221 lines
6.7 KiB
C
221 lines
6.7 KiB
C
// s390-signal.h - Catch runtime signals and turn them into exceptions
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// on an s390 based Linux system.
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/* Copyright (C) 2002 Free Software Foundation
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This file is part of libgcj.
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This software is copyrighted work licensed under the terms of the
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Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
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details. */
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#ifndef JAVA_SIGNAL_H
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#define JAVA_SIGNAL_H 1
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#include <signal.h>
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#include <sys/syscall.h>
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#include <ucontext.h>
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#include <limits.h>
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#define HANDLE_SEGV 1
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#define HANDLE_FPE 1
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#define SIGNAL_HANDLER(_name) \
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static void _name (int, siginfo_t *_si __attribute__((unused)), \
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ucontext_t *_uc __attribute__((unused)))
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/* We no longer need to fiddle with the PSW address in the signal handler;
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this is now all handled correctly in MD_FALLBACK_FRAME_STATE_FOR. */
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#define MAKE_THROW_FRAME(_exception)
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/* According to the JVM spec, "if the dividend is the negative integer
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of the smallest magnitude and the divisor is -1, then overflow occurs
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and the result is equal to the dividend. Despite the overflow, no
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exception occurs".
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We handle this by inspecting the instruction which generated the signal,
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and if dividend and divisor are as above, we simply return from the signal
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handler. This causes execution to continue after the instruction.
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Before returning, we the set result registers as expected. */
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#define HANDLE_DIVIDE_OVERFLOW \
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do \
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{ \
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unsigned char *_eip = (unsigned char *) \
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__builtin_extract_return_addr (_si->si_addr); \
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unsigned long *_regs = _uc->uc_mcontext.gregs; \
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int _r1, _r2, _d2, _x2, _b2; \
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\
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/* First, a couple of helper routines to decode instructions. */ \
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struct _decode \
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{ \
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/* Decode RR instruction format. */ \
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static inline int _is_rr (unsigned char *_eip, \
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unsigned char _op, \
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int *_r1, int *_r2) \
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{ \
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if (_eip[0] == _op) \
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{ \
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*_r1 = _eip[1] >> 4; \
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*_r2 = _eip[1] & 0xf; \
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return 1; \
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} \
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return 0; \
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} \
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\
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/* Decode RX instruction format. */ \
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static inline int _is_rx (unsigned char *_eip, \
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unsigned char _op, \
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int *_r1, int *_d2, int *_x2, int *_b2) \
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{ \
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if (_eip[0] == _op) \
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{ \
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*_r1 = _eip[1] >> 4; \
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*_x2 = _eip[1] & 0xf; \
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*_b2 = _eip[2] >> 4; \
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*_d2 = ((_eip[2] & 0xf) << 8) + _eip[3]; \
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return 1; \
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} \
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return 0; \
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} \
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\
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/* Decode RRE instruction format. */ \
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static inline int _is_rre (unsigned char *_eip, \
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unsigned char _op1, unsigned char _op2,\
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int *_r1, int *_r2) \
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{ \
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if (_eip[0] == _op1 && _eip[1] == _op2) \
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{ \
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*_r1 = _eip[3] >> 4; \
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*_r2 = _eip[3] & 0xf; \
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return 1; \
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} \
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return 0; \
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} \
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\
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/* Decode RXY instruction format. */ \
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static inline int _is_rxy (unsigned char *_eip, \
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unsigned char _op1, unsigned char _op2,\
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int *_r1, int *_d2, int *_x2, int *_b2)\
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{ \
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if (_eip[0] == _op1 && _eip[5] == _op2) \
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{ \
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*_r1 = _eip[1] >> 4; \
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*_x2 = _eip[1] & 0xf; \
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*_b2 = _eip[2] >> 4; \
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*_d2 = ((_eip[2] & 0xf) << 8) + _eip[3] + (_eip[4] << 12); \
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/* We have a 20-bit signed displacement. */ \
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*_d2 = (*_d2 ^ 0x80000) - 0x80000; \
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return 1; \
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} \
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return 0; \
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} \
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\
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/* Compute effective address. */ \
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static inline unsigned long _eff (unsigned long *_regs, \
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long _d, int _x, int _b) \
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{ \
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return _d + (_x? _regs[_x] : 0) + (_b? _regs[_b] : 0); \
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} \
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}; \
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\
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\
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/* DR r1,r2 */ \
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if (_decode::_is_rr (_eip, 0x1d, &_r1, &_r2) \
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&& (int) _regs[_r1] == -1 && (int) _regs[_r1+1] == INT_MIN \
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&& (int) _regs[_r2] == -1) \
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{ \
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_regs[_r1] &= ~0xffffffff; \
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return; \
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} \
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\
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/* D r1,d2(x2,b2) */ \
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if (_decode::_is_rx (_eip, 0x5d, &_r1, &_d2, &_x2, &_b2) \
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&& (int) _regs[_r1] == -1 && (int) _regs[_r1+1] == INT_MIN \
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&& *(int *) _decode::_eff (_regs, _d2, _x2, _b2) == -1) \
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{ \
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_regs[_r1] &= ~0xffffffff; \
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return; \
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} \
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\
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/* DSGR r1,r2 */ \
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if (_decode::_is_rre (_eip, 0xb9, 0x0d, &_r1, &_r2) \
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&& (long) _regs[_r1+1] == LONG_MIN \
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&& (long) _regs[_r2] == -1L) \
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{ \
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_regs[_r1] = 0; \
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return; \
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} \
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\
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/* DSGFR r1,r2 */ \
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if (_decode::_is_rre (_eip, 0xb9, 0x1d, &_r1, &_r2) \
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&& (long) _regs[_r1+1] == LONG_MIN \
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&& (int) _regs[_r2] == -1) \
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{ \
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_regs[_r1] = 0; \
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return; \
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} \
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\
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/* DSG r1,d2(x2,b2) */ \
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if (_decode::_is_rxy (_eip, 0xe3, 0x0d, &_r1, &_d2, &_x2, &_b2) \
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&& (long) _regs[_r1+1] == LONG_MIN \
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&& *(long *) _decode::_eff (_regs, _d2, _x2, _b2) == -1L) \
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{ \
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_regs[_r1] = 0; \
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return; \
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} \
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\
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/* DSGF r1,d2(x2,b2) */ \
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if (_decode::_is_rxy (_eip, 0xe3, 0x1d, &_r1, &_d2, &_x2, &_b2) \
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&& (long) _regs[_r1+1] == LONG_MIN \
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&& *(int *) _decode::_eff (_regs, _d2, _x2, _b2) == -1) \
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{ \
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_regs[_r1] = 0; \
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return; \
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} \
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\
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} \
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while (0)
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/* For an explanation why we cannot simply use sigaction to
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install the handlers, see i386-signal.h. */
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/* We use old_kernel_sigaction here because we're calling the kernel
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directly rather than via glibc. The sigaction structure that the
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syscall uses is a different shape from the one in userland and not
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visible to us in a header file so we define it here. */
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struct old_s390_kernel_sigaction {
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void (*k_sa_handler) (int, siginfo_t *, ucontext_t *);
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unsigned long k_sa_mask;
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unsigned long k_sa_flags;
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void (*sa_restorer) (void);
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};
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#define INIT_SEGV \
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do \
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{ \
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struct old_s390_kernel_sigaction kact; \
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kact.k_sa_handler = catch_segv; \
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kact.k_sa_mask = 0; \
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kact.k_sa_flags = SA_SIGINFO; \
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syscall (SYS_sigaction, SIGSEGV, &kact, NULL); \
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} \
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while (0)
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#define INIT_FPE \
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do \
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{ \
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struct old_s390_kernel_sigaction kact; \
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kact.k_sa_handler = catch_fpe; \
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kact.k_sa_mask = 0; \
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kact.k_sa_flags = SA_SIGINFO; \
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syscall (SYS_sigaction, SIGFPE, &kact, NULL); \
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} \
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while (0)
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#endif /* JAVA_SIGNAL_H */
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