From a7cbb0d041ab52293748ea632575f31451ad101b Mon Sep 17 00:00:00 2001
From: TXuian <1163589503@qq.com>
Date: Fri, 26 Apr 2024 17:39:23 +0800
Subject: [PATCH] delete task only when it's not in running.

---
 .../arch/arm/armv7-a/cortex-a9/core.h         |  2 +-
 .../intr/arm/armv7-a/cortex-a9/error_debug.c  | 68 +++++++++--------
 .../cortex-a9/imx6q-sabrelite/trap_common.c   | 27 +------
 .../cortex-a9/zynq7000-zc702/trap_common.c    | 19 -----
 .../XiZi_AIoT/hardkernel/intr/trap_common.h   |  3 +-
 .../XiZi_AIoT/services/app/test_irq_handler.c |  5 +-
 .../XiZi_AIoT/softkernel/include/multicores.h |  3 +-
 .../XiZi_AIoT/softkernel/include/syscall.h    |  2 +
 .../XiZi_AIoT/softkernel/include/task.h       |  2 +
 .../XiZi_AIoT/softkernel/syscall/sys_exec.c   |  5 +-
 .../XiZi_AIoT/softkernel/syscall/sys_exit.c   | 50 +------------
 .../softkernel/syscall/sys_register_irq.c     | 51 ++++++++++---
 .../XiZi_AIoT/softkernel/task/scheduler.c     | 13 +---
 Ubiquitous/XiZi_AIoT/softkernel/task/task.c   | 74 ++++++++++++++++---
 .../softkernel/trap/default_irq_handler.c     | 11 ++-
 15 files changed, 175 insertions(+), 160 deletions(-)

diff --git a/Ubiquitous/XiZi_AIoT/hardkernel/arch/arm/armv7-a/cortex-a9/core.h b/Ubiquitous/XiZi_AIoT/hardkernel/arch/arm/armv7-a/cortex-a9/core.h
index f8af8ccc9..11043cb7c 100644
--- a/Ubiquitous/XiZi_AIoT/hardkernel/arch/arm/armv7-a/cortex-a9/core.h
+++ b/Ubiquitous/XiZi_AIoT/hardkernel/arch/arm/armv7-a/cortex-a9/core.h
@@ -74,7 +74,7 @@ Modification:
 
 #include "cortex_a9.h"
 
-#define NR_CPU 3
+#define NR_CPU 4
 
 __attribute__((always_inline)) static inline uint32_t user_mode()
 {
diff --git a/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/error_debug.c b/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/error_debug.c
index 1fde315c3..be66c65a2 100644
--- a/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/error_debug.c
+++ b/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/error_debug.c
@@ -110,50 +110,56 @@ void handle_fiq(void)
 extern void context_switch(struct context**, struct context*);
 void dabort_handler(struct trapframe* r)
 {
-    xizi_enter_kernel();
-
-    uint32_t dfs, dfa;
-    __asm__ __volatile__("mrc p15, 0, %0, c5, c0, 0" : "=r"(dfs)::);
-    __asm__ __volatile__("mrc p15, 0, %0, c6, c0, 0" : "=r"(dfa)::);
-
-    if (r->pc < KERN_MEM_BASE) { // Exception occured in User space: exit
-        ERROR("dabort in user space: %s\n", cur_cpu()->task->name);
-        LOG("program counter: 0x%x caused\n", r->pc);
-        LOG("data abort at 0x%x, status 0x%x\n", dfa, dfs);
-        _abort_reason(dfs);
-        dump_tf(r);
-        sys_exit(cur_cpu()->task);
-        context_switch(&cur_cpu()->task->main_thread.context, cur_cpu()->scheduler);
-    } else { // Exception occured in Kernel space: panic
+    if (xizi_is_in_kernel()) {
+        uint32_t dfs, dfa;
+        __asm__ __volatile__("mrc p15, 0, %0, c5, c0, 0" : "=r"(dfs)::);
+        __asm__ __volatile__("mrc p15, 0, %0, c6, c0, 0" : "=r"(dfa)::);
         LOG("program counter: 0x%x caused\n", r->pc);
         LOG("data abort at 0x%x, status 0x%x\n", dfa, dfs);
         _abort_reason(dfs);
         dump_tf(r);
         panic("data abort exception\n");
     }
+
+    xizi_enter_kernel();
+
+    uint32_t dfs, dfa;
+    __asm__ __volatile__("mrc p15, 0, %0, c5, c0, 0" : "=r"(dfs)::);
+    __asm__ __volatile__("mrc p15, 0, %0, c6, c0, 0" : "=r"(dfa)::);
+
+    ERROR("dabort in user space: %s\n", cur_cpu()->task->name);
+    LOG("program counter: 0x%x caused\n", r->pc);
+    LOG("data abort at 0x%x, status 0x%x\n", dfa, dfs);
+    _abort_reason(dfs);
+    dump_tf(r);
+    sys_exit(cur_cpu()->task);
+    context_switch(&cur_cpu()->task->main_thread.context, cur_cpu()->scheduler);
 }
 
 void iabort_handler(struct trapframe* r)
 {
-    xizi_enter_kernel();
-    uint32_t ifs, ifa;
-
-    __asm__ __volatile__("mrc p15, 0, %0, c5, c0, 1" : "=r"(ifs)::);
-    __asm__ __volatile__("mrc p15, 0, %0, c6, c0, 2" : "=r"(ifa)::);
-
-    if (r->pc < KERN_MEM_BASE) { // Exception occured in User space: exit
-        ERROR("iabort in user space: %s\n", cur_cpu()->task->name);
-        LOG("program counter: 0x%x(%s) caused\n", r->pc, cur_cpu()->task);
-        LOG("prefetch abort at 0x%x, status 0x%x\n", ifa, ifs);
-        _abort_reason(ifs);
-        dump_tf(r);
-        sys_exit(cur_cpu()->task);
-        context_switch(&cur_cpu()->task->main_thread.context, cur_cpu()->scheduler);
-    } else { // Exception occured in Kernel space: panic
-        LOG("program counter: 0x%x(%s) caused\n", r->pc, cur_cpu()->task);
+    if (xizi_is_in_kernel()) {
+        uint32_t ifs, ifa;
+        __asm__ __volatile__("mrc p15, 0, %0, c5, c0, 1" : "=r"(ifs)::);
+        __asm__ __volatile__("mrc p15, 0, %0, c6, c0, 2" : "=r"(ifa)::);
+        LOG("program counter: 0x%x caused\n", r->pc);
         LOG("prefetch abort at 0x%x, status 0x%x\n", ifa, ifs);
         _abort_reason(ifs);
         dump_tf(r);
         panic("prefetch abort exception\n");
     }
+
+    xizi_enter_kernel();
+
+    uint32_t ifs, ifa;
+    __asm__ __volatile__("mrc p15, 0, %0, c5, c0, 1" : "=r"(ifs)::);
+    __asm__ __volatile__("mrc p15, 0, %0, c6, c0, 2" : "=r"(ifa)::);
+
+    ERROR("iabort in user space: %s\n", cur_cpu()->task->name);
+    LOG("program counter: 0x%x(%s) caused\n", r->pc, cur_cpu()->task);
+    LOG("prefetch abort at 0x%x, status 0x%x\n", ifa, ifs);
+    _abort_reason(ifs);
+    dump_tf(r);
+    sys_exit(cur_cpu()->task);
+    context_switch(&cur_cpu()->task->main_thread.context, cur_cpu()->scheduler);
 }
diff --git a/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/imx6q-sabrelite/trap_common.c b/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/imx6q-sabrelite/trap_common.c
index b75cab884..b564f8cb7 100644
--- a/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/imx6q-sabrelite/trap_common.c
+++ b/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/imx6q-sabrelite/trap_common.c
@@ -85,9 +85,10 @@ static void _sys_irq_init(int cpu_id)
         vector_base[5] = (uint32_t)handle_reserved; // Reserved
         vector_base[6] = (uint32_t)trap_irq_enter; // IRQ
         vector_base[7] = (uint32_t)handle_fiq; // FIQ
+
+        gic_init();
     }
     /* active hardware irq responser */
-    gic_init();
     xizi_trap_driver.switch_hw_irqtbl((uint32_t*)&_vector_jumper);
 }
 
@@ -139,29 +140,6 @@ static void _bind_irq_handler(int irq, irq_handler_t handler)
     xizi_trap_driver.sw_irqtbl[irq].handler = handler;
 }
 
-static bool _send_sgi(uint32_t irq, uint32_t bitmask, enum SgiFilterType type)
-{
-    if (bitmask > (1 << NR_CPU) - 1) {
-        return false;
-    }
-
-    enum _gicd_sgi_filter sgi_filter;
-    switch (type) {
-    case SgiFilter_TargetList:
-        sgi_filter = kGicSgiFilter_UseTargetList;
-        break;
-    case SgiFilter_AllOtherCPUs:
-        sgi_filter = kGicSgiFilter_AllOtherCPUs;
-        break;
-    default:
-        sgi_filter = kGicSgiFilter_OnlyThisCPU;
-        break;
-    }
-    gic_send_sgi(irq, bitmask, sgi_filter);
-
-    return true;
-}
-
 static uint32_t _hw_before_irq()
 {
 
@@ -217,7 +195,6 @@ static struct XiziTrapDriver xizi_trap_driver = {
     .switch_hw_irqtbl = _switch_hw_irqtbl,
 
     .bind_irq_handler = _bind_irq_handler,
-    .send_sgi = _send_sgi,
 
     .is_interruptable = _is_interruptable,
     .hw_before_irq = _hw_before_irq,
diff --git a/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/zynq7000-zc702/trap_common.c b/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/zynq7000-zc702/trap_common.c
index eed662bd2..bf91b4a63 100644
--- a/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/zynq7000-zc702/trap_common.c
+++ b/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/zynq7000-zc702/trap_common.c
@@ -164,24 +164,6 @@ static void _bind_irq_handler(int irq, irq_handler_t handler)
     xizi_trap_driver.sw_irqtbl[irq].handler = handler;
 }
 
-static bool _send_sgi(uint32_t irq, uint32_t bitmask, enum SgiFilterType type)
-{
-    if (bitmask > (1 << NR_CPU) - 1) {
-        return false;
-    }
-
-    int cpu_id = 0;
-    while (bitmask != 0) {
-        if ((bitmask & 0x1) != 0) {
-            XScuGic_SoftwareIntr(&IntcInstance, irq, cpu_id);
-        }
-        cpu_id++;
-        bitmask >>= 1;
-    }
-
-    return true;
-}
-
 static uint32_t _hw_before_irq()
 {
 
@@ -233,7 +215,6 @@ static struct XiziTrapDriver xizi_trap_driver = {
     .switch_hw_irqtbl = _switch_hw_irqtbl,
 
     .bind_irq_handler = _bind_irq_handler,
-    .send_sgi = _send_sgi,
 
     .is_interruptable = _is_interruptable,
     .hw_before_irq = _hw_before_irq,
diff --git a/Ubiquitous/XiZi_AIoT/hardkernel/intr/trap_common.h b/Ubiquitous/XiZi_AIoT/hardkernel/intr/trap_common.h
index 06a64ca7d..391910045 100644
--- a/Ubiquitous/XiZi_AIoT/hardkernel/intr/trap_common.h
+++ b/Ubiquitous/XiZi_AIoT/hardkernel/intr/trap_common.h
@@ -66,9 +66,8 @@ struct XiziTrapDriver {
     void (*cpu_irq_disable)();
     void (*single_irq_enable)(int irq, int cpu, int prio);
     void (*single_irq_disable)(int irq, int cpu);
-    uint32_t* (*switch_hw_irqtbl)(uint32_t*);
 
-    bool (*send_sgi)(uint32_t, uint32_t, enum SgiFilterType);
+    uint32_t* (*switch_hw_irqtbl)(uint32_t*);
     void (*bind_irq_handler)(int, irq_handler_t);
 
     /* check if no if interruptable */
diff --git a/Ubiquitous/XiZi_AIoT/services/app/test_irq_handler.c b/Ubiquitous/XiZi_AIoT/services/app/test_irq_handler.c
index 8aed9eb14..28e8fdd04 100644
--- a/Ubiquitous/XiZi_AIoT/services/app/test_irq_handler.c
+++ b/Ubiquitous/XiZi_AIoT/services/app/test_irq_handler.c
@@ -35,7 +35,10 @@ IPC_SERVER_INTERFACE(Ipc_intr_3, 1);
 IPC_SERVER_REGISTER_INTERFACES(IpcSwIntrHandler, 1, Ipc_intr_3);
 int main()
 {
-    register_irq(SW_INTERRUPT_3, Ipc_intr_3);
+    if (register_irq(SW_INTERRUPT_3, Ipc_intr_3) == -1) {
+        printf("TEST_SW_HDLR: bind failed");
+        exit();
+    }
     ipc_server_loop(&IpcSwIntrHandler);
 
     exit();
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/include/multicores.h b/Ubiquitous/XiZi_AIoT/softkernel/include/multicores.h
index ed5c90f43..539a3dac9 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/include/multicores.h
+++ b/Ubiquitous/XiZi_AIoT/softkernel/include/multicores.h
@@ -50,4 +50,5 @@ static inline struct CPU* cur_cpu(void)
 struct spinlock whole_kernel_lock;
 
 void xizi_enter_kernel();
-void xizi_leave_kernel();
\ No newline at end of file
+void xizi_leave_kernel();
+bool xizi_is_in_kernel();
\ No newline at end of file
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/include/syscall.h b/Ubiquitous/XiZi_AIoT/softkernel/include/syscall.h
index aa78cbf39..7a3747a8c 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/include/syscall.h
+++ b/Ubiquitous/XiZi_AIoT/softkernel/include/syscall.h
@@ -93,4 +93,6 @@ int sys_state(sys_state_option option, sys_state_info* info);
 int sys_mmap(uintptr_t vaddr, uintptr_t paddr, int len, int is_dev);
 
 int sys_register_irq(int irq_num, int irq_opcode);
+int sys_unbind_irq_all(struct TaskMicroDescriptor* task);
+int sys_unbind_irq(struct TaskMicroDescriptor* task, int irq_num);
 #endif
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/include/task.h b/Ubiquitous/XiZi_AIoT/softkernel/include/task.h
index 726e4f518..a69701ee6 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/include/task.h
+++ b/Ubiquitous/XiZi_AIoT/softkernel/include/task.h
@@ -64,6 +64,8 @@ struct Thread {
 struct TaskMicroDescriptor {
     /* task debug resources */
     int pid;
+    bool bind_irq;
+    bool dead;
     char name[TASK_NAME_MAX_LEN];
 
     /// @todo support return value
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_exec.c b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_exec.c
index ef3011ac9..b087fdb98 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_exec.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_exec.c
@@ -175,9 +175,10 @@ int task_exec(struct TaskMicroDescriptor* task, char* img_start, char* name, cha
     }
     strncpy(task->name, last, sizeof(task->name));
 
-    xizi_pager.free_user_pgdir(&task->pgdir);
+    if (task->pgdir.pd_addr != NULL) {
+        xizi_pager.free_user_pgdir(&task->pgdir);
+    }
     task->pgdir = pgdir;
-
     task->heap_base = ALIGNUP(load_size, PAGE_SIZE);
     task->mem_size = task->heap_base + USER_STACK_SIZE;
     return 0;
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_exit.c b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_exit.c
index 25ebadc11..ca5384910 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_exit.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_exit.c
@@ -39,51 +39,7 @@ Modification:
 int sys_exit(struct TaskMicroDescriptor* ptask)
 {
     assert(ptask != NULL);
-
-    /* handle sessions for condition 1, ref. delete_share_pages() */
-    // close all server_sessions
-    struct server_session* server_session = NULL;
-    while (!IS_DOUBLE_LIST_EMPTY(&ptask->svr_sess_listhead)) {
-        server_session = CONTAINER_OF(ptask->svr_sess_listhead.next, struct server_session, node);
-        // cut the connection from task to session
-        if (!server_session->closed) {
-            xizi_share_page_manager.unmap_task_share_pages(ptask, server_session->buf_addr, CLIENT_SESSION_BACKEND(server_session)->nr_pages);
-            server_session->closed = true;
-        }
-        doubleListDel(&server_session->node);
-        SERVER_SESSION_BACKEND(server_session)->server = NULL;
-        // delete session (also cut connection from session to task)
-        if (SERVER_SESSION_BACKEND(server_session)->client_side.closed) {
-            xizi_share_page_manager.delete_share_pages(SERVER_SESSION_BACKEND(server_session));
-        }
-    }
-    // close all client_sessions
-    struct client_session* client_session = NULL;
-    while (!IS_DOUBLE_LIST_EMPTY(&ptask->cli_sess_listhead)) {
-        client_session = CONTAINER_OF(ptask->cli_sess_listhead.next, struct client_session, node);
-        // cut the connection from task to session
-        if (!client_session->closed) {
-            xizi_share_page_manager.unmap_task_share_pages(ptask, client_session->buf_addr, CLIENT_SESSION_BACKEND(client_session)->nr_pages);
-            client_session->closed = true;
-        }
-        doubleListDel(&client_session->node);
-        CLIENT_SESSION_BACKEND(client_session)->client = NULL;
-        // delete session (also cut connection from session to task)
-        if (CLIENT_SESSION_BACKEND(client_session)->server_side.closed) {
-            xizi_share_page_manager.delete_share_pages(CLIENT_SESSION_BACKEND(client_session));
-        }
-    }
-
-    if (ptask->server_identifier.meta != NULL) {
-        struct TraceTag server_identifier_owner;
-        AchieveResourceTag(&server_identifier_owner, RequireRootTag(), "softkernel/server-identifier");
-        assert(server_identifier_owner.meta != NULL);
-        DeleteResource(&ptask->server_identifier, &server_identifier_owner);
-    }
-
-    // delete task for pcb_list
-    xizi_task_manager.task_yield_noschedule(ptask, true);
-    ptask->state = DEAD;
-
+    ptask->dead = true;
+    xizi_task_manager.task_yield_noschedule(cur_cpu()->task, false);
     return 0;
-}
\ No newline at end of file
+}
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_register_irq.c b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_register_irq.c
index 5b0722070..b45c2f4cc 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_register_irq.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_register_irq.c
@@ -79,26 +79,33 @@ int user_irq_handler(int irq, void* tf, void* arg)
         AchieveResourceTag(&mmu_driver_tag, RequireRootTag(), "/hardkernel/mmu-ac-resource");
         p_mmu_driver = (struct MmuCommonDone*)AchieveResource(&mmu_driver_tag);
     }
-    p_mmu_driver->LoadPgdir((uintptr_t)V2P(kernel_irq_proxy->pgdir.pd_addr));
-    send_irq_to_user(irq);
-    p_mmu_driver->LoadPgdir((uintptr_t)V2P(cur_cpu()->task->pgdir.pd_addr));
 
-    next_task_emergency = irq_forward_table[irq].handle_task;
-    xizi_task_manager.task_yield_noschedule(cur_cpu()->task, false);
+    if (irq_forward_table[irq].handle_task != NULL) {
+        p_mmu_driver->LoadPgdir((uintptr_t)V2P(kernel_irq_proxy->pgdir.pd_addr));
+        send_irq_to_user(irq);
+        p_mmu_driver->LoadPgdir((uintptr_t)V2P(cur_cpu()->task->pgdir.pd_addr));
+
+        next_task_emergency = irq_forward_table[irq].handle_task;
+        xizi_task_manager.task_yield_noschedule(cur_cpu()->task, false);
+    }
     return 0;
 }
 
 extern int create_session_inner(struct TaskMicroDescriptor* client, struct TaskMicroDescriptor* server, int capacity, struct Session* user_session);
 /// @warning no tested.
+
+static struct XiziTrapDriver* p_intr_driver = NULL;
 int sys_register_irq(int irq_num, int irq_opcode)
 {
     // init intr resource;
-    static struct TraceTag intr_ac_tag;
-    if (!AchieveResourceTag(&intr_ac_tag, RequireRootTag(), "hardkernel/intr-ac-resource")) {
-        ERROR("intr not initialized.\n");
-        return -1;
+    if (p_intr_driver == NULL) {
+        struct TraceTag intr_ac_tag;
+        if (!AchieveResourceTag(&intr_ac_tag, RequireRootTag(), "hardkernel/intr-ac-resource")) {
+            ERROR("intr not initialized.\n");
+            return -1;
+        }
+        p_intr_driver = (struct XiziTrapDriver*)AchieveResource(&intr_ac_tag);
     }
-    struct XiziTrapDriver* p_intr_driver = AchieveResource(&intr_ac_tag);
 
     // init kerenl sender proxy
     if (kernel_irq_proxy == NULL) {
@@ -118,6 +125,30 @@ int sys_register_irq(int irq_num, int irq_opcode)
     irq_forward_table[irq_num].opcode = irq_opcode;
     create_session_inner(kernel_irq_proxy, cur_task, PAGE_SIZE, &irq_forward_table[irq_num].session);
     p_intr_driver->bind_irq_handler(irq_num, user_irq_handler);
+    cur_task->bind_irq = true;
 
+    return 0;
+}
+
+int sys_unbind_irq(struct TaskMicroDescriptor* task, int irq_num)
+{
+    if (irq_forward_table[irq_num].handle_task != task) {
+        return -1;
+    }
+
+    irq_forward_table[irq_num].handle_task = NULL;
+    sys_close_session(&irq_forward_table[irq_num].session);
+    DEBUG("Unbind: %s to irq %d", task->name, irq_num);
+    return 0;
+}
+
+int sys_unbind_irq_all(struct TaskMicroDescriptor* task)
+{
+    for (int idx = 0; idx < NR_IRQS; idx++) {
+        if (irq_forward_table[idx].handle_task == task) {
+            sys_unbind_irq(task, idx);
+        }
+    }
+    task->bind_irq = false;
     return 0;
 }
\ No newline at end of file
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/task/scheduler.c b/Ubiquitous/XiZi_AIoT/softkernel/task/scheduler.c
index f693ab871..a19d6a50d 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/task/scheduler.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/task/scheduler.c
@@ -38,12 +38,10 @@ struct TaskMicroDescriptor* max_priority_runnable_task(void)
 
     DOUBLE_LIST_FOR_EACH_ENTRY(task, &xizi_task_manager.task_list_head[priority], node)
     {
-        if (task->state == READY) {
+        if (task->state == READY && !task->dead) {
             // found a runnable task, stop this look up
             return task;
-        } else if (task->state == DEAD) {
-            // found a killed task, stop this loop
-            // change in pcb_list may break this loop, so find a runnable in next look up
+        } else if (task->dead && task->state != RUNNING) {
             xizi_task_manager.free_pcb(task);
             return NULL;
         }
@@ -57,13 +55,10 @@ struct TaskMicroDescriptor* round_robin_runnable_task(uint32_t priority)
 
     DOUBLE_LIST_FOR_EACH_ENTRY(task, &xizi_task_manager.task_list_head[priority], node)
     {
-
-        if (task->state == READY) {
+        if (task->state == READY && !task->dead) {
             // found a runnable task, stop this look up
             return task;
-        } else if (task->state == DEAD) {
-            // found a killed task, stop this loop
-            // change in pcb_list may break this loop, so find a runnable in next look up
+        } else if (task->dead && task->state != RUNNING) {
             xizi_task_manager.free_pcb(task);
             return NULL;
         }
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/task/task.c b/Ubiquitous/XiZi_AIoT/softkernel/task/task.c
index 8e8898c3b..a7c76d4da 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/task/task.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/task/task.c
@@ -32,10 +32,11 @@ Modification:
 #include "core.h"
 
 #include "assert.h"
+#include "kalloc.h"
 #include "log.h"
 #include "multicores.h"
-#include "kalloc.h"
 #include "scheduler.h"
+#include "syscall.h"
 #include "task.h"
 
 struct CPU global_cpus[NR_CPU];
@@ -74,6 +75,59 @@ static struct TaskMicroDescriptor* _alloc_task_cb()
     return task;
 }
 
+int _task_retrieve_sys_resources(struct TaskMicroDescriptor* ptask)
+{
+    assert(ptask != NULL);
+
+    /* handle sessions for condition 1, ref. delete_share_pages() */
+    // close all server_sessions
+    struct server_session* server_session = NULL;
+    while (!IS_DOUBLE_LIST_EMPTY(&ptask->svr_sess_listhead)) {
+        server_session = CONTAINER_OF(ptask->svr_sess_listhead.next, struct server_session, node);
+        // cut the connection from task to session
+        if (!server_session->closed) {
+            xizi_share_page_manager.unmap_task_share_pages(ptask, server_session->buf_addr, CLIENT_SESSION_BACKEND(server_session)->nr_pages);
+            server_session->closed = true;
+        }
+        doubleListDel(&server_session->node);
+        SERVER_SESSION_BACKEND(server_session)->server = NULL;
+        // delete session (also cut connection from session to task)
+        if (SERVER_SESSION_BACKEND(server_session)->client_side.closed) {
+            xizi_share_page_manager.delete_share_pages(SERVER_SESSION_BACKEND(server_session));
+        }
+    }
+    // close all client_sessions
+    struct client_session* client_session = NULL;
+    while (!IS_DOUBLE_LIST_EMPTY(&ptask->cli_sess_listhead)) {
+        client_session = CONTAINER_OF(ptask->cli_sess_listhead.next, struct client_session, node);
+        // cut the connection from task to session
+        if (!client_session->closed) {
+            xizi_share_page_manager.unmap_task_share_pages(ptask, client_session->buf_addr, CLIENT_SESSION_BACKEND(client_session)->nr_pages);
+            client_session->closed = true;
+        }
+        doubleListDel(&client_session->node);
+        CLIENT_SESSION_BACKEND(client_session)->client = NULL;
+        // delete session (also cut connection from session to task)
+        if (CLIENT_SESSION_BACKEND(client_session)->server_side.closed) {
+            xizi_share_page_manager.delete_share_pages(CLIENT_SESSION_BACKEND(client_session));
+        }
+    }
+
+    if (ptask->server_identifier.meta != NULL) {
+        struct TraceTag server_identifier_owner;
+        AchieveResourceTag(&server_identifier_owner, RequireRootTag(), "softkernel/server-identifier");
+        assert(server_identifier_owner.meta != NULL);
+        DeleteResource(&ptask->server_identifier, &server_identifier_owner);
+    }
+
+    // delete registered irq if there is one
+    if (ptask->bind_irq) {
+        sys_unbind_irq_all(ptask);
+    }
+
+    return 0;
+}
+
 /// @brief this function changes task list without locking, so it must be called inside a lock critical area
 /// @param task
 static void _dealloc_task_cb(struct TaskMicroDescriptor* task)
@@ -83,6 +137,8 @@ static void _dealloc_task_cb(struct TaskMicroDescriptor* task)
         return;
     }
 
+    _task_retrieve_sys_resources(task);
+
     // stack is mapped in vspace, so it should be free by pgdir
     if (task->pgdir.pd_addr) {
         xizi_pager.free_user_pgdir(&task->pgdir);
@@ -112,7 +168,7 @@ static void _dealloc_task_cb(struct TaskMicroDescriptor* task)
 extern void trap_return(void);
 void task_prepare_enter()
 {
-    spinlock_unlock(&whole_kernel_lock);
+    xizi_leave_kernel();
     trap_return();
 }
 
@@ -124,10 +180,7 @@ static struct TaskMicroDescriptor* _new_task_cb()
         return NULL;
     }
     // init vm
-    if (!xizi_pager.new_pgdir(&task->pgdir)) {
-        _dealloc_task_cb(task);
-        return NULL;
-    }
+    task->pgdir.pd_addr = NULL;
     /* init basic task member */
     doubleListNodeInit(&task->cli_sess_listhead);
     doubleListNodeInit(&task->svr_sess_listhead);
@@ -180,14 +233,12 @@ static void _scheduler(struct SchedulerRightGroup right_group)
         assert(cur_cpu()->task == NULL);
         if (next_task_emergency != NULL && next_task->state == READY) {
             next_task = next_task_emergency;
-            next_task->state = RUNNING;
         } else {
             next_task = xizi_task_manager.next_runnable_task();
         }
         next_task_emergency = NULL;
         if (next_task != NULL) {
             assert(next_task->state == READY);
-            next_task->state = RUNNING;
         }
         spinlock_unlock(&whole_kernel_lock);
 
@@ -199,11 +250,16 @@ static void _scheduler(struct SchedulerRightGroup right_group)
 
         /* a runnable task */
         spinlock_lock(&whole_kernel_lock);
-        assert(next_task->state == RUNNING);
+        if (next_task->state == READY) {
+            next_task->state = RUNNING;
+        } else {
+            continue;
+        }
         struct CPU* cpu = cur_cpu();
         cpu->task = next_task;
         p_mmu_driver->LoadPgdir((uintptr_t)V2P(next_task->pgdir.pd_addr));
         context_switch(&cpu->scheduler, next_task->main_thread.context);
+        assert(next_task->state != RUNNING);
     }
 }
 
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/trap/default_irq_handler.c b/Ubiquitous/XiZi_AIoT/softkernel/trap/default_irq_handler.c
index 4c7e79904..50395ac65 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/trap/default_irq_handler.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/trap/default_irq_handler.c
@@ -62,8 +62,7 @@ void intr_irq_dispatch(struct trapframe* tf)
     assert(p_intr_driver != NULL);
     uintptr_t int_info = 0;
     if ((int_info = p_intr_driver->hw_before_irq()) == 0) {
-        xizi_leave_kernel();
-        return;
+        goto intr_leave_interrupt;
     }
 
     struct TaskMicroDescriptor* current_task = cur_cpu()->task;
@@ -77,7 +76,7 @@ void intr_irq_dispatch(struct trapframe* tf)
 
     // distribute irq
     irq_handler_t isr = p_intr_driver->sw_irqtbl[irq].handler;
-    if (isr) {
+    if (isr != NULL) {
         isr(irq, tf, NULL);
     } else {
         default_interrupt_routine();
@@ -93,6 +92,7 @@ void intr_irq_dispatch(struct trapframe* tf)
     }
     assert(current_task == cur_cpu()->task);
 
+intr_leave_interrupt:
     xizi_leave_kernel();
 }
 
@@ -106,4 +106,9 @@ void xizi_leave_kernel()
 {
     spinlock_unlock(&whole_kernel_lock);
     p_intr_driver->cpu_irq_enable();
+}
+
+bool xizi_is_in_kernel()
+{
+    return is_spinlock_locked(&whole_kernel_lock);
 }
\ No newline at end of file