gcc/config/pa/pa32-linux.h

   1 /* Definitions for PA_RISC with ELF-32 format
   2    Copyright (C) 2000, 2002 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GCC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21 /* Turn off various SOM crap we don't want.  */
  22 #undef TARGET_ELF32
  23 #define TARGET_ELF32 1
  24
  25 /* The libcall __canonicalize_funcptr_for_compare is referenced in
  26    crtend.o and the reference isn't resolved in objects that don't
  27    compare function pointers.  Thus, we need to play games to provide
  28    a reference in crtbegin.o.  The rest of the define is the same
  29    as that in crtstuff.c  */
  30 #define CTOR_LIST_BEGIN \
  31   asm (".type __canonicalize_funcptr_for_compare,@function\n"           \
  32 "       .text\n"                                                        \
  33 "       .word __canonicalize_funcptr_for_compare-$PIC_pcrel$0");        \
  34   STATIC func_ptr __CTOR_LIST__[1]                                      \
  35     __attribute__ ((__unused__, section(".ctors"),                      \
  36                     aligned(sizeof(func_ptr))))                         \
  37     = { (func_ptr) (-1) }
  38
  39 /* Do code reading to identify a signal frame, and set the frame
  40    state data appropriately.  See unwind-dw2.c for the structs.  */
  41
  42 #ifdef IN_LIBGCC2
  43 #include <signal.h>
  44 #include <sys/ucontext.h>
  45
  46 /* Unfortunately, because of various bugs and changes to the kernel,
  47    we have several cases to deal with.
  48
  49    In 2.4, the signal trampoline is 4 words, and (CONTEXT)->ra should
  50    point directly at the beginning of the trampoline and struct rt_sigframe.
  51
  52    In <= 2.6.5-rc2-pa3, the signal trampoline is 9 words, and
  53    (CONTEXT)->ra points at the 4th word in the trampoline structure.  This
  54    is wrong, it should point at the 5th word.  This is fixed in 2.6.5-rc2-pa4.
  55
  56    To detect these cases, we first take (CONTEXT)->ra, align it to 64-bytes
  57    to get the beginning of the signal frame, and then check offsets 0, 4
  58    and 5 to see if we found the beginning of the trampoline.  This will
  59    tell us how to locate the sigcontext structure.
  60
  61    Note that with a 2.4 64-bit kernel, the signal context is not properly
  62    passed back to userspace so the unwind will not work correctly.  */
  63 #define MD_FALLBACK_FRAME_STATE_FOR(CONTEXT, FS, SUCCESS)               \
  64   do {                                                                  \
  65     unsigned long sp = (unsigned long)(CONTEXT)->ra & ~63;              \
  66     unsigned int *pc = (unsigned int *)sp;                              \
  67     unsigned long off;                                                  \
  68     _Unwind_Ptr new_cfa;                                                \
  69     int i;                                                              \
  70     struct sigcontext *sc;                                              \
  71     struct rt_sigframe {                                                \
  72       struct siginfo info;                                              \
  73       struct ucontext uc;                                               \
  74     } *frame;                                                           \
  75                                                                         \
  76     /* rt_sigreturn trampoline:                                         \
  77        3419000x ldi 0, %r25 or ldi 1, %r25   (x = 0 or 2)               \
  78        3414015a ldi __NR_rt_sigreturn, %r20                             \
  79        e4008200 be,l 0x100(%sr2, %r0), %sr0, %r31                       \
  80        08000240 nop  */                                                 \
  81                                                                         \
  82     if (pc[0] == 0x34190000 || pc[0] == 0x34190002)                     \
  83       off = 4*4;                                                        \
  84     else if (pc[4] == 0x34190000 || pc[4] == 0x34190002)                \
  85       {                                                                 \
  86         pc += 4;                                                        \
  87         off = 10 * 4;                                                   \
  88       }                                                                 \
  89     else if (pc[5] == 0x34190000 || pc[5] == 0x34190002)                \
  90       {                                                                 \
  91         pc += 5;                                                        \
  92         off = 10 * 4;                                                   \
  93       }                                                                 \
  94     else                                                                \
  95       break;                                                            \
  96     if (pc[1] != 0x3414015a                                             \
  97         || pc[2] != 0xe4008200                                          \
  98         || pc[3] != 0x08000240)                                         \
  99       break;                                                            \
 100                                                                         \
 101     frame = (struct rt_sigframe *)(sp + off);                           \
 102     sc = &frame->uc.uc_mcontext;                                        \
 103                                                                         \
 104     new_cfa = sc->sc_gr[30];                                            \
 105     (FS)->cfa_how = CFA_REG_OFFSET;                                     \
 106     (FS)->cfa_reg = 30;                                                 \
 107     (FS)->cfa_offset = new_cfa - (long) (CONTEXT)->cfa;                 \
 108     for (i = 1; i <= 31; i++)                                           \
 109       {                                                                 \
 110         (FS)->regs.reg[i].how = REG_SAVED_OFFSET;                       \
 111         (FS)->regs.reg[i].loc.offset = (long)&sc->sc_gr[i] - new_cfa;   \
 112       }                                                                 \
 113     for (i = 4; i <= 31; i++)                                           \
 114       {                                                                 \
 115         /* FP regs have left and right halves */                        \
 116         (FS)->regs.reg[2*i+24].how = REG_SAVED_OFFSET;                  \
 117         (FS)->regs.reg[2*i+24].loc.offset                               \
 118           = (long)&sc->sc_fr[i] - new_cfa;                              \
 119         (FS)->regs.reg[2*i+24+1].how = REG_SAVED_OFFSET;                \
 120         (FS)->regs.reg[2*i+24+1].loc.offset                             \
 121           = (long)&sc->sc_fr[i] + 4 - new_cfa;                          \
 122       }                                                                 \
 123     (FS)->regs.reg[88].how = REG_SAVED_OFFSET;                          \
 124     (FS)->regs.reg[88].loc.offset = (long) &sc->sc_sar - new_cfa;       \
 125     (FS)->regs.reg[2].how = REG_SAVED_OFFSET;                           \
 126     (FS)->regs.reg[2].loc.offset = (long) &sc->sc_iaoq[0] - new_cfa;    \
 127     (FS)->retaddr_column = 2;                                           \
 128     goto SUCCESS;                                                       \
 129   } while (0)
 130
 131 #endif /* IN_LIBGCC2 */