Hi Geert, On 18/06/18 16:58, Geert Uytterhoeven wrote:
Hi Greg, On Mon, Jun 18, 2018 at 8:06 AM Greg Ungerer <gerg@xxxxxxxxxxxxxx> 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. Signed-off-by: Greg Ungerer <gerg@xxxxxxxxxxxxxx> CC: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> --- arch/m68k/include/asm/mcf_pgalloc.h | 1 + 1 file changed, 1 insertion(+) Matthew: I came across this thread at https://lkml.org/lkml/2018/6/17/163 about a similar problem with openrisc. Based on that I came up with this fix for m68k/ColdFire. Fixes the issue for me. diff --git a/arch/m68k/include/asm/mcf_pgalloc.h b/arch/m68k/include/asm/mcf_pgalloc.h index 8b707c249026..8c441eb57b80 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); }Do you need a call to pgtable_page_dtor() in pte_free(), too? On x86 (and motorola_pgalloc.h and sun3_pgalloc.h FWIW), both functions call pgtable_page_dtor().
I am thinking yes, looking at those other examples. Regards Greg -- To unsubscribe from this list: send the line "unsubscribe linux-m68k" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
