Messages in this thread | | | From | Linus Torvalds <> | Date | Tue, 13 Jul 2021 11:19:29 -0700 | Subject | Re: [mm/vmalloc] 5c1f4e690e: BUG:sleeping_function_called_from_invalid_context_at_mm/page_alloc.c |
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On Tue, Jul 13, 2021 at 7:06 AM kernel test robot <oliver.sang@intel.com> wrote: > > [ 131.014885] BUG: sleeping function called from invalid context at mm/page_alloc.c:4992
Strange. The call chain doesn't actually seem to be anything off: it's writev -> sock_write_iter -> sock_sendmsg -> netlink_sendmsg -> vmalloc.
All good to sleep as far as I can tell. The warning itself seems to be just
might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM);
in prepare_alloc_pages().
I don't see what's wrong with that commit, but it does seem to be very consistent, in that the parent doesn't have it:
> +----------------------------------------------------------------------+------------+------------+ > | | a2afc59fb2 | 5c1f4e690e | > +----------------------------------------------------------------------+------------+------------+ > | BUG:sleeping_function_called_from_invalid_context_at_mm/page_alloc.c | 0 | 54 | > +----------------------------------------------------------------------+------------+------------+
Does anybody see what the problem is there?
There's an odd report _after_ the warning:
[ 131.345319] raw_local_irq_restore() called with IRQs enabled [ 131.366561] RIP: 0010:warn_bogus_irq_restore+0x1d/0x20 [ 131.433334] __alloc_pages_bulk+0xbb8/0xf20
but I think that's might be a result of the BUG(). Maybe. But it might also be indicative of some context confusion - do we end up nesting? Because the BUG() has
[ 131.036625] hardirqs last disabled at (283042): [<ffffffff81656d71>] __alloc_pages_bulk+0xae1/0xf20
which means that the might_sleep_if() happens _after_ __alloc_pages_bulk() has disabled interrupts. That would explain it, but the stack_depot_save() thing actually makes that call chain really hard to read because it duplicates the addresses on the stack.
I don't see the nesting there, but that's what it kind of smells like to me.
Anybody?
Linus
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