sh: Fix unneeded constructor in page table allocation

Matthew Wilcox (Oracle) · Rich Felker · commit be74273aee2c · 2020-08-14T22:05:03.000-04:00
The pgd kmem_cache allocation both specified __GFP_ZERO and had a
constructor which makes no sense.  Remove __GFP_ZERO and zero the user
parts of the pgd explicitly.

Signed-off-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Signed-off-by: Rich Felker &lt;dalias@libc.org&gt;
diff --git a/arch/sh/mm/pgtable.c b/arch/sh/mm/pgtable.c
@@ -2,8 +2,6 @@
 #include <linux/mm.h>
 #include <linux/slab.h>
 
-#define PGALLOC_GFP GFP_KERNEL | __GFP_ZERO
-
 static struct kmem_cache *pgd_cachep;
 #if PAGETABLE_LEVELS > 2
 static struct kmem_cache *pmd_cachep;
@@ -13,6 +11,7 @@ void pgd_ctor(void *x)
 {
 	pgd_t *pgd = x;
 
+	memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
 	memcpy(pgd + USER_PTRS_PER_PGD,
 	       swapper_pg_dir + USER_PTRS_PER_PGD,
 	       (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
@@ -32,7 +31,7 @@ void pgtable_cache_init(void)
 
 pgd_t *pgd_alloc(struct mm_struct *mm)
 {
-	return kmem_cache_alloc(pgd_cachep, PGALLOC_GFP);
+	return kmem_cache_alloc(pgd_cachep, GFP_KERNEL);
 }
 
 void pgd_free(struct mm_struct *mm, pgd_t *pgd)
@@ -48,7 +47,7 @@ void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
 
 pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
 {
-	return kmem_cache_alloc(pmd_cachep, PGALLOC_GFP);
+	return kmem_cache_alloc(pmd_cachep, GFP_KERNEL | __GFP_ZERO);
 }
 
 void pmd_free(struct mm_struct *mm, pmd_t *pmd)

Original file line number	Diff line number	Diff line change
`@@ -2,8 +2,6 @@`
`2`	`2`	`#include <linux/mm.h>`
`3`	`3`	`#include <linux/slab.h>`
`4`	`4`
`5`		`-#define PGALLOC_GFP GFP_KERNEL \| __GFP_ZERO`
`6`		`-`
`7`	`5`	`static struct kmem_cache *pgd_cachep;`
`8`	`6`	`#if PAGETABLE_LEVELS > 2`
`9`	`7`	`static struct kmem_cache *pmd_cachep;`
`@@ -13,6 +11,7 @@ void pgd_ctor(void *x)`
`13`	`11`	`{`
`14`	`12`	`pgd_t *pgd = x;`
`15`	`13`
	`14`	`+ memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));`
`16`	`15`	`memcpy(pgd + USER_PTRS_PER_PGD,`
`17`	`16`	`swapper_pg_dir + USER_PTRS_PER_PGD,`
`18`	`17`	`(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));`
`@@ -32,7 +31,7 @@ void pgtable_cache_init(void)`
`32`	`31`
`33`	`32`	`pgd_t pgd_alloc(struct mm_struct mm)`
`34`	`33`	`{`
`35`		`- return kmem_cache_alloc(pgd_cachep, PGALLOC_GFP);`
	`34`	`+ return kmem_cache_alloc(pgd_cachep, GFP_KERNEL);`
`36`	`35`	`}`
`37`	`36`
`38`	`37`	`void pgd_free(struct mm_struct mm, pgd_t pgd)`
`@@ -48,7 +47,7 @@ void pud_populate(struct mm_struct mm, pud_t pud, pmd_t *pmd)`
`48`	`47`
`49`	`48`	`pmd_t pmd_alloc_one(struct mm_struct mm, unsigned long address)`
`50`	`49`	`{`
`51`		`- return kmem_cache_alloc(pmd_cachep, PGALLOC_GFP);`
	`50`	`+ return kmem_cache_alloc(pmd_cachep, GFP_KERNEL \| __GFP_ZERO);`
`52`	`51`	`}`
`53`	`52`
`54`	`53`	`void pmd_free(struct mm_struct mm, pmd_t pmd)`