Messages in this thread | | | Date | Thu, 14 Apr 2005 10:10:13 +0800 | From | Tomko <> | Subject | Re: Why system call need to copy the date from the userspace before using it |
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Catalin Marinas wrote:
>Tomko <tomko@haha.com> wrote: > > >>Inside the system call , the kernel often copy the data by calling >>copy_from_user() rather than just using strcpy(), is it because the >>memory mapping in kenel space is different from user space? >> >> > >No, it is because this function checks whether the access to the user >space address is OK. There are situations when it can also sleep (page >not present). > > > what u means "OK"? kernel space should have right to access any memory address , can u expained in details what u means "OK"? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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