![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to objc-moninit-i386.c CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [Apple Darwin 0.x] / objc|
Return to objc-moninit-i386.c CVS log | Up to [Apple Darwin 0.x] / objc |
1.1 root 1: /*
2: * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
3: *
4: * @APPLE_LICENSE_HEADER_START@
5: *
6: * "Portions Copyright (c) 1999 Apple Computer, Inc. All Rights
7: * Reserved. This file contains Original Code and/or Modifications of
8: * Original Code as defined in and that are subject to the Apple Public
9: * Source License Version 1.0 (the 'License'). You may not use this file
10: * except in compliance with the License. Please obtain a copy of the
11: * License at http://www.apple.com/publicsource and read it before using
12: * this file.
13: *
14: * The Original Code and all software distributed under the License are
15: * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
16: * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
17: * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
18: * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
19: * License for the specific language governing rights and limitations
20: * under the License."
21: *
22: * @APPLE_LICENSE_HEADER_END@
23: */
24: #ifdef SHLIB
25: #import "shlib.h"
26: #undef moninitobjc
27: #endif
28:
29: #ifndef __i386__
30: #error "this is i386 machine dependent"
31: #endif
32:
33: #include <mach/mach.h>
34:
35: /*
36: * objc_exitPoints is a private_extern defined in the objective-C messager
37: * which is a zero terminated table of a list of text lables to write
38: * instructions which will cause the objective-C messager to then call
39: * moncount for each message it dispatches. The instruction at each of these
40: * text lables is a "jmp *%eax@" instruction. The objective-C messager has
41: * allocated space after each of these instructions for moninitobjc to write
42: * the instructions to call moncount for each message it dispatches.
43: *
44: * The instructions written over the "jmp *%eax@" and the allocated space after
45: * it are:
46: * exitPoint1: jmp *%eax@
47: * | replace with the following instructions
48: * pushl %eax
49: * pushl %eax
50: * pushl 8(%esp)
51: * call _moncount
52: * addl $8,%esp
53: * popl %eax
54: * jmp *%eax@
55: */
56: extern unsigned long objc_exitPoints[];
57:
58: /*
59: * objc_entryPoints is a private_extern defined in the objective-C messager
60: * which is a zero terminated table of a list of text lables that should not
61: * have a call inserted to moncount in their shared library branch table slot.
62: */
63: extern unsigned long objc_entryPoints[];
64:
65: /*
66: * moninitobjc() is a machine dependent routine that causes objective-C
67: * messager to call moncount() for each message it sends.
68: */
69: unsigned long *
70: moninitobjc(
71: unsigned long moncount_addr)
72: {
73: unsigned long i, min, max, addr;
74: char *p;
75: kern_return_t r;
76:
77: if(objc_exitPoints[0] == 0)
78: return(objc_entryPoints);
79:
80: /*
81: * Determine the area to vm_protect() for writing the code.
82: */
83: min = 0xffffffff;
84: max = 0;
85: for(i = 0; objc_exitPoints[i] != 0; i++){
86: if(objc_exitPoints[i] < min)
87: min = objc_exitPoints[i];
88: if(objc_exitPoints[i] > max)
89: max = objc_exitPoints[i];
90: }
91: max += 24;
92:
93: if((r = vm_protect(task_self(), (vm_address_t)min, (vm_size_t)(max-min),
94: FALSE, VM_PROT_READ | VM_PROT_WRITE |
95: VM_PROT_EXECUTE)) != KERN_SUCCESS)
96: return(objc_entryPoints);
97:
98: /*
99: * Write in the code to call moncount.
100: */
101: for(i = 0; objc_exitPoints[i] != 0; i++){
102: p = (char *)(objc_exitPoints[i]);
103: /* pushl %eax */
104: *p++ = 0x50;
105: /* pushl %eax */
106: *p++ = 0x50;
107: /* pushl 8(%esp) */
108: *p++ = 0xff;
109: *p++ = 0x74;
110: *p++ = 0x24;
111: *p++ = 0x08;
112: /* call moncount */
113: addr = moncount_addr - ((unsigned long)p + 5);
114: *p++ = 0xe8;
115: *p++ = (addr) & 0xff;
116: *p++ = (addr >> 8) & 0xff;
117: *p++ = (addr >> 16) & 0xff;
118: *p++ = (addr >> 24) & 0xff;
119: /* addl $0x08,%esp */
120: *p++ = 0x83;
121: *p++ = 0xc4;
122: *p++ = 0x08;
123: /* popl %eax */
124: *p++ = 0x58;
125: /* jmp *%eax@ */
126: *p++ = 0xff;
127: *p++ = 0xe0;
128: }
129: /*
130: * The text cache for the this code now needs to be flushed since
131: * it was just written on so that future calls will get the new
132: * instructions.
133: cache_flush(min, max-min);
134: */
135: asm("jmp 1f");
136: asm("1: nop");
137:
138: return(objc_entryPoints);
139: }
This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.