(cc's added) On Thu, 28 Sep 2006 13:25:48 -0700 Bryce Harrington <bryce@xxxxxxxx> wrote: > Apologies if this has already been reported; It has not. > I didn't spot it on the > list. We've noticed an Oops on AMD64 when running linux-2.6.18-git8 and > -git9, but not -git7: > > mptbase: Initiating ioc0 recovery > Unable to handle kernel NULL pointer dereference at 0000000000000500 RIP: > [<ffffffff80489aa2>] mptspi_dv_renegotiate_work+0xc/0x45 > PGD 0 > Oops: 0000 [1] PREEMPT SMP > CPU 0 > Modules linked in: > Pid: 8, comm: events/0 Not tainted 2.6.18-git8 #1 > RIP: 0010:[<ffffffff80489aa2>] [<ffffffff80489aa2>] mptspi_dv_renegotiate_work+0xc/0x45 > RSP: 0000:ffff81003ec65e40 EFLAGS: 00010282 > RAX: 0000000000000002 RBX: ffff81003e86f640 RCX: 000000000000001e > RDX: 0000000000000001 RSI: 0000000000000213 RDI: 000000000003e86f > RBP: 0000000000000500 R08: ffff81003ec64000 R09: ffff81003ed0cf40 > R10: ffff81003e86f640 R11: ffff81003ed0cf40 R12: ffff81003ed0cf40 > R13: 0000000000000213 R14: ffff81003e86f640 R15: ffffffff80489a96 > FS: 0000000000000000(0000) GS:ffffffff80779000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b > CR2: 0000000000000500 CR3: 0000000000201000 CR4: 00000000000006e0 > Process events/0 (pid: 8, threadinfo ffff81003ec64000, task ffff81007f180740) > Stack: ffff81003ec65ef8 ffff81003e86f640 ffff81003e86f648 ffffffff8023f1bd > ffff81003ed0cf40 ffff81003ed0cf40 ffffffff8023f204 ffff8100016dfd70 > 00000000fffffffc ffffffff80593ffd 0000000000000000 ffffffff8023f300 > Call Trace: > [<ffffffff8023f1bd>] run_workqueue+0x9a/0xe1 > [<ffffffff8023f204>] worker_thread+0x0/0x12e > [<ffffffff8023f300>] worker_thread+0xfc/0x12e > [<ffffffff80229f62>] default_wake_function+0x0/0xe > [<ffffffff80229f62>] default_wake_function+0x0/0xe > [<ffffffff80242433>] kthread+0xc8/0xf1 > [<ffffffff8020a3f8>] child_rip+0xa/0x12 > [<ffffffff8024236b>] kthread+0x0/0xf1 > [<ffffffff8020a3ee>] child_rip+0x0/0x12 > > > Code: 48 8b 45 00 31 f6 48 8b b8 50 01 00 00 e8 5c 4d fe ff 48 85 > RIP [<ffffffff80489aa2>] mptspi_dv_renegotiate_work+0xc/0x45 > RSP <ffff81003ec65e40> > CR2: 0000000000000500 > <6>mptbase: Initiating ioc0 recovery That's very clever. With gcc-4.0.2 and your .config I get (gdb) x/20i mptspi_dv_renegotiate_work 0xffffffff8048475e <mptspi_dv_renegotiate_work>: push %rbp 0xffffffff8048475f <mptspi_dv_renegotiate_work+1>: push %rbx 0xffffffff80484760 <mptspi_dv_renegotiate_work+2>: push %rbp 0xffffffff80484761 <mptspi_dv_renegotiate_work+3>: mov 0x60(%rdi),%rbp 0xffffffff80484765 <mptspi_dv_renegotiate_work+7>: callq 0xffffffff8026df58 <kfree> 0xffffffff8048476a <mptspi_dv_renegotiate_work+12>: mov 0x0(%rbp),%rax 0xffffffff8048476e <mptspi_dv_renegotiate_work+16>: xor %esi,%esi 0xffffffff80484770 <mptspi_dv_renegotiate_work+18>: mov 0x150(%rax),%rdi So on entry to this function, wqw->hd is 0x500. Or kfree() somehow scrogged your %rbp register. > Full console logs showing the above oops are here: > -git7: ok http://crucible.osdl.org/runs/2223/sysinfo/amd01.console > -git8: Oops http://crucible.osdl.org/runs/2233/sysinfo/amd01.console > -git9: Oops http://crucible.osdl.org/runs/2241/sysinfo/amd01.console > > Reference information about the machine this is run on: > http://crucible.osdl.org/runs/2223/sysinfo/amd01.1/ > > Config files: > -git7: http://crucible.osdl.org/runs/2223/sysinfo/amd01.config > -git8: http://crucible.osdl.org/runs/2233/sysinfo/amd01.config > ... > Just checked against latest -git10, same oops: > > http://crucible.osdl.org/runs/2256/sysinfo/amd01.console > > However, it is not occurring on our ita64, x86, or x86_64 systems > running the same kernels. > I'd be suspecting a miscompile, or something horrid in kfree(). Does it change anything if you move that kfree() down a bit? --- a/drivers/message/fusion/mptspi.c~a +++ a/drivers/message/fusion/mptspi.c @@ -790,10 +790,9 @@ mptspi_dv_renegotiate_work(void *data) struct _MPT_SCSI_HOST *hd = wqw->hd; struct scsi_device *sdev; - kfree(wqw); - shost_for_each_device(sdev, hd->ioc->sh) mptspi_dv_device(hd, sdev); + kfree(wqw); } static void _ - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
