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| Commit | Line | Data |
|---|---|---|
| 3f4b8ae4 WN |
1 | /* |
| 2 | * Copyright (c) 1991 Regents of the University of California. | |
| 3 | * All rights reserved. | |
| 4 | * | |
| 5 | * %sccs.include.redist.c% | |
| 6 | * | |
| 7 | * @(#)kgdb_glue.c 7.1 (Berkeley) %G% | |
| 8 | */ | |
| 9 | ||
| 10 | /* | |
| 11 | * This file must be compiled with gcc -fno-defer-pop. | |
| 12 | */ | |
| 13 | ||
| 14 | #ifdef KGDB | |
| 15 | ||
| 16 | #include "param.h" | |
| 17 | #include "../include/frame.h" | |
| 18 | #include "../include/reg.h" | |
| 19 | ||
| 20 | #ifndef lint | |
| 21 | static char rcsid[] = | |
| 22 | "@(#) $Header: /u/donn/c/gdb/kernel/RCS/kgdb_glue.c,v 1.2 91/03/31 16:04:52 donn Exp Locker: donn $ (LBL)"; | |
| 23 | #endif | |
| 24 | ||
| 25 | #define KGDB_STACKSIZE 0x800 | |
| 26 | #define KGDB_STACKWORDS (KGDB_STACKSIZE / sizeof(u_long)) | |
| 27 | ||
| 28 | u_long kgdb_stack[KGDB_STACKWORDS]; | |
| 29 | ||
| 30 | #define getsp(v) asm volatile ("movl %%esp,%0" : "=r" (v)) | |
| 31 | #define setsp(v) asm volatile ("movl %0,%%esp" :: "r" (v)) | |
| 32 | ||
| 33 | static inline void | |
| 34 | copywords(src, dst, nbytes) | |
| 35 | register u_long *src, *dst; | |
| 36 | register u_int nbytes; | |
| 37 | { | |
| 38 | u_long *limit = src + (nbytes / sizeof(u_long)); | |
| 39 | ||
| 40 | do { | |
| 41 | *dst++ = *src++; | |
| 42 | } while (src < limit); | |
| 43 | if (nbytes & 2) | |
| 44 | *(u_short *)dst = *(u_short *)src; | |
| 45 | } | |
| 46 | ||
| 47 | kgdb_trap_glue(frame) | |
| 48 | struct trapframe frame; | |
| 49 | { | |
| 50 | u_long osp, nsp; | |
| 51 | u_int s; | |
| 52 | ||
| 53 | /* | |
| 54 | * On internal traps, the hardware doesn't push ss and esp. | |
| 55 | */ | |
| 56 | u_int fsize = sizeof frame - 2 * sizeof (int); | |
| 57 | #ifdef DONN | |
| 58 | extern int kgdb_debug; | |
| 59 | ||
| 60 | if (kgdb_debug > 3) | |
| 61 | pg("kgdb_trap_glue: entered, fsize = %d\n", fsize); | |
| 62 | #endif | |
| 63 | ||
| 64 | /* | |
| 65 | * After a kernel mode trap, the saved sp doesn't point to the right | |
| 66 | * place. The correct value is the top of the frame. | |
| 67 | */ | |
| 68 | frame.tf_isp = (u_long)(&frame) + fsize; | |
| 69 | ||
| 70 | /* | |
| 71 | * Copy the interrupt context and frame to the new stack. | |
| 72 | * We're throwing away trap()'s frame since we're going to do | |
| 73 | * our own iret. | |
| 74 | */ | |
| 75 | nsp = (u_long)(&kgdb_stack[KGDB_STACKWORDS]) - fsize; | |
| 76 | ||
| 77 | copywords((u_long *)&frame, (u_long *)nsp, fsize); | |
| 78 | ||
| 79 | s = splhigh(); | |
| 80 | ||
| 81 | getsp(osp); | |
| 82 | setsp(nsp); | |
| 83 | ||
| 84 | if (kgdb_trap(frame.tf_trapno, (struct frame *)nsp) == 0) { | |
| 85 | /* | |
| 86 | * Get back on kernel stack. This thread of control | |
| 87 | * will return back up through trap(). If kgdb_trap() | |
| 88 | * returns 0, it didn't handle the trap at all so | |
| 89 | * the stack is still intact and everything will | |
| 90 | * unwind okay from here up. | |
| 91 | */ | |
| 92 | setsp(osp); | |
| 93 | splx(s); | |
| 94 | return 0; | |
| 95 | } | |
| 96 | ||
| 97 | /* | |
| 98 | * Copy back context, which has possibly changed. Even the | |
| 99 | * sp might have changed. | |
| 100 | */ | |
| 101 | osp = ((struct trapframe *)nsp)->tf_isp - fsize; | |
| 102 | copywords((u_long *)nsp, (u_long *)osp, fsize); | |
| 103 | setsp(osp); | |
| 104 | ||
| 105 | /* | |
| 106 | * Restore the possible new context from frame. | |
| 107 | */ | |
| 108 | asm volatile ("pop %es; pop %ds; popal; nop; addl $8,%esp; iret"); | |
| 109 | } | |
| 110 | ||
| 111 | int kgdb_testval; | |
| 112 | ||
| 113 | kgdb_test(i) | |
| 114 | { | |
| 115 | ++kgdb_testval; | |
| 116 | return i + 1; | |
| 117 | } | |
| 118 | ||
| 119 | #endif |