A question about ipcperm() call?

[John Baldwin]

On Sunday 23 July 2006 22:07, 李尚杰 wrote:
> The code for ipcperm() call :

>  93                 if (mode & IPC_M) {
>  94                         error = suser(td);
>  95                         if (error)
>  96                                 return (error);
>  97                 }

> 116         if ((mode & perm->mode) != mode) {
> 117                 if (suser(td) != 0)
> 118                         return (EACCES);
> 119         }
> 
> why not directly return the error in line 94?

If suser() returns 0 and you just did 'return(suser(td))' then you would not 
perform the additional security check in lines 116-119 which could result in 
allowing access to an IPC object when it should be restricted.

-- 
John Baldwin