Hi Greg, Did this patch get dropped ?. IIRC, we agreed that we could keep this patch and it is 3.13 stable backport which i need to send a new version.
-aneesh [email protected] writes: > This is a note to let you know that I've just added the patch titled > > powerpc/thp: Fix crash on mremap > > to the 3.12-stable tree which can be found at: > > http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary > > The filename of the patch is: > powerpc-thp-fix-crash-on-mremap.patch > and it can be found in the queue-3.12 subdirectory. > > If you, or anyone else, feels it should not be added to the stable tree, > please let <[email protected]> know about it. > > > From b3084f4db3aeb991c507ca774337c7e7893ed04f Mon Sep 17 00:00:00 2001 > From: "Aneesh Kumar K.V" <[email protected]> > Date: Mon, 13 Jan 2014 11:34:24 +0530 > Subject: powerpc/thp: Fix crash on mremap > > From: "Aneesh Kumar K.V" <[email protected]> > > commit b3084f4db3aeb991c507ca774337c7e7893ed04f upstream. > > This patch fix the below crash > > NIP [c00000000004cee4] .__hash_page_thp+0x2a4/0x440 > LR [c0000000000439ac] .hash_page+0x18c/0x5e0 > ... > Call Trace: > [c000000736103c40] [00001ffffb000000] 0x1ffffb000000(unreliable) > [437908.479693] [c000000736103d50] [c0000000000439ac] .hash_page+0x18c/0x5e0 > [437908.479699] [c000000736103e30] [c00000000000924c] .do_hash_page+0x4c/0x58 > > On ppc64 we use the pgtable for storing the hpte slot information and > store address to the pgtable at a constant offset (PTRS_PER_PMD) from > pmd. On mremap, when we switch the pmd, we need to withdraw and deposit > the pgtable again, so that we find the pgtable at PTRS_PER_PMD offset > from new pmd. > > We also want to move the withdraw and deposit before the set_pmd so > that, when page fault find the pmd as trans huge we can be sure that > pgtable can be located at the offset. > > Signed-off-by: Aneesh Kumar K.V <[email protected]> > Acked-by: Kirill A. Shutemov <[email protected]> > Signed-off-by: Benjamin Herrenschmidt <[email protected]> > Signed-off-by: Greg Kroah-Hartman <[email protected]> > > > --- > arch/Kconfig | 3 +++ > arch/powerpc/platforms/Kconfig.cputype | 1 + > mm/huge_memory.c | 12 ++++++++++++ > 3 files changed, 16 insertions(+) > > --- a/arch/Kconfig > +++ b/arch/Kconfig > @@ -365,6 +365,9 @@ config HAVE_ARCH_TRANSPARENT_HUGEPAGE > config HAVE_ARCH_SOFT_DIRTY > bool > > +config ARCH_THP_MOVE_PMD_ALWAYS_WITHDRAW > + bool > + > config HAVE_MOD_ARCH_SPECIFIC > bool > help > --- a/arch/powerpc/platforms/Kconfig.cputype > +++ b/arch/powerpc/platforms/Kconfig.cputype > @@ -71,6 +71,7 @@ config PPC_BOOK3S_64 > select PPC_FPU > select PPC_HAVE_PMU_SUPPORT > select SYS_SUPPORTS_HUGETLBFS > + select ARCH_THP_MOVE_PMD_ALWAYS_WITHDRAW > select HAVE_ARCH_TRANSPARENT_HUGEPAGE if PPC_64K_PAGES > > config PPC_BOOK3E_64 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -1474,8 +1474,20 @@ int move_huge_pmd(struct vm_area_struct > > ret = __pmd_trans_huge_lock(old_pmd, vma); > if (ret == 1) { > +#ifdef CONFIG_ARCH_THP_MOVE_PMD_ALWAYS_WITHDRAW > + pgtable_t pgtable; > +#endif > pmd = pmdp_get_and_clear(mm, old_addr, old_pmd); > VM_BUG_ON(!pmd_none(*new_pmd)); > +#ifdef CONFIG_ARCH_THP_MOVE_PMD_ALWAYS_WITHDRAW > + /* > + * Archs like ppc64 use pgtable to store per pmd > + * specific information. So when we switch the pmd, > + * we should also withdraw and deposit the pgtable > + */ > + pgtable = pgtable_trans_huge_withdraw(mm, old_pmd); > + pgtable_trans_huge_deposit(mm, new_pmd, pgtable); > +#endif > set_pmd_at(mm, new_addr, new_pmd, pmd_mksoft_dirty(pmd)); > spin_unlock(&mm->page_table_lock); > } > > > Patches currently in stable-queue which might be from > [email protected] are > > queue-3.12/powerpc-thp-fix-crash-on-mremap.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
