Booting a ColdFire m68k core with MMU enabled causes a "bad page state"
oops since commit 1d40a5ea01d5 ("mm: mark pages in use for page tables"):
BUG: Bad page state in process sh pfn:01ce2
page:004fefc8 count:0 mapcount:-1024 mapping:00000000 index:0x0
flags: 0x0()
raw: 00000000 00000000 00000000 fffffbff 00000000 00000100 00000200 00000000
raw: 039c4000
page dumped because: nonzero mapcount
Modules linked in:
CPU: 0 PID: 22 Comm: sh Not tainted 4.17.0-07461-g1d40a5ea01d5 #13
Fix by calling pgtable_page_dtor() in our __pte_free_tlb() code path,
so that the PG_table flag is cleared before we free the pte page.
Note that I had to change the type of pte_free() to be static from
extern. Otherwise you get a lot of warnings like this:
./arch/m68k/include/asm/mcf_pgalloc.h:80:2: warning: ‘pgtable_page_dtor’ is static but used in inline function ‘pte_free’ which is not static
pgtable_page_dtor(page);
^
And making it static is consistent with our use of this in the other
m68k pgalloc definitions of pte_free().
Signed-off-by: Greg Ungerer <[email protected]>
CC: Matthew Wilcox <[email protected]>
---
arch/m68k/include/asm/mcf_pgalloc.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
v2: add a call to pgtable_page_dtor() in pte_free() as well
diff --git a/arch/m68k/include/asm/mcf_pgalloc.h b/arch/m68k/include/asm/mcf_pgalloc.h
index 8b707c249026..12fe700632f4 100644
--- a/arch/m68k/include/asm/mcf_pgalloc.h
+++ b/arch/m68k/include/asm/mcf_pgalloc.h
@@ -44,6 +44,7 @@ extern inline pmd_t *pmd_alloc_kernel(pgd_t *pgd, unsigned long address)
static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t page,
unsigned long address)
{
+ pgtable_page_dtor(page);
__free_page(page);
}
@@ -74,8 +75,9 @@ static inline struct page *pte_alloc_one(struct mm_struct *mm,
return page;
}
-extern inline void pte_free(struct mm_struct *mm, struct page *page)
+static inline void pte_free(struct mm_struct *mm, struct page *page)
{
+ pgtable_page_dtor(page);
__free_page(page);
}
--
2.17.1
On Tue, Jun 19, 2018 at 2:47 AM Greg Ungerer <[email protected]> wrote:
>
> Booting a ColdFire m68k core with MMU enabled causes a "bad page state"
> oops since commit 1d40a5ea01d5 ("mm: mark pages in use for page tables"):
>
> BUG: Bad page state in process sh pfn:01ce2
> page:004fefc8 count:0 mapcount:-1024 mapping:00000000 index:0x0
> flags: 0x0()
> raw: 00000000 00000000 00000000 fffffbff 00000000 00000100 00000200 00000000
> raw: 039c4000
> page dumped because: nonzero mapcount
> Modules linked in:
> CPU: 0 PID: 22 Comm: sh Not tainted 4.17.0-07461-g1d40a5ea01d5 #13
>
> Fix by calling pgtable_page_dtor() in our __pte_free_tlb() code path,
> so that the PG_table flag is cleared before we free the pte page.
>
> Note that I had to change the type of pte_free() to be static from
> extern. Otherwise you get a lot of warnings like this:
>
> ./arch/m68k/include/asm/mcf_pgalloc.h:80:2: warning: ‘pgtable_page_dtor’ is static but used in inline function ‘pte_free’ which is not static
> pgtable_page_dtor(page);
> ^
>
> And making it static is consistent with our use of this in the other
> m68k pgalloc definitions of pte_free().
>
> Signed-off-by: Greg Ungerer <[email protected]>
> CC: Matthew Wilcox <[email protected]>
CC: Matthew Wilcox <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds