kernel/vserver/history.c

   1 /*
   2  *  kernel/vserver/history.c
   3  *
   4  *  Virtual Context History Backtrace
   5  *
   6  *  Copyright (C) 2004-2005  Herbert Pötzl
   7  *
   8  *  V0.01  basic structure
   9  *  V0.02  hash/unhash and trace
  10  *  V0.03  preemption fixes
  11  *
  12  */
  13
  14 #include <linux/config.h>
  15 #include <linux/errno.h>
  16 #include <linux/module.h>
  17 #include <linux/types.h>
  18 #include <linux/ctype.h>
  19
  20 #include <asm/uaccess.h>
  21 #include <asm/atomic.h>
  22 #include <asm/unistd.h>
  23
  24 #include <linux/vserver/debug.h>
  25
  26
  27 #ifdef  CONFIG_VSERVER_HISTORY
  28 #define VXH_SIZE        CONFIG_VSERVER_HISTORY_SIZE
  29 #else
  30 #define VXH_SIZE        64
  31 #endif
  32
  33 struct _vx_history {
  34         unsigned int counter;
  35
  36         struct _vx_hist_entry entry[VXH_SIZE+1];
  37 };
  38
  39
  40 DEFINE_PER_CPU(struct _vx_history, vx_history_buffer);
  41
  42 unsigned volatile int vxh_active = 1;
  43
  44 static atomic_t sequence = ATOMIC_INIT(0);
  45
  46
  47 /*      vxh_advance()
  48
  49         * requires disabled preemption                          */
  50
  51 struct _vx_hist_entry *vxh_advance(void *loc)
  52 {
  53         unsigned int cpu = smp_processor_id();
  54         struct _vx_history *hist = &per_cpu(vx_history_buffer, cpu);
  55         struct _vx_hist_entry *entry;
  56         unsigned int index;
  57
  58         index = vxh_active ? (hist->counter++ % VXH_SIZE) : VXH_SIZE;
  59         entry = &hist->entry[index];
  60
  61         entry->seq = atomic_inc_return(&sequence);
  62         entry->loc = loc;
  63         return entry;
  64 }
  65
  66
  67 #define VXH_LOC_FMTS    "(#%04x,*%d):%p"
  68
  69 #define VXH_LOC_ARGS(e) (e)->seq, cpu, (e)->loc
  70
  71
  72 #define VXH_VXI_FMTS    "%p[#%d,%d.%d]"
  73
  74 #define VXH_VXI_ARGS(e) (e)->vxi.ptr,                   \
  75                         (e)->vxi.ptr?(e)->vxi.xid:0,    \
  76                         (e)->vxi.ptr?(e)->vxi.usecnt:0, \
  77                         (e)->vxi.ptr?(e)->vxi.tasks:0
  78
  79 void    vxh_dump_entry(struct _vx_hist_entry *e, unsigned cpu)
  80 {
  81         switch (e->type) {
  82         case VXH_THROW_OOPS:
  83                 printk( VXH_LOC_FMTS " oops \n", VXH_LOC_ARGS(e));
  84                 break;
  85
  86         case VXH_GET_VX_INFO:
  87         case VXH_PUT_VX_INFO:
  88                 printk( VXH_LOC_FMTS " %s_vx_info " VXH_VXI_FMTS "\n",
  89                         VXH_LOC_ARGS(e),
  90                         (e->type==VXH_GET_VX_INFO)?"get":"put",
  91                         VXH_VXI_ARGS(e));
  92                 break;
  93
  94         case VXH_INIT_VX_INFO:
  95         case VXH_SET_VX_INFO:
  96         case VXH_CLR_VX_INFO:
  97                 printk( VXH_LOC_FMTS " %s_vx_info " VXH_VXI_FMTS " @%p\n",
  98                         VXH_LOC_ARGS(e),
  99                         (e->type==VXH_INIT_VX_INFO)?"init":
 100                         ((e->type==VXH_SET_VX_INFO)?"set":"clr"),
 101                         VXH_VXI_ARGS(e), e->sc.data);
 102                 break;
 103
 104         case VXH_CLAIM_VX_INFO:
 105         case VXH_RELEASE_VX_INFO:
 106                 printk( VXH_LOC_FMTS " %s_vx_info " VXH_VXI_FMTS " @%p\n",
 107                         VXH_LOC_ARGS(e),
 108                         (e->type==VXH_CLAIM_VX_INFO)?"claim":"release",
 109                         VXH_VXI_ARGS(e), e->sc.data);
 110                 break;
 111
 112         case VXH_ALLOC_VX_INFO:
 113         case VXH_DEALLOC_VX_INFO:
 114                 printk( VXH_LOC_FMTS " %s_vx_info " VXH_VXI_FMTS "\n",
 115                         VXH_LOC_ARGS(e),
 116                         (e->type==VXH_ALLOC_VX_INFO)?"alloc":"dealloc",
 117                         VXH_VXI_ARGS(e));
 118                 break;
 119
 120         case VXH_HASH_VX_INFO:
 121         case VXH_UNHASH_VX_INFO:
 122                 printk( VXH_LOC_FMTS " __%s_vx_info " VXH_VXI_FMTS "\n",
 123                         VXH_LOC_ARGS(e),
 124                         (e->type==VXH_HASH_VX_INFO)?"hash":"unhash",
 125                         VXH_VXI_ARGS(e));
 126                 break;
 127
 128         case VXH_LOC_VX_INFO:
 129         case VXH_LOOKUP_VX_INFO:
 130         case VXH_CREATE_VX_INFO:
 131                 printk( VXH_LOC_FMTS " __%s_vx_info [#%d] -> " VXH_VXI_FMTS "\n",
 132                         VXH_LOC_ARGS(e),
 133                         (e->type==VXH_CREATE_VX_INFO)?"create":
 134                         ((e->type==VXH_LOC_VX_INFO)?"loc":"lookup"),
 135                         e->ll.arg, VXH_VXI_ARGS(e));
 136                 break;
 137         }
 138 }
 139
 140 static void __vxh_dump_history(void)
 141 {
 142         unsigned int i,j;
 143
 144         printk("History:\tSEQ: %8x\tNR_CPUS: %d\n",
 145                 atomic_read(&sequence), NR_CPUS);
 146
 147         for (i=0; i < VXH_SIZE; i++) {
 148                 for (j=0; j < NR_CPUS; j++) {
 149                         struct _vx_history *hist =
 150                                 &per_cpu(vx_history_buffer, j);
 151                         unsigned int index = (hist->counter-i) % VXH_SIZE;
 152                         struct _vx_hist_entry *entry = &hist->entry[index];
 153
 154                         vxh_dump_entry(entry, j);
 155                 }
 156         }
 157 }
 158
 159 void    vxh_dump_history(void)
 160 {
 161         vxh_active = 0;
 162 #ifdef CONFIG_SMP
 163         local_irq_enable();
 164         smp_send_stop();
 165         local_irq_disable();
 166 #endif
 167         __vxh_dump_history();
 168 }
 169
 170
 171 /* vserver syscall commands below here */
 172
 173
 174 int     vc_dump_history(uint32_t id)
 175 {
 176         vxh_active = 0;
 177         __vxh_dump_history();
 178         vxh_active = 1;
 179
 180         return 0;
 181 }
 182
 183 EXPORT_SYMBOL_GPL(vxh_advance);
 184