lkml.org 
[lkml]   [2018]   [Feb]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 12/64] fs/userfaultfd: teach userfaultfd_must_wait() about range locking
Date
From: Davidlohr Bueso <dave@stgolabs.net>

And make use of mm_is_locked() which is why we pass down the
vmf->lockrange.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
---
fs/userfaultfd.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index e3089865fd52..883fbffb284e 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -217,13 +217,14 @@ static inline bool userfaultfd_huge_must_wait(struct userfaultfd_ctx *ctx,
struct vm_area_struct *vma,
unsigned long address,
unsigned long flags,
- unsigned long reason)
+ unsigned long reason,
+ struct range_lock *mmrange)
{
struct mm_struct *mm = ctx->mm;
pte_t *pte;
bool ret = true;

- VM_BUG_ON(!rwsem_is_locked(&mm->mmap_sem));
+ VM_BUG_ON(!mm_is_locked(mm, mmrange));

pte = huge_pte_offset(mm, address, vma_mmu_pagesize(vma));
if (!pte)
@@ -247,7 +248,8 @@ static inline bool userfaultfd_huge_must_wait(struct userfaultfd_ctx *ctx,
struct vm_area_struct *vma,
unsigned long address,
unsigned long flags,
- unsigned long reason)
+ unsigned long reason,
+ struct range_lock *mmrange)
{
return false; /* should never get here */
}
@@ -263,7 +265,8 @@ static inline bool userfaultfd_huge_must_wait(struct userfaultfd_ctx *ctx,
static inline bool userfaultfd_must_wait(struct userfaultfd_ctx *ctx,
unsigned long address,
unsigned long flags,
- unsigned long reason)
+ unsigned long reason,
+ struct range_lock *mmrange)
{
struct mm_struct *mm = ctx->mm;
pgd_t *pgd;
@@ -273,7 +276,7 @@ static inline bool userfaultfd_must_wait(struct userfaultfd_ctx *ctx,
pte_t *pte;
bool ret = true;

- VM_BUG_ON(!rwsem_is_locked(&mm->mmap_sem));
+ VM_BUG_ON(!mm_is_locked(mm, mmrange));

pgd = pgd_offset(mm, address);
if (!pgd_present(*pgd))
@@ -365,7 +368,7 @@ int handle_userfault(struct vm_fault *vmf, unsigned long reason)
* Coredumping runs without mmap_sem so we can only check that
* the mmap_sem is held, if PF_DUMPCORE was not set.
*/
- WARN_ON_ONCE(!rwsem_is_locked(&mm->mmap_sem));
+ WARN_ON_ONCE(!mm_is_locked(mm, vmf->lockrange));

ctx = vmf->vma->vm_userfaultfd_ctx.ctx;
if (!ctx)
@@ -473,11 +476,12 @@ int handle_userfault(struct vm_fault *vmf, unsigned long reason)

if (!is_vm_hugetlb_page(vmf->vma))
must_wait = userfaultfd_must_wait(ctx, vmf->address, vmf->flags,
- reason);
+ reason, vmf->lockrange);
else
must_wait = userfaultfd_huge_must_wait(ctx, vmf->vma,
vmf->address,
- vmf->flags, reason);
+ vmf->flags, reason,
+ vmf->lockrange);
up_read(&mm->mmap_sem);

if (likely(must_wait && !READ_ONCE(ctx->released) &&
--
2.13.6
\
 
 \ /
  Last update: 2018-02-05 02:44    [W:0.232 / U:0.120 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site