arch/ia64/ia32/ia32_traps.c

   1 /*
   2  * IA-32 exception handlers
   3  *
   4  * Copyright (C) 2000 Asit K. Mallick <asit.k.mallick@intel.com>
   5  * Copyright (C) 2001-2002 Hewlett-Packard Co
   6  *      David Mosberger-Tang <davidm@hpl.hp.com>
   7  *
   8  * 06/16/00     A. Mallick      added siginfo for most cases (close to IA32)
   9  * 09/29/00     D. Mosberger    added ia32_intercept()
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/sched.h>
  14
  15 #include "ia32priv.h"
  16
  17 #include <asm/intrinsics.h>
  18 #include <asm/ptrace.h>
  19
  20 int
  21 ia32_intercept (struct pt_regs *regs, unsigned long isr)
  22 {
  23         switch ((isr >> 16) & 0xff) {
  24               case 0:   /* Instruction intercept fault */
  25               case 4:   /* Locked Data reference fault */
  26               case 1:   /* Gate intercept trap */
  27                 return -1;
  28
  29               case 2:   /* System flag trap */
  30                 if (((isr >> 14) & 0x3) >= 2) {
  31                         /* MOV SS, POP SS instructions */
  32                         ia64_psr(regs)->id = 1;
  33                         return 0;
  34                 } else
  35                         return -1;
  36         }
  37         return -1;
  38 }
  39
  40 int
  41 ia32_exception (struct pt_regs *regs, unsigned long isr)
  42 {
  43         struct siginfo siginfo;
  44
  45         /* initialize these fields to avoid leaking kernel bits to user space: */
  46         siginfo.si_errno = 0;
  47         siginfo.si_flags = 0;
  48         siginfo.si_isr = 0;
  49         siginfo.si_imm = 0;
  50         switch ((isr >> 16) & 0xff) {
  51               case 1:
  52               case 2:
  53                 siginfo.si_signo = SIGTRAP;
  54                 if (isr == 0)
  55                         siginfo.si_code = TRAP_TRACE;
  56                 else if (isr & 0x4)
  57                         siginfo.si_code = TRAP_BRANCH;
  58                 else
  59                         siginfo.si_code = TRAP_BRKPT;
  60                 break;
  61
  62               case 3:
  63                 siginfo.si_signo = SIGTRAP;
  64                 siginfo.si_code = TRAP_BRKPT;
  65                 break;
  66
  67               case 0:   /* Divide fault */
  68                 siginfo.si_signo = SIGFPE;
  69                 siginfo.si_code = FPE_INTDIV;
  70                 break;
  71
  72               case 4:   /* Overflow */
  73               case 5:   /* Bounds fault */
  74                 siginfo.si_signo = SIGFPE;
  75                 siginfo.si_code = 0;
  76                 break;
  77
  78               case 6:   /* Invalid Op-code */
  79                 siginfo.si_signo = SIGILL;
  80                 siginfo.si_code = ILL_ILLOPN;
  81                 break;
  82
  83               case 7:   /* FP DNA */
  84               case 8:   /* Double Fault */
  85               case 9:   /* Invalid TSS */
  86               case 11:  /* Segment not present */
  87               case 12:  /* Stack fault */
  88               case 13:  /* General Protection Fault */
  89                 siginfo.si_signo = SIGSEGV;
  90                 siginfo.si_code = 0;
  91                 break;
  92
  93               case 16:  /* Pending FP error */
  94                 {
  95                         unsigned long fsr, fcr;
  96
  97                         fsr = ia64_getreg(_IA64_REG_AR_FSR);
  98                         fcr = ia64_getreg(_IA64_REG_AR_FCR);
  99
 100                         siginfo.si_signo = SIGFPE;
 101                         /*
 102                          * (~cwd & swd) will mask out exceptions that are not set to unmasked
 103                          * status.  0x3f is the exception bits in these regs, 0x200 is the
 104                          * C1 reg you need in case of a stack fault, 0x040 is the stack
 105                          * fault bit.  We should only be taking one exception at a time,
 106                          * so if this combination doesn't produce any single exception,
 107                          * then we have a bad program that isn't synchronizing its FPU usage
 108                          * and it will suffer the consequences since we won't be able to
 109                          * fully reproduce the context of the exception
 110                          */
 111                         siginfo.si_isr = isr;
 112                         siginfo.si_flags = __ISR_VALID;
 113                         switch(((~fcr) & (fsr & 0x3f)) | (fsr & 0x240)) {
 114                                 case 0x000:
 115                                 default:
 116                                         siginfo.si_code = 0;
 117                                         break;
 118                                 case 0x001: /* Invalid Op */
 119                                 case 0x040: /* Stack Fault */
 120                                 case 0x240: /* Stack Fault | Direction */
 121                                         siginfo.si_code = FPE_FLTINV;
 122                                         break;
 123                                 case 0x002: /* Denormalize */
 124                                 case 0x010: /* Underflow */
 125                                         siginfo.si_code = FPE_FLTUND;
 126                                         break;
 127                                 case 0x004: /* Zero Divide */
 128                                         siginfo.si_code = FPE_FLTDIV;
 129                                         break;
 130                                 case 0x008: /* Overflow */
 131                                         siginfo.si_code = FPE_FLTOVF;
 132                                         break;
 133                                 case 0x020: /* Precision */
 134                                         siginfo.si_code = FPE_FLTRES;
 135                                         break;
 136                         }
 137
 138                         break;
 139                 }
 140
 141               case 17:  /* Alignment check */
 142                 siginfo.si_signo = SIGSEGV;
 143                 siginfo.si_code = BUS_ADRALN;
 144                 break;
 145
 146               case 19:  /* SSE Numeric error */
 147                 siginfo.si_signo = SIGFPE;
 148                 siginfo.si_code = 0;
 149                 break;
 150
 151               default:
 152                 return -1;
 153         }
 154         force_sig_info(siginfo.si_signo, &siginfo, current);
 155         return 0;
 156 }