Messages in this thread | | | Date | Mon, 19 Mar 2007 11:53:02 -0700 (PDT) | From | Davide Libenzi <> | Subject | Re: [patch 2/13] signal/timer/event fds v6 - signalfd core ... |
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On Mon, 19 Mar 2007, Eric W. Biederman wrote:
> Davide Libenzi <davidel@xmailserver.org> writes: > > > struct signalfd_siginfo { > > __u32 signo; /* si_signo */ > > __s32 err; /* si_errno */ > > __s32 code; /* si_code */ > > __u32 pid; /* si_pid */ > > __u32 uid; /* si_uid */ > > __s32 fd; /* si_fd */ > > __u32 tid; /* si_fd */ > > __u32 band; /* si_band */ > > __u32 overrun; /* si_overrun */ > > __u32 trapno; /* si_trapno */ > > __s32 status; /* si_status */ > > __s32 svint; /* si_int */ > > __u64 svptr; /* si_ptr */ > > __u64 utime; /* si_utime */ > > __u64 stime; /* si_stime */ > > __u64 addr; /* si_addr */ > > }; > > Shouldn't we pad this to 128 bytes like we do siginfo in case there are > more fields we need to include, or we need to extend the size of some > field?
Yes, I guess we can.
> I'm tempted to suggest we have a per arch function that tests current > to see if we are in a compat process or not so we can just use > siginfo. But that is probably overkill. > > > + > > + > > +struct signalfd_ctx { > > + struct list_head lnk; > > + wait_queue_head_t wqh; > > + sigset_t sigmask; > > + struct task_struct *tsk; > > +}; > > I think you want to use a struct pid *pid instead of a pointer to the > task struct here. It is slightly less efficient (one more > dereference) but it means that we won't pin the task struct in memory > indefinitely. Pinning the task_struct like this makes for a very > interesting way to get around the limits on the number of processes a > user can have.
Hmm, when the task is detached from the sighand, we get a notify, so I could do a put from there. This would avoid the extra de-reference. I need to verify locking though ...
- Davide
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