On 9/27/18 2:50 PM, Kirill A. Shutemov wrote: >> diff --git a/mm/mmap.c b/mm/mmap.c >> index 017bcfa..0d2fae1 100644 >> --- a/mm/mmap.c >> +++ b/mm/mmap.c >> @@ -193,9 +193,11 @@ static int do_brk_flags(unsigned long addr, unsigned >> long request, unsigned long >> unsigned long retval; >> unsigned long newbrk, oldbrk; >> struct mm_struct *mm = current->mm; >> + unsigned long origbrk = mm->brk; > > Is it safe to read mm->brk outside the lock?
Good catch! I guess not, parallel brk()'s could then race.
