mm/debug_vm_pgtable: remove unused code

The variables used by old implementation isn't needed as we switched to
"struct pgtable_debug_args".  Lets remove them and related code in
debug_vm_pgtable().

Link: https://lkml.kernel.org/r/20210809092631.1888748-12-gshan@redhat.comSigned-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>	[powerpc 8xx]
Tested-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>	[s390]
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chunyu Hu <chuhu@redhat.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/debug_vm_pgtable.c

@@ -1189,14 +1189,6 @@ static int __init init_args(struct pgtable_debug_args *args)
 static int __init debug_vm_pgtable(void)
 {
 	struct pgtable_debug_args args;
-	struct vm_area_struct *vma;
-	struct mm_struct *mm;
-	pgd_t *pgdp;
-	p4d_t *p4dp;
-	pud_t *pudp;
-	pmd_t *pmdp, *saved_pmdp, pmd;
-	pgtable_t saved_ptep;
-	unsigned long vaddr;
 	spinlock_t *ptl = NULL;
 	int idx, ret;
 
@@ -1205,41 +1197,6 @@ static int __init debug_vm_pgtable(void)
 	if (ret)
 		return ret;
 
-	vaddr = get_random_vaddr();
-	mm = mm_alloc();
-	if (!mm) {
-		pr_err("mm_struct allocation failed\n");
-		return 1;
-	}
-
-	vma = vm_area_alloc(mm);
-	if (!vma) {
-		pr_err("vma allocation failed\n");
-		return 1;
-	}
-
-	pgdp = pgd_offset(mm, vaddr);
-	p4dp = p4d_alloc(mm, pgdp, vaddr);
-	pudp = pud_alloc(mm, p4dp, vaddr);
-	pmdp = pmd_alloc(mm, pudp, vaddr);
-	/*
-	 * Allocate pgtable_t
-	 */
-	if (pte_alloc(mm, pmdp)) {
-		pr_err("pgtable allocation failed\n");
-		return 1;
-	}
-
-	/*
-	 * Save all the page table page addresses as the page table
-	 * entries will be used for testing with random or garbage
-	 * values. These saved addresses will be used for freeing
-	 * page table pages.
-	 */
-	pmd = READ_ONCE(*pmdp);
-	saved_pmdp = pmd_offset(pudp, 0UL);
-	saved_ptep = pmd_pgtable(pmd);
-
 	/*
 	 * Iterate over the protection_map[] to make sure that all
 	 * the basic page table transformation validations just hold
@@ -1322,17 +1279,6 @@ static int __init debug_vm_pgtable(void)
 	pgd_populate_tests(&args);
 	spin_unlock(&(args.mm->page_table_lock));
 
-	p4d_free(mm, p4d_offset(pgdp, 0UL));
-	pud_free(mm, pud_offset(p4dp, 0UL));
-	pmd_free(mm, saved_pmdp);
-	pte_free(mm, saved_ptep);
-
-	vm_area_free(vma);
-	mm_dec_nr_puds(mm);
-	mm_dec_nr_pmds(mm);
-	mm_dec_nr_ptes(mm);
-	mmdrop(mm);
-
 	destroy_args(&args);
 	return 0;
 }