> -----Original Message----- > From: [email protected] [mailto:[email protected]] On > Behalf Of Yin Kangkai > Sent: Monday, January 06, 2014 5:51 AM > To: Yang, Chengwei > Cc: [email protected] > Subject: Re: [Dev] Important Tizen 3 package installation details! > > On 2014-01-06, 19:57 +0800, Yang Chengwei wrote: > > On Mon, Jan 06, 2014 at 12:20:07PM +0100, Patrick Ohly wrote: > > > On Mon, 2014-01-06 at 18:11 +0800, Yang Chengwei wrote: > > > > On Thu, Jan 02, 2014 at 10:48:16PM +0000, Schaufler, Casey wrote: > > > > > You can change the Smack label of your process to “_” by: > > > > > > > > > > > > > > > > > > > > # echo _ > /proc/self/attr/current > > > > > > > > Isn't the /proc/self point to the current "echo" process? > > > > > > Not always. This relies on echo being a builtin command of the > > > current shell, so the command really does change the label of the > > > current shell process when using e.g. bash. > > > > Oh, yes, there is a builtin echo in bash, so echo always the builtin > > one rather the one from coreutils. Thanks! > > Hi, even echo is not the builtin one, > > # echo _ > /proc/self/attr/current > > will still change the shell label, because it's shell/bash open the > /proc/self/attr/current, not /bin/echo. that's my understanding.
Run the experiment! It does need to be the builtin. The fork() occurs before the redirection in the shell, so the process that opens /proc/self/attr/current is the one that exec()s /bin/echo, not the one the remains the shell. > Regards, > Kangkai > _______________________________________________ > Dev mailing list > [email protected] > https://lists.tizen.org/listinfo/dev _______________________________________________ Dev mailing list [email protected] https://lists.tizen.org/listinfo/dev
