LXR linux/arch/ia64/kernel/unwind

   1/*
   2 * Copyright (C) 2000, 2002-2003 Hewlett-Packard Co
   3 *      David Mosberger-Tang <davidm@hpl.hp.com>
   4 *
   5 * Kernel unwind support.
   6 */
   7
   8#define UNW_VER(x)              ((x) >> 48)
   9#define UNW_FLAG_MASK           0x0000ffff00000000
  10#define UNW_FLAG_OSMASK         0x0000f00000000000
  11#define UNW_FLAG_EHANDLER(x)    ((x) & 0x0000000100000000L)
  12#define UNW_FLAG_UHANDLER(x)    ((x) & 0x0000000200000000L)
  13#define UNW_LENGTH(x)           ((x) & 0x00000000ffffffffL)
  14
  15enum unw_register_index {
  16        /* primary unat: */
  17        UNW_REG_PRI_UNAT_GR,
  18        UNW_REG_PRI_UNAT_MEM,
  19
  20        /* register stack */
  21        UNW_REG_BSP,                                    /* register stack pointer */
  22        UNW_REG_BSPSTORE,
  23        UNW_REG_PFS,                                    /* previous function state */
  24        UNW_REG_RNAT,
  25        /* memory stack */
  26        UNW_REG_PSP,                                    /* previous memory stack pointer */
  27        /* return pointer: */
  28        UNW_REG_RP,
  29
  30        /* preserved registers: */
  31        UNW_REG_R4, UNW_REG_R5, UNW_REG_R6, UNW_REG_R7,
  32        UNW_REG_UNAT, UNW_REG_PR, UNW_REG_LC, UNW_REG_FPSR,
  33        UNW_REG_B1, UNW_REG_B2, UNW_REG_B3, UNW_REG_B4, UNW_REG_B5,
  34        UNW_REG_F2, UNW_REG_F3, UNW_REG_F4, UNW_REG_F5,
  35        UNW_REG_F16, UNW_REG_F17, UNW_REG_F18, UNW_REG_F19,
  36        UNW_REG_F20, UNW_REG_F21, UNW_REG_F22, UNW_REG_F23,
  37        UNW_REG_F24, UNW_REG_F25, UNW_REG_F26, UNW_REG_F27,
  38        UNW_REG_F28, UNW_REG_F29, UNW_REG_F30, UNW_REG_F31,
  39        UNW_NUM_REGS
  40};
  41
  42struct unw_info_block {
  43        u64 header;
  44        u64 desc[0];            /* unwind descriptors */
  45        /* personality routine and language-specific data follow behind descriptors */
  46};
  47
  48struct unw_table {
  49        struct unw_table *next;         /* must be first member! */
  50        const char *name;
  51        unsigned long gp;               /* global pointer for this load-module */
  52        unsigned long segment_base;     /* base for offsets in the unwind table entries */
  53        unsigned long start;
  54        unsigned long end;
  55        const struct unw_table_entry *array;
  56        unsigned long length;
  57};
  58
  59enum unw_where {
  60        UNW_WHERE_NONE,                 /* register isn't saved at all */
  61        UNW_WHERE_GR,                   /* register is saved in a general register */
  62        UNW_WHERE_FR,                   /* register is saved in a floating-point register */
  63        UNW_WHERE_BR,                   /* register is saved in a branch register */
  64        UNW_WHERE_SPREL,                /* register is saved on memstack (sp-relative) */
  65        UNW_WHERE_PSPREL,               /* register is saved on memstack (psp-relative) */
  66        /*
  67         * At the end of each prologue these locations get resolved to
  68         * UNW_WHERE_PSPREL and UNW_WHERE_GR, respectively:
  69         */
  70        UNW_WHERE_SPILL_HOME,           /* register is saved in its spill home */
  71        UNW_WHERE_GR_SAVE               /* register is saved in next general register */
  72};
  73
  74#define UNW_WHEN_NEVER  0x7fffffff
  75
  76struct unw_reg_info {
  77        unsigned long val;              /* save location: register number or offset */
  78        enum unw_where where;           /* where the register gets saved */
  79        int when;                       /* when the register gets saved */
  80};
  81
  82struct unw_reg_state {
  83        struct unw_reg_state *next;             /* next (outer) element on state stack */
  84        struct unw_reg_info reg[UNW_NUM_REGS];  /* register save locations */
  85};
  86
  87struct unw_labeled_state {
  88        struct unw_labeled_state *next;         /* next labeled state (or NULL) */
  89        unsigned long label;                    /* label for this state */
  90        struct unw_reg_state saved_state;
  91};
  92
  93struct unw_state_record {
  94        unsigned int first_region : 1;  /* is this the first region? */
  95        unsigned int done : 1;          /* are we done scanning descriptors? */
  96        unsigned int any_spills : 1;    /* got any register spills? */
  97        unsigned int in_body : 1;       /* are we inside a body (as opposed to a prologue)? */
  98        unsigned long flags;            /* see UNW_FLAG_* in unwind.h */
  99
 100        u8 *imask;                      /* imask of spill_mask record or NULL */
 101        unsigned long pr_val;           /* predicate values */
 102        unsigned long pr_mask;          /* predicate mask */
 103        long spill_offset;              /* psp-relative offset for spill base */
 104        int region_start;
 105        int region_len;
 106        int epilogue_start;
 107        int epilogue_count;
 108        int when_target;
 109
 110        u8 gr_save_loc;                 /* next general register to use for saving a register */
 111        u8 return_link_reg;             /* branch register in which the return link is passed */
 112
 113        struct unw_labeled_state *labeled_states;       /* list of all labeled states */
 114        struct unw_reg_state curr;      /* current state */
 115};
 116
 117enum unw_nat_type {
 118        UNW_NAT_NONE,           /* NaT not represented */
 119        UNW_NAT_VAL,            /* NaT represented by NaT value (fp reg) */
 120        UNW_NAT_MEMSTK,         /* NaT value is in unat word at offset OFF  */
 121        UNW_NAT_REGSTK          /* NaT is in rnat */
 122};
 123
 124enum unw_insn_opcode {
 125        UNW_INSN_ADD,                   /* s[dst] += val */
 126        UNW_INSN_ADD_PSP,               /* s[dst] = (s.psp + val) */
 127        UNW_INSN_ADD_SP,                /* s[dst] = (s.sp + val) */
 128        UNW_INSN_MOVE,                  /* s[dst] = s[val] */
 129        UNW_INSN_MOVE2,                 /* s[dst] = s[val]; s[dst+1] = s[val+1] */
 130        UNW_INSN_MOVE_STACKED,          /* s[dst] = ia64_rse_skip(*s.bsp, val) */
 131        UNW_INSN_SETNAT_MEMSTK,         /* s[dst+1].nat.type = MEMSTK;
 132                                           s[dst+1].nat.off = *s.pri_unat - s[dst] */
 133        UNW_INSN_SETNAT_TYPE,           /* s[dst+1].nat.type = val */
 134        UNW_INSN_LOAD,                  /* s[dst] = *s[val] */
 135        UNW_INSN_MOVE_SCRATCH,          /* s[dst] = scratch reg "val" */
 136        UNW_INSN_MOVE_CONST,            /* s[dst] = constant reg "val" */
 137};
 138
 139struct unw_insn {
 140        unsigned int opc        :  4;
 141        unsigned int dst        :  9;
 142        signed int val          : 19;
 143};
 144
 145/*
 146 * Preserved general static registers (r4-r7) give rise to two script
 147 * instructions; everything else yields at most one instruction; at
 148 * the end of the script, the psp gets popped, accounting for one more
 149 * instruction.
 150 */
 151#define UNW_MAX_SCRIPT_LEN      (UNW_NUM_REGS + 5)
 152
 153struct unw_script {
 154        unsigned long ip;               /* ip this script is for */
 155        unsigned long pr_mask;          /* mask of predicates script depends on */
 156        unsigned long pr_val;           /* predicate values this script is for */
 157        rwlock_t lock;
 158        unsigned int flags;             /* see UNW_FLAG_* in unwind.h */
 159        unsigned short lru_chain;       /* used for least-recently-used chain */
 160        unsigned short coll_chain;      /* used for hash collisions */
 161        unsigned short hint;            /* hint for next script to try (or -1) */
 162        unsigned short count;           /* number of instructions in script */
 163        struct unw_insn insn[UNW_MAX_SCRIPT_LEN];
 164};
 165