return next;
}
-static int do_brk(unsigned long addr, unsigned long len, struct list_head *uf);
-
+static int do_brk_flags(unsigned long addr, unsigned long request, unsigned long flags,
+ struct list_head *uf);
SYSCALL_DEFINE1(brk, unsigned long, brk)
{
unsigned long retval;
goto out;
/* Ok, looks good - let it rip. */
- if (do_brk(oldbrk, newbrk-oldbrk, &uf) < 0)
+ if (do_brk_flags(oldbrk, newbrk-oldbrk, 0, &uf) < 0)
goto out;
set_brk:
return 0;
}
+static inline u64 file_mmap_size_max(struct file *file, struct inode *inode)
+{
+ if (S_ISREG(inode->i_mode))
+ return MAX_LFS_FILESIZE;
+
+ if (S_ISBLK(inode->i_mode))
+ return MAX_LFS_FILESIZE;
+
+ /* Special "we do even unsigned file positions" case */
+ if (file->f_mode & FMODE_UNSIGNED_OFFSET)
+ return 0;
+
+ /* Yes, random drivers might want more. But I'm tired of buggy drivers */
+ return ULONG_MAX;
+}
+
+static inline bool file_mmap_ok(struct file *file, struct inode *inode,
+ unsigned long pgoff, unsigned long len)
+{
+ u64 maxsize = file_mmap_size_max(file, inode);
+
+ if (maxsize && len > maxsize)
+ return false;
+ maxsize -= len;
+ if (pgoff > maxsize >> PAGE_SHIFT)
+ return false;
+ return true;
+}
+
/*
* The caller must hold down_write(¤t->mm->mmap_sem).
*/
if (file) {
struct inode *inode = file_inode(file);
+ if (!file_mmap_ok(file, inode, pgoff, len))
+ return -EOVERFLOW;
+
switch (flags & MAP_TYPE) {
case MAP_SHARED:
if ((prot&PROT_WRITE) && !(file->f_mode&FMODE_WRITE))
{
struct mm_struct *mm = vma->vm_mm;
struct vm_area_struct *prev;
- int error;
+ int error = 0;
address &= PAGE_MASK;
- error = security_mmap_addr(address);
- if (error)
- return error;
+ if (address < mmap_min_addr)
+ return -EPERM;
/* Enforce stack_guard_gap */
prev = vma->vm_prev;
* anonymous maps. eventually we may be able to do some
* brk-specific accounting here.
*/
-static int do_brk_flags(unsigned long addr, unsigned long request, unsigned long flags, struct list_head *uf)
+static int do_brk_flags(unsigned long addr, unsigned long len, unsigned long flags, struct list_head *uf)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma, *prev;
- unsigned long len;
struct rb_node **rb_link, *rb_parent;
pgoff_t pgoff = addr >> PAGE_SHIFT;
int error;
- len = PAGE_ALIGN(request);
- if (len < request)
- return -ENOMEM;
- if (!len)
- return 0;
-
/* Until we need other flags, refuse anything except VM_EXEC. */
if ((flags & (~VM_EXEC)) != 0)
return -EINVAL;
return 0;
}
-static int do_brk(unsigned long addr, unsigned long len, struct list_head *uf)
-{
- return do_brk_flags(addr, len, 0, uf);
-}
-
-int vm_brk_flags(unsigned long addr, unsigned long len, unsigned long flags)
+int vm_brk_flags(unsigned long addr, unsigned long request, unsigned long flags)
{
struct mm_struct *mm = current->mm;
+ unsigned long len;
int ret;
bool populate;
LIST_HEAD(uf);
+ len = PAGE_ALIGN(request);
+ if (len < request)
+ return -ENOMEM;
+ if (!len)
+ return 0;
+
if (down_write_killable(&mm->mmap_sem))
return -EINTR;
/* mm's last user has gone, and its about to be pulled down */
mmu_notifier_release(mm);
+ if (unlikely(mm_is_oom_victim(mm))) {
+ /*
+ * Manually reap the mm to free as much memory as possible.
+ * Then, as the oom reaper does, set MMF_OOM_SKIP to disregard
+ * this mm from further consideration. Taking mm->mmap_sem for
+ * write after setting MMF_OOM_SKIP will guarantee that the oom
+ * reaper will not run on this mm again after mmap_sem is
+ * dropped.
+ *
+ * Nothing can be holding mm->mmap_sem here and the above call
+ * to mmu_notifier_release(mm) ensures mmu notifier callbacks in
+ * __oom_reap_task_mm() will not block.
+ *
+ * This needs to be done before calling munlock_vma_pages_all(),
+ * which clears VM_LOCKED, otherwise the oom reaper cannot
+ * reliably test it.
+ */
+ mutex_lock(&oom_lock);
+ __oom_reap_task_mm(mm);
+ mutex_unlock(&oom_lock);
+
+ set_bit(MMF_OOM_SKIP, &mm->flags);
+ down_write(&mm->mmap_sem);
+ up_write(&mm->mmap_sem);
+ }
+
if (mm->locked_vm) {
vma = mm->mmap;
while (vma) {
/* update_hiwater_rss(mm) here? but nobody should be looking */
/* Use -1 here to ensure all VMAs in the mm are unmapped */
unmap_vmas(&tlb, vma, 0, -1);
-
- if (unlikely(mm_is_oom_victim(mm))) {
- /*
- * Wait for oom_reap_task() to stop working on this
- * mm. Because MMF_OOM_SKIP is already set before
- * calling down_read(), oom_reap_task() will not run
- * on this "mm" post up_write().
- *
- * mm_is_oom_victim() cannot be set from under us
- * either because victim->mm is already set to NULL
- * under task_lock before calling mmput and oom_mm is
- * set not NULL by the OOM killer only if victim->mm
- * is found not NULL while holding the task_lock.
- */
- set_bit(MMF_OOM_SKIP, &mm->flags);
- down_write(&mm->mmap_sem);
- up_write(&mm->mmap_sem);
- }
free_pgtables(&tlb, vma, FIRST_USER_ADDRESS, USER_PGTABLES_CEILING);
tlb_finish_mmu(&tlb, 0, -1);
projects / GitHub / LineageOS / android_kernel_motorola_exynos9610.git / blobdiff