Messages in this thread | | | Date | Fri, 17 Mar 2006 15:28:58 +0530 | From | Prasanna S Panchamukhi <> | Subject | Re: Kernel Oops-jprobe |
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> > >DEVPATH=/module/sysensor SUBSYSTEM=module[17192146.124000] Unable to > > >handle kernel paging request at virtual address 080c9566 > > The address looks like a user space address. Since sys_open() passes > user space arguments - in this case a pointer to the filename. Are you > derefencing the pointer correctly? > > I think the handler should first copy_from_user().
User must not call copy_from_user() in the handler, since preemption is disabled and the copy_from_user might cause a page fault that might sleep if the user page is not in the memory. Although the latest patch posted on lkml tries to fixup the exception, it may some times not succeed and the data collected might be incorrect.
> > Moreover your stack is > [17192146.124000] Call Trace: > [17192146.124000] [<c01c6384>] vscnprintf+0x17/0x24 > [17192146.124000] [<c0116c7d>] vprintk+0x62/0x22a > [17192146.124000] [<c02a8682>] int3+0x1e/0x24 > [17192146.124000] [<c0116c18>] printk+0xe/0x11 > [17192146.124000] [<e05610ac>] jsys_open+0x1d/0x28 [sysensor] > [17192146.124000] [<c0102cef>] sysenter_past_esp+0x54/0x75 > [17192146.124000] Code: 77 03 c6 03 20 4d 43 85 ed 7f f1 e9 9e 01 00 > 00 89 f0 89 fa 83 c6 04 8b 08 b8 19 14 2d c0 81 f9 ff 0f 00 00 0f 46 > c8 89 c8 eb 06 <80> 38 00 74 07 40 4a 83 fa ff 75 f4 29 c8 f6 04 24 10 > 89 c7 75 > > and in the code posted, there is no printk in jsys_open(). Have you > sent a revised version of your probe module?
Also from the above stack trace, looks like you had a int3 elsewhere(in printk) also when jsys_open() was executed.
Thanks Prasanna -- Prasanna S Panchamukhi Linux Technology Center India Software Labs, IBM Bangalore Email: prasanna@in.ibm.com Ph: 91-80-51776329 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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