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Date: Tue, 6 Jul 2021 14:17:47 +0800
From: Gavin Shan <gshan@...hat.com>
To: linux-mm@...ck.org
Cc: linux-kernel@...r.kernel.org, anshuman.khandual@....com,
catalin.marinas@....com, will@...nel.org,
akpm@...ux-foundation.org, shan.gavin@...il.com, chuhu@...hat.com
Subject: [PATCH 11/12] mm/debug_vm_pgtable: Remove unused code
The variables used by old implementation isn't needed as we switched
to "struct vm_pgtable_debug". Lets just remove them.
Signed-off-by: Gavin Shan <gshan@...hat.com>
---
mm/debug_vm_pgtable.c | 99 +++----------------------------------------
1 file changed, 6 insertions(+), 93 deletions(-)
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index 7bc26808033c..1fd6d73d2152 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -32,14 +32,6 @@
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
-/*
- * Please refer Documentation/vm/arch_pgtable_helpers.rst for the semantics
- * expectations that are being validated here. All future changes in here
- * or the documentation need to be in sync.
- */
-
-#define VMFLAGS (VM_READ|VM_WRITE|VM_EXEC)
-
/*
* On s390 platform, the lower 4 bits are used to identify given page table
* entry type. But these bits might affect the ability to clear entries with
@@ -1025,7 +1017,12 @@ static int __init alloc_mem(struct vm_pgtable_debug *debug)
phys_addr_t phys;
int ret = 0;
- /* Initialize the debugging data */
+ /*
+ * Initialize the debugging data. For @page_prot, please refer
+ * Documentation/vm/arch_pgtable_helpers.rst for the semantics
+ * expectations that are being validated here. All future changes
+ * in here or the documentation need to be in sync.
+ */
debug->mm = NULL;
debug->vma = NULL;
debug->pgdp = NULL;
@@ -1137,17 +1134,6 @@ static int __init alloc_mem(struct vm_pgtable_debug *debug)
static int __init debug_vm_pgtable(void)
{
struct vm_pgtable_debug debug;
- struct vm_area_struct *vma;
- struct mm_struct *mm;
- pgd_t *pgdp;
- p4d_t *p4dp, *saved_p4dp;
- pud_t *pudp, *saved_pudp;
- pmd_t *pmdp, *saved_pmdp, pmd;
- pgtable_t saved_ptep;
- pgprot_t prot, protnone;
- phys_addr_t paddr;
- unsigned long vaddr, pte_aligned, pmd_aligned;
- unsigned long pud_aligned, p4d_aligned, pgd_aligned;
spinlock_t *ptl = NULL;
int idx, ret;
@@ -1156,68 +1142,6 @@ static int __init debug_vm_pgtable(void)
if (ret)
return ret;
- prot = vm_get_page_prot(VMFLAGS);
- vaddr = get_random_vaddr();
- mm = mm_alloc();
- if (!mm) {
- pr_err("mm_struct allocation failed\n");
- return 1;
- }
-
- /*
- * __P000 (or even __S000) will help create page table entries with
- * PROT_NONE permission as required for pxx_protnone_tests().
- */
- protnone = __P000;
-
- vma = vm_area_alloc(mm);
- if (!vma) {
- pr_err("vma allocation failed\n");
- return 1;
- }
-
- /*
- * PFN for mapping at PTE level is determined from a standard kernel
- * text symbol. But pfns for higher page table levels are derived by
- * masking lower bits of this real pfn. These derived pfns might not
- * exist on the platform but that does not really matter as pfn_pxx()
- * helpers will still create appropriate entries for the test. This
- * helps avoid large memory block allocations to be used for mapping
- * at higher page table levels.
- */
- paddr = __pa_symbol(&start_kernel);
-
- pte_aligned = (paddr & PAGE_MASK) >> PAGE_SHIFT;
- pmd_aligned = (paddr & PMD_MASK) >> PAGE_SHIFT;
- pud_aligned = (paddr & PUD_MASK) >> PAGE_SHIFT;
- p4d_aligned = (paddr & P4D_MASK) >> PAGE_SHIFT;
- pgd_aligned = (paddr & PGDIR_MASK) >> PAGE_SHIFT;
- WARN_ON(!pfn_valid(pte_aligned));
-
- 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_p4dp = p4d_offset(pgdp, 0UL);
- saved_pudp = pud_offset(p4dp, 0UL);
- 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
@@ -1299,17 +1223,6 @@ static int __init debug_vm_pgtable(void)
pgd_populate_tests(&debug);
spin_unlock(&(debug.mm->page_table_lock));
- p4d_free(mm, saved_p4dp);
- pud_free(mm, saved_pudp);
- 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);
-
free_mem(&debug);
return 0;
}
--
2.23.0
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