I believe the stack size is 2 pages (8k on x86). As I understand it the task structure is located at the bottom of the stack. So if you already had just over 1k on your stack and you put another 7k on there then your going to be overwritting your task structure. If you put 8k on then perhaps your overwritting some other vital kernel structure that is cause a different (but equally nasty) behaviour. Either way you should consider allocating dynamically ( using vmalloc(), kmalloc(), etc.) rather then statically. HTH dom -----Original Message----- From: kernelnewbies-bounce@nl.linux.org [mailto:kernelnewbies-bounce@nl.linux.org] On Behalf Of pankaj chauhan Sent: Sunday, December 21, 2003 6:59 AM To: kernelnewbies@nl.linux.org Subject: kernel stack overflow hi all , i was just trying to overflow the kernel stack of a process , so i tried to initialize a large arraay in init function of a module , and i got two different behaviours for two different sizes : 1. char array[ 8 * 1024 ] = {0} - machine freezes , when i insmod the module . ultimately i have to press reset . 2. char array[ 7 * 1024 ] = {0} - machine reboots , everytime i insmod the module . i am not understanding the reason difference in the behaviours . plz explain the cause of two different behaviours . thanx rgds , pankaj chauhan ________________________________________________________________________ Yahoo! India Mobile: Download the latest polyphonic ringtones. Go to http://in.mobile.yahoo.com -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/ -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
