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-rw-r--r--fs/proc/task_mmu.c17
-rw-r--r--include/asm-i386/pgtable.h3
-rw-r--r--include/asm-um/pgtable.h2
-rw-r--r--mm/mempolicy.c7
-rw-r--r--mm/mprotect.c7
-rw-r--r--mm/msync.c21
-rw-r--r--mm/swapfile.c20
7 files changed, 30 insertions, 47 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 7c89b4549049..7e5e7ec2e36d 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -203,13 +203,14 @@ static void smaps_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
struct mem_size_stats *mss)
{
pte_t *pte, ptent;
+ spinlock_t *ptl;
unsigned long pfn;
struct page *page;
- pte = pte_offset_map(pmd, addr);
+ pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
do {
ptent = *pte;
- if (pte_none(ptent) || !pte_present(ptent))
+ if (!pte_present(ptent))
continue;
mss->resident += PAGE_SIZE;
@@ -230,8 +231,8 @@ static void smaps_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
mss->private_clean += PAGE_SIZE;
}
} while (pte++, addr += PAGE_SIZE, addr != end);
- pte_unmap(pte - 1);
- cond_resched_lock(&vma->vm_mm->page_table_lock);
+ pte_unmap_unlock(pte - 1, ptl);
+ cond_resched();
}
static inline void smaps_pmd_range(struct vm_area_struct *vma, pud_t *pud,
@@ -285,17 +286,11 @@ static inline void smaps_pgd_range(struct vm_area_struct *vma,
static int show_smap(struct seq_file *m, void *v)
{
struct vm_area_struct *vma = v;
- struct mm_struct *mm = vma->vm_mm;
struct mem_size_stats mss;
memset(&mss, 0, sizeof mss);
-
- if (mm) {
- spin_lock(&mm->page_table_lock);
+ if (vma->vm_mm)
smaps_pgd_range(vma, vma->vm_start, vma->vm_end, &mss);
- spin_unlock(&mm->page_table_lock);
- }
-
return show_map_internal(m, v, &mss);
}
diff --git a/include/asm-i386/pgtable.h b/include/asm-i386/pgtable.h
index d101ac414f07..0e3ec809352d 100644
--- a/include/asm-i386/pgtable.h
+++ b/include/asm-i386/pgtable.h
@@ -203,7 +203,8 @@ extern unsigned long pg0[];
#define pte_present(x) ((x).pte_low & (_PAGE_PRESENT | _PAGE_PROTNONE))
#define pte_clear(mm,addr,xp) do { set_pte_at(mm, addr, xp, __pte(0)); } while (0)
-#define pmd_none(x) (!pmd_val(x))
+/* To avoid harmful races, pmd_none(x) should check only the lower when PAE */
+#define pmd_none(x) (!(unsigned long)pmd_val(x))
#define pmd_present(x) (pmd_val(x) & _PAGE_PRESENT)
#define pmd_clear(xp) do { set_pmd(xp, __pmd(0)); } while (0)
#define pmd_bad(x) ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
diff --git a/include/asm-um/pgtable.h b/include/asm-um/pgtable.h
index 616d02b57ea9..ac64eb955868 100644
--- a/include/asm-um/pgtable.h
+++ b/include/asm-um/pgtable.h
@@ -138,7 +138,7 @@ extern unsigned long pg0[1024];
#define pte_clear(mm,addr,xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEWPAGE))
-#define pmd_none(x) (!(pmd_val(x) & ~_PAGE_NEWPAGE))
+#define pmd_none(x) (!((unsigned long)pmd_val(x) & ~_PAGE_NEWPAGE))
#define pmd_bad(x) ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
#define pmd_present(x) (pmd_val(x) & _PAGE_PRESENT)
#define pmd_clear(xp) do { pmd_val(*(xp)) = _PAGE_NEWPAGE; } while (0)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 11d824f282f1..902d4c9eccdc 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -228,9 +228,9 @@ static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
{
pte_t *orig_pte;
pte_t *pte;
+ spinlock_t *ptl;
- spin_lock(&vma->vm_mm->page_table_lock);
- orig_pte = pte = pte_offset_map(pmd, addr);
+ orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
do {
unsigned long pfn;
unsigned int nid;
@@ -246,8 +246,7 @@ static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
if (!node_isset(nid, *nodes))
break;
} while (pte++, addr += PAGE_SIZE, addr != end);
- pte_unmap(orig_pte);
- spin_unlock(&vma->vm_mm->page_table_lock);
+ pte_unmap_unlock(orig_pte, ptl);
return addr != end;
}
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 672a76fddd5e..17a2b52b753b 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -29,8 +29,9 @@ static void change_pte_range(struct mm_struct *mm, pmd_t *pmd,
unsigned long addr, unsigned long end, pgprot_t newprot)
{
pte_t *pte;
+ spinlock_t *ptl;
- pte = pte_offset_map(pmd, addr);
+ pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
do {
if (pte_present(*pte)) {
pte_t ptent;
@@ -44,7 +45,7 @@ static void change_pte_range(struct mm_struct *mm, pmd_t *pmd,
lazy_mmu_prot_update(ptent);
}
} while (pte++, addr += PAGE_SIZE, addr != end);
- pte_unmap(pte - 1);
+ pte_unmap_unlock(pte - 1, ptl);
}
static inline void change_pmd_range(struct mm_struct *mm, pud_t *pud,
@@ -88,7 +89,6 @@ static void change_protection(struct vm_area_struct *vma,
BUG_ON(addr >= end);
pgd = pgd_offset(mm, addr);
flush_cache_range(vma, addr, end);
- spin_lock(&mm->page_table_lock);
do {
next = pgd_addr_end(addr, end);
if (pgd_none_or_clear_bad(pgd))
@@ -96,7 +96,6 @@ static void change_protection(struct vm_area_struct *vma,
change_pud_range(mm, pgd, addr, next, newprot);
} while (pgd++, addr = next, addr != end);
flush_tlb_range(vma, start, end);
- spin_unlock(&mm->page_table_lock);
}
static int
diff --git a/mm/msync.c b/mm/msync.c
index 860395486060..0e040e9c39d8 100644
--- a/mm/msync.c
+++ b/mm/msync.c
@@ -17,28 +17,22 @@
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
-/*
- * Called with mm->page_table_lock held to protect against other
- * threads/the swapper from ripping pte's out from under us.
- */
-
static void msync_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
unsigned long addr, unsigned long end)
{
- struct mm_struct *mm = vma->vm_mm;
pte_t *pte;
+ spinlock_t *ptl;
int progress = 0;
again:
- pte = pte_offset_map(pmd, addr);
+ pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
do {
unsigned long pfn;
struct page *page;
if (progress >= 64) {
progress = 0;
- if (need_resched() ||
- need_lockbreak(&mm->page_table_lock))
+ if (need_resched() || need_lockbreak(ptl))
break;
}
progress++;
@@ -58,8 +52,8 @@ again:
set_page_dirty(page);
progress += 3;
} while (pte++, addr += PAGE_SIZE, addr != end);
- pte_unmap(pte - 1);
- cond_resched_lock(&mm->page_table_lock);
+ pte_unmap_unlock(pte - 1, ptl);
+ cond_resched();
if (addr != end)
goto again;
}
@@ -97,7 +91,6 @@ static inline void msync_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
static void msync_page_range(struct vm_area_struct *vma,
unsigned long addr, unsigned long end)
{
- struct mm_struct *mm = vma->vm_mm;
pgd_t *pgd;
unsigned long next;
@@ -110,16 +103,14 @@ static void msync_page_range(struct vm_area_struct *vma,
return;
BUG_ON(addr >= end);
- pgd = pgd_offset(mm, addr);
+ pgd = pgd_offset(vma->vm_mm, addr);
flush_cache_range(vma, addr, end);
- spin_lock(&mm->page_table_lock);
do {
next = pgd_addr_end(addr, end);
if (pgd_none_or_clear_bad(pgd))
continue;
msync_pud_range(vma, pgd, addr, next);
} while (pgd++, addr = next, addr != end);
- spin_unlock(&mm->page_table_lock);
}
/*
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 296e0bbf7836..510f0039b000 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -401,8 +401,6 @@ void free_swap_and_cache(swp_entry_t entry)
* No need to decide whether this PTE shares the swap entry with others,
* just let do_wp_page work it out if a write is requested later - to
* force COW, vm_page_prot omits write permission from any private vma.
- *
- * vma->vm_mm->page_table_lock is held.
*/
static void unuse_pte(struct vm_area_struct *vma, pte_t *pte,
unsigned long addr, swp_entry_t entry, struct page *page)
@@ -424,23 +422,25 @@ static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
unsigned long addr, unsigned long end,
swp_entry_t entry, struct page *page)
{
- pte_t *pte;
pte_t swp_pte = swp_entry_to_pte(entry);
+ pte_t *pte;
+ spinlock_t *ptl;
+ int found = 0;
- pte = pte_offset_map(pmd, addr);
+ pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
do {
/*
* swapoff spends a _lot_ of time in this loop!
* Test inline before going to call unuse_pte.
*/
if (unlikely(pte_same(*pte, swp_pte))) {
- unuse_pte(vma, pte, addr, entry, page);
- pte_unmap(pte);
- return 1;
+ unuse_pte(vma, pte++, addr, entry, page);
+ found = 1;
+ break;
}
} while (pte++, addr += PAGE_SIZE, addr != end);
- pte_unmap(pte - 1);
- return 0;
+ pte_unmap_unlock(pte - 1, ptl);
+ return found;
}
static inline int unuse_pmd_range(struct vm_area_struct *vma, pud_t *pud,
@@ -522,12 +522,10 @@ static int unuse_mm(struct mm_struct *mm,
down_read(&mm->mmap_sem);
lock_page(page);
}
- spin_lock(&mm->page_table_lock);
for (vma = mm->mmap; vma; vma = vma->vm_next) {
if (vma->anon_vma && unuse_vma(vma, entry, page))
break;
}
- spin_unlock(&mm->page_table_lock);
up_read(&mm->mmap_sem);
/*
* Currently unuse_mm cannot fail, but leave error handling
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.