Re: [patch] For 2.4: syscall revoke.

2000-10-17 Thread Dr. Werner Fink
So ... how can a revoke system call be implemented without changing vfs too much? IMHO this system call is missed. There are some really interesting interfaces using block or character devices which shouldn't be usable for users because of the lack of secure revoking of such a device. Therefore

Re: [patch] For 2.4: syscall revoke.

2000-10-13 Thread Alexander Viro
On Fri, 13 Oct 2000, Alan Cox wrote: > > writer might be OK, but AFAICS there is nothing of that sort in the > > tree. We have such spinlocks, but I don't see how to apply that idea to > > semaphores. Besides, it ought to be small - every struct file will have to > > contain such beast. > > It

Re: [patch] For 2.4: syscall revoke.

2000-10-13 Thread Alan Cox
> writer might be OK, but AFAICS there is nothing of that sort in the > tree. We have such spinlocks, but I don't see how to apply that idea to > semaphores. Besides, it ought to be small - every struct file will have to > contain such beast. It would mean a check when putting a file handle, whic

Re: [patch] For 2.4: syscall revoke.

2000-10-13 Thread Alexander Viro
On Fri, 13 Oct 2000, Alan Cox wrote: > > 1) one process does read() on device, another does revoke() > > followed by rmmod. Oops - nothing holds module in memory, the first > > process is executing code from that module (->read(), that is) and > > we unmap that code. > > > > 2) every a

Re: [patch] For 2.4: syscall revoke.

2000-10-13 Thread Alan Cox
> 1) one process does read() on device, another does revoke() > followed by rmmod. Oops - nothing holds module in memory, the first > process is executing code from that module (->read(), that is) and > we unmap that code. > > 2) every access to ->f_op suddenly becomes unsafe. Basical

Re: [patch] For 2.4: syscall revoke.

2000-10-13 Thread Alexander Viro
On Fri, 13 Oct 2000, Dr. Werner Fink wrote: > > Hi, > > hopefully this mail isn't lost because of a nervous `d' finger ;^) > Last week I've finished the work on the system call revoke for 2.4 and > done some changes on it suggested by the vendors security list. > > Due to the security is

[patch] For 2.4: syscall revoke.

2000-10-13 Thread Dr. Werner Fink
Hi, hopefully this mail isn't lost because of a nervous `d' finger ;^) Last week I've finished the work on the system call revoke for 2.4 and done some changes on it suggested by the vendors security list. Due to the security issue of the syscall revoke, it would nice to see this patch goin