| 1 | /* This file contains a simple exception handler. Exceptions in user
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| 2 | * processes are converted to signals. Exceptions in a kernel task cause
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| 3 | * a panic.
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| 4 | */
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| 5 |
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| 6 | #include "kernel.h"
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| 7 | #include <signal.h>
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| 8 | #include "proc.h"
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| 9 |
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| 10 | /*===========================================================================*
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| 11 | * exception *
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| 12 | *===========================================================================*/
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| 13 | PUBLIC void exception(vec_nr)
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| 14 | unsigned vec_nr;
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| 15 | {
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| 16 | /* An exception or unexpected interrupt has occurred. */
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| 17 |
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| 18 | struct ex_s {
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| 19 | char *msg;
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| 20 | int signum;
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| 21 | int minprocessor;
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| 22 | };
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| 23 | static struct ex_s ex_data[] = {
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| 24 | { "Divide error", SIGFPE, 86 },
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| 25 | { "Debug exception", SIGTRAP, 86 },
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| 26 | { "Nonmaskable interrupt", SIGBUS, 86 },
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| 27 | { "Breakpoint", SIGEMT, 86 },
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| 28 | { "Overflow", SIGFPE, 86 },
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| 29 | { "Bounds check", SIGFPE, 186 },
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| 30 | { "Invalid opcode", SIGILL, 186 },
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| 31 | { "Coprocessor not available", SIGFPE, 186 },
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| 32 | { "Double fault", SIGBUS, 286 },
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| 33 | { "Copressor segment overrun", SIGSEGV, 286 },
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| 34 | { "Invalid TSS", SIGSEGV, 286 },
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| 35 | { "Segment not present", SIGSEGV, 286 },
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| 36 | { "Stack exception", SIGSEGV, 286 }, /* STACK_FAULT already used */
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| 37 | { "General protection", SIGSEGV, 286 },
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| 38 | { "Page fault", SIGSEGV, 386 }, /* not close */
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| 39 | { NIL_PTR, SIGILL, 0 }, /* probably software trap */
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| 40 | { "Coprocessor error", SIGFPE, 386 },
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| 41 | };
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| 42 | register struct ex_s *ep;
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| 43 | struct proc *saved_proc;
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| 44 |
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| 45 | /* Save proc_ptr, because it may be changed by debug statements. */
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| 46 | saved_proc = proc_ptr;
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| 47 |
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| 48 | ep = &ex_data[vec_nr];
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| 49 |
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| 50 | if (vec_nr == 2) { /* spurious NMI on some machines */
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| 51 | kprintf("got spurious NMI\n");
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| 52 | return;
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| 53 | }
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| 54 |
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| 55 | /* If an exception occurs while running a process, the k_reenter variable
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| 56 | * will be zero. Exceptions in interrupt handlers or system traps will make
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| 57 | * k_reenter larger than zero.
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| 58 | */
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| 59 | if (k_reenter == 0 && ! iskernelp(saved_proc)) {
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| 60 | cause_sig(proc_nr(saved_proc), ep->signum);
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| 61 | return;
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| 62 | }
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| 63 |
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| 64 | /* Exception in system code. This is not supposed to happen. */
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| 65 | if (ep->msg == NIL_PTR || machine.processor < ep->minprocessor)
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| 66 | kprintf("\nIntel-reserved exception %d\n", vec_nr);
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| 67 | else
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| 68 | kprintf("\n%s\n", ep->msg);
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| 69 | kprintf("k_reenter = %d ", k_reenter);
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| 70 | kprintf("process %d (%s), ", proc_nr(saved_proc), saved_proc->p_name);
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| 71 | kprintf("pc = %u:0x%x", (unsigned) saved_proc->p_reg.cs,
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| 72 | (unsigned) saved_proc->p_reg.pc);
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| 73 |
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| 74 | panic("exception in a kernel task", NO_NUM);
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| 75 | }
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| 76 |
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