Merge tag 'kvm-4.13-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm

[karo-tx-linux.git] / mm / mmap.c

diff --git a/mm/mmap.c b/mm/mmap.c
index 7f8cfe9d9b4d06000632f1779051daa0361cd4b4..f19efcf7541878093eb3c3323a597cf8d1da5ae2 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2177,7 +2177,6 @@ static int acct_stack_growth(struct vm_area_struct *vma,
                             unsigned long size, unsigned long grow)
 {
        struct mm_struct *mm = vma->vm_mm;
-       struct rlimit *rlim = current->signal->rlim;
        unsigned long new_start;
 
        /* address space limit tests */
@@ -2185,7 +2184,7 @@ static int acct_stack_growth(struct vm_area_struct *vma,
                return -ENOMEM;
 
        /* Stack limit test */
-       if (size > READ_ONCE(rlim[RLIMIT_STACK].rlim_cur))
+       if (size > rlimit(RLIMIT_STACK))
                return -ENOMEM;
 
        /* mlock limit tests */
@@ -2193,7 +2192,7 @@ static int acct_stack_growth(struct vm_area_struct *vma,
                unsigned long locked;
                unsigned long limit;
                locked = mm->locked_vm + grow;
-               limit = READ_ONCE(rlim[RLIMIT_MEMLOCK].rlim_cur);
+               limit = rlimit(RLIMIT_MEMLOCK);
                limit >>= PAGE_SHIFT;
                if (locked > limit && !capable(CAP_IPC_LOCK))
                        return -ENOMEM;
@@ -2232,7 +2231,7 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
 
        /* Guard against exceeding limits of the address space. */
        address &= PAGE_MASK;
-       if (address >= TASK_SIZE)
+       if (address >= (TASK_SIZE & PAGE_MASK))
                return -ENOMEM;
        address += PAGE_SIZE;
 
@@ -2244,7 +2243,8 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
                gap_addr = TASK_SIZE;
 
        next = vma->vm_next;
-       if (next && next->vm_start < gap_addr) {
+       if (next && next->vm_start < gap_addr &&
+                       (next->vm_flags & (VM_WRITE|VM_READ|VM_EXEC))) {
                if (!(next->vm_flags & VM_GROWSUP))
                        return -ENOMEM;
                /* Check that both stack segments have the same anon_vma? */
@@ -2315,7 +2315,6 @@ int expand_downwards(struct vm_area_struct *vma,
 {
        struct mm_struct *mm = vma->vm_mm;
        struct vm_area_struct *prev;
-       unsigned long gap_addr;
        int error;
 
        address &= PAGE_MASK;
@@ -2324,14 +2323,12 @@ int expand_downwards(struct vm_area_struct *vma,
                return error;
 
        /* Enforce stack_guard_gap */
-       gap_addr = address - stack_guard_gap;
-       if (gap_addr > address)
-               return -ENOMEM;
        prev = vma->vm_prev;
-       if (prev && prev->vm_end > gap_addr) {
-               if (!(prev->vm_flags & VM_GROWSDOWN))
+       /* Check that both stack segments have the same anon_vma? */
+       if (prev && !(prev->vm_flags & VM_GROWSDOWN) &&
+                       (prev->vm_flags & (VM_WRITE|VM_READ|VM_EXEC))) {
+               if (address - prev->vm_end < stack_guard_gap)
                        return -ENOMEM;
-               /* Check that both stack segments have the same anon_vma? */
        }
 
        /* We must make sure the anon_vma is allocated. */