src/stub_binding_helper.s

   1 /*
   2  * Copyright (c) 1999-2006 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24
  25
  26 #ifdef __i386__
  27 /*
  28  * This is the interface for the stub_binding_helper for i386:
  29  * The caller has pushed the address of the a lazy pointer to be filled in
  30  * and pushed the address of the the mach header this pointer comes from.
  31  *
  32  * sp+4 address of lazy pointer
  33  * sp+0 address of mach header
  34  *
  35  * Some inter-image function calls pass parameters in registers EAX, ECX, EDX, or XXM0-3,
  36  * Therefore those registers need to be preserved during the lazy binding.
  37  *
  38  * After the symbol has been resolved and the lazy pointer filled in, this jumps
  39  * to the target address.
  40  */
  41 #define MH_PARAM_OUT                    0
  42 #define LP_PARAM_OUT                    4
  43 #define XMMM0_SAVE                      16      /* 16-byte align */
  44 #define XMMM1_SAVE                      32
  45 #define XMMM2_SAVE                      48
  46 #define XMMM3_SAVE                      64
  47 #define EAX_SAVE                        84
  48 #define ECX_SAVE                        88
  49 #define EDX_SAVE                        92
  50 #define LP_LOCAL                        96
  51 #define MH_LOCAL                        100
  52 #define STACK_SIZE                      100     /* must be 4 mod 16 so that stack winds up 16-byte aliged  */
  53 #define LP_OLD_BP_SAVE                  104
  54
  55     .text
  56     .align 4,0x90
  57         .globl _stub_binding_helper_i386_old
  58 _stub_binding_helper_i386_old:
  59         pushl           $0
  60     .globl _stub_binding_helper
  61     .globl _misaligned_stack_error
  62 _stub_binding_helper:
  63         subl            $STACK_SIZE,%esp            # makes stack 16-byte aligned
  64         movl            %eax,EAX_SAVE(%esp)
  65         movl            LP_OLD_BP_SAVE(%esp),%eax   # get lazy-pointer meta-parameter
  66         movl            %eax,LP_LOCAL(%esp)
  67         movl            %ebp,LP_OLD_BP_SAVE(%esp)   # store epb back chain
  68         movl            %esp,%ebp                   # set epb to be this frame
  69         add             $LP_OLD_BP_SAVE,%ebp
  70         movl            %ecx,ECX_SAVE(%esp)
  71         movl            %edx,EDX_SAVE(%esp)
  72         .align 0,0x90
  73 _misaligned_stack_error:
  74         movdqa          %xmm0,XMMM0_SAVE(%esp)
  75         movdqa          %xmm1,XMMM1_SAVE(%esp)
  76         movdqa          %xmm2,XMMM2_SAVE(%esp)
  77         movdqa          %xmm3,XMMM3_SAVE(%esp)
  78 _stub_binding_helper_interface2:
  79         movl            MH_LOCAL(%esp),%eax     # call dyld::bindLazySymbol(mh, lazy_ptr)
  80         movl            %eax,MH_PARAM_OUT(%esp)
  81         movl            LP_LOCAL(%esp),%eax
  82         movl            %eax,LP_PARAM_OUT(%esp)
  83         call            __ZN4dyld14bindLazySymbolEPK11mach_headerPm
  84         movdqa          XMMM0_SAVE(%esp),%xmm0  # restore registers
  85         movdqa          XMMM1_SAVE(%esp),%xmm1
  86         movdqa          XMMM2_SAVE(%esp),%xmm2
  87         movdqa          XMMM3_SAVE(%esp),%xmm3
  88         movl            ECX_SAVE(%esp),%ecx
  89         movl            EDX_SAVE(%esp),%edx
  90         movl            %eax,%ebp               # move target address to epb
  91         movl            EAX_SAVE(%esp),%eax     # restore eaz
  92         addl            $STACK_SIZE+4,%esp      # cut back stack
  93         xchg            %ebp, (%esp)            # restore ebp and set target to top of stack
  94         ret                                     # jump to target
  95
  96 #endif /* __i386__ */
  97
  98
  99 #if __x86_64__
 100 /*
 101  * This is the interface for the stub_binding_helper for x86_64:
 102  * The caller has pushed the address of the a lazy pointer to be filled in with
 103  * the value for the defined symbol and pushed the address of the the mach
 104  * header this pointer comes from.
 105  *
 106  * sp+8 address of lazy pointer
 107  * sp+0 address of mach header
 108  *
 109  * All parameters registers must be preserved.
 110  *
 111  * After the symbol has been resolved and the pointer filled in this is to pop
 112  * these arguments off the stack and jump to the address of the defined symbol.
 113  */
 114 #define MH_PARAM_BP                     8
 115 #define LP_PARAM_BP                     16
 116
 117 #define RDI_SAVE                        0
 118 #define RSI_SAVE                        8
 119 #define RDX_SAVE                        16
 120 #define RCX_SAVE                        24
 121 #define R8_SAVE                         32
 122 #define R9_SAVE                         40
 123 #define RAX_SAVE                        48
 124 #define XMMM0_SAVE                      64    /* 16-byte align */
 125 #define XMMM1_SAVE                      80
 126 #define XMMM2_SAVE                      96
 127 #define XMMM3_SAVE                      112
 128 #define XMMM4_SAVE                      128
 129 #define XMMM5_SAVE                      144
 130 #define XMMM6_SAVE                      160
 131 #define XMMM7_SAVE                      176
 132 #define STACK_SIZE                      192 /*  (XMMM7_SAVE+16) must be 16 byte aligned too */
 133
 134     .text
 135     .align 2,0x90
 136     .globl _stub_binding_helper
 137 _stub_binding_helper:
 138         pushq           %rbp
 139         movq            %rsp,%rbp
 140         subq            $STACK_SIZE,%rsp        # at this point stack is 16-byte aligned because two meta-parameters where pushed
 141         movq            %rdi,RDI_SAVE(%rsp)     # save registers that might be used as parameters
 142         movq            %rsi,RSI_SAVE(%rsp)
 143         movq            %rdx,RDX_SAVE(%rsp)
 144         movq            %rcx,RCX_SAVE(%rsp)
 145         movq            %r8,R8_SAVE(%rsp)
 146         movq            %r9,R9_SAVE(%rsp)
 147         movq            %rax,RAX_SAVE(%rsp)
 148         movdqa          %xmm0,XMMM0_SAVE(%rsp)
 149         movdqa          %xmm1,XMMM1_SAVE(%rsp)
 150         movdqa          %xmm2,XMMM2_SAVE(%rsp)
 151         movdqa          %xmm3,XMMM3_SAVE(%rsp)
 152         movdqa          %xmm4,XMMM4_SAVE(%rsp)
 153         movdqa          %xmm5,XMMM5_SAVE(%rsp)
 154         movdqa          %xmm6,XMMM6_SAVE(%rsp)
 155         movdqa          %xmm7,XMMM7_SAVE(%rsp)
 156         movq            MH_PARAM_BP(%rbp),%rdi  # call dyld::bindLazySymbol(mh, lazy_ptr)
 157         movq            LP_PARAM_BP(%rbp),%rsi
 158         call            __ZN4dyld14bindLazySymbolEPK11mach_headerPm
 159         movq            %rax,%r11               # save target
 160         movdqa          XMMM0_SAVE(%rsp),%xmm0  # restore registers
 161         movdqa          XMMM1_SAVE(%rsp),%xmm1
 162         movdqa          XMMM2_SAVE(%rsp),%xmm2
 163         movdqa          XMMM3_SAVE(%rsp),%xmm3
 164         movdqa          XMMM4_SAVE(%rsp),%xmm4
 165         movdqa          XMMM5_SAVE(%rsp),%xmm5
 166         movdqa          XMMM6_SAVE(%rsp),%xmm6
 167         movdqa          XMMM7_SAVE(%rsp),%xmm7
 168         movq            RDI_SAVE(%rsp),%rdi
 169         movq            RSI_SAVE(%rsp),%rsi
 170         movq            RDX_SAVE(%rsp),%rdx
 171         movq            RCX_SAVE(%rsp),%rcx
 172         movq            R8_SAVE(%rsp),%r8
 173         movq            R9_SAVE(%rsp),%r9
 174         movq            RAX_SAVE(%rsp),%rax
 175         addq            $STACK_SIZE,%rsp
 176         popq            %rbp
 177         addq            $16,%rsp                # remove meta-parameters
 178         jmp             *%r11                   # jmp to target
 179
 180 #endif
 181
 182
 183 #if __arm__ && !__ARM_ARCH_7K__
 184 /*
 185  * This is the interface for the old stub_binding_helper for ARM:
 186  * The caller has pushed the address of the a lazy pointer to be filled in with
 187  * the value for the defined symbol and pushed the address of the the mach
 188  * header this pointer comes from.
 189  *
 190  * sp+4        address of lazy pointer
 191  * sp+0        address of mach header
 192  *
 193  * After the symbol has been resolved and the pointer filled in this is to pop
 194  * these arguments off the stack and jump to the address of the defined symbol.
 195  */
 196
 197         .text
 198         .align 2
 199         .globl  _stub_binding_helper
 200 _stub_binding_helper:
 201         stmfd   sp!, {r0,r1,r2,r3,r7,lr}        // save registers
 202         add     r7, sp, #16                     // point FP to previous FP
 203
 204         ldr     r0, [sp, #24]                   // move address of mach header to 1st parameter
 205         ldr     r1, [sp, #28]                   // move address of lazy pointer to 2nd parameter
 206
 207         // call dyld::bindLazySymbol(mh, lazy_symbol_pointer_address)
 208         bl      __ZN4dyld14bindLazySymbolEPK11mach_headerPm
 209         mov     ip, r0                          // move the symbol`s address into ip
 210
 211         ldmfd   sp!, {r0,r1,r2,r3,r7,lr}        // restore registers
 212         add     sp, sp, #8                      // remove meta-parameters
 213
 214         bx      ip                              // jump to the symbol`s address that was bound
 215
 216 #endif /* __arm__ */
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