Rust supports KASAN via LLVM, but prior to this patch, the flags aren't
set properly.
Suggested-by: Miguel Ojeda <ojeda@xxxxxxxxxx>
Signed-off-by: Matthew Maurer <mmaurer@xxxxxxxxxx>
---
scripts/Makefile.kasan | 51 +++++++++++++++++++++++----------
scripts/Makefile.lib | 3 ++
scripts/generate_rust_target.rs | 1 +
3 files changed, 40 insertions(+), 15 deletions(-)
diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan
index 390658a2d5b7..bfd37be9cc45 100644
--- a/scripts/Makefile.kasan
+++ b/scripts/Makefile.kasan
@@ -12,6 +12,9 @@ endif
KASAN_SHADOW_OFFSET ?= $(CONFIG_KASAN_SHADOW_OFFSET)
cc-param = $(call cc-option, -mllvm -$(1), $(call cc-option, --param $(1)))
+rustc-param = $(call rustc-option, -Cllvm-args=-$(1),)
+
+check-args = $(foreach arg,$(2),$(call $(1),$(arg)))
ifdef CONFIG_KASAN_STACK
stack_enable := 1
@@ -28,6 +31,7 @@ else
endif
CFLAGS_KASAN_MINIMAL := -fsanitize=kernel-address
+RUSTFLAGS_KASAN_MINIMAL := -Zsanitizer=kernel-address -Zsanitizer-recover=kernel-address
# -fasan-shadow-offset fails without -fsanitize
CFLAGS_KASAN_SHADOW := $(call cc-option, -fsanitize=kernel-address \
@@ -35,44 +39,61 @@ CFLAGS_KASAN_SHADOW := $(call cc-option, -fsanitize=kernel-address \
$(call cc-option, -fsanitize=kernel-address \
-mllvm -asan-mapping-offset=$(KASAN_SHADOW_OFFSET)))
+# The minimum supported `rustc` version has a minimum supported LLVM
+# version late enough that we can assume support for -asan-mapping-offset
+RUSTFLAGS_KASAN_SHADOW := $(RUSTFLAGS_KASAN_MINIMAL) \
+ -Cllvm-args=-asan-mapping-offset=$(KASAN_SHADOW_OFFSET)
+
+KASAN_PARAMS :=
+
ifeq ($(strip $(CFLAGS_KASAN_SHADOW)),)
CFLAGS_KASAN := $(CFLAGS_KASAN_MINIMAL)
+ # We still need to consider this case for Rust because we want Rust code
+ # to match the behavior of possibly old C compilers when linked together.
+ ifdef CONFIG_RUST
+ RUSTFLAGS_KASAN := $(RUSTFLAGS_KASAN_MINIMAL)
+ endif
else
- # Now add all the compiler specific options that are valid standalone
- CFLAGS_KASAN := $(CFLAGS_KASAN_SHADOW) \
- $(call cc-param,asan-globals=1) \
- $(call cc-param,asan-instrumentation-with-call-threshold=$(call_threshold)) \
- $(call cc-param,asan-instrument-allocas=1)
+ KASAN_PARAMS += asan-globals=1 asan-instrumentation-with-call-threshold=$(call_threshold) asan-instrument-allocas=1
+ CFLAGS_KASAN := $(CFLAGS_KASAN_SHADOW)
+ ifdef CONFIG_RUST
+ RUSTFLAGS_KASAN := $(RUSTFLAGS_KASAN_SHADOW)
+ endif
endif
-CFLAGS_KASAN += $(call cc-param,asan-stack=$(stack_enable))
+KASAN_PARAMS += asan-stack=$(stack_enable)
# Instrument memcpy/memset/memmove calls by using instrumented __asan_mem*()
# instead. With compilers that don't support this option, compiler-inserted
# memintrinsics won't be checked by KASAN on GENERIC_ENTRY architectures.
-CFLAGS_KASAN += $(call cc-param,asan-kernel-mem-intrinsic-prefix=1)
+KASAN_PARAMS += asan-kernel-mem-intrinsic-prefix=1
endif # CONFIG_KASAN_GENERIC
ifdef CONFIG_KASAN_SW_TAGS
ifdef CONFIG_KASAN_INLINE
- instrumentation_flags := $(call cc-param,hwasan-mapping-offset=$(KASAN_SHADOW_OFFSET))
+ KASAN_PARAMS += hwasan-mapping-offset=$(KASAN_SHADOW_OFFSET)
else
- instrumentation_flags := $(call cc-param,hwasan-instrument-with-calls=1)
+ KASAN_PARAMS += hwasan-instrument-with-calls=1
endif
-CFLAGS_KASAN := -fsanitize=kernel-hwaddress \
- $(call cc-param,hwasan-instrument-stack=$(stack_enable)) \
- $(call cc-param,hwasan-use-short-granules=0) \
- $(call cc-param,hwasan-inline-all-checks=0) \
- $(instrumentation_flags)
+KASAN_PARAMS += hwasan-instrument-stack=$(stack_enable) hwasan-use-short-granules=0 hwasan-inline-all-checks=0 $(instrumentation_params)
+CFLAGS_KASAN := -fsanitize=kernel-hwaddress
# Instrument memcpy/memset/memmove calls by using instrumented __hwasan_mem*().
ifeq ($(call clang-min-version, 150000)$(call gcc-min-version, 130000),y)
CFLAGS_KASAN += $(call cc-param,hwasan-kernel-mem-intrinsic-prefix=1)
endif
+ifdef CONFIG_RUST
+ RUSTFLAGS_KASAN := -Zsanitizer=kernel-hwaddress -Zsanitizer-recover=kernel-hwaddress
+endif
+
endif # CONFIG_KASAN_SW_TAGS
-export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE
+# Add all as-supported KASAN LLVM parameters requested by the configuration
+CFLAGS_KASAN += $(call check-args, cc-param, $(KASAN_PARAMS))
+RUSTFLAGS_KASAN += $(call check-args, rustc-param, $(KASAN_PARAMS))
+
+export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE RUSTFLAGS_KASAN
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index fe3668dc4954..27999da3d382 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -167,6 +167,9 @@ ifneq ($(CONFIG_KASAN_HW_TAGS),y)
_c_flags += $(if $(patsubst n%,, \
$(KASAN_SANITIZE_$(target-stem).o)$(KASAN_SANITIZE)$(is-kernel-object)), \
$(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE))
+_rust_flags += $(if $(patsubst n%,, \
+ $(KASAN_SANITIZE_$(target-stem).o)$(KASAN_SANITIZE)$(is-kernel-object)), \
+ $(RUSTFLAGS_KASAN))
endif
endif
diff --git a/scripts/generate_rust_target.rs b/scripts/generate_rust_target.rs
index 8a0644c0beed..1a4d468c575f 100644
--- a/scripts/generate_rust_target.rs
+++ b/scripts/generate_rust_target.rs
@@ -187,6 +187,7 @@ fn main() {
}
ts.push("features", features);
ts.push("llvm-target", "x86_64-linux-gnu");
+ ts.push("supported-sanitizers", ["kernel-address"]);
ts.push("target-pointer-width", "64");
} else if cfg.has("X86_32") {
// This only works on UML, as i386 otherwise needs regparm support in rustc
--
2.46.0.76.ge559c4bf1a-goog
