Add a CONFIG_STACK_VALIDATION option which will run "stacktool check"
for each .o file to ensure the validity of its stack metadata.
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
Makefile | 5 ++++-
arch/Kconfig | 6 ++++++
lib/Kconfig.debug | 12 ++++++++++++
scripts/Makefile.build | 38 ++++++++++++++++++++++++++++++++++----
scripts/mod/Makefile | 2 ++
5 files changed, 58 insertions(+), 5 deletions(-)
diff --git a/Makefile b/Makefile
index 70dea02..8e518fe 100644
--- a/Makefile
+++ b/Makefile
@@ -986,7 +986,10 @@ prepare0: archprepare FORCE
$(Q)$(MAKE) $(build)=.
# All the preparing..
-prepare: prepare0
+prepare: prepare0 prepare-stacktool
+
+PHONY += prepare-stacktool
+prepare-stacktool: $(if $(CONFIG_STACK_VALIDATION), tools/stacktool FORCE)
# Generate some files
# ---------------------------------------------------------------------------
diff --git a/arch/Kconfig b/arch/Kconfig
index 671810c..b20f472 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -527,6 +527,12 @@ config HAVE_COPY_THREAD_TLS
normal C parameter passing, rather than extracting the syscall
argument from pt_regs.
+config HAVE_STACK_VALIDATION
+ bool
+ help
+ Architecture supports the stacktool host tool, which adds
+ compile-time stack metadata validation.
+
#
# ABI hall of shame
#
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index ee1ac1c..a984656 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -342,6 +342,18 @@ config FRAME_POINTER
larger and slower, but it gives very useful debugging information
in case of kernel bugs. (precise oopses/stacktraces/warnings)
+config STACK_VALIDATION
+ bool "Enable compile-time stack metadata validation"
+ depends on HAVE_STACK_VALIDATION
+ default n
+ help
+ Add compile-time checks to validate stack metadata, including frame
+ pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
+ that runtime stack traces are more reliable.
+
+ For more information, see
+ tools/stacktool/Documentation/stack-validation.txt.
+
config DEBUG_FORCE_WEAK_PER_CPU
bool "Force weak per-cpu definitions"
depends on DEBUG_KERNEL
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 01df30a..5ec40fc 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -241,10 +241,31 @@ cmd_record_mcount = \
fi;
endif
+ifdef CONFIG_STACK_VALIDATION
+
+__stacktool_obj := $(objtree)/tools/stacktool/stacktool
+
+stacktool_args = check
+ifndef CONFIG_FRAME_POINTER
+stacktool_args += --no-fp
+endif
+
+# Set STACKTOOL_foo.o=n to skip stack metadata validation for a file.
+# Set STACKTOOL=n to skip stack metadata validation for a directory.
+stacktool_obj = $(if $(patsubst n%,, \
+ $(STACKTOOL_$(basetarget).o)$(STACKTOOL)y), \
+ $(__stacktool_obj))
+cmd_stacktool = $(if $(patsubst n%,, \
+ $(STACKTOOL_$(basetarget).o)$(STACKTOOL)y), \
+ $(__stacktool_obj) $(stacktool_args) "$(@)";)
+
+endif # CONFIG_STACK_VALIDATION
+
define rule_cc_o_c
$(call echo-cmd,checksrc) $(cmd_checksrc) \
$(call echo-cmd,cc_o_c) $(cmd_cc_o_c); \
$(cmd_modversions) \
+ $(cmd_stacktool) \
$(call echo-cmd,record_mcount) \
$(cmd_record_mcount) \
scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' > \
@@ -253,14 +274,23 @@ define rule_cc_o_c
mv -f $(dot-target).tmp $(dot-target).cmd
endef
+define rule_as_o_S
+ $(call echo-cmd,as_o_S) $(cmd_as_o_S); \
+ $(cmd_stacktool) \
+ scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,as_o_S)' > \
+ $(dot-target).tmp; \
+ rm -f $(depfile); \
+ mv -f $(dot-target).tmp $(dot-target).cmd
+endef
+
# Built-in and composite module parts
-$(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
+$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(stacktool_obj) FORCE
$(call cmd,force_checksrc)
$(call if_changed_rule,cc_o_c)
# Single-part modules are special since we need to mark them in $(MODVERDIR)
-$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
+$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(stacktool_obj) FORCE
$(call cmd,force_checksrc)
$(call if_changed_rule,cc_o_c)
@{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod)
@@ -290,8 +320,8 @@ $(obj)/%.s: $(src)/%.S FORCE
quiet_cmd_as_o_S = AS $(quiet_modtag) $@
cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
-$(obj)/%.o: $(src)/%.S FORCE
- $(call if_changed_dep,as_o_S)
+$(obj)/%.o: $(src)/%.S $(stacktool_obj) FORCE
+ $(call if_changed_rule,as_o_S)
targets += $(real-objs-y) $(real-objs-m) $(lib-y)
targets += $(extra-y) $(MAKECMDGOALS) $(always)
diff --git a/scripts/mod/Makefile b/scripts/mod/Makefile
index c11212f..496184d 100644
--- a/scripts/mod/Makefile
+++ b/scripts/mod/Makefile
@@ -1,3 +1,5 @@
+STACKTOOL := n
+
hostprogs-y := modpost mk_elfconfig
always := $(hostprogs-y) empty.o
--
2.4.3
--
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