kernel/system/do_update.c

   1 /* The kernel call implemented in this file:
   2  *   m_type:    SYS_UPDATE
   3  *
   4  * The parameters for this kernel call are:
   5  *    m2_i1:    SYS_UPD_SRC_ENDPT       (source process endpoint)
   6  *    m2_i2:    SYS_UPD_DST_ENDPT       (destination process endpoint)
   7  */
   8
   9 #include "kernel/system.h"
  10 #include "kernel/ipc.h"
  11 #include <string.h>
  12 #include <assert.h>
  13
  14 #if USE_UPDATE
  15
  16 #define DEBUG 0
  17
  18 #define proc_is_updatable(p) \
  19     (RTS_ISSET(p, RTS_NO_PRIV) || RTS_ISSET(p, RTS_SIG_PENDING) \
  20     || (RTS_ISSET(p, RTS_RECEIVING) && !RTS_ISSET(p, RTS_SENDING)))
  21
  22 static void adjust_proc_slot(struct proc *rp, struct proc *from_rp);
  23 static void adjust_priv_slot(struct priv *privp, struct priv
  24         *from_privp);
  25 static void swap_proc_slot_pointer(struct proc **rpp, struct proc
  26         *src_rp, struct proc *dst_rp);
  27
  28 /*===========================================================================*
  29  *                              do_update                                    *
  30  *===========================================================================*/
  31 int do_update(struct proc * caller, message * m_ptr)
  32 {
  33 /* Handle sys_update(). Update a process into another by swapping their process
  34  * slots.
  35  */
  36   endpoint_t src_e, dst_e;
  37   int src_p, dst_p;
  38   struct proc *src_rp, *dst_rp;
  39   struct priv *src_privp, *dst_privp;
  40   struct proc orig_src_proc;
  41   struct proc orig_dst_proc;
  42   struct priv orig_src_priv;
  43   struct priv orig_dst_priv;
  44   int i;
  45
  46   /* Lookup slots for source and destination process. */
  47   src_e = m_ptr->SYS_UPD_SRC_ENDPT;
  48   if(!isokendpt(src_e, &src_p)) {
  49       return EINVAL;
  50   }
  51   src_rp = proc_addr(src_p);
  52   src_privp = priv(src_rp);
  53   if(!(src_privp->s_flags & SYS_PROC)) {
  54       return EPERM;
  55   }
  56
  57   dst_e = m_ptr->SYS_UPD_DST_ENDPT;
  58   if(!isokendpt(dst_e, &dst_p)) {
  59       return EINVAL;
  60   }
  61   dst_rp = proc_addr(dst_p);
  62   dst_privp = priv(dst_rp);
  63   if(!(dst_privp->s_flags & SYS_PROC)) {
  64       return EPERM;
  65   }
  66
  67   assert(!proc_is_runnable(src_rp) && !proc_is_runnable(dst_rp));
  68
  69   /* Check if processes are updatable. */
  70   if(!proc_is_updatable(src_rp) || !proc_is_updatable(dst_rp)) {
  71       return EBUSY;
  72   }
  73
  74 #if DEBUG
  75   printf("do_update: updating %d (%s, %d, %d) into %d (%s, %d, %d)\n",
  76       src_rp->p_endpoint, src_rp->p_name, src_rp->p_nr, priv(src_rp)->s_proc_nr,
  77       dst_rp->p_endpoint, dst_rp->p_name, dst_rp->p_nr, priv(dst_rp)->s_proc_nr);
  78
  79   proc_stacktrace(src_rp);
  80   proc_stacktrace(dst_rp);
  81   printf("do_update: curr ptproc %d\n", get_cpulocal_var(ptproc)->p_endpoint);
  82 #endif
  83
  84   /* Let destination inherit the target mask from source. */
  85   for (i=0; i < NR_SYS_PROCS; i++) {
  86       if (get_sys_bit(priv(src_rp)->s_ipc_to, i)) {
  87           set_sendto_bit(dst_rp, i);
  88       }
  89   }
  90
  91   /* Save existing data. */
  92   orig_src_proc = *src_rp;
  93   orig_src_priv = *(priv(src_rp));
  94   orig_dst_proc = *dst_rp;
  95   orig_dst_priv = *(priv(dst_rp));
  96
  97   /* Swap slots. */
  98   *src_rp = orig_dst_proc;
  99   *src_privp = orig_dst_priv;
 100   *dst_rp = orig_src_proc;
 101   *dst_privp = orig_src_priv;
 102
 103   /* Adjust process slots. */
 104   adjust_proc_slot(src_rp, &orig_src_proc);
 105   adjust_proc_slot(dst_rp, &orig_dst_proc);
 106
 107   /* Adjust privilege slots. */
 108   adjust_priv_slot(priv(src_rp), &orig_src_priv);
 109   adjust_priv_slot(priv(dst_rp), &orig_dst_priv);
 110
 111   /* Swap global process slot addresses. */
 112   swap_proc_slot_pointer(get_cpulocal_var_ptr(ptproc), src_rp, dst_rp);
 113
 114 #if DEBUG
 115   printf("do_update: updated %d (%s, %d, %d) into %d (%s, %d, %d)\n",
 116       src_rp->p_endpoint, src_rp->p_name, src_rp->p_nr, priv(src_rp)->s_proc_nr,
 117       dst_rp->p_endpoint, dst_rp->p_name, dst_rp->p_nr, priv(dst_rp)->s_proc_nr);
 118
 119   proc_stacktrace(src_rp);
 120   proc_stacktrace(dst_rp);
 121   printf("do_update: curr ptproc %d\n", get_cpulocal_var(ptproc)->p_endpoint);
 122 #endif
 123
 124 #ifdef CONFIG_SMP
 125   bits_fill(src_rp->p_stale_tlb, CONFIG_MAX_CPUS);
 126   bits_fill(dst_rp->p_stale_tlb, CONFIG_MAX_CPUS);
 127 #endif
 128
 129   return OK;
 130 }
 131
 132 /*===========================================================================*
 133  *                           adjust_proc_slot                                *
 134  *===========================================================================*/
 135 static void adjust_proc_slot(struct proc *rp, struct proc *from_rp)
 136 {
 137   /* Preserve endpoints, slot numbers, priv structure, and IPC. */
 138   rp->p_endpoint = from_rp->p_endpoint;
 139   rp->p_nr = from_rp->p_nr;
 140   rp->p_priv = from_rp->p_priv;
 141   priv(rp)->s_proc_nr = from_rp->p_nr;
 142   rp->p_caller_q = from_rp->p_caller_q;
 143
 144   /* preserve scheduling */
 145   rp->p_scheduler = from_rp->p_scheduler;
 146 #ifdef CONFIG_SMP
 147   rp->p_cpu = from_rp->p_cpu;
 148   memcpy(rp->p_cpu_mask, from_rp->p_cpu_mask,
 149                   sizeof(bitchunk_t) * BITMAP_CHUNKS(CONFIG_MAX_CPUS));
 150 #endif
 151 }
 152
 153 /*===========================================================================*
 154  *                           adjust_priv_slot                                *
 155  *===========================================================================*/
 156 static void adjust_priv_slot(struct priv *privp, struct priv *from_privp)
 157 {
 158   /* Preserve privilege ids and non-privilege stuff in the priv structure. */
 159   privp->s_id = from_privp->s_id;
 160   privp->s_notify_pending = from_privp->s_notify_pending;
 161   privp->s_int_pending = from_privp->s_int_pending;
 162   privp->s_sig_pending = from_privp->s_sig_pending;
 163   privp->s_alarm_timer = from_privp->s_alarm_timer;
 164 }
 165
 166 /*===========================================================================*
 167  *                         swap_proc_slot_pointer                            *
 168  *===========================================================================*/
 169 static void swap_proc_slot_pointer(struct proc **rpp, struct proc *src_rp,
 170     struct proc *dst_rp)
 171 {
 172   if(*rpp == src_rp) {
 173       *rpp = dst_rp;
 174   }
 175   else if(*rpp == dst_rp) {
 176       *rpp = src_rp;
 177   }
 178 }
 179
 180 #endif /* USE_UPDATE */
 181