一个汇编的问题__C33_sys_write_Breakpoint_read_write_378_

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一个汇编的问题

来源: 互联网发布时间：2016-11-09

本文导语: .section .data output: .ascii "what the fuck~!!n" .section .text .global main main: movl $4,%eax #syscall_write movl $1,%ebx #(fd = 1 )== stdout movl $output,%ecx #string addr movl $1000,%edx #size,but overflo...

.section .data
   output:
   .ascii "what the fuck~!!n"
   .section .text
   .global main
   main:
   movl $4,%eax #syscall_write
   movl $1,%ebx #(fd = 1 )== stdout
   movl $output,%ecx #string addr
   movl $1000,%edx #size,but overflow?
   int $0x80
   movl $1,%eax
   movl $0,%ebx
   int $0x80
/*我自己猜测的对应c代码为*/
   #include
   int main()
   {
           char *buf = "what the fuck~!!n";
           write(1,buf,1000);
   }
c语言编译后的可执行代码会溢出（打出n多垃圾...）汇编代码产生的可执行打印正确的字符串。
c语言打印出乱码可以理解，可是汇编不打印乱码不能理解。。。
编译都为命令：
gcc -o

对内核sys_write下断点调试结果
汇编的

Breakpoint 4, sys_write (fd=1, buf=0x80484a0 "what the fuck~!!n", count=1000) at fs/read_write.c:378
378             if (file) {
(gdb) c
Continuing.
[New Thread 3443]
[Switching to Thread 3443]

Breakpoint 4, sys_write (fd=3, buf=0xbfc2309b "", count=1) at fs/read_write.c:378
378             if (file) {
(gdb) c
Continuing.
[Switching to Thread 3155]

Breakpoint 4, sys_write (fd=2,
    buf=0x937c808 "vmlinux1:~# om[C33[C33[C33[C33[C33[C33[C33[Cls33[K", '锟? ..., count=12)
    at fs/read_write.c:378
378             if (file) {

-----------------------------------

这个是c语言的

Breakpoint 4, sys_write (fd=1, buf=0x8049568 "waht the fuck~!!n", count=1000) at fs/read_write.c:378
378             if (file) {
(gdb)
Continuing.
[Switching to Thread 3155]

Breakpoint 4, sys_write (fd=2,
    buf=0x937c808 "vmlinux1:~# om[C33[C33[C33[C33[C33[C33[C33[Cls33[K", '锟? ..., count=12)
    at fs/read_write.c:378
378             if (file) {
(gdb)
Continuing.

Breakpoint 4, sys_write (fd=2,
    buf=0x937c808 ".mlinux1:~# om[C33[C33[C33[C33[C33[C33[C33[Cls33[K", '锟? ..., count=1)
    at fs/read_write.c:378
378             if (file) {
(gdb)
Continuing.

Breakpoint 4, sys_write (fd=2,
    buf=0x937c808 "/mlinux1:~# om[C33[C33[C33[C33[C33[C33[C33[Cls33[K", '锟? ..., count=1)
    at fs/read_write.c:378
378             if (file) {
(gdb)
Continuing.

Breakpoint 4, sys_write (fd=2,
    buf=0x937c808 "amlinux1:~# om[C33[C33[C33[C33[C33[C33[C33[Cls33[K", '锟? ..., count=1)
    at fs/read_write.c:378

应该是write处理不一样