kern/arch/x86/trap64.c

   1 /* Copyright (c) 2009-13 The Regents of the University of California
   2  * Barret Rhoden <brho@cs.berkeley.edu>
   3  * See LICENSE for details.
   4  *
   5  * x86 trap.c bit-specific functions. */
   6
   7 #include <arch/mmu.h>
   8 #include <arch/x86.h>
   9 #include <arch/arch.h>
  10 #include <arch/console.h>
  11 #include <arch/apic.h>
  12 #include <ros/common.h>
  13 #include <smp.h>
  14 #include <assert.h>
  15 #include <pmap.h>
  16 #include <trap.h>
  17 #include <monitor.h>
  18 #include <process.h>
  19 #include <mm.h>
  20 #include <stdio.h>
  21 #include <slab.h>
  22 #include <syscall.h>
  23 #include <kdebug.h>
  24 #include <kmalloc.h>
  25
  26 /* Starts running the current TF, just using ret. */
  27 void pop_kernel_ctx(struct kernel_ctx *ctx)
  28 {
  29         struct sw_trapframe *tf = &ctx->sw_tf;
  30         /* We're starting at rbx's spot in the sw_tf */
  31         asm volatile ("movq %0, %%rsp;          "
  32                                   "popq %%rbx;              "
  33                                   "popq %%rbp;              "
  34                                   "popq %%r12;              "
  35                                   "popq %%r13;              "
  36                                   "popq %%r14;              "
  37                                   "popq %%r15;              "
  38                                   "popq %%rax;              " /* pop rip */
  39                                   "popq %%rsp;              "
  40                                   "jmp *%%rax;              " /* stored rip */
  41                                   : : "g"(&ctx->sw_tf.tf_rbx) : "memory");
  42         panic("ret failed");
  43 }
  44
  45 void print_trapframe(struct hw_trapframe *hw_tf)
  46 {
  47         static spinlock_t ptf_lock = SPINLOCK_INITIALIZER_IRQSAVE;
  48
  49         struct per_cpu_info *pcpui = &per_cpu_info[core_id()];
  50         /* This is only called in debug scenarios, and often when the kernel trapped
  51          * and needs to tell us about it.  Disable the lock checker so it doesn't go
  52          * nuts when we print/panic */
  53         pcpui->__lock_depth_disabled++;
  54         spin_lock_irqsave(&ptf_lock);
  55         printk("HW TRAP frame at %p on core %d\n", hw_tf, core_id());
  56         printk("  rax  0x%016lx\n",           hw_tf->tf_rax);
  57         printk("  rbx  0x%016lx\n",           hw_tf->tf_rbx);
  58         printk("  rcx  0x%016lx\n",           hw_tf->tf_rcx);
  59         printk("  rdx  0x%016lx\n",           hw_tf->tf_rdx);
  60         printk("  rbp  0x%016lx\n",           hw_tf->tf_rbp);
  61         printk("  rsi  0x%016lx\n",           hw_tf->tf_rsi);
  62         printk("  rdi  0x%016lx\n",           hw_tf->tf_rdi);
  63         printk("  r8   0x%016lx\n",           hw_tf->tf_r8);
  64         printk("  r9   0x%016lx\n",           hw_tf->tf_r9);
  65         printk("  r10  0x%016lx\n",           hw_tf->tf_r10);
  66         printk("  r11  0x%016lx\n",           hw_tf->tf_r11);
  67         printk("  r12  0x%016lx\n",           hw_tf->tf_r12);
  68         printk("  r13  0x%016lx\n",           hw_tf->tf_r13);
  69         printk("  r14  0x%016lx\n",           hw_tf->tf_r14);
  70         printk("  r15  0x%016lx\n",           hw_tf->tf_r15);
  71         printk("  trap 0x%08x %s\n",          hw_tf->tf_trapno,
  72                                               x86_trapname(hw_tf->tf_trapno));
  73         /* FYI: these aren't physically adjacent to trap and err */
  74         if (hw_tf->tf_cs == GD_KT)
  75                 printk("  gsbs 0x%016lx\n",       read_msr(MSR_GS_BASE));
  76         else
  77                 printk("  gsbs 0x%016lx\n",       hw_tf->tf_gsbase);
  78         printk("  fsbs 0x%016lx\n",           hw_tf->tf_fsbase);
  79         printk("  err  0x--------%08x\n",     hw_tf->tf_err);
  80         printk("  rip  0x%016lx\n",           hw_tf->tf_rip);
  81         printk("  cs   0x------------%04x\n", hw_tf->tf_cs);
  82         printk("  flag 0x%016lx\n",           hw_tf->tf_rflags);
  83         printk("  rsp  0x%016lx\n",           hw_tf->tf_rsp);
  84         printk("  ss   0x------------%04x\n", hw_tf->tf_ss);
  85         spin_unlock_irqsave(&ptf_lock);
  86         pcpui->__lock_depth_disabled--;
  87
  88         /* Used in trapentry64.S */
  89         static_assert(offsetof(struct hw_trapframe, tf_cs) -
  90                       offsetof(struct hw_trapframe, tf_rax) == 0x90);
  91         /* Used in trap64.h */
  92         static_assert(offsetof(struct per_cpu_info, stacktop) == 0);
  93 }
  94
  95 void print_swtrapframe(struct sw_trapframe *sw_tf)
  96 {
  97         static spinlock_t ptf_lock = SPINLOCK_INITIALIZER_IRQSAVE;
  98         struct per_cpu_info *pcpui = &per_cpu_info[core_id()];
  99         pcpui->__lock_depth_disabled++;
 100         spin_lock_irqsave(&ptf_lock);
 101         printk("SW TRAP frame at %p on core %d\n", sw_tf, core_id());
 102         printk("  rbx  0x%016lx\n",           sw_tf->tf_rbx);
 103         printk("  rbp  0x%016lx\n",           sw_tf->tf_rbp);
 104         printk("  r12  0x%016lx\n",           sw_tf->tf_r12);
 105         printk("  r13  0x%016lx\n",           sw_tf->tf_r13);
 106         printk("  r14  0x%016lx\n",           sw_tf->tf_r14);
 107         printk("  r15  0x%016lx\n",           sw_tf->tf_r15);
 108         printk("  gsbs 0x%016lx\n",           sw_tf->tf_gsbase);
 109         printk("  fsbs 0x%016lx\n",           sw_tf->tf_fsbase);
 110         printk("  rip  0x%016lx\n",           sw_tf->tf_rip);
 111         printk("  rsp  0x%016lx\n",           sw_tf->tf_rsp);
 112         printk(" mxcsr 0x%08x\n",             sw_tf->tf_mxcsr);
 113         printk(" fpucw 0x%04x\n",             sw_tf->tf_fpucw);
 114         spin_unlock_irqsave(&ptf_lock);
 115         pcpui->__lock_depth_disabled--;
 116 }
 117
 118 void page_fault_handler(struct hw_trapframe *hw_tf)
 119 {
 120         uintptr_t fault_va = rcr2();
 121         int prot = hw_tf->tf_err & PF_ERROR_WRITE ? PROT_WRITE : PROT_READ;
 122         int err;
 123
 124         /* TODO - handle kernel page faults */
 125         if ((hw_tf->tf_cs & 3) == 0) {
 126                 print_trapframe(hw_tf);
 127                 panic("Page Fault in the Kernel at 0x%08x!", fault_va);
 128                 /* if we want to do something like kill a process or other code, be
 129                  * aware we are in a sort of irq-like context, meaning the main kernel
 130                  * code we 'interrupted' could be holding locks - even irqsave locks. */
 131         }
 132         /* safe to reenable after rcr2 */
 133         enable_irq();
 134         if ((err = handle_page_fault(current, fault_va, prot))) {
 135                 /* Destroy the faulting process */
 136                 printk("[%08x] user %s fault va %p ip %p on core %d with err %d\n",
 137                        current->pid, prot & PROT_READ ? "READ" : "WRITE", fault_va,
 138                        hw_tf->tf_rip, core_id(), err);
 139                 print_trapframe(hw_tf);
 140                 /* Turn this on to help debug bad function pointers */
 141                 printd("rsp %p\n\t 0(rsp): %p\n\t 8(rsp): %p\n\t 16(rsp): %p\n"
 142                        "\t24(rsp): %p\n", hw_tf->tf_rsp,
 143                        *(uintptr_t*)(hw_tf->tf_rsp +  0),
 144                        *(uintptr_t*)(hw_tf->tf_rsp +  8),
 145                        *(uintptr_t*)(hw_tf->tf_rsp + 16),
 146                        *(uintptr_t*)(hw_tf->tf_rsp + 24));
 147                 proc_destroy(current);
 148         }
 149 }