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 | 57 ++++++++++++++++++++++++---------
scripts/Makefile.lib | 3 ++
scripts/generate_rust_target.rs | 1 +
3 files changed, 45 insertions(+), 16 deletions(-)
diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan
index aab4154af00a..97570df40a98 100644
--- a/scripts/Makefile.kasan
+++ b/scripts/Makefile.kasan
@@ -12,6 +12,11 @@ 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)))
+
+kasan_params :=
ifdef CONFIG_KASAN_STACK
stack_enable := 1
@@ -41,39 +46,59 @@ CFLAGS_KASAN := $(call cc-option, -fsanitize=kernel-address \
$(call cc-option, -fsanitize=kernel-address \
-mllvm -asan-mapping-offset=$(KASAN_SHADOW_OFFSET)))
-# Now, add other parameters enabled similarly in both GCC and Clang.
-# As some of them are not supported by older compilers, use cc-param.
-CFLAGS_KASAN += $(call cc-param,asan-instrumentation-with-call-threshold=$(call_threshold)) \
- $(call cc-param,asan-stack=$(stack_enable)) \
- $(call cc-param,asan-instrument-allocas=1) \
- $(call cc-param,asan-globals=1)
+# The minimum supported `rustc` version has a minimum supported LLVM
+# version late enough that we can assume support for -asan-mapping-offset.
+RUSTFLAGS_KASAN := -Zsanitizer=kernel-address \
+ -Zsanitizer-recover=kernel-address \
+ -Cllvm-args=-asan-mapping-offset=$(KASAN_SHADOW_OFFSET)
+
+# Now, add other parameters enabled similarly in GCC, Clang, and rustc.
+# As some of them are not supported by older compilers, these will be filtered
+# through `cc-param` or `rust-param` as applicable.
+kasan_params += asan-instrumentation-with-call-threshold=$(call_threshold) \
+ asan-stack=$(stack_enable) \
+ asan-instrument-allocas=1 \
+ asan-globals=1
# 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
+CFLAGS_KASAN := -fsanitize=kernel-hwaddress
+
+# This sets flags that will enable KHWASAN once enabled in Rust. These will
+# not work today, and is guarded against in dependencies for CONFIG_RUST.
+RUSTFLAGS_KASAN := -Zsanitizer=kernel-hwaddress \
+ -Zsanitizer-recover=kernel-hwaddress
+
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
# 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)
+ kasan_params += hwasan-kernel-mem-intrinsic-prefix=1
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))
+
+ifdef CONFIG_RUST
+ # Avoid calling `rustc-param` unless Rust is enabled.
+ RUSTFLAGS_KASAN += $(call check-args, rustc-param, $(kasan_params))
+endif # CONFIG_RUST
+
+export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE RUSTFLAGS_KASAN
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 9f06f6aaf7fc..4a58636705e0 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -167,6 +167,9 @@ ifneq ($(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 ced405d35c5d..c24c2abd67db 100644
--- a/scripts/generate_rust_target.rs
+++ b/scripts/generate_rust_target.rs
@@ -192,6 +192,7 @@ 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("LOONGARCH") {
panic!("loongarch uses the builtin rustc loongarch64-unknown-none-softfloat target");
--
2.46.0.184.g6999bdac58-goog
