This source file includes following definitions.
- verify_area
- copy_mem
- copy_process
- find_empty_process
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13 #include <errno.h>
14
15 #include <linux/sched.h>
16 #include <linux/kernel.h>
17 #include <asm/segment.h>
18 #include <asm/system.h>
19
20 extern void write_verify(unsigned long address);
21
22 long last_pid=0;
23
24 void verify_area(void * addr,int size)
25 {
26 unsigned long start;
27
28 start = (unsigned long) addr;
29 size += start & 0xfff;
30 start &= 0xfffff000;
31 start += get_base(current->ldt[2]);
32 while (size>0) {
33 size -= 4096;
34 write_verify(start);
35 start += 4096;
36 }
37 }
38
39 int copy_mem(int nr,struct task_struct * p)
40 {
41 unsigned long old_data_base,new_data_base,data_limit;
42 unsigned long old_code_base,new_code_base,code_limit;
43
44 code_limit=get_limit(0x0f);
45 data_limit=get_limit(0x17);
46 old_code_base = get_base(current->ldt[1]);
47 old_data_base = get_base(current->ldt[2]);
48 if (old_data_base != old_code_base)
49 panic("We don't support separate I&D");
50 if (data_limit < code_limit)
51 panic("Bad data_limit");
52 new_data_base = new_code_base = nr * 0x4000000;
53 p->start_code = new_code_base;
54 set_base(p->ldt[1],new_code_base);
55 set_base(p->ldt[2],new_data_base);
56 if (copy_page_tables(old_data_base,new_data_base,data_limit)) {
57 free_page_tables(new_data_base,data_limit);
58 return -ENOMEM;
59 }
60 return 0;
61 }
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67
68 int copy_process(int nr,long ebp,long edi,long esi,long gs,long none,
69 long ebx,long ecx,long edx,
70 long fs,long es,long ds,
71 long eip,long cs,long eflags,long esp,long ss)
72 {
73 struct task_struct *p;
74 int i;
75 struct file *f;
76
77 p = (struct task_struct *) get_free_page();
78 if (!p)
79 return -EAGAIN;
80 task[nr] = p;
81 *p = *current;
82 p->state = TASK_UNINTERRUPTIBLE;
83 p->pid = last_pid;
84 p->father = current->pid;
85 p->counter = p->priority;
86 p->signal = 0;
87 p->alarm = 0;
88 p->leader = 0;
89 p->utime = p->stime = 0;
90 p->cutime = p->cstime = 0;
91 p->start_time = jiffies;
92 p->tss.back_link = 0;
93 p->tss.esp0 = PAGE_SIZE + (long) p;
94 p->tss.ss0 = 0x10;
95 p->tss.eip = eip;
96 p->tss.eflags = eflags;
97 p->tss.eax = 0;
98 p->tss.ecx = ecx;
99 p->tss.edx = edx;
100 p->tss.ebx = ebx;
101 p->tss.esp = esp;
102 p->tss.ebp = ebp;
103 p->tss.esi = esi;
104 p->tss.edi = edi;
105 p->tss.es = es & 0xffff;
106 p->tss.cs = cs & 0xffff;
107 p->tss.ss = ss & 0xffff;
108 p->tss.ds = ds & 0xffff;
109 p->tss.fs = fs & 0xffff;
110 p->tss.gs = gs & 0xffff;
111 p->tss.ldt = _LDT(nr);
112 p->tss.trace_bitmap = 0x80000000;
113 if (last_task_used_math == current)
114 __asm__("clts ; fnsave %0"::"m" (p->tss.i387));
115 if (copy_mem(nr,p)) {
116 task[nr] = NULL;
117 free_page((long) p);
118 return -EAGAIN;
119 }
120 for (i=0; i<NR_OPEN;i++)
121 if (f=p->filp[i])
122 f->f_count++;
123 if (current->pwd)
124 current->pwd->i_count++;
125 if (current->root)
126 current->root->i_count++;
127 if (current->executable)
128 current->executable->i_count++;
129 set_tss_desc(gdt+(nr<<1)+FIRST_TSS_ENTRY,&(p->tss));
130 set_ldt_desc(gdt+(nr<<1)+FIRST_LDT_ENTRY,&(p->ldt));
131 p->state = TASK_RUNNING;
132 return last_pid;
133 }
134
135 int find_empty_process(void)
136 {
137 int i;
138
139 repeat:
140 if ((++last_pid)<0) last_pid=1;
141 for(i=0 ; i<NR_TASKS ; i++)
142 if (task[i] && task[i]->pid == last_pid) goto repeat;
143 for(i=1 ; i<NR_TASKS ; i++)
144 if (!task[i])
145 return i;
146 return -EAGAIN;
147 }