[RFC 13/18] limits: track RLIMIT_AS actual max

[Topi Miettinen]

Track maximum size of address space, presented in /proc/self/limits.

Signed-off-by: Topi Miettinen <toiwoton@xxxxxxxxx>
---
 mm/mmap.c   | 4 ++++
 mm/mremap.c | 3 +++
 2 files changed, 7 insertions(+)

diff --git a/mm/mmap.c b/mm/mmap.c
index 4e683dd..4876c21 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2706,6 +2706,9 @@ static int do_brk(unsigned long addr, unsigned long len)
 out:
 	perf_event_mmap(vma);
 	mm->total_vm += len >> PAGE_SHIFT;
+
+	bump_rlimit(RLIMIT_AS, mm->total_vm << PAGE_SHIFT);
+
 	mm->data_vm += len >> PAGE_SHIFT;
 	if (flags & VM_LOCKED)
 		mm->locked_vm += (len >> PAGE_SHIFT);
@@ -2926,6 +2929,7 @@ bool may_expand_vm(struct mm_struct *mm, vm_flags_t flags, unsigned long npages)
 void vm_stat_account(struct mm_struct *mm, vm_flags_t flags, long npages)
 {
 	mm->total_vm += npages;
+	bump_rlimit(RLIMIT_AS, mm->total_vm << PAGE_SHIFT);
 
 	if (is_exec_mapping(flags))
 		mm->exec_vm += npages;
diff --git a/mm/mremap.c b/mm/mremap.c
index ade3e13..6be3c01 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -397,6 +397,9 @@ static struct vm_area_struct *vma_to_resize(unsigned long addr,
 	if (vma->vm_flags & VM_LOCKED)
 		bump_rlimit(RLIMIT_MEMLOCK, (mm->locked_vm << PAGE_SHIFT) +
 			    new_len - old_len);
+	bump_rlimit(RLIMIT_AS, (mm->total_vm << PAGE_SHIFT) +
+		    new_len - old_len);
+
 	return vma;
 }
 
-- 
2.8.1