mm: warn about VmData over RLIMIT_DATA

[deliverable/linux.git] / mm / mmap.c

diff --git a/mm/mmap.c b/mm/mmap.c
index 84b12624ceb01d83762172634179825b086961fd..cfc0cdca421ec4c90449395a4e53ef7284aed308 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -42,6 +42,7 @@
 #include <linux/memory.h>
 #include <linux/printk.h>
 #include <linux/userfaultfd_k.h>
+#include <linux/moduleparam.h>
 
 #include <asm/uaccess.h>
 #include <asm/cacheflush.h>
@@ -69,6 +70,8 @@ const int mmap_rnd_compat_bits_max = CONFIG_ARCH_MMAP_RND_COMPAT_BITS_MAX;
 int mmap_rnd_compat_bits __read_mostly = CONFIG_ARCH_MMAP_RND_COMPAT_BITS;
 #endif
 
+static bool ignore_rlimit_data = true;
+core_param(ignore_rlimit_data, ignore_rlimit_data, bool, 0644);
 
 static void unmap_region(struct mm_struct *mm,
                struct vm_area_struct *vma, struct vm_area_struct *prev,
@@ -2982,9 +2985,17 @@ bool may_expand_vm(struct mm_struct *mm, vm_flags_t flags, unsigned long npages)
        if (mm->total_vm + npages > rlimit(RLIMIT_AS) >> PAGE_SHIFT)
                return false;
 
-       if ((flags & (VM_WRITE | VM_SHARED | (VM_STACK_FLAGS &
-                               (VM_GROWSUP | VM_GROWSDOWN)))) == VM_WRITE)
-               return mm->data_vm + npages <= rlimit(RLIMIT_DATA);
+       if (is_data_mapping(flags) &&
+           mm->data_vm + npages > rlimit(RLIMIT_DATA) >> PAGE_SHIFT) {
+               if (ignore_rlimit_data)
+                       pr_warn_once("%s (%d): VmData %lu exceed data ulimit "
+                                    "%lu. Will be forbidden soon.\n",
+                                    current->comm, current->pid,
+                                    (mm->data_vm + npages) << PAGE_SHIFT,
+                                    rlimit(RLIMIT_DATA));
+               else
+                       return false;
+       }
 
        return true;
 }
@@ -2993,11 +3004,11 @@ void vm_stat_account(struct mm_struct *mm, vm_flags_t flags, long npages)
 {
        mm->total_vm += npages;
 
-       if ((flags & (VM_EXEC | VM_WRITE)) == VM_EXEC)
+       if (is_exec_mapping(flags))
                mm->exec_vm += npages;
-       else if (flags & (VM_STACK_FLAGS & (VM_GROWSUP | VM_GROWSDOWN)))
+       else if (is_stack_mapping(flags))
                mm->stack_vm += npages;
-       else if ((flags & (VM_WRITE | VM_SHARED)) == VM_WRITE)
+       else if (is_data_mapping(flags))
                mm->data_vm += npages;
 }