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Пример 6 4 Обработчик арифметических



Пример 6.4. Обработчик арифметических исключений в ядре Linux I

/*

* Iinux/arch/i386/traps.c *
* Copyright (С) 1991, 1992 Linus Torvalds *
* Поддержка Pentium III FXSR, SSE
* Gareth Hughes <gareth@valinux.com>, May 2000 */
void die(const char * str, struct pt_regs * regs, long err) I
console_verbose(); spin_lock_irq(&die_lock); Printk("%s: %041x\n", str, err & Oxffff}; show_registers(regs);
sPin_unlock_irq(&die_lock);
do_exit (SIGSEGV) ;
static inline void die_if_kernel (const char * str, struct pt_regs * regs long err)
{
if ( ! (regs->eflags & VM_MASK) && ! (3 & regs->xcs) ) die (str, regs, err);
static inline unsigned long get_cr2 (void) { unsigned long address;
/* получить адрес */
_ asm _ ("movl %%cr2, %0" : "=r" (address));
return address;
static void inline do_trap(int trapnr, int signr, char *str, int vm86,
struct pt_regs * regs, long error_code, siginfo_t *info) { if (vm86 && regs->eflags & VM_MASK)
goto vm86_trap; if ( ! (regs->xcs & 3) ) goto kernel_trap;
trap_signal: {
struct task_struct *tsk = current; tsk->thread. error_code = error_code; tsk->thread. trap_no = trapnr; if (info)
force_sig_info (signr, info, tsk) ; else
force_sig (signr, tsk) ; return;
kernel_trap:
unsigned long fixup = search_exception_table(regs->eip); if (fixup)
regs->eip = fixup; else
die(str, regs, error_code); return;
vm86_trap: {
int ret = handle_vm86_trap((struct kernel_vm86_regs *) regs, er-ror_code, trapnr);
if (ret) goto trap_signal; return;
fldefine DO_ERROR(trapnr, signr, str, name) \
asmlinkage void do_tt#name(struct pt_regs * regs, long error_code) \ { \ do_trap(trapnr, signr, str, 0, regs, error_code, NULL); \
Idefine DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \ asmlinkage void do_t#name(struct pt_regs * regs, long error_code) \ { \
siginfo_t info; \
info.si_signo = signr; \
info.si_errno =0; \
info.si_code = sicode; \
info.si_addr = (void *)siaddr; \
do^trap(trapnr, signr, str, 0, regs, error_code, Sinfo); \ }
ttdefine DO_VM86_ERROR(trapnr, signr, str, name) \
asmlinkage void do_##name(struct pt_regs * regs, long error_code) \ ( \
do_trap(trapnr, signr, str, 1, regs, error_code, NULL); \ }
ttdefine DO_VM86__ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
I
asmlinkage void do_##name(struct pt_regs * regs, long error_code) \ { \
siginfo_t info; \
info.si_signo = signr; \
info.si_errno =0; \
info.si_code = sicode; \
info.si_addr = (void *)siaddr; \
do_trap(trapnr, signr, str, 1, regs, error_code, sinfo); \
' "
DO_VM86_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->eip)
DO_VM86_ERROR( 3, SIGTRAP, "int3", int3)
DO_VM86_ERROR( 4, SIGSEGV, "overflow", overflow)
DO_VM86_ERROR( 5, SIGSEGV, "bounds", bounds)
DO_ERROR_INFO( 6, SIGILL, "invalid operand", invalid_op, ILL_ILLOPN, regs->eip)
DO_VM86_ERROR( 7, SIGSEGV, "device not available", device_not_available) DO_ERROR( 8, SIGSEGV, "double fault", double_fault)
DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coproces-sor_segment_overrun)
DO_ERROR(10, SIGSEGV, "invalid TSS", invalidJTSSl
DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
DO_ERROR(12, SIGBUS, "stack segment", stack_segment)
DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN,
get_cr2 () )

 











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