The usual result will be instant and spectacular failure (the kernel hanging is unlikely). Your kernel will oops, and you will see something like the following: Unable to handle kernel NULL pointer dereference at virtual address 00000000 printing eip: c48370c3 *pde = 00000000 Oops: 0002 CPU: 0 EIP: 0010:[<c48370c3>] EFLAGS: 00010286 eax: ffffffea ebx: c2281a20 ecx: c48370c0 edx: c2281a40 esi: 4000c000 edi: 4000c000 ebp: c38adf8c esp: c38adf8c ds: 0018 es: 0018 ss: 0018 Process ls (pid: 23171, stackpage=c38ad000) Stack: 0000010e c01356e6 c2281a20 4000c000 0000010e ... ... ... [from Rubini and Corbet] and you will most certainly have to reboot the machine. Whether anything worse happens is indeterminable - if you're writing to a device and the kernel throws its hands up then you run the risk of a corrupt filesystem, for example. Don't develop filesystem drivers on hardware containing data you care about. Best Wishes David Gillies San Jose Costa Rica --- Frank.A.Uepping@t-online.de wrote: > What happens when a null pointer is dereferenced in > the Linux kernel? > How fatal is this to the running kernel/system? > Is there need to reboot the kernel? > > /FAU > > > -- > Kernelnewbies: Help each other learn about the Linux > kernel. > Archive: > http://mail.nl.linux.org/kernelnewbies/ > FAQ: http://kernelnewbies.org/faq/ > __________________________________ Do you Yahoo!? Yahoo! Hotjobs: Enter the "Signing Bonus" Sweepstakes http://hotjobs.sweepstakes.yahoo.com/signingbonus -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
