プログラムの実行はどのようにして行われるのか、Linuxカーネルのコードから探る：main()関数の前には何があるのか（終）（2/2 ページ）

296:void
297: start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
298: {
299:	set_user_gs(regs, 0);
300:	regs->fs		 = 0;
301:	regs->ds		 = __USER_DS;
302:	regs->es		 = __USER_DS;
303:	regs->ss		 = __USER_DS;
304:	regs->cs		 = __USER_CS;
305:	regs->ip		 = new_ip;
306:	regs->sp		 = new_sp;
...

1279:/*
1280: * cycle the list of binary formats handler, until one recognizes the image
1281: */
1282:int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
1283:{
...
1307:			int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary;
...
1314:			retval = fn(bprm, regs);
...

...
934:	 retval = create_elf_tables(bprm, &loc->elf_ex,
935:			 load_addr, interp_load_addr);
...

136:static int
137:create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
138:			unsigned long load_addr, unsigned long interp_load_addr)
139:{
...
278:		 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
279:		 if (__put_user(argc, sp++))
280:			 return -EFAULT;
281:		 argv = sp;
282:		 envp = argv + argc + 1;
283:
284:		 /* Populate argv and envp */
285:		 p = current->mm->arg_end = current->mm->arg_start;
286:		 while (argc-- > 0) {
287:			 size_t len;
288:			 if (__put_user((elf_addr_t)p, argv++))
289:				 return -EFAULT;
290:			 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
291:			 if (!len || len > MAX_ARG_STRLEN)
292:				 return -EINVAL;
293:			 p += len;
294:		 }
295:		 if (__put_user(0, argv))
296:			 return -EFAULT;
...

55:	 .text
56:	 .globl _start
57:	 .type _start,@function
58:	 _start:
...
63:	 /* Extract the arguments as encoded on the stack and set up
64:	    the arguments for `main': argc, argv. envp will be determined
65:	    later in __libc_start_main. */
66:	 popl %esi		 /* Pop the argument count. */
67:	 movl %esp, %ecx	 /* argv starts just at the current stack top.*/
...
108:	 pushl %ecx		 /* Push second argument: argv. */
109:	 pushl %esi		 /* Push first argument: argc. */
110:
111:	 pushl $main
112:
113:	 /* Call the user's main function, and exit with its value.
114:	    But let the libc call main.	 */
115:	 call __libc_start_main
...