Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
| 15 | enum 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 | |
| 42 | struct unw_info_block { |
| 43 | u64 header; |
| 44 | u64 desc[0]; /* unwind descriptors */ |
| 45 | /* personality routine and language-specific data follow behind descriptors */ |
| 46 | }; |
| 47 | |
| 48 | struct 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 | |
| 59 | enum 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 | |
| 76 | struct 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 | |
| 82 | struct 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 | |
| 87 | struct 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 | |
| 93 | struct 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 | |
| 117 | enum 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 | |
| 124 | enum 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 | |
| 139 | struct 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 | |
| 153 | struct 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 | }; |