6:44 a.m.
On 2019-11-05, kbuild test robot <lkp(a)intel.com> wrote:
FYI, we noticed a +573 bytes kernel size regression due to commit:
commit: 00f2dfd8c2a40f6dd7a74eae598a174484d848c4 (open: introduce openat2(2) syscall)
Details as below (size data is obtained by `nm --size-sort vmlinux`):
97a4cce0: namei: LOOKUP_{IN_ROOT,BENEATH}: permit limited ".." resolution
00f2dfd8: open: introduce openat2(2) syscall
+-----------------------+----------+----------+-------+
| symbol | 97a4cce0 | 00f2dfd8 | delta |
+-----------------------+----------+----------+-------+
| bzImage | 439168 | 439424 | 256 |
| nm.t.build_open_flags | 214 | 349 | 135 |
| nm.T.__se_sys_openat2 | 0 | 122 | 122 |
| nm.T.sys_openat2 | 0 | 122 | 122 |
| nm.t.do_sys_openat2 | 0 | 116 | 116 |
| nm.t.build_open_how | 0 | 78 | 78 |
| nm.T.file_open_name | 41 | 73 | 32 |
| nm.T.file_open_root | 52 | 84 | 32 |
| nm.D.sys_call_table | 1744 | 1752 | 8 |
| nm.T.__se_sys_openat | 26 | 23 | -3 |
| nm.T.sys_openat | 26 | 23 | -3 |
| nm.T.__se_sys_open | 27 | 24 | -3 |
| nm.T.sys_open | 27 | 24 | -3 |
| nm.T.do_sys_open | 121 | 61 | -60 |
+-----------------------+----------+----------+-------+
I'm not sure I understand what is meant by "regression" in this context.
Surely new code will always result in a code size increase. Or is it
that the largest symbols are increasing in size? Is there something I
should do, or is it reasonable that the size has increased (given my
changes in build_open_flags)?
Thanks.
--
Aleksa Sarai
Senior Software Engineer (Containers)
SUSE Linux GmbH
<https://www.cyphar.com/>