From: Jan Kara <jack@suse.cz> To: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: dan.j.williams@intel.com, akpm@linux-foundation.org, Jan Kara <jack@suse.cz>, linux-nvdimm@lists.01.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, stable@vger.kernel.org Subject: Re: [PATCH] mm: Fix modifying of page protection by insert_pfn_pmd() Date: Mon, 1 Apr 2019 10:14:41 +0200 [thread overview] Message-ID: <20190401081441.GD4826@quack2.suse.cz> (raw) In-Reply-To: <20190330054121.27831-1-aneesh.kumar@linux.ibm.com> On Sat 30-03-19 11:11:21, Aneesh Kumar K.V wrote: > With some architectures like ppc64, set_pmd_at() cannot cope with > a situation where there is already some (different) valid entry present. > > Use pmdp_set_access_flags() instead to modify the pfn which is built to > deal with modifying existing PMD entries. > > This is similar to > commit cae85cb8add3 ("mm/memory.c: fix modifying of page protection by insert_pfn()") > > We also do similar update w.r.t insert_pfn_pud eventhough ppc64 don't support > pud pfn entries now. > > CC: stable@vger.kernel.org > Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Thanks for fixing this! The patch looks good to me. Feel free to add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > mm/huge_memory.c | 31 +++++++++++++++++++++++++++++++ > 1 file changed, 31 insertions(+) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 404acdcd0455..f7dca413c4b2 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -755,6 +755,20 @@ static void insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, > spinlock_t *ptl; > > ptl = pmd_lock(mm, pmd); > + if (!pmd_none(*pmd)) { > + if (write) { > + if (pmd_pfn(*pmd) != pfn_t_to_pfn(pfn)) { > + WARN_ON_ONCE(!is_huge_zero_pmd(*pmd)); > + goto out_unlock; > + } > + entry = pmd_mkyoung(*pmd); > + entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); > + if (pmdp_set_access_flags(vma, addr, pmd, entry, 1)) > + update_mmu_cache_pmd(vma, addr, pmd); > + } > + goto out_unlock; > + } > + > entry = pmd_mkhuge(pfn_t_pmd(pfn, prot)); > if (pfn_t_devmap(pfn)) > entry = pmd_mkdevmap(entry); > @@ -770,6 +784,7 @@ static void insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, > > set_pmd_at(mm, addr, pmd, entry); > update_mmu_cache_pmd(vma, addr, pmd); > +out_unlock: > spin_unlock(ptl); > } > > @@ -821,6 +836,20 @@ static void insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, > spinlock_t *ptl; > > ptl = pud_lock(mm, pud); > + if (!pud_none(*pud)) { > + if (write) { > + if (pud_pfn(*pud) != pfn_t_to_pfn(pfn)) { > + WARN_ON_ONCE(!is_huge_zero_pud(*pud)); > + goto out_unlock; > + } > + entry = pud_mkyoung(*pud); > + entry = maybe_pud_mkwrite(pud_mkdirty(entry), vma); > + if (pudp_set_access_flags(vma, addr, pud, entry, 1)) > + update_mmu_cache_pud(vma, addr, pud); > + } > + goto out_unlock; > + } > + > entry = pud_mkhuge(pfn_t_pud(pfn, prot)); > if (pfn_t_devmap(pfn)) > entry = pud_mkdevmap(entry); > @@ -830,6 +859,8 @@ static void insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, > } > set_pud_at(mm, addr, pud, entry); > update_mmu_cache_pud(vma, addr, pud); > + > +out_unlock: > spin_unlock(ptl); > } > > -- > 2.20.1 > -- Jan Kara <jack@suse.com> SUSE Labs, CR
WARNING: multiple messages have this Message-ID (diff)
From: Jan Kara <jack@suse.cz> To: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Jan Kara <jack@suse.cz>, linux-nvdimm@lists.01.org, stable@vger.kernel.org, linux-mm@kvack.org, dan.j.williams@intel.com, linuxppc-dev@lists.ozlabs.org, akpm@linux-foundation.org Subject: Re: [PATCH] mm: Fix modifying of page protection by insert_pfn_pmd() Date: Mon, 1 Apr 2019 10:14:41 +0200 [thread overview] Message-ID: <20190401081441.GD4826@quack2.suse.cz> (raw) In-Reply-To: <20190330054121.27831-1-aneesh.kumar@linux.ibm.com> On Sat 30-03-19 11:11:21, Aneesh Kumar K.V wrote: > With some architectures like ppc64, set_pmd_at() cannot cope with > a situation where there is already some (different) valid entry present. > > Use pmdp_set_access_flags() instead to modify the pfn which is built to > deal with modifying existing PMD entries. > > This is similar to > commit cae85cb8add3 ("mm/memory.c: fix modifying of page protection by insert_pfn()") > > We also do similar update w.r.t insert_pfn_pud eventhough ppc64 don't support > pud pfn entries now. > > CC: stable@vger.kernel.org > Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Thanks for fixing this! The patch looks good to me. Feel free to add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > mm/huge_memory.c | 31 +++++++++++++++++++++++++++++++ > 1 file changed, 31 insertions(+) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 404acdcd0455..f7dca413c4b2 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -755,6 +755,20 @@ static void insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, > spinlock_t *ptl; > > ptl = pmd_lock(mm, pmd); > + if (!pmd_none(*pmd)) { > + if (write) { > + if (pmd_pfn(*pmd) != pfn_t_to_pfn(pfn)) { > + WARN_ON_ONCE(!is_huge_zero_pmd(*pmd)); > + goto out_unlock; > + } > + entry = pmd_mkyoung(*pmd); > + entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); > + if (pmdp_set_access_flags(vma, addr, pmd, entry, 1)) > + update_mmu_cache_pmd(vma, addr, pmd); > + } > + goto out_unlock; > + } > + > entry = pmd_mkhuge(pfn_t_pmd(pfn, prot)); > if (pfn_t_devmap(pfn)) > entry = pmd_mkdevmap(entry); > @@ -770,6 +784,7 @@ static void insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, > > set_pmd_at(mm, addr, pmd, entry); > update_mmu_cache_pmd(vma, addr, pmd); > +out_unlock: > spin_unlock(ptl); > } > > @@ -821,6 +836,20 @@ static void insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, > spinlock_t *ptl; > > ptl = pud_lock(mm, pud); > + if (!pud_none(*pud)) { > + if (write) { > + if (pud_pfn(*pud) != pfn_t_to_pfn(pfn)) { > + WARN_ON_ONCE(!is_huge_zero_pud(*pud)); > + goto out_unlock; > + } > + entry = pud_mkyoung(*pud); > + entry = maybe_pud_mkwrite(pud_mkdirty(entry), vma); > + if (pudp_set_access_flags(vma, addr, pud, entry, 1)) > + update_mmu_cache_pud(vma, addr, pud); > + } > + goto out_unlock; > + } > + > entry = pud_mkhuge(pfn_t_pud(pfn, prot)); > if (pfn_t_devmap(pfn)) > entry = pud_mkdevmap(entry); > @@ -830,6 +859,8 @@ static void insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, > } > set_pud_at(mm, addr, pud, entry); > update_mmu_cache_pud(vma, addr, pud); > + > +out_unlock: > spin_unlock(ptl); > } > > -- > 2.20.1 > -- Jan Kara <jack@suse.com> SUSE Labs, CR
next prev parent reply other threads:[~2019-04-01 8:14 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-03-30 5:41 [PATCH] mm: Fix modifying of page protection by insert_pfn_pmd() Aneesh Kumar K.V 2019-03-30 5:41 ` Aneesh Kumar K.V 2019-04-01 8:14 ` Jan Kara [this message] 2019-04-01 8:14 ` Jan Kara [not found] ` <20190330054121.27831-1-aneesh.kumar-tEXmvtCZX7AybS5Ee8rs3A@public.gmane.org> 2019-04-01 10:49 ` Sasha Levin 2019-04-01 10:49 ` Sasha Levin
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