linux-stable/scripts/Makefile.gcc-plugins
Andrew Donnellan 012e8d2034 gcc-plugins: Undefine LATENT_ENTROPY_PLUGIN when plugin disabled for a file
Commit 36d4b36b69 ("lib/nodemask: inline next_node_in() and
node_random()") refactored some code by moving node_random() from
lib/nodemask.c to include/linux/nodemask.h, thus requiring nodemask.h to
include random.h, which conditionally defines add_latent_entropy()
depending on whether the macro LATENT_ENTROPY_PLUGIN is defined.

This broke the build on powerpc, where nodemask.h is indirectly included
in arch/powerpc/kernel/prom_init.c, part of the early boot machinery that
is excluded from the latent entropy plugin using
DISABLE_LATENT_ENTROPY_PLUGIN. It turns out that while we add a gcc flag
to disable the actual plugin, we don't undefine LATENT_ENTROPY_PLUGIN.

This leads to the following:

    CC      arch/powerpc/kernel/prom_init.o
  In file included from ./include/linux/nodemask.h:97,
                   from ./include/linux/mmzone.h:17,
                   from ./include/linux/gfp.h:7,
                   from ./include/linux/xarray.h:15,
                   from ./include/linux/radix-tree.h:21,
                   from ./include/linux/idr.h:15,
                   from ./include/linux/kernfs.h:12,
                   from ./include/linux/sysfs.h:16,
                   from ./include/linux/kobject.h:20,
                   from ./include/linux/pci.h:35,
                   from arch/powerpc/kernel/prom_init.c:24:
  ./include/linux/random.h: In function 'add_latent_entropy':
  ./include/linux/random.h:25:46: error: 'latent_entropy' undeclared (first use in this function); did you mean 'add_latent_entropy'?
     25 |         add_device_randomness((const void *)&latent_entropy, sizeof(latent_entropy));
        |                                              ^~~~~~~~~~~~~~
        |                                              add_latent_entropy
  ./include/linux/random.h:25:46: note: each undeclared identifier is reported only once for each function it appears in
  make[2]: *** [scripts/Makefile.build:249: arch/powerpc/kernel/prom_init.o] Fehler 1
  make[1]: *** [scripts/Makefile.build:465: arch/powerpc/kernel] Fehler 2
  make: *** [Makefile:1855: arch/powerpc] Error 2

Change the DISABLE_LATENT_ENTROPY_PLUGIN flags to undefine
LATENT_ENTROPY_PLUGIN for files where the plugin is disabled.

Cc: Yury Norov <yury.norov@gmail.com>
Fixes: 38addce8b6 ("gcc-plugins: Add latent_entropy plugin")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216367
Link: https://lore.kernel.org/linuxppc-dev/alpine.DEB.2.22.394.2208152006320.289321@ramsan.of.borg/
Reported-by: Erhard Furtner <erhard_f@mailbox.org>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220816051720.44108-1-ajd@linux.ibm.com
2022-08-16 12:25:53 -07:00

63 lines
2.6 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0
gcc-plugin-$(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) += latent_entropy_plugin.so
gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) \
+= -DLATENT_ENTROPY_PLUGIN
ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
DISABLE_LATENT_ENTROPY_PLUGIN += -fplugin-arg-latent_entropy_plugin-disable -ULATENT_ENTROPY_PLUGIN
endif
export DISABLE_LATENT_ENTROPY_PLUGIN
gcc-plugin-$(CONFIG_GCC_PLUGIN_STRUCTLEAK) += structleak_plugin.so
gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK_VERBOSE) \
+= -fplugin-arg-structleak_plugin-verbose
gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF) \
+= -fplugin-arg-structleak_plugin-byref
gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL) \
+= -fplugin-arg-structleak_plugin-byref-all
ifdef CONFIG_GCC_PLUGIN_STRUCTLEAK
DISABLE_STRUCTLEAK_PLUGIN += -fplugin-arg-structleak_plugin-disable
endif
export DISABLE_STRUCTLEAK_PLUGIN
gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK) \
+= -DSTRUCTLEAK_PLUGIN
gcc-plugin-$(CONFIG_GCC_PLUGIN_STACKLEAK) += stackleak_plugin.so
gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK) \
+= -DSTACKLEAK_PLUGIN
gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK) \
+= -fplugin-arg-stackleak_plugin-track-min-size=$(CONFIG_STACKLEAK_TRACK_MIN_SIZE)
gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK) \
+= -fplugin-arg-stackleak_plugin-arch=$(SRCARCH)
gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK_VERBOSE) \
+= -fplugin-arg-stackleak_plugin-verbose
ifdef CONFIG_GCC_PLUGIN_STACKLEAK
DISABLE_STACKLEAK_PLUGIN += -fplugin-arg-stackleak_plugin-disable
endif
export DISABLE_STACKLEAK_PLUGIN
gcc-plugin-$(CONFIG_GCC_PLUGIN_ARM_SSP_PER_TASK) += arm_ssp_per_task_plugin.so
ifdef CONFIG_GCC_PLUGIN_ARM_SSP_PER_TASK
DISABLE_ARM_SSP_PER_TASK_PLUGIN += -fplugin-arg-arm_ssp_per_task_plugin-disable
endif
export DISABLE_ARM_SSP_PER_TASK_PLUGIN
# All the plugin CFLAGS are collected here in case a build target needs to
# filter them out of the KBUILD_CFLAGS.
GCC_PLUGINS_CFLAGS := $(strip $(addprefix -fplugin=$(objtree)/scripts/gcc-plugins/, $(gcc-plugin-y)) $(gcc-plugin-cflags-y))
export GCC_PLUGINS_CFLAGS
# Add the flags to the build!
KBUILD_CFLAGS += $(GCC_PLUGINS_CFLAGS)
# Some plugins are enabled outside of this Makefile, but they still need to
# be included in GCC_PLUGIN so they can get built.
gcc-plugin-external-$(CONFIG_GCC_PLUGIN_SANCOV) \
+= sancov_plugin.so
gcc-plugin-external-$(CONFIG_GCC_PLUGIN_RANDSTRUCT) \
+= randomize_layout_plugin.so
# All enabled GCC plugins are collected here for building in
# scripts/gcc-scripts/Makefile.
GCC_PLUGIN := $(gcc-plugin-y) $(gcc-plugin-external-y)
export GCC_PLUGIN