Building lib/ubsan.c with gcc-9 results in a ton of nasty warnings
like this one:
lib/ubsan.c warning: conflicting types for built-in function
‘__ubsan_handle_negate_overflow’; expected ‘void(void *, void *)’ [-Wbuiltin-declaration-mismatch]
The kernel's declarations of __ubsan_handle_*() often uses 'unsigned long'
types in parameters while GCC these parameters as 'void *' types,
hence the mismatch.
Fix this by using 'void *' to match GCC's declarations.
Reported-by: Linus Torvalds <[email protected]>
Signed-off-by: Andrey Ryabinin <[email protected]>
Fixes: c6d308534aef ("UBSAN: run-time undefined behavior sanity checker")
Cc: <[email protected]>
---
lib/ubsan.c | 49 +++++++++++++++++++++++--------------------------
1 file changed, 23 insertions(+), 26 deletions(-)
diff --git a/lib/ubsan.c b/lib/ubsan.c
index e4162f59a81c..1e9e2ab25539 100644
--- a/lib/ubsan.c
+++ b/lib/ubsan.c
@@ -86,11 +86,13 @@ static bool is_inline_int(struct type_descriptor *type)
return bits <= inline_bits;
}
-static s_max get_signed_val(struct type_descriptor *type, unsigned long val)
+static s_max get_signed_val(struct type_descriptor *type, void *val)
{
if (is_inline_int(type)) {
unsigned extra_bits = sizeof(s_max)*8 - type_bit_width(type);
- return ((s_max)val) << extra_bits >> extra_bits;
+ unsigned long ulong_val = (unsigned long)val;
+
+ return ((s_max)ulong_val) << extra_bits >> extra_bits;
}
if (type_bit_width(type) == 64)
@@ -99,15 +101,15 @@ static s_max get_signed_val(struct type_descriptor *type, unsigned long val)
return *(s_max *)val;
}
-static bool val_is_negative(struct type_descriptor *type, unsigned long val)
+static bool val_is_negative(struct type_descriptor *type, void *val)
{
return type_is_signed(type) && get_signed_val(type, val) < 0;
}
-static u_max get_unsigned_val(struct type_descriptor *type, unsigned long val)
+static u_max get_unsigned_val(struct type_descriptor *type, void *val)
{
if (is_inline_int(type))
- return val;
+ return (unsigned long)val;
if (type_bit_width(type) == 64)
return *(u64 *)val;
@@ -116,7 +118,7 @@ static u_max get_unsigned_val(struct type_descriptor *type, unsigned long val)
}
static void val_to_string(char *str, size_t size, struct type_descriptor *type,
- unsigned long value)
+ void *value)
{
if (type_is_int(type)) {
if (type_bit_width(type) == 128) {
@@ -163,8 +165,8 @@ static void ubsan_epilogue(unsigned long *flags)
current->in_ubsan--;
}
-static void handle_overflow(struct overflow_data *data, unsigned long lhs,
- unsigned long rhs, char op)
+static void handle_overflow(struct overflow_data *data, void *lhs,
+ void *rhs, char op)
{
struct type_descriptor *type = data->type;
@@ -191,8 +193,7 @@ static void handle_overflow(struct overflow_data *data, unsigned long lhs,
}
void __ubsan_handle_add_overflow(struct overflow_data *data,
- unsigned long lhs,
- unsigned long rhs)
+ void *lhs, void *rhs)
{
handle_overflow(data, lhs, rhs, '+');
@@ -200,23 +201,21 @@ void __ubsan_handle_add_overflow(struct overflow_data *data,
EXPORT_SYMBOL(__ubsan_handle_add_overflow);
void __ubsan_handle_sub_overflow(struct overflow_data *data,
- unsigned long lhs,
- unsigned long rhs)
+ void *lhs, void *rhs)
{
handle_overflow(data, lhs, rhs, '-');
}
EXPORT_SYMBOL(__ubsan_handle_sub_overflow);
void __ubsan_handle_mul_overflow(struct overflow_data *data,
- unsigned long lhs,
- unsigned long rhs)
+ void *lhs, void *rhs)
{
handle_overflow(data, lhs, rhs, '*');
}
EXPORT_SYMBOL(__ubsan_handle_mul_overflow);
void __ubsan_handle_negate_overflow(struct overflow_data *data,
- unsigned long old_val)
+ void *old_val)
{
unsigned long flags;
char old_val_str[VALUE_LENGTH];
@@ -237,8 +236,7 @@ EXPORT_SYMBOL(__ubsan_handle_negate_overflow);
void __ubsan_handle_divrem_overflow(struct overflow_data *data,
- unsigned long lhs,
- unsigned long rhs)
+ void *lhs, void *rhs)
{
unsigned long flags;
char rhs_val_str[VALUE_LENGTH];
@@ -323,7 +321,7 @@ static void ubsan_type_mismatch_common(struct type_mismatch_data_common *data,
}
void __ubsan_handle_type_mismatch(struct type_mismatch_data *data,
- unsigned long ptr)
+ void *ptr)
{
struct type_mismatch_data_common common_data = {
.location = &data->location,
@@ -332,12 +330,12 @@ void __ubsan_handle_type_mismatch(struct type_mismatch_data *data,
.type_check_kind = data->type_check_kind
};
- ubsan_type_mismatch_common(&common_data, ptr);
+ ubsan_type_mismatch_common(&common_data, (unsigned long)ptr);
}
EXPORT_SYMBOL(__ubsan_handle_type_mismatch);
void __ubsan_handle_type_mismatch_v1(struct type_mismatch_data_v1 *data,
- unsigned long ptr)
+ void *ptr)
{
struct type_mismatch_data_common common_data = {
@@ -347,12 +345,12 @@ void __ubsan_handle_type_mismatch_v1(struct type_mismatch_data_v1 *data,
.type_check_kind = data->type_check_kind
};
- ubsan_type_mismatch_common(&common_data, ptr);
+ ubsan_type_mismatch_common(&common_data, (unsigned long)ptr);
}
EXPORT_SYMBOL(__ubsan_handle_type_mismatch_v1);
void __ubsan_handle_vla_bound_not_positive(struct vla_bound_data *data,
- unsigned long bound)
+ void *bound)
{
unsigned long flags;
char bound_str[VALUE_LENGTH];
@@ -369,8 +367,7 @@ void __ubsan_handle_vla_bound_not_positive(struct vla_bound_data *data,
}
EXPORT_SYMBOL(__ubsan_handle_vla_bound_not_positive);
-void __ubsan_handle_out_of_bounds(struct out_of_bounds_data *data,
- unsigned long index)
+void __ubsan_handle_out_of_bounds(struct out_of_bounds_data *data, void *index)
{
unsigned long flags;
char index_str[VALUE_LENGTH];
@@ -388,7 +385,7 @@ void __ubsan_handle_out_of_bounds(struct out_of_bounds_data *data,
EXPORT_SYMBOL(__ubsan_handle_out_of_bounds);
void __ubsan_handle_shift_out_of_bounds(struct shift_out_of_bounds_data *data,
- unsigned long lhs, unsigned long rhs)
+ void *lhs, void *rhs)
{
unsigned long flags;
struct type_descriptor *rhs_type = data->rhs_type;
@@ -439,7 +436,7 @@ void __ubsan_handle_builtin_unreachable(struct unreachable_data *data)
EXPORT_SYMBOL(__ubsan_handle_builtin_unreachable);
void __ubsan_handle_load_invalid_value(struct invalid_value_data *data,
- unsigned long val)
+ void *val)
{
unsigned long flags;
char val_str[VALUE_LENGTH];
--
2.21.0
The kernel the kernel is built with -Wvla for some time, so is not supposed
to have any variable length arrays. Remove vla bounds checking from ubsan
since it's useless now.
Signed-off-by: Andrey Ryabinin <[email protected]>
---
lib/ubsan.c | 18 ------------------
lib/ubsan.h | 5 -----
scripts/Makefile.ubsan | 1 -
3 files changed, 24 deletions(-)
diff --git a/lib/ubsan.c b/lib/ubsan.c
index 1e9e2ab25539..c4859c2d2f1b 100644
--- a/lib/ubsan.c
+++ b/lib/ubsan.c
@@ -349,24 +349,6 @@ void __ubsan_handle_type_mismatch_v1(struct type_mismatch_data_v1 *data,
}
EXPORT_SYMBOL(__ubsan_handle_type_mismatch_v1);
-void __ubsan_handle_vla_bound_not_positive(struct vla_bound_data *data,
- void *bound)
-{
- unsigned long flags;
- char bound_str[VALUE_LENGTH];
-
- if (suppress_report(&data->location))
- return;
-
- ubsan_prologue(&data->location, &flags);
-
- val_to_string(bound_str, sizeof(bound_str), data->type, bound);
- pr_err("variable length array bound value %s <= 0\n", bound_str);
-
- ubsan_epilogue(&flags);
-}
-EXPORT_SYMBOL(__ubsan_handle_vla_bound_not_positive);
-
void __ubsan_handle_out_of_bounds(struct out_of_bounds_data *data, void *index)
{
unsigned long flags;
diff --git a/lib/ubsan.h b/lib/ubsan.h
index f4d8d0bd4016..b8fa83864467 100644
--- a/lib/ubsan.h
+++ b/lib/ubsan.h
@@ -57,11 +57,6 @@ struct nonnull_arg_data {
int arg_index;
};
-struct vla_bound_data {
- struct source_location location;
- struct type_descriptor *type;
-};
-
struct out_of_bounds_data {
struct source_location location;
struct type_descriptor *array_type;
diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan
index 38b2b4818e8e..019771b845c5 100644
--- a/scripts/Makefile.ubsan
+++ b/scripts/Makefile.ubsan
@@ -3,7 +3,6 @@ ifdef CONFIG_UBSAN
CFLAGS_UBSAN += $(call cc-option, -fsanitize=shift)
CFLAGS_UBSAN += $(call cc-option, -fsanitize=integer-divide-by-zero)
CFLAGS_UBSAN += $(call cc-option, -fsanitize=unreachable)
- CFLAGS_UBSAN += $(call cc-option, -fsanitize=vla-bound)
CFLAGS_UBSAN += $(call cc-option, -fsanitize=signed-integer-overflow)
CFLAGS_UBSAN += $(call cc-option, -fsanitize=bounds)
CFLAGS_UBSAN += $(call cc-option, -fsanitize=object-size)
--
2.21.0