linux-stable.git/include/asm-x86/pgalloc.h, branch linux-2.6.27.y

x86, mm: fix pte_free()

2009-02-02T16:28:08+00:00

commit 42ef73fe134732b2e91c0326df5fd568da17c4b2 upstream.

On -rt we were seeing spurious bad page states like:

Bad page state in process 'firefox'
page:c1bc2380 flags:0x40000000 mapping:c1bc2390 mapcount:0 count:0
Trying to fix it up, but a reboot is needed
Backtrace:
Pid: 503, comm: firefox Not tainted 2.6.26.8-rt13 #3
[] ? printk+0x14/0x19
[] bad_page+0x4e/0x79
[] free_hot_cold_page+0x5b/0x1d3
[] free_hot_page+0xf/0x11
[] __free_pages+0x20/0x2b
[] __pte_alloc+0x87/0x91
[] handle_mm_fault+0xe4/0x733
[] ? rt_mutex_down_read_trylock+0x57/0x63
[] ? rt_mutex_down_read_trylock+0x57/0x63
[] do_page_fault+0x36f/0x88a

This is the case where a concurrent fault already installed the PTE and
we get to free the newly allocated one.

This is due to pgtable_page_ctor() doing the spin_lock_init(&page->ptl)
which is overlaid with the {private, mapping} struct.

union {
    struct {
        unsigned long private;
        struct address_space *mapping;
    };
    spinlock_t ptl;
    struct kmem_cache *slab;
    struct page *first_page;
};

Normally the spinlock is small enough to not stomp on page->mapping, but
PREEMPT_RT=y has huge 'spin'locks.

But lockdep kernels should also be able to trigger this splat, as the
lock tracking code grows the spinlock to cover page->mapping.

The obvious fix is calling pgtable_page_dtor() like the regular pte free
path __pte_free_tlb() does.

It seems all architectures except x86 and nm10300 already do this, and
nm10300 doesn't seem to use pgtable_page_ctor(), which suggests it
doesn't do SMP or simply doesnt do MMU at all or something.

Signed-off-by: Peter Zijlstra 
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

x86/paravirt: add a pgd_alloc/free hooks

2008-07-08T11:11:01+00:00

Add hooks which are called at pgd_alloc/free time.  The pgd_alloc hook
may return an error code, which if non-zero, causes the pgd allocation
to be failed.  The hooks may be used to allocate/free auxillary
per-pgd information.

also fix:

> * Ingo Molnar  wrote:
>
>  include/asm/pgalloc.h: In function ‘paravirt_pgd_free':
>  include/asm/pgalloc.h:14: error: parameter name omitted
>  arch/x86/kernel/entry_64.S: In file included from
>  arch/x86/kernel/traps_64.c:51:include/asm/pgalloc.h: In function ‘paravirt_pgd_free':
>  include/asm/pgalloc.h:14: error: parameter name omitted

Signed-off-by: Jeremy Fitzhardinge 
Cc: xen-devel 
Cc: Stephen Tweedie 
Cc: Eduardo Habkost 
Cc: Mark McLoughlin 
Signed-off-by: Ingo Molnar

x86: demacro pgalloc paravirt stubs

2008-04-24T21:57:31+00:00

Turn paravirt stubs into inline functions, so that the arguments are
still typechecked.

Signed-off-by: Jeremy Fitzhardinge 

Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner

x86: add pud_alloc for 4-level pagetables

2008-04-24T21:57:31+00:00

Signed-off-by: Jeremy Fitzhardinge 
Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner

x86: rename paravirt_alloc_pt etc after the pagetable structure

2008-04-24T21:57:31+00:00

Rename (alloc|release)_(pt|pd) to pte/pmd to explicitly match the name
of the appropriate pagetable level structure.

[ x86.git merge work by Mark McLoughlin  ]

Signed-off-by: Jeremy Fitzhardinge 
Signed-off-by: Ingo Molnar 
Signed-off-by: Mark McLoughlin 
Signed-off-by: Thomas Gleixner

x86: move pgalloc pud and pgd operations into common place

2008-04-24T21:57:30+00:00

Signed-off-by: Jeremy Fitzhardinge 
Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner

x86: move pmd functions into common asm/pgalloc.h

2008-04-24T21:57:30+00:00

Common definitions for 3-level pagetable functions.

Signed-off-by: Jeremy Fitzhardinge 
Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner

x86: move pte functions into common asm/pgalloc.h

2008-04-24T21:57:30+00:00

Common definitions for 2-level pagetable functions.

Signed-off-by: Jeremy Fitzhardinge 
Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner

x86: put paravirt stubs into common asm/pgalloc.h

2008-04-24T21:57:30+00:00

Signed-off-by: Jeremy Fitzhardinge 
Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner

x86: add common mm/pgtable.c

2008-04-24T21:57:30+00:00

Add a common arch/x86/mm/pgtable.c file for common pagetable functions.

Signed-off-by: Jeremy Fitzhardinge 
Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner