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simple unix question

simple unix question# Unix - 噫吁兮，危乎高哉

d*o2002-11-24 08:11

1 楼

In Unix-like systems, can a user process execute code in the kernel?
Is it a yes or no?
My understanding is user can not access kernel directly, but not quite sure
about the "code in the kernel". Anyone can enlight me on this?
Thanks!!

r*d2002-11-24 08:11

2 楼

what does your "process" mean?
user can use setuid to run the program as another user such as root but must
get permission from root, I mean if you run a program owned by the root,
your program can let you behave like a root

【在 d*o 的大作中提到】

: In Unix-like systems, can a user process execute code in the kernel?
: Is it a yes or no?
: My understanding is user can not access kernel directly, but not quite sure
: about the "code in the kernel". Anyone can enlight me on this?
: Thanks!!

p*f2002-11-24 08:11

3 楼

running as root is not the same thing as "execute code in the kernel"
user process can access kernel code indirectly through syscalls, or
the kernel can run part of its code on behalf of a user process.
BTW, (almost) the same thing for process running as root.

【在 r*****d 的大作中提到】

: what does your "process" mean?
: user can use setuid to run the program as another user such as root but must
: get permission from root, I mean if you run a program owned by the root,
: your program can let you behave like a root

d*o2002-11-24 08:11

4 楼

Thanks!

【在 p******f 的大作中提到】

:
: running as root is not the same thing as "execute code in the kernel"
: user process can access kernel code indirectly through syscalls, or
: the kernel can run part of its code on behalf of a user process.
: BTW, (almost) the same thing for process running as root.