From: Gavin Shan <gshan@redhat.com>
To: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org, anshuman.khandual@arm.com,
catalin.marinas@arm.com, will@kernel.org,
akpm@linux-foundation.org, chuhu@redhat.com,
shan.gavin@gmail.com
Subject: [PATCH v3 12/12] mm/debug_vm_pgtable: Fix corrupted page flag
Date: Mon, 19 Jul 2021 21:06:13 +0800 [thread overview]
Message-ID: <20210719130613.334901-13-gshan@redhat.com> (raw)
In-Reply-To: <20210719130613.334901-1-gshan@redhat.com>
In page table entry modifying tests, set_xxx_at() are used to populate
the page table entries. On ARM64, PG_arch_1 is set to the target page
flag if execution permission is given. The page flag is kept when the
page is free'd to buddy's free area list. However, it will trigger page
checking failure when it's pulled from the buddy's free area list, as
the following warning messages indicate.
BUG: Bad page state in process memhog pfn:08000
page:0000000015c0a628 refcount:0 mapcount:0 \
mapping:0000000000000000 index:0x1 pfn:0x8000
flags: 0x7ffff8000000800(arch_1|node=0|zone=0|lastcpupid=0xfffff)
raw: 07ffff8000000800 dead000000000100 dead000000000122 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: PAGE_FLAGS_CHECK_AT_PREP flag(s) set
This fixes the issue by clearing PG_arch_1 through flush_dcache_page()
after set_xxx_at() is called.
Signed-off-by: Gavin Shan <gshan@redhat.com>
---
mm/debug_vm_pgtable.c | 32 ++++++++++++++++++++++++++++----
1 file changed, 28 insertions(+), 4 deletions(-)
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index 4f7bf1c9724a..de9def6f7ce1 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -29,6 +29,8 @@
#include <linux/start_kernel.h>
#include <linux/sched/mm.h>
#include <linux/io.h>
+
+#include <asm/cacheflush.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
@@ -118,6 +120,7 @@ static void __init pte_basic_tests(struct pgtable_debug_args *args, int idx)
static void __init pte_advanced_tests(struct pgtable_debug_args *args)
{
+ struct page *page;
pte_t pte;
/*
@@ -127,13 +130,16 @@ static void __init pte_advanced_tests(struct pgtable_debug_args *args)
*/
pr_debug("Validating PTE advanced\n");
- if (args->pte_pfn == ULONG_MAX) {
+ page = (args->pte_pfn != ULONG_MAX) ?
+ pfn_to_page(args->pte_pfn) : NULL;
+ if (!page) {
pr_debug("%s: Skipped\n", __func__);
return;
}
pte = pfn_pte(args->pte_pfn, args->page_prot);
set_pte_at(args->mm, args->vaddr, args->ptep, pte);
+ flush_dcache_page(page);
ptep_set_wrprotect(args->mm, args->vaddr, args->ptep);
pte = ptep_get(args->ptep);
WARN_ON(pte_write(pte));
@@ -145,6 +151,7 @@ static void __init pte_advanced_tests(struct pgtable_debug_args *args)
pte = pte_wrprotect(pte);
pte = pte_mkclean(pte);
set_pte_at(args->mm, args->vaddr, args->ptep, pte);
+ flush_dcache_page(page);
pte = pte_mkwrite(pte);
pte = pte_mkdirty(pte);
ptep_set_access_flags(args->vma, args->vaddr, args->ptep, pte, 1);
@@ -157,6 +164,7 @@ static void __init pte_advanced_tests(struct pgtable_debug_args *args)
pte = pfn_pte(args->pte_pfn, args->page_prot);
pte = pte_mkyoung(pte);
set_pte_at(args->mm, args->vaddr, args->ptep, pte);
+ flush_dcache_page(page);
ptep_test_and_clear_young(args->vma, args->vaddr, args->ptep);
pte = ptep_get(args->ptep);
WARN_ON(pte_young(pte));
@@ -215,6 +223,7 @@ static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx)
static void __init pmd_advanced_tests(struct pgtable_debug_args *args)
{
+ struct page *page;
pmd_t pmd;
unsigned long vaddr = (args->vaddr & HPAGE_PMD_MASK);
@@ -222,7 +231,9 @@ static void __init pmd_advanced_tests(struct pgtable_debug_args *args)
return;
pr_debug("Validating PMD advanced\n");
- if (args->pmd_pfn == ULONG_MAX) {
+ page = (args->pmd_pfn != ULONG_MAX) ?
+ pfn_to_page(args->pmd_pfn) : NULL;
+ if (!page) {
pr_debug("%s: Skipped\n", __func__);
return;
}
@@ -231,6 +242,7 @@ static void __init pmd_advanced_tests(struct pgtable_debug_args *args)
pmd = pfn_pmd(args->pmd_pfn, args->page_prot);
set_pmd_at(args->mm, vaddr, args->pmdp, pmd);
+ flush_dcache_page(page);
pmdp_set_wrprotect(args->mm, vaddr, args->pmdp);
pmd = READ_ONCE(*(args->pmdp));
WARN_ON(pmd_write(pmd));
@@ -242,6 +254,7 @@ static void __init pmd_advanced_tests(struct pgtable_debug_args *args)
pmd = pmd_wrprotect(pmd);
pmd = pmd_mkclean(pmd);
set_pmd_at(args->mm, vaddr, args->pmdp, pmd);
+ flush_dcache_page(page);
pmd = pmd_mkwrite(pmd);
pmd = pmd_mkdirty(pmd);
pmdp_set_access_flags(args->vma, vaddr, args->pmdp, pmd, 1);
@@ -254,6 +267,7 @@ static void __init pmd_advanced_tests(struct pgtable_debug_args *args)
pmd = pmd_mkhuge(pfn_pmd(args->pmd_pfn, args->page_prot));
pmd = pmd_mkyoung(pmd);
set_pmd_at(args->mm, vaddr, args->pmdp, pmd);
+ flush_dcache_page(page);
pmdp_test_and_clear_young(args->vma, vaddr, args->pmdp);
pmd = READ_ONCE(*(args->pmdp));
WARN_ON(pmd_young(pmd));
@@ -340,6 +354,7 @@ static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx)
static void __init pud_advanced_tests(struct pgtable_debug_args *args)
{
+ struct page *page;
unsigned long vaddr = (args->vaddr & HPAGE_PUD_MASK);
pud_t pud;
@@ -347,13 +362,16 @@ static void __init pud_advanced_tests(struct pgtable_debug_args *args)
return;
pr_debug("Validating PUD advanced\n");
- if (args->pud_pfn == ULONG_MAX) {
+ page = (args->pud_pfn != ULONG_MAX) ?
+ pfn_to_page(args->pud_pfn) : NULL;
+ if (!page) {
pr_debug("%s: Skipped\n", __func__);
return;
}
pud = pfn_pud(args->pud_pfn, args->page_prot);
set_pud_at(args->mm, vaddr, args->pudp, pud);
+ flush_dcache_page(page);
pudp_set_wrprotect(args->mm, vaddr, args->pudp);
pud = READ_ONCE(*(args->pudp));
WARN_ON(pud_write(pud));
@@ -367,6 +385,7 @@ static void __init pud_advanced_tests(struct pgtable_debug_args *args)
pud = pud_wrprotect(pud);
pud = pud_mkclean(pud);
set_pud_at(args->mm, vaddr, args->pudp, pud);
+ flush_dcache_page(page);
pud = pud_mkwrite(pud);
pud = pud_mkdirty(pud);
pudp_set_access_flags(args->vma, vaddr, args->pudp, pud, 1);
@@ -382,6 +401,7 @@ static void __init pud_advanced_tests(struct pgtable_debug_args *args)
pud = pfn_pud(args->pud_pfn, args->page_prot);
pud = pud_mkyoung(pud);
set_pud_at(args->mm, vaddr, args->pudp, pud);
+ flush_dcache_page(page);
pudp_test_and_clear_young(args->vma, vaddr, args->pudp);
pud = READ_ONCE(*(args->pudp));
WARN_ON(pud_young(pud));
@@ -596,10 +616,13 @@ static void __init pgd_populate_tests(struct pgtable_debug_args *args) { }
static void __init pte_clear_tests(struct pgtable_debug_args *args)
{
+ struct page *page;
pte_t pte;
pr_debug("Validating PTE clear\n");
- if (args->pte_pfn == ULONG_MAX) {
+ page = (args->pte_pfn != ULONG_MAX) ?
+ pfn_to_page(args->pte_pfn) : NULL;
+ if (!page) {
pr_debug("%s: Skipped\n", __func__);
return;
}
@@ -609,6 +632,7 @@ static void __init pte_clear_tests(struct pgtable_debug_args *args)
pte = __pte(pte_val(pte) | RANDOM_ORVALUE);
#endif
set_pte_at(args->mm, args->vaddr, args->ptep, pte);
+ flush_dcache_page(page);
barrier();
pte_clear(args->mm, args->vaddr, args->ptep);
pte = ptep_get(args->ptep);
--
2.23.0
next prev parent reply other threads:[~2021-07-19 13:08 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-19 13:06 [PATCH v3 00/12] mm/debug_vm_pgtable: Enhancements Gavin Shan
2021-07-19 13:06 ` [PATCH v3 01/12] mm/debug_vm_pgtable: Introduce struct pgtable_debug_args Gavin Shan
2021-07-21 5:44 ` Anshuman Khandual
2021-07-21 10:20 ` Gavin Shan
2021-07-21 10:39 ` Anshuman Khandual
2021-07-21 10:59 ` Anshuman Khandual
2021-07-21 11:59 ` Gavin Shan
2021-07-22 4:41 ` Anshuman Khandual
2021-07-22 6:23 ` Gavin Shan
2021-07-22 7:08 ` Anshuman Khandual
2021-07-23 0:43 ` Gavin Shan
2021-07-19 13:06 ` [PATCH v3 02/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in basic tests Gavin Shan
2021-07-21 5:57 ` Anshuman Khandual
2021-07-21 11:57 ` Gavin Shan
2021-07-19 13:06 ` [PATCH v3 03/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in leaf and savewrite tests Gavin Shan
2021-07-19 13:06 ` [PATCH v3 04/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in protnone and devmap tests Gavin Shan
2021-07-19 13:06 ` [PATCH v3 05/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in soft_dirty and swap tests Gavin Shan
2021-07-19 13:06 ` [PATCH v3 06/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in migration and thp tests Gavin Shan
2021-07-19 13:06 ` [PATCH v3 07/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in PTE modifying tests Gavin Shan
2021-07-22 5:56 ` Anshuman Khandual
2021-07-22 6:37 ` Gavin Shan
2021-07-23 2:39 ` Anshuman Khandual
2021-07-23 4:23 ` Gavin Shan
2021-07-19 13:06 ` [PATCH v3 08/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in PMD " Gavin Shan
2021-07-22 5:45 ` Anshuman Khandual
2021-07-22 6:41 ` Gavin Shan
2021-07-22 7:11 ` Anshuman Khandual
2021-07-23 1:00 ` Gavin Shan
2021-07-23 2:33 ` Anshuman Khandual
2021-07-19 13:06 ` [PATCH v3 09/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in PUD " Gavin Shan
2021-07-22 5:39 ` Anshuman Khandual
2021-07-22 6:47 ` Gavin Shan
2021-07-19 13:06 ` [PATCH v3 10/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in PGD and P4D " Gavin Shan
2021-07-22 5:09 ` Anshuman Khandual
2021-07-22 6:50 ` Gavin Shan
2021-07-19 13:06 ` [PATCH v3 11/12] mm/debug_vm_pgtable: Remove unused code Gavin Shan
2021-07-22 4:51 ` Anshuman Khandual
2021-07-22 6:53 ` Gavin Shan
2021-07-19 13:06 ` Gavin Shan [this message]
2021-07-21 10:18 ` [PATCH v3 12/12] mm/debug_vm_pgtable: Fix corrupted page flag Anshuman Khandual
2021-07-21 12:03 ` Gavin Shan
2021-07-22 3:51 ` Anshuman Khandual
2021-07-22 6:54 ` Gavin Shan
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