[PATCH] arm64: Clear the stack
From: Kees Cook <hidden>
Date: 2018-06-29 20:19:53
Also in:
lkml
On Fri, Jun 29, 2018 at 12:05 PM, Laura Abbott [off-list ref] wrote:
Implementation of stackleak based heavily on the x86 version Signed-off-by: Laura Abbott <redacted> [...] +#define current_top_of_stack() (task_stack_page(current) + THREAD_SIZE) +#define on_thread_stack() (on_task_stack(current, current_stack_pointer))
nit on types here. I get some warnings:
kernel/stackleak.c:55:12: warning: assignment makes integer from
pointer without a cast [-Wint-conversion]
boundary = current_top_of_stack();
^
kernel/stackleak.c:65:24: warning: assignment makes integer from
pointer without a cast [-Wint-conversion]
current->lowest_stack = current_top_of_stack() - THREAD_SIZE / 64;
^
So I think this needs to be:
+#define current_top_of_stack() ((unsigned long)task_stack_page(current) + \
+ THREAD_SIZE)
quoted hunk ↗ jump to hunk
diff --git a/scripts/Makefile.gcc-plugins b/scripts/Makefile.gcc-plugins index a535742a1c06..972ce4ca7f6a 100644 --- a/scripts/Makefile.gcc-plugins +++ b/scripts/Makefile.gcc-plugins@@ -37,11 +37,14 @@ ifdef CONFIG_GCC_PLUGINS gcc-plugin-$(CONFIG_GCC_PLUGIN_STACKLEAK) += stackleak_plugin.so gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK) += -DSTACKLEAK_PLUGIN -fplugin-arg-stackleak_plugin-track-min-size=$(CONFIG_STACKLEAK_TRACK_MIN_SIZE) + ifdef CONFIG_GCC_PLUGIN_STACKLEAK + DISABLE_STACKLEAK_PLUGIN += -fplugin-arg-stackleak_plugin-disable + endif GCC_PLUGINS_CFLAGS := $(strip $(addprefix -fplugin=$(objtree)/scripts/gcc-plugins/, $(gcc-plugin-y)) $(gcc-plugin-cflags-y)) export PLUGINCC GCC_PLUGINS_CFLAGS GCC_PLUGIN GCC_PLUGIN_SUBDIR - export SANCOV_PLUGIN DISABLE_LATENT_ENTROPY_PLUGIN + export SANCOV_PLUGIN DISABLE_LATENT_ENTROPY_PLUGIN DISABLE_STACKLEAK_PLUGIN ifneq ($(PLUGINCC),) # SANCOV_PLUGIN can be only in CFLAGS_KCOV because avoid duplication.
If there is a v14, I think this hunk should be taken there, since it's part of the common code. Otherwise, this works for me and passes the lkdtm tests. -Kees -- Kees Cook Pixel Security