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1da177e4 LT |
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 | }; |