Re: [PATCH, take4] FUTEX : new PRIVATE futexes

Eric Dumazet
2007-04-07T11:55:07Z

Jakub Jelinek a écrit :
> On Sat, Apr 07, 2007 at 10:43:39AM +0200, Eric Dumazet wrote:
>> get_futex_key() does a check against sizeof(u32) regardless of futex being 64bits or not.
>> So it is possible a 64bit futex spans two pages of memory...
>
> That would be a user bug. 32-bit futexes have to be 32-bit aligned, 64-bit
> futexes have to be 64-bit aligned.

I am not sure what you want to say.

User doing sys_futex64(0x......FFC, FUTEX_WAKE_OP, ...) and crashing kernel or
corrupting data is ok because its a user bug ?

User is allowed to do anything, kernel must check and protect innocents.