upd: crash redirect to ptys

Author: Rishies2010

src/cpu/isr.c

@@ -158,8 +158,85 @@ static void kernel_exception_screen(registers_t *regs)
     halt_forever();
 }
 
+static void pty_fault_write(pty_buf_t *pty, const char *msg)
+{
+    if (!pty || !msg)
+        return;
+
+    uint64_t rflags = spinlock_acquire_irqsave(&pty->lock);
+    if (!pty->master_open) {
+        spinlock_release_irqrestore(&pty->lock, rflags);
+        return;
+    }
+
+    for (size_t i = 0; msg[i]; i++) {
+        if (pty->s2m_count >= PTY_BUF_SIZE)
+            break;
+        if (msg[i] == '\n') {
+            pty->s2m_data[pty->s2m_write] = '\r';
+            pty->s2m_write = (pty->s2m_write + 1) % PTY_BUF_SIZE;
+            pty->s2m_count++;
+            if (pty->s2m_count >= PTY_BUF_SIZE)
+                break;
+        }
+        pty->s2m_data[pty->s2m_write] = (uint8_t)msg[i];
+        pty->s2m_write = (pty->s2m_write + 1) % PTY_BUF_SIZE;
+        pty->s2m_count++;
+    }
+
+    spinlock_release_irqrestore(&pty->lock, rflags);
+}
+
+static void userspace_exception_report(registers_t *regs)
+{
+    task_t *task = sched_current_task();
+    if (!task) {
+        sched_yield();
+        return;
+    }
+
+    task->userspace_faults++;
+    task->last_userspace_fault = regs->int_no;
+
+    fd_entry_t *err = NULL;
+    if (task->fd_table && task->fd_table->entries[2].used)
+        err = &task->fd_table->entries[2];
+
+    if (err && err->type == FD_PTY_SLAVE && err->pty) {
+        uint64_t cr2 = 0;
+        if (regs->int_no == PAGE_FAULT)
+            asm volatile("mov %%cr2, %0" : "=r"(cr2));
+
+        char msg[768];
+        if (regs->int_no == PAGE_FAULT) {
+            snprintf(msg, sizeof(msg),
+                "\n%s: %s in %s (pid %d)\n"
+                "  fault=0x%016lx rip=0x%016lx rsp=0x%016lx error=0x%016lx\n",
+                "ZenOS", exception_title(regs->int_no), task->name, task->pid,
+                cr2, regs->rip, regs->userrsp, regs->err_code);
+        } else {
+            snprintf(msg, sizeof(msg),
+                "\n%s: %s in %s (pid %d)\n"
+                "  rip=0x%016lx rsp=0x%016lx error=0x%016lx\n",
+                "ZenOS", exception_title(regs->int_no), task->name, task->pid,
+                regs->rip, regs->userrsp, regs->err_code);
+        }
+        log(msg, 3, 0);
+        pty_fault_write(err->pty, msg);
+    }
+
+    task->exit_code = 128 + (int)regs->int_no;
+    task->state = TASK_DEAD;
+    sched_yield();
+}
+
 void isr_handler(registers_t* regs)
 {
+    if (regs->int_no < 32 && (regs->cs & 3)) {
+        userspace_exception_report(regs);
+        return;
+    }
+
     if (regs->int_no < 32 && !(regs->cs & 3))
         kernel_exception_screen(regs);
 

src/kernel/sched.c

@@ -440,6 +440,8 @@ task_t *task_create_user_from_parent(void (*entry)(void), const char *name, page
     task->wait_result_pid = -1;
     task->waiting_on_pid = 0;
     task->wait_collected = 0;
+    task->userspace_faults = 0;
+    task->last_userspace_fault = 0;
     if (parent && parent->fd_table)
     {
         task->fd_table = fd_table_clone(parent->fd_table);
@@ -1190,6 +1192,8 @@ pid_t sched_fork(uint64_t syscall_frame_ptr)
     child->wait_result_pid = -1;
     child->waiting_on_pid = 0;
     child->wait_collected = 0;
+    child->userspace_faults = 0;
+    child->last_userspace_fault = 0;
     child->pinned_cpu = sched_pick_user_cpu_locked();
     child->running_cpu = -1;
     child->last_cpu = -1;

src/kernel/sched.h

@@ -65,6 +65,8 @@ typedef struct task
     pid_t wait_result_pid;
     uint8_t waiting_on_pid;
     uint8_t wait_collected;
+    uint32_t userspace_faults;
+    uint64_t last_userspace_fault;
 
     uint64_t futex_wait_addr;
     int futex_woken;