On 11/14, Ingo Molnar wrote: > > * Oleg Nesterov <[EMAIL PROTECTED]> wrote: > > > > [18073.371126] Unable to handle kernel NULL pointer dereference at > > > 0000000000000120 RIP: > > > [18073.371134] [<ffffffff8023572e>] check_preempt_wakeup+0x6e/0x110 > > > [18073.371144] PGD 81f9067 PUD 81c8067 PMD 0 > > > [18073.371151] Oops: 0000 [1] PREEMPT SMP > > > [18073.371157] CPU 2 > > > [18073.371161] Modules linked in: vfat fat > > > [18073.371168] Pid: 4639, comm: kwin Not tainted 2.6.24-rc1 #1 > > > [18073.371171] RIP: 0010:[<ffffffff8023572e>] [<ffffffff8023572e>] > > > check_preempt_wakeup+0x6e/0x110 > > > [18073.371177] RSP: 0018:ffff810008531a78 EFLAGS: 00010006 > > > [18073.371179] RAX: 0000000000000000 RBX: 0000000000000000 RCX: > > > 0000000000000000 > > > [18073.371183] RDX: ffff810004441bf0 RSI: ffff81000801e860 RDI: > > > ffff81000444ab80 > > > [18073.371186] RBP: ffff810008531aa8 R08: 000000d0d47a4a90 R09: > > > 0000000000000000 > > > [18073.371188] R10: ffff810004441bf0 R11: 0000000000000001 R12: > > > ffff810006520400 > > > [18073.371190] R13: ffff81000801e860 R14: ffff81000a63a000 R15: > > > ffff81000443d8e0 > > > [18073.371193] FS: 00002b7d646a86f0(0000) GS:ffff810004c11780(0000) > > > knlGS:0000000000000000 > > > [18073.371196] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > > > [18073.371199] CR2: 0000000000000120 CR3: 0000000008495000 CR4: > > > 00000000000006e0 > > > [18073.371202] DR0: 0000000000000000 DR1: 0000000000000000 DR2: > > > 0000000000000000 > > > [18073.371211] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: > > > 0000000000000400 > > > [18073.371214] Process kwin (pid: 4639, threadinfo ffff810008530000, task > > > ffff81000840a860) > > > [18073.371216] Stack: ffff81000444ab80 0000000000000001 ffff81000801e860 > > > ffff81000444ab80 > > > [18073.371231] 0000000000000002 ffff81000443d8e0 ffff810008531b38 > > > ffffffff8023061e > > > [18073.371238] 0000000000000000 ffff810004441b80 0000000000000002 > > > 0000000100000000 > > > [18073.371245] Call Trace: > > > [18073.371250] [<ffffffff8023061e>] try_to_wake_up+0x2fe/0x3a0 > > > > I suspect I see the bug in that area, but I am not sure it can explain > > this trace completely. > > there's a fix pending from Dmitry - please see below. It took days for > Grant to trigger the crash so it needs some time to be confirmed but it > could explain the crash in theory.
Yes I agree, it can explain the crash. However, this patch can't fix the bug I was talking about (of course, unless I missed something). It is still possible that the "fair_sched_class" task can have ->se.cfs_rq/parent pointing to the freed memory, no? Oleg. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
