* [PATCH] mm/mprotect: fix compilation warning because of unused 'mm' varaible
@ 2019-05-08 8:50 Mike Rapoport
2019-05-13 20:51 ` Song Liu
0 siblings, 1 reply; 3+ messages in thread
From: Mike Rapoport @ 2019-05-08 8:50 UTC (permalink / raw)
To: Andrew Morton; +Cc: linux-mm, Mike Rapoport
Since commit 0cbe3e26abe0 ("mm: update ptep_modify_prot_start/commit to
take vm_area_struct as arg") the only place that uses the local 'mm'
variable in change_pte_range() is the call to set_pte_at().
Many architectures define set_pte_at() as macro that does not use the 'mm'
parameter, which generates the following compilation warning:
CC mm/mprotect.o
mm/mprotect.c: In function 'change_pte_range':
mm/mprotect.c:42:20: warning: unused variable 'mm' [-Wunused-variable]
struct mm_struct *mm = vma->vm_mm;
^~
Fix it by passing vma->mm to set_pte_at() and dropping the local 'mm'
variable in change_pte_range().
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---
mm/mprotect.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 028c724..61bfe24 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -39,7 +39,6 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
unsigned long addr, unsigned long end, pgprot_t newprot,
int dirty_accountable, int prot_numa)
{
- struct mm_struct *mm = vma->vm_mm;
pte_t *pte, oldpte;
spinlock_t *ptl;
unsigned long pages = 0;
@@ -136,7 +135,7 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
newpte = swp_entry_to_pte(entry);
if (pte_swp_soft_dirty(oldpte))
newpte = pte_swp_mksoft_dirty(newpte);
- set_pte_at(mm, addr, pte, newpte);
+ set_pte_at(vma->mm, addr, pte, newpte);
pages++;
}
--
2.7.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] mm/mprotect: fix compilation warning because of unused 'mm' varaible
2019-05-08 8:50 [PATCH] mm/mprotect: fix compilation warning because of unused 'mm' varaible Mike Rapoport
@ 2019-05-13 20:51 ` Song Liu
2019-05-13 20:54 ` Song Liu
0 siblings, 1 reply; 3+ messages in thread
From: Song Liu @ 2019-05-13 20:51 UTC (permalink / raw)
To: Mike Rapoport; +Cc: Andrew Morton, Linux-MM
On Wed, May 8, 2019 at 4:50 AM Mike Rapoport <rppt@linux.ibm.com> wrote:
>
> Since commit 0cbe3e26abe0 ("mm: update ptep_modify_prot_start/commit to
> take vm_area_struct as arg") the only place that uses the local 'mm'
> variable in change_pte_range() is the call to set_pte_at().
>
> Many architectures define set_pte_at() as macro that does not use the 'mm'
> parameter, which generates the following compilation warning:
>
> CC mm/mprotect.o
> mm/mprotect.c: In function 'change_pte_range':
> mm/mprotect.c:42:20: warning: unused variable 'mm' [-Wunused-variable]
> struct mm_struct *mm = vma->vm_mm;
> ^~
>
> Fix it by passing vma->mm to set_pte_at() and dropping the local 'mm'
> variable in change_pte_range().
>
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
> ---
> mm/mprotect.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/mm/mprotect.c b/mm/mprotect.c
> index 028c724..61bfe24 100644
> --- a/mm/mprotect.c
> +++ b/mm/mprotect.c
> @@ -39,7 +39,6 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
> unsigned long addr, unsigned long end, pgprot_t newprot,
> int dirty_accountable, int prot_numa)
> {
> - struct mm_struct *mm = vma->vm_mm;
> pte_t *pte, oldpte;
> spinlock_t *ptl;
> unsigned long pages = 0;
> @@ -136,7 +135,7 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
> newpte = swp_entry_to_pte(entry);
> if (pte_swp_soft_dirty(oldpte))
> newpte = pte_swp_mksoft_dirty(newpte);
> - set_pte_at(mm, addr, pte, newpte);
> + set_pte_at(vma->mm, addr, pte, newpte);
This should be vma->vm_mm.
Thanks,
Song
>
> pages++;
> }
> --
> 2.7.4
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] mm/mprotect: fix compilation warning because of unused 'mm' varaible
2019-05-13 20:51 ` Song Liu
@ 2019-05-13 20:54 ` Song Liu
0 siblings, 0 replies; 3+ messages in thread
From: Song Liu @ 2019-05-13 20:54 UTC (permalink / raw)
To: Mike Rapoport; +Cc: Andrew Morton, Linux-MM
On Mon, May 13, 2019 at 4:51 PM Song Liu <liu.song.a23@gmail.com> wrote:
>
> On Wed, May 8, 2019 at 4:50 AM Mike Rapoport <rppt@linux.ibm.com> wrote:
> >
> > Since commit 0cbe3e26abe0 ("mm: update ptep_modify_prot_start/commit to
> > take vm_area_struct as arg") the only place that uses the local 'mm'
> > variable in change_pte_range() is the call to set_pte_at().
> >
> > Many architectures define set_pte_at() as macro that does not use the 'mm'
> > parameter, which generates the following compilation warning:
> >
> > CC mm/mprotect.o
> > mm/mprotect.c: In function 'change_pte_range':
> > mm/mprotect.c:42:20: warning: unused variable 'mm' [-Wunused-variable]
> > struct mm_struct *mm = vma->vm_mm;
> > ^~
> >
> > Fix it by passing vma->mm to set_pte_at() and dropping the local 'mm'
> > variable in change_pte_range().
> >
> > Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
> > ---
> > mm/mprotect.c | 3 +--
> > 1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/mm/mprotect.c b/mm/mprotect.c
> > index 028c724..61bfe24 100644
> > --- a/mm/mprotect.c
> > +++ b/mm/mprotect.c
> > @@ -39,7 +39,6 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
> > unsigned long addr, unsigned long end, pgprot_t newprot,
> > int dirty_accountable, int prot_numa)
> > {
> > - struct mm_struct *mm = vma->vm_mm;
> > pte_t *pte, oldpte;
> > spinlock_t *ptl;
> > unsigned long pages = 0;
> > @@ -136,7 +135,7 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
> > newpte = swp_entry_to_pte(entry);
> > if (pte_swp_soft_dirty(oldpte))
> > newpte = pte_swp_mksoft_dirty(newpte);
> > - set_pte_at(mm, addr, pte, newpte);
> > + set_pte_at(vma->mm, addr, pte, newpte);
>
> This should be vma->vm_mm.
And we need to fix another reference to mm:
diff --git i/mm/mprotect.c w/mm/mprotect.c
index 8bdba81685d6..bf38dfbbb4b4 100644
--- i/mm/mprotect.c
+++ w/mm/mprotect.c
@@ -135,7 +135,7 @@ static unsigned long change_pte_range(struct
vm_area_struct *vma, pmd_t *pmd,
newpte = swp_entry_to_pte(entry);
if (pte_swp_soft_dirty(oldpte))
newpte = pte_swp_mksoft_dirty(newpte);
- set_pte_at(vma->mm, addr, pte, newpte);
+ set_pte_at(vma->vm_mm, addr, pte, newpte);
pages++;
}
@@ -149,7 +149,7 @@ static unsigned long change_pte_range(struct
vm_area_struct *vma, pmd_t *pmd,
*/
make_device_private_entry_read(&entry);
newpte = swp_entry_to_pte(entry);
- set_pte_at(mm, addr, pte, newpte);
+ set_pte_at(vma->vm_mm, addr, pte, newpte);
pages++;
}
^ permalink raw reply related [flat|nested] 3+ messages in thread
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2019-05-08 8:50 [PATCH] mm/mprotect: fix compilation warning because of unused 'mm' varaible Mike Rapoport
2019-05-13 20:51 ` Song Liu
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