STAGE1) + $(SECTOR_COUNT_BT_STAGE1) )

scripts/build_image.sh

@@ -25,10 +25,6 @@ function verify_subimage_and_push() {
         echo "The ${subimage} size isn't divisible by 512" >&2
         exit 2
     fi
-    if [ "$(( $fsize / 512 ))" -lt ${min_sectors:?} ]; then
-        echo "The ${subimage} uses less sectors than ${min_sectors:?}" >&2
-        exit 2
-    fi
     if [ "$(( $fsize / 512 ))" -gt ${max_sectors:?} ]; then
         echo "The ${subimage} uses more sectors than ${max_sectors:?}" >&2
         exit 2

src/kernel/interrupts/exceptions.c

@@ -39,9 +39,8 @@ extern void _interrupt_handler_0x1F_exception();
 
 void interrupt_handler_0x00_0x1F_exception(int id, int err_code, int ds, int ss, int ip, int cs, int eflag) {
     panic_screen_init();
-    unsigned int abs_address =
     print_log("Hardware exception %d (0x%x) triggered", id, id);
-    print_log("  Error Code: %x or %x", err_code);
+    print_log("  Error Code: %x", err_code);
     print_log("  CS    : %x (GDT entry)", cs);
     print_log("  DS    : %x (GDT entry)", ds);
     print_log("  SS    : %x (GDT entry)", ss);

src/kernel/interrupts/timer.asm

@@ -63,17 +63,16 @@ global create_infant_process_irq0_stack
         mov ss, edx
         mov esp, esi
 
-        pop gs
-        pop fs
-        pop es
-        pop ds
-        ; add esp, 16
-        ; mov eax, cs
-        ; add eax, 8
-        ; mov gs, eax
-        ; mov fs, eax
-        ; mov es, eax
-        ; mov ds, eax
+        ; pop gs
+        ; pop fs
+        ; pop es
+        ; pop ds
+        add esp, 16
+        mov eax, ss ; ss and ds should be same for MOST purpose. This will break something :(
+        mov gs, eax
+        mov fs, eax
+        mov es, eax
+        mov ds, eax
 
 
         mov [esp+36], ecx ; cs

src/kernel/process/allocation.c

@@ -218,7 +218,8 @@ int process_fork(unsigned int ppid) {
     nprocess->sp = process->sp;
     nprocess->ip = process->ip;
 
-    process->state = STATE_EXIT;
+    // HERE
+    // process->state = STATE_EXIT;
 
     size_t size = min(
         memmgr_app_size(ppid),
@@ -234,7 +235,7 @@ int process_fork(unsigned int ppid) {
         0,
         size
     );
-    print_log("copy success");
+    // print_log("copy success");
     // PANIC(0, "A");
     return npid;
 }

src/kernel/process/process.c

@@ -47,6 +47,7 @@ int syscall_1_process_wait(int pid, int blocked_on_pid) {
 int syscall_1_process_fork(int user_pid, int op) {
     switch (op) {
         case SYSCALL_PROCESS_SUB_FORK_MARK_READY:
+            // print_log("FORK REQUESTED:: %d", user_pid);
             return process_fork_mark_ready(user_pid);
         case SYSCALL_PROCESS_SUB_FORK_CHECK_READY:
             return process_fork_check_ready(user_pid);

src/kernel/process/scheduler.c

@@ -36,6 +36,7 @@ void process_scheduler_stash_state() {
         if(process->state == STATE_EXIT) {
             // process unallocate ready to be killed
             process->state = STATE_COLD;
+            // print_log("process_killed: %d", id);
         } else if(process->state == STATE_RUNNING) {
             // process move running process to ready
             process->state = STATE_READY;
@@ -49,7 +50,11 @@ int process_scheduler_get_next_pid(int lastpid) {
 }
 
 static void handle_fork(unsigned int ppid, struct Process *process) {
+    // if(process->flagirq0_fork_ready>0 && ppid!=2) {
+    //    print_log("[ignore] handle fork for %d", ppid);
+    // }
     if(process->flagirq0_fork_ready>0) {
+        // print_log("handle fork for %d", ppid);
         int npid = process_fork(ppid);
         if(npid<0) {
             process->flagirq0_fork_ready = -1; // request failed;
@@ -76,15 +81,16 @@ void process_scheduler(int *_e_ip, int *_e_cs, int *_e_sp, int *_e_ss) {
 
     struct Process *process = get_process(pid);
     process_scheduler_stash_state();
-    handle_fork(pid, process);
 
     if(process->state != STATE_COLD) {
         // if last process is still alive
         process->cs = e_cs;
         process->ip = e_ip;
         process->ss = e_ss;
         process->sp = e_sp;
+        handle_fork(pid, process);
     }
+
     // last process can be
     //  - RUNNING
     //  - BLOCK  # TODO: implement
@@ -96,7 +102,8 @@ void process_scheduler(int *_e_ip, int *_e_cs, int *_e_sp, int *_e_ss) {
     }
 
     if(pid != npid) {
-        print_log("[process_scheduler] pid: %d -> %d", pid, npid);
+        // print_log("[process_scheduler] pid: %d -> %d", pid, npid);
+        // print_log("[process_scheduler] pid: %d -> %d, at eip: %x", pid, npid, e_ip);
     }
 
     struct Process *nprocess = get_process(npid);

src/usr/lib/process.c

@@ -75,13 +75,15 @@ int fork() {
     }
     // fork requested.
     // let's process scheduler fork the job.
-    printf("calling yield\n");
+    // printf("calling yield\n");
     yield();
-    while(1);
-    printf("yield over\n");
+    // while(1);
+    // exit(0);
+    // while(1);
+    // printf("yield over\n");
     // fork request should be complete by now.
     int status = SYSCALL_A2(SYSCALL_PROCESS, SYSCALL_PROCESS_SUB_FORK, SYSCALL_PROCESS_SUB_FORK_CHECK_READY);
-    printf("fork_check_ready: %d\n", status);
+    // printf("fork_check_ready: %d\n", status);
     if(status < 0) {
         // request either failed
         // or still waiting: it's a bad state, but we are going to let that slide.

src/usr/local/src/ls.c

@@ -14,7 +14,6 @@ void process() {
 }
 
 int main(int argc,char *argv[]) {
-    __asm__("CLI");
 
     int p = fork();
     printf("fork() = %d\n", p);