From mboxrd@z Thu Jan 1 00:00:00 1970 From: Philippe Gerum In-Reply-To: <4580307C.3040401@domain.hid> References: <45802F00.1090008@domain.hid> <4580307C.3040401@domain.hid> Content-Type: text/plain Date: Wed, 13 Dec 2006 18:28:08 +0100 Message-Id: <1166030889.5360.175.camel@domain.hid> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [Adeos-main] Re: [PATCH] 2.6.19: Fix irq_disable in early start_kernel Reply-To: rpm@xenomai.org List-Id: General discussion about Adeos List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: adeos-main On Wed, 2006-12-13 at 17:55 +0100, Jan Kiszka wrote: > Jan Kiszka wrote: > > Hi Philippe, > > > > this was a nice bug: After applying some totally unrelated cleanup patch > > that removes a few useless EXPORT_SYMBOLS from ipipe, I got this during > > boot: > > > > ... > > Xenomai: hal/x86 started. > > BUG: unable to handle kernel NULL pointer dereference at virtual address > > 000000f1 > > ... > > EIP is at kref_get+0x9/0x43 > > ... > > Call Trace: > > [] kobject_get+0x12/0x17 > > [] sysfs_create_link+0xda/0x140 > > [] class_device_add+0x217/0x3dc > > [] class_device_register+0x12/0x15 > > [] class_device_create+0x84/0xa5 > > [] misc_register+0x109/0x140 > > [] xnheap_mount+0x9a/0xa2 > > [] __xeno_sys_init+0xd9/0x15d > > [] init+0x127/0x2dc > > [] kernel_thread_helper+0x7/0x10 > > > > The reason: xnheap_dev.dev=1!? But that field is located untouched in a > > static structure, i.e. *must* be 0! Interrupting the kernel shortly > > after boot already returned it as 1. Finally, after breaking at the > > beginning of start_kernel, I got the expected 0 and then quickly found > > the messed-up piece of code a few lines below. > > > > Please apply attached patch, I suspect it is a typo (ipipe isn't > > initialised at this point to handle such requests, so the stall bit > > ended up in xnheap_dev for me - who knows what can happen on other > > setups...). > > Gasp. Fixed, thanks. -- Philippe.