[WIP] Enable -fsanitize=implicit-signed-integer-truncation
Signed-off-by: Kees Cook <keescook@chromium.org>
diff --git a/lib/test_ubsan.c b/lib/test_ubsan.c
index 276c121..112a5f0 100644
--- a/lib/test_ubsan.c
+++ b/lib/test_ubsan.c
@@ -53,6 +53,15 @@ static void test_ubsan_divrem_overflow(void)
val /= val2;
}
+static void test_ubsan_truncate_signed(void)
+{
+ volatile long val = LONG_MAX;
+ volatile int val2 = 0;
+
+ UBSAN_TEST(CONFIG_UBSAN_SIGNED_WRAP);
+ val2 = val;
+}
+
static void test_ubsan_shift_out_of_bounds(void)
{
volatile int neg = -1, wrap = 4;
@@ -127,6 +136,7 @@ static const test_ubsan_fp test_ubsan_array[] = {
test_ubsan_sub_overflow,
test_ubsan_mul_overflow,
test_ubsan_negate_overflow,
+ test_ubsan_truncate_signed,
test_ubsan_shift_out_of_bounds,
test_ubsan_out_of_bounds,
test_ubsan_load_invalid_value,
diff --git a/lib/ubsan.c b/lib/ubsan.c
index ee5d86e..b6e9747 100644
--- a/lib/ubsan.c
+++ b/lib/ubsan.c
@@ -289,6 +289,30 @@ void __ubsan_handle_negate_overflow(void *_data, void *old_val)
}
EXPORT_SYMBOL(__ubsan_handle_negate_overflow);
+void __ubsan_handle_implicit_conversion(void *_data, void *from_val, void *to_val)
+{
+ struct implicit_conversion_data *data = _data;
+ char from_val_str[VALUE_LENGTH];
+ char to_val_str[VALUE_LENGTH];
+
+ if (suppress_report(&data->location))
+ return;
+
+ val_to_string(from_val_str, sizeof(from_val_str), data->from_type, from_val);
+ val_to_string(to_val_str, sizeof(to_val_str), data->to_type, to_val);
+
+ ubsan_prologue(&data->location, "implicit-conversion");
+
+ pr_err("cannot represent %s value %s during %s %s, truncated to %s\n",
+ data->from_type->type_name,
+ from_val_str,
+ type_check_kinds[data->type_check_kind],
+ data->to_type->type_name,
+ to_val_str);
+
+ ubsan_epilogue();
+}
+EXPORT_SYMBOL(__ubsan_handle_implicit_conversion);
void __ubsan_handle_divrem_overflow(void *_data, void *lhs, void *rhs)
{
diff --git a/lib/ubsan.h b/lib/ubsan.h
index ad46579..10e5681 100644
--- a/lib/ubsan.h
+++ b/lib/ubsan.h
@@ -62,6 +62,13 @@ struct overflow_data {
struct type_descriptor *type;
};
+struct implicit_conversion_data {
+ struct source_location location;
+ struct type_descriptor *from_type;
+ struct type_descriptor *to_type;
+ unsigned char type_check_kind;
+};
+
struct type_mismatch_data {
struct source_location location;
struct type_descriptor *type;
@@ -130,6 +137,7 @@ void __ubsan_handle_mul_overflow(void *data, void *lhs, void *rhs);
void __ubsan_handle_negate_overflow(void *_data, void *old_val);
void __ubsan_handle_divrem_overflow(void *_data, void *lhs, void *rhs);
void __ubsan_handle_divrem_overflow_abort(void *_data, void *lhs, void *rhs);
+void __ubsan_handle_implicit_conversion(void *_data, void *lhs, void *rhs);
void __ubsan_handle_type_mismatch(struct type_mismatch_data *data, void *ptr);
void __ubsan_handle_type_mismatch_v1(void *_data, void *ptr);
void __ubsan_handle_out_of_bounds(void *_data, void *index);
diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan
index 69713cc..de77545 100644
--- a/scripts/Makefile.ubsan
+++ b/scripts/Makefile.ubsan
@@ -14,5 +14,6 @@
export CFLAGS_UBSAN := $(ubsan-cflags-y)
-ubsan-wrap-signed-cflags-$(CONFIG_UBSAN_SIGNED_WRAP) += -fsanitize=signed-integer-wrap
+ubsan-wrap-signed-cflags-$(CONFIG_UBSAN_SIGNED_WRAP) += -fsanitize=signed-integer-wrap \
+ -fsanitize=implicit-signed-integer-truncation
export CFLAGS_UBSAN_WRAP_SIGNED := $(ubsan-wrap-signed-cflags-y)
