diff options
| author | Alexander Popov <alex.popov@linux.com> | 2018-12-06 18:13:07 +0300 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2018-12-06 20:10:23 +0300 |
| commit | 8fb2dfb228df785bbeb4d055a74402ef4b07fc25 (patch) | |
| tree | f059127218ca9008224b9fd884c3e01438328885 | |
| parent | e9c7d656610e3fff7c96b199d418add2528aea6e (diff) | |
| download | linux-8fb2dfb228df785bbeb4d055a74402ef4b07fc25.tar.xz | |
stackleak: Register the 'stackleak_cleanup' pass before the '*free_cfg' pass
Currently the 'stackleak_cleanup' pass deleting a CALL insn is executed
after the 'reload' pass. That allows gcc to do some weird optimization in
function prologues and epilogues, which are generated later [1].
Let's avoid that by registering the 'stackleak_cleanup' pass before
the '*free_cfg' pass. It's the moment when the stack frame size is
already final, function prologues and epilogues are generated, and the
machine-dependent code transformations are not done.
[1] https://www.openwall.com/lists/kernel-hardening/2018/11/23/2
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Alexander Popov <alex.popov@linux.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
| -rw-r--r-- | scripts/gcc-plugins/stackleak_plugin.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/scripts/gcc-plugins/stackleak_plugin.c b/scripts/gcc-plugins/stackleak_plugin.c index 2f48da98b5d4..dbd37460c573 100644 --- a/scripts/gcc-plugins/stackleak_plugin.c +++ b/scripts/gcc-plugins/stackleak_plugin.c @@ -363,10 +363,12 @@ __visible int plugin_init(struct plugin_name_args *plugin_info, PASS_POS_INSERT_BEFORE); /* - * The stackleak_cleanup pass should be executed after the - * "reload" pass, when the stack frame size is final. + * The stackleak_cleanup pass should be executed before the "*free_cfg" + * pass. It's the moment when the stack frame size is already final, + * function prologues and epilogues are generated, and the + * machine-dependent code transformations are not done. */ - PASS_INFO(stackleak_cleanup, "reload", 1, PASS_POS_INSERT_AFTER); + PASS_INFO(stackleak_cleanup, "*free_cfg", 1, PASS_POS_INSERT_BEFORE); if (!plugin_default_version_check(version, &gcc_version)) { error(G_("incompatible gcc/plugin versions")); |