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