diff options
| -rw-r--r-- | mm/mmap.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index 14d36be65ce7..270bd8d504b8 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -703,6 +703,18 @@ retry: } /* + * Determine if the allocation needs to ensure that there is no + * existing mapping within it's guard gaps, for use as start_gap. + */ +static inline unsigned long stack_guard_placement(vm_flags_t vm_flags) +{ + if (vm_flags & VM_SHADOW_STACK) + return PAGE_SIZE; + + return 0; +} + +/* * Search for an unmapped address range. * * We are looking for a range that: @@ -763,6 +775,7 @@ generic_get_unmapped_area(struct file *filp, unsigned long addr, info.length = len; info.low_limit = mm->mmap_base; info.high_limit = mmap_end; + info.start_gap = stack_guard_placement(vm_flags); return vm_unmapped_area(&info); } @@ -812,6 +825,7 @@ generic_get_unmapped_area_topdown(struct file *filp, unsigned long addr, info.length = len; info.low_limit = PAGE_SIZE; info.high_limit = arch_get_mmap_base(addr, mm->mmap_base); + info.start_gap = stack_guard_placement(vm_flags); addr = vm_unmapped_area(&info); /* |