[PATCH 0/4] mm: trivial sparse and checkpatch fixes

[PATCH 0/4] mm: trivial sparse and checkpatch fixes

[Tobin C. Harding]

From: Tobin C Harding <me@tobin.cc>

This patchset fixes trivial sparse and checkpatch errors/warnings. The
majority of the changes are whitespace only. The only code changes are
replace 0 with NULL, and remove extraneous braces around single statement.

Patchset aims to only make changes when they objectively increase the
cleanliness of the code, does not touch line over 80 warnings.

Changes have been tested by building and booting kernel.

Tobin C Harding (4):
  mm: Fix sparse, use plain integer as NULL pointer
  mm: Fix checkpatch warnings, whitespace
  mm: Fix checkpatch errors, whitespace errors
  mm: Fix checkpatch warning, extraneous braces

 mm/memory.c | 66 ++++++++++++++++++++++++++++++-------------------------------
 1 file changed, 32 insertions(+), 34 deletions(-)

-- 
2.7.4

[PATCH 1/4] mm: Fix sparse, use plain integer as NULL pointer

[Tobin C. Harding]

From: Tobin C Harding <me@tobin.cc>

Patch fixes sparse warning: Using plain integer as NULL pointer. Replaces
assignment of 0 to pointer with NULL assignment.

Signed-off-by: Tobin C Harding <me@tobin.cc>
---
 mm/memory.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index 6bf2b47..cc5fa12 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2905,7 +2905,7 @@ static int pte_alloc_one_map(struct vm_fault *vmf)
 		atomic_long_inc(&vma->vm_mm->nr_ptes);
 		pmd_populate(vma->vm_mm, vmf->pmd, vmf->prealloc_pte);
 		spin_unlock(vmf->ptl);
-		vmf->prealloc_pte = 0;
+		vmf->prealloc_pte = NULL;
 	} else if (unlikely(pte_alloc(vma->vm_mm, vmf->pmd, vmf->address))) {
 		return VM_FAULT_OOM;
 	}
@@ -2953,7 +2953,7 @@ static void deposit_prealloc_pte(struct vm_fault *vmf)
 	 * count that as nr_ptes.
 	 */
 	atomic_long_inc(&vma->vm_mm->nr_ptes);
-	vmf->prealloc_pte = 0;
+	vmf->prealloc_pte = NULL;
 }
 
 static int do_set_pmd(struct vm_fault *vmf, struct page *page)
@@ -3359,7 +3359,7 @@ static int do_fault(struct vm_fault *vmf)
 	/* preallocated pagetable is unused: free it */
 	if (vmf->prealloc_pte) {
 		pte_free(vma->vm_mm, vmf->prealloc_pte);
-		vmf->prealloc_pte = 0;
+		vmf->prealloc_pte = NULL;
 	}
 	return ret;
 }
-- 
2.7.4

[PATCH 2/4] mm: Fix checkpatch warnings, whitespace

[Tobin C. Harding]

From: Tobin C Harding <me@tobin.cc>

Patch fixes whitespace checkpatch warnings.

Signed-off-by: Tobin C Harding <me@tobin.cc>
---
 mm/memory.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index cc5fa12..3562314 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -30,7 +30,7 @@
 
 /*
  * 05.04.94  -  Multi-page memory management added for v1.1.
- * 		Idea by Alex Bligh (alex@cconcepts.co.uk)
+ *              Idea by Alex Bligh (alex@cconcepts.co.uk)
  *
  * 16.07.99  -  Support of BIGMEM added by Gerhard Wichert, Siemens AG
  *		(Gerhard.Wichert@pdb.siemens.de)
@@ -82,9 +82,9 @@
 #ifndef CONFIG_NEED_MULTIPLE_NODES
 /* use the per-pgdat data instead for discontigmem - mbligh */
 unsigned long max_mapnr;
-struct page *mem_map;
-
 EXPORT_SYMBOL(max_mapnr);
+
+struct page *mem_map;
 EXPORT_SYMBOL(mem_map);
 #endif
 
@@ -96,7 +96,6 @@ EXPORT_SYMBOL(mem_map);
  * and ZONE_HIGHMEM.
  */
 void * high_memory;
-
 EXPORT_SYMBOL(high_memory);
 
 /*
@@ -120,10 +119,10 @@ static int __init disable_randmaps(char *s)
 __setup("norandmaps", disable_randmaps);
 
 unsigned long zero_pfn __read_mostly;
-unsigned long highest_memmap_pfn __read_mostly;
-
 EXPORT_SYMBOL(zero_pfn);
 
+unsigned long highest_memmap_pfn __read_mostly;
+
 /*
  * CONFIG_MMU architectures set up ZERO_PAGE in their paging_init()
  */
@@ -3696,8 +3695,8 @@ int handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
                  * VM_FAULT_OOM), there is no need to kill anything.
                  * Just clean up the OOM state peacefully.
                  */
-                if (task_in_memcg_oom(current) && !(ret & VM_FAULT_OOM))
-                        mem_cgroup_oom_synchronize(false);
+		if (task_in_memcg_oom(current) && !(ret & VM_FAULT_OOM))
+			mem_cgroup_oom_synchronize(false);
 	}
 
 	/*
-- 
2.7.4

[PATCH 3/4] mm: Fix checkpatch errors, whitespace errors

[Tobin C. Harding]

From: Tobin C Harding <me@tobin.cc>

Patch fixes whitespace checkpatch errors.

Signed-off-by: Tobin C Harding <me@tobin.cc>
---
 mm/memory.c | 42 +++++++++++++++++++++---------------------
 1 file changed, 21 insertions(+), 21 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index 3562314..35fb8b2 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -95,7 +95,7 @@ EXPORT_SYMBOL(mem_map);
  * highstart_pfn must be the same; there must be no gap between ZONE_NORMAL
  * and ZONE_HIGHMEM.
  */
-void * high_memory;
+void *high_memory;
 EXPORT_SYMBOL(high_memory);
 
 /*
@@ -555,7 +555,7 @@ void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *vma,
 
 		if (is_vm_hugetlb_page(vma)) {
 			hugetlb_free_pgd_range(tlb, addr, vma->vm_end,
-				floor, next? next->vm_start: ceiling);
+				floor, next ? next->vm_start : ceiling);
 		} else {
 			/*
 			 * Optimization: gather nearby vmas into one call down
@@ -568,7 +568,7 @@ void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *vma,
 				unlink_file_vma(vma);
 			}
 			free_pgd_range(tlb, addr, vma->vm_end,
-				floor, next? next->vm_start: ceiling);
+				floor, next ? next->vm_start : ceiling);
 		}
 		vma = next;
 	}
@@ -1447,10 +1447,10 @@ EXPORT_SYMBOL_GPL(zap_vma_ptes);
 pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr,
 			spinlock_t **ptl)
 {
-	pgd_t * pgd = pgd_offset(mm, addr);
-	pud_t * pud = pud_alloc(mm, pgd, addr);
+	pgd_t *pgd = pgd_offset(mm, addr);
+	pud_t *pud = pud_alloc(mm, pgd, addr);
 	if (pud) {
-		pmd_t * pmd = pmd_alloc(mm, pud, addr);
+		pmd_t *pmd = pmd_alloc(mm, pud, addr);
 		if (pmd) {
 			VM_BUG_ON(pmd_trans_huge(*pmd));
 			return pte_alloc_map_lock(mm, pmd, addr, ptl);
@@ -2509,7 +2509,7 @@ void unmap_mapping_range(struct address_space *mapping,
 			hlen = ULONG_MAX - hba + 1;
 	}
 
-	details.check_mapping = even_cows? NULL: mapping;
+	details.check_mapping = even_cows ? NULL : mapping;
 	details.first_index = hba;
 	details.last_index = hba + hlen - 1;
 	if (details.last_index < details.first_index)
@@ -3391,14 +3391,14 @@ static int do_numa_page(struct vm_fault *vmf)
 	int flags = 0;
 
 	/*
-	* The "pte" at this point cannot be used safely without
-	* validation through pte_unmap_same(). It's of NUMA type but
-	* the pfn may be screwed if the read is non atomic.
-	*
-	* We can safely just do a "set_pte_at()", because the old
-	* page table entry is not accessible, so there would be no
-	* concurrent hardware modifications to the PTE.
-	*/
+	 * The "pte" at this point cannot be used safely without
+	 * validation through pte_unmap_same(). It's of NUMA type but
+	 * the pfn may be screwed if the read is non atomic.
+	 *
+	 * We can safely just do a "set_pte_at()", because the old
+	 * page table entry is not accessible, so there would be no
+	 * concurrent hardware modifications to the PTE.
+	 */
 	vmf->ptl = pte_lockptr(vma->vm_mm, vmf->pmd);
 	spin_lock(vmf->ptl);
 	if (unlikely(!pte_same(*vmf->pte, pte))) {
@@ -3689,12 +3689,12 @@ int handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
 
 	if (flags & FAULT_FLAG_USER) {
 		mem_cgroup_oom_disable();
-                /*
-                 * The task may have entered a memcg OOM situation but
-                 * if the allocation error was handled gracefully (no
-                 * VM_FAULT_OOM), there is no need to kill anything.
-                 * Just clean up the OOM state peacefully.
-                 */
+		/*
+		 * The task may have entered a memcg OOM situation but
+		 * if the allocation error was handled gracefully (no
+		 * VM_FAULT_OOM), there is no need to kill anything.
+		 * Just clean up the OOM state peacefully.
+		 */
 		if (task_in_memcg_oom(current) && !(ret & VM_FAULT_OOM))
 			mem_cgroup_oom_synchronize(false);
 	}
-- 
2.7.4

[PATCH 4/4] mm: Fix checkpatch warning, extraneous braces

[Tobin C. Harding]

From: Tobin C Harding <me@tobin.cc>

Patch fixes checkpatch warning on use of braces around a single
statement.

Signed-off-by: Tobin C Harding <me@tobin.cc>
---
 mm/memory.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index 35fb8b2..654e6f4 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1128,9 +1128,8 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
 	arch_enter_lazy_mmu_mode();
 	do {
 		pte_t ptent = *pte;
-		if (pte_none(ptent)) {
+		if (pte_none(ptent))
 			continue;
-		}
 
 		if (pte_present(ptent)) {
 			struct page *page;
-- 
2.7.4

Re: [PATCH 2/4] mm: Fix checkpatch warnings, whitespace

[David Rientjes]

On Thu, 2 Feb 2017, Tobin C. Harding wrote:

> @@ -3696,8 +3695,8 @@ int handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
>                   * VM_FAULT_OOM), there is no need to kill anything.
>                   * Just clean up the OOM state peacefully.
>                   */
> -                if (task_in_memcg_oom(current) && !(ret & VM_FAULT_OOM))
> -                        mem_cgroup_oom_synchronize(false);
> +		if (task_in_memcg_oom(current) && !(ret & VM_FAULT_OOM))
> +			mem_cgroup_oom_synchronize(false);
>  	}
>  
>  	/*

The comment suffers from the same problem.

Re: [PATCH 2/4] mm: Fix checkpatch warnings, whitespace

[Tobin Harding]

On Wed, Feb 01, 2017 at 04:48:28PM -0800, David Rientjes wrote:
> On Thu, 2 Feb 2017, Tobin C. Harding wrote:
> 
> > @@ -3696,8 +3695,8 @@ int handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
> >                   * VM_FAULT_OOM), there is no need to kill anything.
> >                   * Just clean up the OOM state peacefully.
> >                   */
> > -                if (task_in_memcg_oom(current) && !(ret & VM_FAULT_OOM))
> > -                        mem_cgroup_oom_synchronize(false);
> > +		if (task_in_memcg_oom(current) && !(ret & VM_FAULT_OOM))
> > +			mem_cgroup_oom_synchronize(false);
> >  	}
> >  
> >  	/*
> 
> The comment suffers from the same problem.

The comment is fixed in the next patch of the set. The fixes are in
separate patches because one was a checkpatch warning and one was an
error.

Any comments on the structure of the patchset most appreciated.


thanks,
Tobin.

Re: [PATCH 1/4] mm: Fix sparse, use plain integer as NULL pointer

[Kirill A. Shutemov]

On Thu, Feb 02, 2017 at 10:37:17AM +1100, Tobin C. Harding wrote:
> From: Tobin C Harding <me@tobin.cc>
> 
> Patch fixes sparse warning: Using plain integer as NULL pointer. Replaces
> assignment of 0 to pointer with NULL assignment.
> 
> Signed-off-by: Tobin C Harding <me@tobin.cc>

I wrote this part when ARC had pgtable_t defined as 'unsigned long', so
NULL wasn't an option, but 0 was as it's valid pointer according to spec.

Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>

-- 
 Kirill A. Shutemov