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authorDan Williams <dan.j.williams@intel.com>2017-11-29 16:10:18 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-11-29 18:40:42 -0800
commitc7da82b894e9eef60a04a15f065a8502341bf13b (patch)
treec59fd3cca98b6247bcd36f2cea370c3ce746b4e2
parentmm: replace pud_write with pud_access_permitted in fault + gup paths (diff)
downloadlinux-dev-c7da82b894e9eef60a04a15f065a8502341bf13b.tar.xz
linux-dev-c7da82b894e9eef60a04a15f065a8502341bf13b.zip
mm: replace pmd_write with pmd_access_permitted in fault + gup paths
The 'access_permitted' helper is used in the gup-fast path and goes beyond the simple _PAGE_RW check to also: - validate that the mapping is writable from a protection keys standpoint - validate that the pte has _PAGE_USER set since all fault paths where pmd_write is must be referencing user-memory. Link: http://lkml.kernel.org/r/151043111049.2842.15241454964150083466.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/sparc/mm/gup.c2
-rw-r--r--fs/dax.c3
-rw-r--r--mm/hmm.c4
-rw-r--r--mm/huge_memory.c4
-rw-r--r--mm/memory.c2
5 files changed, 8 insertions, 7 deletions
diff --git a/arch/sparc/mm/gup.c b/arch/sparc/mm/gup.c
index 5ae2d0a01a70..33c0f8bb0f33 100644
--- a/arch/sparc/mm/gup.c
+++ b/arch/sparc/mm/gup.c
@@ -75,7 +75,7 @@ static int gup_huge_pmd(pmd_t *pmdp, pmd_t pmd, unsigned long addr,
if (!(pmd_val(pmd) & _PAGE_VALID))
return 0;
- if (write && !pmd_write(pmd))
+ if (!pmd_access_permitted(pmd, write))
return 0;
refs = 0;
diff --git a/fs/dax.c b/fs/dax.c
index 95981591977a..78b72c48374e 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -627,7 +627,8 @@ static void dax_mapping_entry_mkclean(struct address_space *mapping,
if (pfn != pmd_pfn(*pmdp))
goto unlock_pmd;
- if (!pmd_dirty(*pmdp) && !pmd_write(*pmdp))
+ if (!pmd_dirty(*pmdp)
+ && !pmd_access_permitted(*pmdp, WRITE))
goto unlock_pmd;
flush_cache_page(vma, address, pfn);
diff --git a/mm/hmm.c b/mm/hmm.c
index ea19742a5d60..93718a391611 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -391,11 +391,11 @@ again:
if (pmd_protnone(pmd))
return hmm_vma_walk_clear(start, end, walk);
- if (write_fault && !pmd_write(pmd))
+ if (!pmd_access_permitted(pmd, write_fault))
return hmm_vma_walk_clear(start, end, walk);
pfn = pmd_pfn(pmd) + pte_index(addr);
- flag |= pmd_write(pmd) ? HMM_PFN_WRITE : 0;
+ flag |= pmd_access_permitted(pmd, WRITE) ? HMM_PFN_WRITE : 0;
for (; addr < end; addr += PAGE_SIZE, i++, pfn++)
pfns[i] = hmm_pfn_t_from_pfn(pfn) | flag;
return 0;
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 4fe2491056a0..05b729f45e8a 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -877,7 +877,7 @@ struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
*/
WARN_ONCE(flags & FOLL_COW, "mm: In follow_devmap_pmd with FOLL_COW set");
- if (flags & FOLL_WRITE && !pmd_write(*pmd))
+ if (!pmd_access_permitted(*pmd, flags & FOLL_WRITE))
return NULL;
if (pmd_present(*pmd) && pmd_devmap(*pmd))
@@ -1393,7 +1393,7 @@ out_unlock:
*/
static inline bool can_follow_write_pmd(pmd_t pmd, unsigned int flags)
{
- return pmd_write(pmd) ||
+ return pmd_access_permitted(pmd, WRITE) ||
((flags & FOLL_FORCE) && (flags & FOLL_COW) && pmd_dirty(pmd));
}
diff --git a/mm/memory.c b/mm/memory.c
index 25d283d46ea3..416e451a707e 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4046,7 +4046,7 @@ static int __handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
if (pmd_protnone(orig_pmd) && vma_is_accessible(vma))
return do_huge_pmd_numa_page(&vmf, orig_pmd);
- if (dirty && !pmd_write(orig_pmd)) {
+ if (dirty && !pmd_access_permitted(orig_pmd, WRITE)) {
ret = wp_huge_pmd(&vmf, orig_pmd);
if (!(ret & VM_FAULT_FALLBACK))
return ret;