Re: [patch] x86: some lock annotations for user copy paths

From: Ingo Molnar
Date: Wed Sep 10 2008 - 08:12:38 EST



* Ingo Molnar <mingo@xxxxxxx> wrote:

> > shouldn't some of that be conditional on pagefault_disable() 'n
> > such?
>
> i dont think so - those have their own special __atomic user-copy
> primitives which Nick didnt touch.

hm, but the prefetch bits were touched, and -tip testing stumbled upon
this false positive:

[ 66.187448] PM: Adding info for No Bus:vcsa12
[ 67.138685] evbug.c: Event. Dev: input0, Type: 20, Code: 0, Value: 500
[ 80.149087] BUG: sleeping function called from invalid context at arch/x86/mm/fault.c:122
[ 80.157344] in_atomic(): 1, irqs_disabled(): 0, pid: 6811, name: gam_server
[ 80.164315] no locks held by gam_server/6811.
[ 80.168685] Pid: 6811, comm: gam_server Not tainted 2.6.27-rc6-tip-00187-gbfd4ed7-dirty #2
[ 80.177013] Call Trace:
[ 80.179454] [<ffffffff8026c1e8>] ? __debug_show_held_locks+0x22/0x24
[ 80.185876] [<ffffffff80242c4d>] __might_sleep+0x104/0x109
[ 80.191430] [<ffffffff8022fd25>] is_prefetch+0xe8/0x228
[ 80.196760] [<ffffffff8023050b>] do_page_fault+0x5d8/0x9a9
[ 80.202361] [<ffffffff802c8218>] ? sys_newstat+0x36/0x41
[ 80.207774] [<ffffffff80c3b2fa>] error_exit+0x0/0xb9

so i've excluded these commits for now. (once there's a fix i can
continue testing it)

Ingo
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