| 1 | // i386-signal.h - Catch runtime signals and turn them into exceptions
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| 2 | // on an i386 based Linux system.
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| 3 |
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| 4 | /* Copyright (C) 1998, 1999, 2001, 2002 Free Software Foundation
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| 5 |
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| 6 | This file is part of libgcj.
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| 7 |
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| 8 | This software is copyrighted work licensed under the terms of the
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| 9 | Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
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| 10 | details. */
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| 11 |
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| 12 |
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| 13 | #ifndef JAVA_SIGNAL_H
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| 14 | #define JAVA_SIGNAL_H 1
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| 15 |
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| 16 | #include <signal.h>
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| 17 | #include <sys/syscall.h>
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| 18 |
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| 19 | #define HANDLE_SEGV 1
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| 20 | #define HANDLE_FPE 1
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| 21 |
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| 22 | #define SIGNAL_HANDLER(_name) \
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| 23 | static void _name (int _dummy)
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| 24 |
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| 25 | #define MAKE_THROW_FRAME(_exception) \
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| 26 | do \
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| 27 | { \
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| 28 | void **_p = (void **)&_dummy; \
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| 29 | struct sigcontext_struct *_regs = (struct sigcontext_struct *)++_p; \
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| 30 | \
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| 31 | /* Advance the program counter so that it is after the start of the \
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| 32 | instruction: the x86 exception handler expects \
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| 33 | the PC to point to the instruction after a call. */ \
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| 34 | _regs->eip += 2; \
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| 35 | \
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| 36 | } \
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| 37 | while (0)
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| 38 |
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| 39 | #define HANDLE_DIVIDE_OVERFLOW \
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| 40 | do \
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| 41 | { \
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| 42 | void **_p = (void **)&_dummy; \
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| 43 | struct sigcontext_struct *_regs = (struct sigcontext_struct *)++_p; \
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| 44 | \
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| 45 | register unsigned char *_eip = (unsigned char *)_regs->eip; \
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| 46 | \
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| 47 | /* According to the JVM spec, "if the dividend is the negative \
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| 48 | * integer of the smallest magnitude and the divisor is -1, then \
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| 49 | * overflow occurs and the result is equal to the dividend. Despite \
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| 50 | * the overflow, no exception occurs". \
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| 51 | \
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| 52 | * We handle this by inspecting the instruction which generated the \
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| 53 | * signal and advancing eip to point to the following instruction. \
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| 54 | * As the instructions are variable length it is necessary to do a \
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| 55 | * little calculation to figure out where the following instruction \
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| 56 | * actually is. \
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| 57 | \
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| 58 | */ \
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| 59 | \
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| 60 | if (_eip[0] == 0xf7) \
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| 61 | { \
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| 62 | unsigned char _modrm = _eip[1]; \
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| 63 | \
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| 64 | if (_regs->eax == 0x80000000 \
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| 65 | && ((_modrm >> 3) & 7) == 7) /* Signed divide */ \
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| 66 | { \
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| 67 | _regs->edx = 0; /* the remainder is zero */ \
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| 68 | switch (_modrm >> 6) \
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| 69 | { \
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| 70 | case 0: \
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| 71 | if ((_modrm & 7) == 5) \
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| 72 | _eip += 4; \
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| 73 | break; \
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| 74 | case 1: \
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| 75 | _eip += 1; \
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| 76 | break; \
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| 77 | case 2: \
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| 78 | _eip += 4; \
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| 79 | break; \
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| 80 | case 3: \
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| 81 | break; \
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| 82 | } \
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| 83 | _eip += 2; \
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| 84 | _regs->eip = (unsigned long)_eip; \
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| 85 | return; \
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| 86 | } \
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| 87 | else \
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| 88 | { \
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| 89 | /* Advance the program counter so that it is after the start \
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