runtime/unwind/unwind.h

   1 /* -*- linux-c -*-
   2  *
   3  * dwarf unwinder header file
   4  * Copyright (C) 2008, 2009 Red Hat Inc.
   5  * Copyright (C) 2002-2006 Novell, Inc.
   6  *
   7  * This file is part of systemtap, and is free software.  You can
   8  * redistribute it and/or modify it under the terms of the GNU General
   9  * Public License (GPL); either version 2, or (at your option) any
  10  * later version.
  11  */
  12
  13 #ifndef _STP_UNWIND_H_
  14 #define _STP_UNWIND_H_
  15
  16 #ifdef STP_USE_DWARF_UNWINDER
  17
  18 #if defined (__x86_64__)
  19 #include "x86_64.h"
  20 #elif  defined (__i386__)
  21 #include "i386.h"
  22 #else
  23 #error "Unsupported dwarf unwind architecture"
  24 #endif
  25
  26 #define STP_MAX_STACK_DEPTH 8
  27
  28 #ifndef BUILD_BUG_ON_ZERO
  29 #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
  30 #endif
  31
  32
  33 #define EXTRA_INFO(f) { \
  34                 BUILD_BUG_ON_ZERO(offsetof(struct unwind_frame_info, f) \
  35                                   % FIELD_SIZEOF(struct unwind_frame_info, f)) \
  36                 + offsetof(struct unwind_frame_info, f) \
  37                   / FIELD_SIZEOF(struct unwind_frame_info, f), \
  38                 FIELD_SIZEOF(struct unwind_frame_info, f) \
  39         }
  40 #define PTREGS_INFO(f) EXTRA_INFO(regs.f)
  41
  42 static const struct {
  43         unsigned offs:BITS_PER_LONG / 2;
  44         unsigned width:BITS_PER_LONG / 2;
  45 } reg_info[] = {
  46         UNW_REGISTER_INFO
  47 };
  48
  49 #undef PTREGS_INFO
  50 #undef EXTRA_INFO
  51
  52 #ifndef REG_INVALID
  53 #define REG_INVALID(r) (reg_info[r].width == 0)
  54 #endif
  55
  56 #define DW_CFA_nop                          0x00
  57 #define DW_CFA_set_loc                      0x01
  58 #define DW_CFA_advance_loc1                 0x02
  59 #define DW_CFA_advance_loc2                 0x03
  60 #define DW_CFA_advance_loc4                 0x04
  61 #define DW_CFA_offset_extended              0x05
  62 #define DW_CFA_restore_extended             0x06
  63 #define DW_CFA_undefined                    0x07
  64 #define DW_CFA_same_value                   0x08
  65 #define DW_CFA_register                     0x09
  66 #define DW_CFA_remember_state               0x0a
  67 #define DW_CFA_restore_state                0x0b
  68 #define DW_CFA_def_cfa                      0x0c
  69 #define DW_CFA_def_cfa_register             0x0d
  70 #define DW_CFA_def_cfa_offset               0x0e
  71 #define DW_CFA_def_cfa_expression           0x0f
  72 #define DW_CFA_expression                   0x10
  73 #define DW_CFA_offset_extended_sf           0x11
  74 #define DW_CFA_def_cfa_sf                   0x12
  75 #define DW_CFA_def_cfa_offset_sf            0x13
  76 #define DW_CFA_val_offset                   0x14
  77 #define DW_CFA_val_offset_sf                0x15
  78 #define DW_CFA_val_expression               0x16
  79 #define DW_CFA_lo_user                      0x1c
  80 #define DW_CFA_GNU_window_save              0x2d
  81 #define DW_CFA_GNU_args_size                0x2e
  82 #define DW_CFA_GNU_negative_offset_extended 0x2f
  83 #define DW_CFA_hi_user                      0x3f
  84
  85 #define DW_EH_PE_absptr   0x00
  86 #define DW_EH_PE_leb128   0x01
  87 #define DW_EH_PE_data2    0x02
  88 #define DW_EH_PE_data4    0x03
  89 #define DW_EH_PE_data8    0x04
  90 #define DW_EH_PE_FORM     0x07 /* mask */
  91 #define DW_EH_PE_signed   0x08 /* signed versions of above have this bit set */
  92
  93 #define DW_EH_PE_pcrel    0x10
  94 #define DW_EH_PE_textrel  0x20
  95 #define DW_EH_PE_datarel  0x30
  96 #define DW_EH_PE_funcrel  0x40
  97 #define DW_EH_PE_aligned  0x50
  98 #define DW_EH_PE_ADJUST   0x70 /* mask */
  99 #define DW_EH_PE_indirect 0x80
 100 #define DW_EH_PE_omit     0xff
 101
 102 typedef unsigned long uleb128_t;
 103 typedef   signed long sleb128_t;
 104
 105 static struct unwind_table {
 106         unsigned long pc; /* text */
 107         unsigned long range; /* text_size */
 108         const void *address; /* unwind_data */
 109         unsigned long size; /* unwind_data_len */
 110         const unsigned char *header; /* unwind_header */
 111         unsigned long hdrsz;
 112         struct unwind_table *link;
 113         const char *name; /* module name */
 114 } root_table;
 115
 116 struct unwind_item {
 117         enum item_location {
 118                 Nowhere,
 119                 Memory,
 120                 Register,
 121                 Value
 122         } where;
 123         uleb128_t value;
 124 };
 125
 126 struct unwind_state {
 127         uleb128_t loc, org;
 128         const u8 *cieStart, *cieEnd;
 129         uleb128_t codeAlign;
 130         sleb128_t dataAlign;
 131         struct cfa {
 132                 uleb128_t reg, offs;
 133         } cfa;
 134         struct unwind_item regs[ARRAY_SIZE(reg_info)];
 135         unsigned stackDepth:8;
 136         unsigned version:8;
 137         const u8 *label;
 138         const u8 *stack[STP_MAX_STACK_DEPTH];
 139 };
 140
 141 static const struct cfa badCFA = { ARRAY_SIZE(reg_info), 1 };
 142 static unsigned long read_pointer(const u8 **pLoc,
 143                                   const void *end,
 144                                   signed ptrType);
 145 static const u32 bad_cie, not_fde;
 146 static const u32 *cie_for_fde(const u32 *fde, void *table,
 147                               uint32_t table_len, int is_ehframe);
 148 static signed fde_pointer_type(const u32 *cie,
 149                                void *table, uint32_t table_len);
 150
 151
 152 #endif /* STP_USE_DWARF_UNWINDER */
 153 #endif /*_STP_UNWIND_H_*/