获取“调用‘__bad_copy_to’”声明属性错误：复制目标大小太小”禁用优化后

Question

这是Linux设备驱动程序的一部分。

uint32_t val = 0;
static long axpu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
...
 copy_from_user(&val,(int32_t *)arg, sizeof(val));
...
}

我可以编译好的，并进行一些调试。避免某些代码被优化。我像这样更改了代码。

#pragma GCC push_options
#pragma GCC optimize ("O0")
uint32_t val = 0;
static long axpu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
...
 copy_from_user(&val,(int32_t *)arg, sizeof(val));   // <-- line 364
...
}
#pragma GCC pop_options

这是我已经使用了一段时间的技巧，而且工作正常。（只是我在Linux内核代码中用于启动调试）。这次，我正在为设备驱动程序做。现在，编译器给了我这个错误。

In file included from ./arch/arm64/include/asm/preempt.h:5,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/seqlock.h:36,
                 from ./include/linux/time.h:6,
                 from ./arch/arm64/include/asm/stat.h:12,
                 from ./include/linux/stat.h:6,
                 from ./include/linux/module.h:10,
                 from /home/ckim/testlin540/axpu_ldd_kc.c:8:
In function 'check_copy_size',
    inlined from 'copy_from_user' at ./include/linux/uaccess.h:143:6,
    inlined from 'axpu_ioctl' at /home/ckim/testlin540/axpu_ldd_kc.c:364:4:
./include/linux/thread_info.h:160:4: error: call to '__bad_copy_to' declared with attribute error: copy destination size is too small
  160 |    __bad_copy_to();
      |    ^~~~~~~~~~~~~~~

我尝试将#pragma的内容围绕#include＆llt; linux/uaccess.h＆gt;徒劳地。
有些有些说这是GCC问题，但我不确定。这是Linux-5.4.188代码，这是编译器版本。

ckim@ckim-ubuntu:~/testlin540$ aarch64-none-linux-gnu-gcc --version
aarch64-none-linux-gnu-gcc (GNU Toolchain for the A-profile Architecture 10.2-2020.11 (arm-10.16)) 10.2.1 20201103
Copyright (C) 2020 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.