src/setjmp/x86_64/_sigtramp.s

   1 /*
   2  * Copyright (c) 2007, 2011 Apple 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 #include <sys/syscall.h>
  25
  26 #define UC_TRAD                 1
  27 #define UC_FLAVOR               30
  28
  29 /* Structure fields for ucontext and mcontext.  */
  30 #define UCONTEXT_UC_MCONTEXT    48
  31
  32 #define MCONTEXT_ES_EXCEPTION   0
  33 #define MCONTEXT_SS_RAX         16
  34 #define MCONTEXT_SS_RBX         24
  35 #define MCONTEXT_SS_RCX         32
  36 #define MCONTEXT_SS_RDX         40
  37 #define MCONTEXT_SS_RDI         48
  38 #define MCONTEXT_SS_RSI         56
  39 #define MCONTEXT_SS_RBP         64
  40 #define MCONTEXT_SS_RSP         72
  41 #define MCONTEXT_SS_R8          80
  42 #define MCONTEXT_SS_RIP         144
  43
  44 /* register use:
  45         %rbx    uctx
  46         %r12    token
  47
  48 void
  49 _sigtramp(
  50         union __sigaction_u __sigaction_u,      %rdi
  51         int                     sigstyle,       %rsi
  52         int                     sig,            %rdx
  53         siginfo_t               *sinfo,         %rcx
  54         ucontext_t              *uctx           %r8
  55         uintptr_t               token           %r8
  56 )
  57 */
  58
  59 #if RDAR_35834092
  60         .private_extern __sigtramp
  61 #endif
  62         .globl __sigtramp
  63         .text
  64         .align 4,0x90
  65 __sigtramp:
  66 Lstart:
  67         /* Although this routine does not need any stack frame, various parts
  68            of the OS can't analyse the stack without them.  */
  69         pushq   %rbp
  70         movq    %rsp, %rbp
  71
  72         movq    %rdi, %rax      # set up address for call
  73
  74 #if defined(__DYNAMIC__)
  75         incl    ___in_sigtramp(%rip)
  76 #endif
  77         /* Save uctx in %rbx.  */
  78         movq    %r8, %rbx
  79         /* Save token in %r12.  */
  80         movq    %r9, %r12
  81         /* Call the signal handler.
  82            Some variants are not supposed to get the last two parameters,
  83            but the test to prevent this is more expensive than just passing
  84            them.  */
  85         movl    %edx, %edi
  86         movq    %rcx, %rsi
  87         movq    %r8, %rdx
  88 Lcall_start:
  89         call    *%rax
  90 Lcall_end:
  91 #if defined(__DYNAMIC__)
  92         decl    ___in_sigtramp(%rip)
  93 #endif
  94         movq    %rbx, %rdi
  95         movl    $ UC_FLAVOR, %esi
  96         movq    %r12, %rdx
  97         callq   ___sigreturn
  98         ud2 /* __sigreturn returning is a fatal error */
  99         ret
 100 Lend:
 101
 102 /* DWARF unwind table #defines.  */
 103 #define DW_CFA_advance_loc_4 0x44
 104 #define DW_CFA_def_cfa 0x0c
 105 #define DW_CFA_def_cfa_expression 0x0F
 106 #define DW_CFA_expression 0x10
 107 #define DW_CFA_val_expression 0x16
 108 #define DW_CFA_offset(column) 0x80+(column)
 109
 110 /* DWARF expression #defines.  */
 111 #define DW_OP_deref 0x06
 112 #define DW_OP_const1u 0x08
 113 #define DW_OP_dup 0x12
 114 #define DW_OP_drop 0x13
 115 #define DW_OP_over 0x14
 116 #define DW_OP_pick 0x15
 117 #define DW_OP_swap 0x16
 118 #define DW_OP_rot 0x17
 119 #define DW_OP_abs 0x19
 120 #define DW_OP_and 0x1a
 121 #define DW_OP_div 0x1b
 122 #define DW_OP_minus 0x1c
 123 #define DW_OP_mod 0x1d
 124 #define DW_OP_mul 0x1e
 125 #define DW_OP_neg 0x1f
 126 #define DW_OP_not 0x20
 127 #define DW_OP_or 0x21
 128 #define DW_OP_plus 0x22
 129 #define DW_OP_plus_uconst 0x23
 130 #define DW_OP_shl 0x24
 131 #define DW_OP_shr 0x25
 132 #define DW_OP_shra 0x26
 133 #define DW_OP_xor 0x27
 134 #define DW_OP_skip 0x2f
 135 #define DW_OP_bra 0x28
 136 #define DW_OP_eq 0x29
 137 #define DW_OP_ge 0x2A
 138 #define DW_OP_gt 0x2B
 139 #define DW_OP_le 0x2C
 140 #define DW_OP_lt 0x2D
 141 #define DW_OP_ne 0x2E
 142 #define DW_OP_lit(n) 0x30+(n)
 143 #define DW_OP_breg(n) 0x70+(n)
 144 #define DW_OP_deref_size 0x94
 145
 146 /* The location expression we'll use.  */
 147
 148 #define loc_expr_for_reg(regno, offs)                           \
 149         .byte DW_CFA_expression, regno, 5 /* block length */,   \
 150          DW_OP_breg(3), UCONTEXT_UC_MCONTEXT, DW_OP_deref,      \
 151          DW_OP_plus_uconst, offs
 152
 153 /* For r8 through r13 */
 154 #define loc_expr_rN(regno) \
 155   loc_expr_for_reg(regno, MCONTEXT_SS_R8+(8*(regno-8)))
 156
 157 /* For r14 through r15 */
 158 #define loc_expr_rN_long(regno)                                         \
 159         .byte DW_CFA_expression, regno, 6 /* block length */,           \
 160          DW_OP_breg(3), UCONTEXT_UC_MCONTEXT, DW_OP_deref,              \
 161          DW_OP_plus_uconst, MCONTEXT_SS_R8+(8*(regno-8)), 1
 162
 163         /* Unwind tables.  */
 164         .section __TEXT,__eh_frame,coalesced,no_toc+strip_static_syms+live_support
 165 EH_frame1:
 166         .set L$set$0,LECIE1-LSCIE1
 167         .long L$set$0   # Length of Common Information Entry
 168 LSCIE1:
 169         .long   0       # CIE Identifier Tag
 170         .byte   0x1     # CIE Version
 171         .ascii "zRS\0"  # CIE Augmentation
 172         .byte   0x1     # uleb128 0x1; CIE Code Alignment Factor
 173         .byte   0x78    # sleb128 -8; CIE Data Alignment Factor
 174         .byte   0x10    # CIE RA Column
 175         .byte   0x1     # uleb128 0x1; Augmentation size
 176         .byte   0x10    # FDE Encoding (pcrel)
 177         .byte   DW_CFA_def_cfa
 178         .byte   0x7     # uleb128 0x5
 179         .byte   0x8     # uleb128 0x4
 180         .byte   DW_CFA_offset(16)
 181         .byte   0x1     # uleb128 0x1
 182         .byte   DW_CFA_offset(16)       // duplicate DW_CFA_offset (rip, -8) tells linker to not make compact unwind
 183         .byte   0x1     # uleb128 0x1
 184         .align 3
 185 LECIE1:
 186         .globl _sigtramp.eh
 187 _sigtramp.eh:
 188 LSFDE1:
 189         .set L$set$1,LEFDE1-LASFDE1
 190         .long L$set$1   # FDE Length
 191 LASFDE1:
 192         .long   LASFDE1-EH_frame1       # FDE CIE offset
 193         .quad   Lstart-.        # FDE initial location
 194         .set L$set$2,Lend-Lstart
 195         .quad   L$set$2 # FDE address range
 196         .byte   0x0     # uleb128 0x0; Augmentation size
 197
 198         /* Now for the expressions, which all compute
 199            uctx->uc_mcontext->register
 200            for each register.
 201
 202            Describe even the registers that are not call-saved because they
 203            might be being used in the prologue to save other registers.
 204            Only integer registers are described at present.    */
 205
 206         loc_expr_for_reg (0, MCONTEXT_SS_RAX)
 207         loc_expr_for_reg (1, MCONTEXT_SS_RDX)
 208         loc_expr_for_reg (2, MCONTEXT_SS_RCX)
 209         loc_expr_for_reg (3, MCONTEXT_SS_RBX)
 210         loc_expr_for_reg (4, MCONTEXT_SS_RSI)
 211         loc_expr_for_reg (5, MCONTEXT_SS_RDI)
 212         loc_expr_for_reg (6, MCONTEXT_SS_RBP)
 213         loc_expr_for_reg (7, MCONTEXT_SS_RSP)
 214         loc_expr_rN (8)
 215         loc_expr_rN (9)
 216         loc_expr_rN (10)
 217         loc_expr_rN (11)
 218         loc_expr_rN (12)
 219         loc_expr_rN (13)
 220         loc_expr_rN_long (14)
 221         loc_expr_rN_long (15)
 222
 223         /* The Intel architecture classifies exceptions into three categories,
 224            'faults' which put the address of the faulting instruction
 225            in EIP, 'traps' which put the following instruction in EIP,
 226            and 'aborts' which don't typically report the instruction
 227            causing the exception.
 228
 229            The traps are #BP and #OF.  */
 230
 231         .byte DW_CFA_val_expression, 16
 232         .set L$set$3,Lpc_end-Lpc_start
 233         .byte L$set$3
 234 Lpc_start:
 235         /* Push the mcontext address twice.  */
 236         .byte DW_OP_breg(3), UCONTEXT_UC_MCONTEXT, DW_OP_deref, DW_OP_dup
 237         /* Find the value of EIP.  */
 238         .byte   DW_OP_plus_uconst, MCONTEXT_SS_RIP, MCONTEXT_SS_RIP >> 7
 239         .byte   DW_OP_deref, DW_OP_swap
 240         /* Determine the exception type.  */
 241         .byte   DW_OP_plus_uconst, MCONTEXT_ES_EXCEPTION, DW_OP_deref_size, 4
 242         /* Check whether it is #BP (3) or #OF (4).  */
 243         .byte   DW_OP_dup, DW_OP_lit(3), DW_OP_ne
 244         .byte    DW_OP_swap, DW_OP_lit(4), DW_OP_ne, DW_OP_and
 245         /* If it is not, then add 1 to the instruction address, so as to point
 246            within or past the faulting instruction.  */
 247         .byte   DW_OP_plus
 248 Lpc_end:
 249
 250         /* The CFA will have been saved as the value of RSP (it is not
 251            RSP+8).  */
 252         .byte DW_CFA_def_cfa_expression
 253         .set L$set$4,Lcfa_end-Lcfa_start
 254         .byte L$set$4
 255 Lcfa_start:
 256         .byte DW_OP_breg(3), UCONTEXT_UC_MCONTEXT, DW_OP_deref
 257         .byte  DW_OP_plus_uconst, MCONTEXT_SS_RSP, DW_OP_deref
 258 Lcfa_end:
 259
 260         .align 3
 261 LEFDE1:
 262
 263         .subsections_via_symbols