Re: [PATCH] futex:fix robust futex alignment exception

[Thomas Gleixner]

On Fri, 15 Mar 2019, Peter Zijlstra wrote:

> On Fri, Mar 15, 2019 at 03:44:38AM +0000, chenjie6@xxxxxxxxxx wrote:
> > From: chen jie <chenjie6@xxxxxxxxxx>
> 
> > [11542.215247] [<c017b1d4>] (cmpxchg_futex_value_locked) from [<c017da50>] (handle_futex_death+0x78/0xcc)
> > [11542.215259] [<c017da50>] (handle_futex_death) from [<c017dba8>] (exit_robust_list+0x104/0x160)
> > [11542.215273] [<c017dba8>] (exit_robust_list) from [<c011b40c>] (mm_release+0x1c/0x108)
> > [11542.215287] [<c011b40c>] (mm_release) from [<c011f9a4>] (do_exit+0x218/0x9a4)
> > [11542.215299] [<c011f9a4>] (do_exit) from [<c0120250>] (do_group_exit+0xac/0xf4)
> > [11542.215311] [<c0120250>] (do_group_exit) from [<c01202a8>] (__wake_up_parent+0x0/0x18)
> 
> > Signed-off-by: chen jie <chenjie6@xxxxxxxxxx>
> 
> Reviewed-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> 
> However, should there not also be alignment tests on set_robust_list()?
> 
> Also; do_futex() should probably check uaddr and uaddr2.
> 
> That is; why aren't there any alignment tests anywhere? Or am I just
> gone blind?

uaddrs for the futex syscalls are checked in get_futex_key().

Thanks,

	tglx