This source file includes following definitions.
- ret_from_sys_call
- start_thread
- exit_thread
- flush_thread
- copy_thread
- dump_thread
- sys_execve
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11 #include <linux/errno.h>
12 #include <linux/sched.h>
13 #include <linux/kernel.h>
14 #include <linux/mm.h>
15 #include <linux/stddef.h>
16 #include <linux/unistd.h>
17 #include <linux/ptrace.h>
18 #include <linux/malloc.h>
19 #include <linux/ldt.h>
20 #include <linux/user.h>
21 #include <linux/a.out.h>
22
23 #include <asm/segment.h>
24 #include <asm/system.h>
25
26 asmlinkage void ret_from_sys_call(void) __asm__("ret_from_sys_call");
27
28
29
30
31 asmlinkage int sys_idle(void)
32 {
33 int i;
34
35 if (current->pid != 0)
36 return -EPERM;
37
38
39 for (i = 0 ; i < 768 ; i++)
40 swapper_pg_dir[i] = 0;
41
42
43 current->counter = -100;
44 for (;;) {
45 if (hlt_works_ok && !need_resched)
46 __asm__("hlt");
47 schedule();
48 }
49 }
50
51
52
53
54 void start_thread(struct pt_regs * regs, unsigned long eip, unsigned long esp)
55 {
56 regs->eip = eip;
57 regs->esp = esp;
58 }
59
60
61
62
63 void exit_thread(void)
64 {
65
66 __asm__ __volatile__("mov %w0,%%fs ; mov %w0,%%gs ; lldt %w0"
67 :
68 : "r" (0));
69 current->tss.ldt = 0;
70 if (current->ldt) {
71 void * ldt = current->ldt;
72 current->ldt = NULL;
73 vfree(ldt);
74 }
75 }
76
77 void flush_thread(void)
78 {
79 int i;
80
81 if (current->ldt) {
82 free_page((unsigned long) current->ldt);
83 current->ldt = NULL;
84 for (i=1 ; i<NR_TASKS ; i++) {
85 if (task[i] == current) {
86 set_ldt_desc(gdt+(i<<1)+
87 FIRST_LDT_ENTRY,&default_ldt, 1);
88 load_ldt(i);
89 }
90 }
91 }
92
93 for (i=0 ; i<8 ; i++)
94 current->debugreg[i] = 0;
95 }
96
97 #define IS_CLONE (regs->orig_eax == __NR_clone)
98
99 unsigned long copy_thread(int nr, unsigned long clone_flags, struct task_struct * p, struct pt_regs * regs)
100 {
101 int i;
102 struct pt_regs * childregs;
103
104 p->tss.es = KERNEL_DS;
105 p->tss.cs = KERNEL_CS;
106 p->tss.ss = KERNEL_DS;
107 p->tss.ds = KERNEL_DS;
108 p->tss.fs = USER_DS;
109 p->tss.gs = KERNEL_DS;
110 p->tss.ss0 = KERNEL_DS;
111 p->tss.esp0 = p->kernel_stack_page + PAGE_SIZE;
112 p->tss.tr = _TSS(nr);
113 childregs = ((struct pt_regs *) (p->kernel_stack_page + PAGE_SIZE)) - 1;
114 p->tss.esp = (unsigned long) childregs;
115 p->tss.eip = (unsigned long) ret_from_sys_call;
116 *childregs = *regs;
117 childregs->eax = 0;
118 p->tss.back_link = 0;
119 p->tss.eflags = regs->eflags & 0xffffcfff;
120 if (IS_CLONE) {
121 if (regs->ebx)
122 childregs->esp = regs->ebx;
123 clone_flags = regs->ecx;
124 if (childregs->esp == regs->esp)
125 clone_flags |= COPYVM;
126 }
127 p->tss.ldt = _LDT(nr);
128 if (p->ldt) {
129 p->ldt = (struct desc_struct*) vmalloc(LDT_ENTRIES*LDT_ENTRY_SIZE);
130 if (p->ldt != NULL)
131 memcpy(p->ldt, current->ldt, LDT_ENTRIES*LDT_ENTRY_SIZE);
132 }
133 set_tss_desc(gdt+(nr<<1)+FIRST_TSS_ENTRY,&(p->tss));
134 if (p->ldt)
135 set_ldt_desc(gdt+(nr<<1)+FIRST_LDT_ENTRY,p->ldt, 512);
136 else
137 set_ldt_desc(gdt+(nr<<1)+FIRST_LDT_ENTRY,&default_ldt, 1);
138 p->tss.bitmap = offsetof(struct thread_struct,io_bitmap);
139 for (i = 0; i < IO_BITMAP_SIZE+1 ; i++)
140 p->tss.io_bitmap[i] = ~0;
141 if (last_task_used_math == current)
142 __asm__("clts ; fnsave %0 ; frstor %0":"=m" (p->tss.i387));
143 return clone_flags;
144 }
145
146
147
148
149 void dump_thread(struct pt_regs * regs, struct user * dump)
150 {
151 int i;
152
153
154 dump->magic = CMAGIC;
155 dump->start_code = 0;
156 dump->start_stack = regs->esp & ~(PAGE_SIZE - 1);
157 dump->u_tsize = ((unsigned long) current->mm->end_code) >> 12;
158 dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1))) >> 12;
159 dump->u_dsize -= dump->u_tsize;
160 dump->u_ssize = 0;
161 for (i = 0; i < 8; i++)
162 dump->u_debugreg[i] = current->debugreg[i];
163
164 if (dump->start_stack < TASK_SIZE)
165 dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> 12;
166
167 dump->regs = *regs;
168
169
170
171 if (hard_math) {
172 if ((dump->u_fpvalid = current->used_math) != 0) {
173 if (last_task_used_math == current)
174 __asm__("clts ; fnsave %0": :"m" (dump->i387));
175 else
176 memcpy(&dump->i387,¤t->tss.i387.hard,sizeof(dump->i387));
177 }
178 } else {
179
180
181 dump->u_fpvalid = 0;
182 }
183 }
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187
188 asmlinkage int sys_execve(struct pt_regs regs)
189 {
190 int error;
191 char * filename;
192
193 error = getname((char *) regs.ebx, &filename);
194 if (error)
195 return error;
196 error = do_execve(filename, (char **) regs.ecx, (char **) regs.edx, ®s);
197 putname(filename);
198 return error;
199 }