diff options
| author | Martin Liska <mliska@suse.cz> | 2018-11-30 15:25:15 +0100 |
|---|---|---|
| committer | Martin Liska <marxin@gcc.gnu.org> | 2018-11-30 14:25:15 +0000 |
| commit | 6e644a50045f8032b6d6ff19eb70d8b33dfc4dae (patch) | |
| tree | b6ab18da4eaeb67ce5e78a93ed2b4b84bfa0b637 /gcc/cfgexpand.c | |
| parent | b49f1a7e7c85add83637cf7df46b8fc9b5b299e9 (diff) | |
Make red zone size more flexible for stack variables (PR sanitizer/81715).
2018-11-30 Martin Liska <mliska@suse.cz>
PR sanitizer/81715
* asan.c (asan_shadow_cst): Remove, partially transform
into flush_redzone_payload.
(RZ_BUFFER_SIZE): New.
(struct asan_redzone_buffer): New.
(asan_redzone_buffer::emit_redzone_byte): Likewise.
(asan_redzone_buffer::flush_redzone_payload): Likewise.
(asan_redzone_buffer::flush_if_full): Likewise.
(asan_emit_stack_protection): Use asan_redzone_buffer class
that is responsible for proper aligned stores and flushing
of shadow memory payload.
* asan.h (ASAN_MIN_RED_ZONE_SIZE): New.
(asan_var_and_redzone_size): Likewise.
* cfgexpand.c (expand_stack_vars): Use smaller alignment
(ASAN_MIN_RED_ZONE_SIZE) in order to make shadow memory
for automatic variables more compact.
2018-11-30 Martin Liska <mliska@suse.cz>
PR sanitizer/81715
* c-c++-common/asan/asan-stack-small.c: New test.
From-SVN: r266664
Diffstat (limited to 'gcc/cfgexpand.c')
| -rw-r--r-- | gcc/cfgexpand.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c index 21bdcdaeaa3..5e23bc242b9 100644 --- a/gcc/cfgexpand.c +++ b/gcc/cfgexpand.c @@ -1125,13 +1125,17 @@ expand_stack_vars (bool (*pred) (size_t), struct stack_vars_data *data) && stack_vars[i].size.is_constant ()) { prev_offset = align_base (prev_offset, - MAX (alignb, ASAN_RED_ZONE_SIZE), + MAX (alignb, ASAN_MIN_RED_ZONE_SIZE), !FRAME_GROWS_DOWNWARD); tree repr_decl = NULL_TREE; - offset - = alloc_stack_frame_space (stack_vars[i].size - + ASAN_RED_ZONE_SIZE, - MAX (alignb, ASAN_RED_ZONE_SIZE)); + unsigned HOST_WIDE_INT size + = asan_var_and_redzone_size (stack_vars[i].size.to_constant ()); + if (data->asan_vec.is_empty ()) + size = MAX (size, ASAN_RED_ZONE_SIZE); + + unsigned HOST_WIDE_INT alignment = MAX (alignb, + ASAN_MIN_RED_ZONE_SIZE); + offset = alloc_stack_frame_space (size, alignment); data->asan_vec.safe_push (prev_offset); /* Allocating a constant amount of space from a constant |