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-rw-r--r--fs/proc/proc_sysctl.c7
-rw-r--r--fs/proc/task_mmu.c53
2 files changed, 36 insertions, 24 deletions
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 317899222d7f..d2018f70d1fa 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -1770,6 +1770,12 @@ static int process_sysctl_arg(char *param, char *val,
return 0;
}
+ if (!val)
+ return -EINVAL;
+ len = strlen(val);
+ if (len == 0)
+ return -EINVAL;
+
/*
* To set sysctl options, we use a temporary mount of proc, look up the
* respective sys/ file and write to it. To avoid mounting it when no
@@ -1811,7 +1817,6 @@ static int process_sysctl_arg(char *param, char *val,
file, param, val);
goto out;
}
- len = strlen(val);
wret = kernel_write(file, val, len, &pos);
if (wret < 0) {
err = wret;
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index ee5a235b3056..602e3a52884d 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1035,6 +1035,25 @@ struct clear_refs_private {
};
#ifdef CONFIG_MEM_SOFT_DIRTY
+
+#define is_cow_mapping(flags) (((flags) & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE)
+
+static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
+{
+ struct page *page;
+
+ if (!pte_write(pte))
+ return false;
+ if (!is_cow_mapping(vma->vm_flags))
+ return false;
+ if (likely(!atomic_read(&vma->vm_mm->has_pinned)))
+ return false;
+ page = vm_normal_page(vma, addr, pte);
+ if (!page)
+ return false;
+ return page_maybe_dma_pinned(page);
+}
+
static inline void clear_soft_dirty(struct vm_area_struct *vma,
unsigned long addr, pte_t *pte)
{
@@ -1049,6 +1068,8 @@ static inline void clear_soft_dirty(struct vm_area_struct *vma,
if (pte_present(ptent)) {
pte_t old_pte;
+ if (pte_is_pinned(vma, addr, ptent))
+ return;
old_pte = ptep_modify_prot_start(vma, addr, pte);
ptent = pte_wrprotect(old_pte);
ptent = pte_clear_soft_dirty(ptent);
@@ -1215,41 +1236,26 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
.type = type,
};
+ if (mmap_write_lock_killable(mm)) {
+ count = -EINTR;
+ goto out_mm;
+ }
if (type == CLEAR_REFS_MM_HIWATER_RSS) {
- if (mmap_write_lock_killable(mm)) {
- count = -EINTR;
- goto out_mm;
- }
-
/*
* Writing 5 to /proc/pid/clear_refs resets the peak
* resident set size to this mm's current rss value.
*/
reset_mm_hiwater_rss(mm);
- mmap_write_unlock(mm);
- goto out_mm;
+ goto out_unlock;
}
- if (mmap_read_lock_killable(mm)) {
- count = -EINTR;
- goto out_mm;
- }
tlb_gather_mmu(&tlb, mm, 0, -1);
if (type == CLEAR_REFS_SOFT_DIRTY) {
for (vma = mm->mmap; vma; vma = vma->vm_next) {
if (!(vma->vm_flags & VM_SOFTDIRTY))
continue;
- mmap_read_unlock(mm);
- if (mmap_write_lock_killable(mm)) {
- count = -EINTR;
- goto out_mm;
- }
- for (vma = mm->mmap; vma; vma = vma->vm_next) {
- vma->vm_flags &= ~VM_SOFTDIRTY;
- vma_set_page_prot(vma);
- }
- mmap_write_downgrade(mm);
- break;
+ vma->vm_flags &= ~VM_SOFTDIRTY;
+ vma_set_page_prot(vma);
}
mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY,
@@ -1261,7 +1267,8 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
if (type == CLEAR_REFS_SOFT_DIRTY)
mmu_notifier_invalidate_range_end(&range);
tlb_finish_mmu(&tlb, 0, -1);
- mmap_read_unlock(mm);
+out_unlock:
+ mmap_write_unlock(mm);
out_mm:
mmput(mm);
}