1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Copyright (C) 2000, 2002-2003 Hewlett-Packard Co 4 * David Mosberger-Tang <davidm@hpl.hp.com> 5 * 6 * Kernel unwind support. 7 */ 8 9 #define UNW_VER(x) ((x) >> 48) 10 #define UNW_FLAG_MASK 0x0000ffff00000000 11 #define UNW_FLAG_OSMASK 0x0000f00000000000 12 #define UNW_FLAG_EHANDLER(x) ((x) & 0x0000000100000000L) 13 #define UNW_FLAG_UHANDLER(x) ((x) & 0x0000000200000000L) 14 #define UNW_LENGTH(x) ((x) & 0x00000000ffffffffL) 15 16 enum unw_register_index { 17 /* primary unat: */ 18 UNW_REG_PRI_UNAT_GR, 19 UNW_REG_PRI_UNAT_MEM, 20 21 /* register stack */ 22 UNW_REG_BSP, /* register stack pointer */ 23 UNW_REG_BSPSTORE, 24 UNW_REG_PFS, /* previous function state */ 25 UNW_REG_RNAT, 26 /* memory stack */ 27 UNW_REG_PSP, /* previous memory stack pointer */ 28 /* return pointer: */ 29 UNW_REG_RP, 30 31 /* preserved registers: */ 32 UNW_REG_R4, UNW_REG_R5, UNW_REG_R6, UNW_REG_R7, 33 UNW_REG_UNAT, UNW_REG_PR, UNW_REG_LC, UNW_REG_FPSR, 34 UNW_REG_B1, UNW_REG_B2, UNW_REG_B3, UNW_REG_B4, UNW_REG_B5, 35 UNW_REG_F2, UNW_REG_F3, UNW_REG_F4, UNW_REG_F5, 36 UNW_REG_F16, UNW_REG_F17, UNW_REG_F18, UNW_REG_F19, 37 UNW_REG_F20, UNW_REG_F21, UNW_REG_F22, UNW_REG_F23, 38 UNW_REG_F24, UNW_REG_F25, UNW_REG_F26, UNW_REG_F27, 39 UNW_REG_F28, UNW_REG_F29, UNW_REG_F30, UNW_REG_F31, 40 UNW_NUM_REGS 41 }; 42 43 struct unw_info_block { 44 u64 header; 45 u64 desc[0]; /* unwind descriptors */ 46 /* personality routine and language-specific data follow behind descriptors */ 47 }; 48 49 struct unw_table { 50 struct unw_table *next; /* must be first member! */ 51 const char *name; 52 unsigned long gp; /* global pointer for this load-module */ 53 unsigned long segment_base; /* base for offsets in the unwind table entries */ 54 unsigned long start; 55 unsigned long end; 56 const struct unw_table_entry *array; 57 unsigned long length; 58 }; 59 60 enum unw_where { 61 UNW_WHERE_NONE, /* register isn't saved at all */ 62 UNW_WHERE_GR, /* register is saved in a general register */ 63 UNW_WHERE_FR, /* register is saved in a floating-point register */ 64 UNW_WHERE_BR, /* register is saved in a branch register */ 65 UNW_WHERE_SPREL, /* register is saved on memstack (sp-relative) */ 66 UNW_WHERE_PSPREL, /* register is saved on memstack (psp-relative) */ 67 /* 68 * At the end of each prologue these locations get resolved to 69 * UNW_WHERE_PSPREL and UNW_WHERE_GR, respectively: 70 */ 71 UNW_WHERE_SPILL_HOME, /* register is saved in its spill home */ 72 UNW_WHERE_GR_SAVE /* register is saved in next general register */ 73 }; 74 75 #define UNW_WHEN_NEVER 0x7fffffff 76 77 struct unw_reg_info { 78 unsigned long val; /* save location: register number or offset */ 79 enum unw_where where; /* where the register gets saved */ 80 int when; /* when the register gets saved */ 81 }; 82 83 struct unw_reg_state { 84 struct unw_reg_state *next; /* next (outer) element on state stack */ 85 struct unw_reg_info reg[UNW_NUM_REGS]; /* register save locations */ 86 }; 87 88 struct unw_labeled_state { 89 struct unw_labeled_state *next; /* next labeled state (or NULL) */ 90 unsigned long label; /* label for this state */ 91 struct unw_reg_state saved_state; 92 }; 93 94 struct unw_state_record { 95 unsigned int first_region : 1; /* is this the first region? */ 96 unsigned int done : 1; /* are we done scanning descriptors? */ 97 unsigned int any_spills : 1; /* got any register spills? */ 98 unsigned int in_body : 1; /* are we inside a body (as opposed to a prologue)? */ 99 unsigned long flags; /* see UNW_FLAG_* in unwind.h */ 100 101 u8 *imask; /* imask of spill_mask record or NULL */ 102 unsigned long pr_val; /* predicate values */ 103 unsigned long pr_mask; /* predicate mask */ 104 long spill_offset; /* psp-relative offset for spill base */ 105 int region_start; 106 int region_len; 107 int epilogue_start; 108 int epilogue_count; 109 int when_target; 110 111 u8 gr_save_loc; /* next general register to use for saving a register */ 112 u8 return_link_reg; /* branch register in which the return link is passed */ 113 114 struct unw_labeled_state *labeled_states; /* list of all labeled states */ 115 struct unw_reg_state curr; /* current state */ 116 }; 117 118 enum unw_nat_type { 119 UNW_NAT_NONE, /* NaT not represented */ 120 UNW_NAT_VAL, /* NaT represented by NaT value (fp reg) */ 121 UNW_NAT_MEMSTK, /* NaT value is in unat word at offset OFF */ 122 UNW_NAT_REGSTK /* NaT is in rnat */ 123 }; 124 125 enum unw_insn_opcode { 126 UNW_INSN_ADD, /* s[dst] += val */ 127 UNW_INSN_ADD_PSP, /* s[dst] = (s.psp + val) */ 128 UNW_INSN_ADD_SP, /* s[dst] = (s.sp + val) */ 129 UNW_INSN_MOVE, /* s[dst] = s[val] */ 130 UNW_INSN_MOVE2, /* s[dst] = s[val]; s[dst+1] = s[val+1] */ 131 UNW_INSN_MOVE_STACKED, /* s[dst] = ia64_rse_skip(*s.bsp, val) */ 132 UNW_INSN_SETNAT_MEMSTK, /* s[dst+1].nat.type = MEMSTK; 133 s[dst+1].nat.off = *s.pri_unat - s[dst] */ 134 UNW_INSN_SETNAT_TYPE, /* s[dst+1].nat.type = val */ 135 UNW_INSN_LOAD, /* s[dst] = *s[val] */ 136 UNW_INSN_MOVE_SCRATCH, /* s[dst] = scratch reg "val" */ 137 UNW_INSN_MOVE_CONST, /* s[dst] = constant reg "val" */ 138 }; 139 140 struct unw_insn { 141 unsigned int opc : 4; 142 unsigned int dst : 9; 143 signed int val : 19; 144 }; 145 146 /* 147 * Preserved general static registers (r4-r7) give rise to two script 148 * instructions; everything else yields at most one instruction; at 149 * the end of the script, the psp gets popped, accounting for one more 150 * instruction. 151 */ 152 #define UNW_MAX_SCRIPT_LEN (UNW_NUM_REGS + 5) 153 154 struct unw_script { 155 unsigned long ip; /* ip this script is for */ 156 unsigned long pr_mask; /* mask of predicates script depends on */ 157 unsigned long pr_val; /* predicate values this script is for */ 158 rwlock_t lock; 159 unsigned int flags; /* see UNW_FLAG_* in unwind.h */ 160 unsigned short lru_chain; /* used for least-recently-used chain */ 161 unsigned short coll_chain; /* used for hash collisions */ 162 unsigned short hint; /* hint for next script to try (or -1) */ 163 unsigned short count; /* number of instructions in script */ 164 struct unw_insn insn[UNW_MAX_SCRIPT_LEN]; 165 }; 166