gcc/ada/sigtramp-qnx.c

   1 /****************************************************************************
   2  *                                                                          *
   3  *                         GNAT COMPILER COMPONENTS                         *
   4  *                                                                          *
   5  *                             S I G T R A M P                              *
   6  *                                                                          *
   7  *                         Asm Implementation File                          *
   8  *                                                                          *
   9  *           Copyright (C) 2017-2018, Free Software Foundation, Inc.        *
  10  *                                                                          *
  11  * GNAT is free software;  you can  redistribute it  and/or modify it under *
  12  * terms of the  GNU General Public License as published  by the Free Soft- *
  13  * ware  Foundation;  either version 3,  or (at your option) any later ver- *
  14  * sion.  GNAT is distributed in the hope that it will be useful, but WITH- *
  15  * OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY *
  16  * or FITNESS FOR A PARTICULAR PURPOSE.                                     *
  17  *                                                                          *
  18  * As a special exception under Section 7 of GPL version 3, you are granted *
  19  * additional permissions described in the GCC Runtime Library Exception,   *
  20  * version 3.1, as published by the Free Software Foundation.               *
  21  *                                                                          *
  22  * In particular,  you can freely  distribute your programs  built with the *
  23  * GNAT Pro compiler, including any required library run-time units,  using *
  24  * any licensing terms  of your choosing.  See the AdaCore Software License *
  25  * for full details.                                                        *
  26  *                                                                          *
  27  * GNAT was originally developed  by the GNAT team at  New York University. *
  28  * Extensive contributions were provided by Ada Core Technologies Inc.      *
  29  *                                                                          *
  30  ****************************************************************************/
  31
  32 /**********************************************
  33  * QNX version of the __gnat_sigtramp service *
  34  **********************************************/
  35
  36 #include <ucontext.h>
  37
  38 #include "sigtramp.h"
  39 /* See sigtramp.h for a general explanation of functionality.  */
  40
  41 extern void __gnat_sigtramp_common
  42   (int signo, void *siginfo, void *sigcontext,
  43    __sigtramphandler_t * handler);
  44
  45 void __gnat_sigtramp (int signo, void *si, void *sc,
  46                       __sigtramphandler_t * handler)
  47      __attribute__((optimize(2)));
  48
  49 void __gnat_sigtramp (int signo, void *si, void *ucontext,
  50                       __sigtramphandler_t * handler)
  51 {
  52   struct sigcontext *mcontext = &((ucontext_t *) ucontext)->uc_mcontext;
  53
  54   __gnat_sigtramp_common (signo, si, mcontext, handler);
  55 }
  56
  57 /* asm string construction helpers.  */
  58
  59 #define STR(TEXT) #TEXT
  60 /* stringify expanded TEXT, surrounding it with double quotes.  */
  61
  62 #define S(E) STR(E)
  63 /* stringify E, which will resolve as text but may contain macros
  64    still to be expanded.  */
  65
  66 /* asm (TEXT) outputs <tab>TEXT. These facilitate the output of
  67    multiline contents:  */
  68 #define TAB(S) "\t" S
  69 #define CR(S)  S "\n"
  70
  71 #undef TCR
  72 #define TCR(S) TAB(CR(S))
  73
  74 /* Trampoline body block
  75    ---------------------  */
  76
  77 #define COMMON_CFI(REG) \
  78   ".cfi_offset " S(REGNO_##REG) "," S(REG_OFFSET_##REG)
  79
  80 #ifdef __x86_64__
  81 /*****************************************
  82  *               x86-64                  *
  83  *****************************************/
  84
  85 // CFI register numbers
  86 #define REGNO_RAX 0
  87 #define REGNO_RDX 1
  88 #define REGNO_RCX 2
  89 #define REGNO_RBX 3
  90 #define REGNO_RSI 4
  91 #define REGNO_RDI 5
  92 #define REGNO_RBP 6
  93 #define REGNO_RSP 7
  94 #define REGNO_R8 8
  95 #define REGNO_R9 9
  96 #define REGNO_R10 10
  97 #define REGNO_R11 11
  98 #define REGNO_R12 12
  99 #define REGNO_R13 13
 100 #define REGNO_R14 14
 101 #define REGNO_R15 15 /* Used as CFA */
 102 #define REGNO_RPC 16 /* aka %rip */
 103
 104 //  Registers offset from the regset structure
 105 #define REG_OFFSET_RDI 0x00
 106 #define REG_OFFSET_RSI 0x08
 107 #define REG_OFFSET_RDX 0x10
 108 #define REG_OFFSET_R10 0x18
 109 #define REG_OFFSET_R8  0x20
 110 #define REG_OFFSET_R9  0x28
 111 #define REG_OFFSET_RAX 0x30
 112 #define REG_OFFSET_RBX 0x38
 113 #define REG_OFFSET_RBP 0x40
 114 #define REG_OFFSET_RCX 0x48
 115 #define REG_OFFSET_R11 0x50
 116 #define REG_OFFSET_R12 0x58
 117 #define REG_OFFSET_R13 0x60
 118 #define REG_OFFSET_R14 0x68
 119 #define REG_OFFSET_R15 0x70
 120 #define REG_OFFSET_RPC 0x78 /* RIP */
 121 #define REG_OFFSET_RSP 0x90
 122
 123 #define CFI_COMMON_REGS \
 124 CR("# CFI for common registers\n") \
 125 TCR(COMMON_CFI(RSP)) \
 126 TCR(COMMON_CFI(R15)) \
 127 TCR(COMMON_CFI(R14)) \
 128 TCR(COMMON_CFI(R13)) \
 129 TCR(COMMON_CFI(R12)) \
 130 TCR(COMMON_CFI(R11)) \
 131 TCR(COMMON_CFI(RCX)) \
 132 TCR(COMMON_CFI(RBP)) \
 133 TCR(COMMON_CFI(RBX)) \
 134 TCR(COMMON_CFI(RAX)) \
 135 TCR(COMMON_CFI(R9)) \
 136 TCR(COMMON_CFI(R8)) \
 137 TCR(COMMON_CFI(R10)) \
 138 TCR(COMMON_CFI(RSI)) \
 139 TCR(COMMON_CFI(RDI)) \
 140 TCR(COMMON_CFI(RDX)) \
 141 TCR(COMMON_CFI(RPC)) \
 142 TCR(".cfi_return_column " S(REGNO_RPC))
 143
 144 #define SIGTRAMP_BODY     \
 145 TCR(".cfi_def_cfa 15, 0") \
 146 CFI_COMMON_REGS \
 147 CR("") \
 148 TCR("# Allocate frame and save the non-volatile") \
 149 TCR("# registers we're going to modify") \
 150 TCR("subq       $8, %rsp") \
 151 TCR("# Setup CFA_REG = context, which we'll retrieve as our CFA value") \
 152 TCR("movq       %rdx, %r15") \
 153 TCR("# Call the real handler. The signo, siginfo and sigcontext") \
 154 TCR("# arguments are the same as those we received") \
 155 TCR("call       *%rcx") \
 156 TCR("# This part should never be executed") \
 157 TCR("addq       $8, %rsp") \
 158 TCR("ret")
 159 #endif
 160
 161 #ifdef __aarch64__
 162 /*****************************************
 163  *               Aarch64                 *
 164  *****************************************/
 165
 166 /* CFA reg: any callee saved register will do */
 167 #define CFA_REG  19
 168
 169 /* General purpose registers */
 170 #define REG_OFFSET_GR(n)     (n * 8)
 171 #define REGNO_GR(n)   n
 172
 173 /* ELR value offset withing the mcontext registers list */
 174 #define REG_OFFSET_ELR           (32 * 8)
 175 /* The register used to hold the PC value to restore. We need a scratch
 176    register.  */
 177 #define REGNO_PC      9
 178
 179 #define CFI_DEF_CFA \
 180   TCR(".cfi_def_cfa " S(CFA_REG) ", 0")
 181
 182 /* This restores the callee-saved registers, the FP, the LR, and the SP.
 183    A scratch register is used as return column to indicate the new value
 184    for PC */
 185 #define CFI_COMMON_REGS \
 186   CR("# CFI for common registers\n") \
 187   TCR(COMMON_CFI(GR(18))) \
 188   TCR(COMMON_CFI(GR(19))) \
 189   TCR(COMMON_CFI(GR(20))) \
 190   TCR(COMMON_CFI(GR(21))) \
 191   TCR(COMMON_CFI(GR(22))) \
 192   TCR(COMMON_CFI(GR(23))) \
 193   TCR(COMMON_CFI(GR(24))) \
 194   TCR(COMMON_CFI(GR(25))) \
 195   TCR(COMMON_CFI(GR(26))) \
 196   TCR(COMMON_CFI(GR(27))) \
 197   TCR(COMMON_CFI(GR(28))) \
 198   TCR(COMMON_CFI(GR(29))) \
 199   TCR(COMMON_CFI(GR(30))) \
 200   TCR(COMMON_CFI(GR(31))) \
 201   TCR(".cfi_offset " S(REGNO_PC) "," S(REG_OFFSET_ELR)) \
 202   TCR(".cfi_return_column " S(REGNO_PC))
 203
 204 #define SIGTRAMP_BODY \
 205   CFI_DEF_CFA \
 206   CFI_COMMON_REGS \
 207   TCR("# Allocate the frame (16bytes aligned) and push FP and LR") \
 208   TCR("stp x29, x30, [sp, #-32]!") \
 209   TCR("add x29, sp, 0") \
 210   TCR("# Push register used to hold the CFA on stack") \
 211   TCR("str x" S(CFA_REG) ", [sp, 16]")  \
 212   TCR("# Set the CFA: x2 value") \
 213   TCR("mov x" S(CFA_REG) ", x2") \
 214   TCR("# Call the handler") \
 215   TCR("blr x3") \
 216   TCR("# Release our frame and return (should never get here!).") \
 217   TCR("ldr x" S(CFA_REG) ", [sp, 16]") \
 218   TCR("ldp x29, x30, [sp], 32") \
 219   TCR("ret")
 220
 221 #endif /* AARCH64 */
 222
 223 /* Symbol definition block
 224    -----------------------  */
 225
 226 #if defined (__x86_64__) || defined (__aarch64__)
 227 #define FUNC_ALIGN TCR(".p2align 4,,15")
 228 #else
 229 #define FUNC_ALIGN
 230 #endif
 231
 232 #define SIGTRAMP_START(SYM)       \
 233 CR("# " S(SYM) " cfi trampoline") \
 234 TCR(".type " S(SYM) ", @function") \
 235 CR("") \
 236 FUNC_ALIGN \
 237 CR(S(SYM) ":") \
 238 TCR(".cfi_startproc") \
 239 TCR(".cfi_signal_frame")
 240
 241 /* Symbol termination block
 242    ------------------------  */
 243
 244 #define SIGTRAMP_END(SYM) \
 245 CR(".cfi_endproc") \
 246 TCR(".size " S(SYM) ", .-" S(SYM))
 247
 248 /*----------------------------
 249   -- And now, the real code --
 250   ---------------------------- */
 251
 252 /* Text section start.  The compiler isn't aware of that switch.  */
 253
 254 asm (".text\n"
 255      TCR(".align 2"));
 256
 257 /* sigtramp stub for common registers.  */
 258
 259 #define TRAMP_COMMON __gnat_sigtramp_common
 260
 261 asm (SIGTRAMP_START(TRAMP_COMMON));
 262 asm (SIGTRAMP_BODY);
 263 asm (SIGTRAMP_END(TRAMP_COMMON));