Hi Kees,
sparse (make C=1) gives me this warnings today...
./include/linux/overflow.h:254:13: error: undefined identifier '__builtin_mul_overflow'
./include/linux/overflow.h:254:13: error: incorrect type in conditional
./include/linux/overflow.h:254:13: got void
./include/linux/overflow.h:256:13: error: undefined identifier '__builtin_add_overflow'
./include/linux/overflow.h:256:13: error: incorrect type in conditional
./include/linux/overflow.h:256:13: got void
This hunk obviously fixes it, but I'm really not sure if it is a proper
fix.
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index f1a7492a5cc8..15e55b89e952 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -344,6 +344,6 @@
*/
#define uninitialized_var(x) x = x
-#if GCC_VERSION >= 50100
+#if GCC_VERSION >= 50100 && !defined(__CHECKER__)
#define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
#endif
Any idea?
Regards,
Miroslav
On Thu, Jun 7, 2018 at 4:01 AM, Miroslav Benes <[email protected]> wrote:
>
> Hi Kees,
>
> sparse (make C=1) gives me this warnings today...
>
> ./include/linux/overflow.h:254:13: error: undefined identifier '__builtin_mul_overflow'
> ./include/linux/overflow.h:254:13: error: incorrect type in conditional
> ./include/linux/overflow.h:254:13: got void
> ./include/linux/overflow.h:256:13: error: undefined identifier '__builtin_add_overflow'
> ./include/linux/overflow.h:256:13: error: incorrect type in conditional
> ./include/linux/overflow.h:256:13: got void
>
> This hunk obviously fixes it, but I'm really not sure if it is a proper
> fix.
>
> diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
> index f1a7492a5cc8..15e55b89e952 100644
> --- a/include/linux/compiler-gcc.h
> +++ b/include/linux/compiler-gcc.h
> @@ -344,6 +344,6 @@
> */
> #define uninitialized_var(x) x = x
>
> -#if GCC_VERSION >= 50100
> +#if GCC_VERSION >= 50100 && !defined(__CHECKER__)
> #define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
> #endif
>
> Any idea?
Hi! Yeah, that's probably the correct approach. If the checker doesn't
have it, the builtins need to be disabled. :)
Can you send this with a Signed-off-by line, etc, and I'll take it for
sending to Linus?
Thanks!
-Kees
--
Kees Cook
Pixel Security
On 2018-06-07 20:35, Kees Cook wrote:
> On Thu, Jun 7, 2018 at 4:01 AM, Miroslav Benes <[email protected]> wrote:
>>
>> Hi Kees,
>>
>> sparse (make C=1) gives me this warnings today...
>>
>> ./include/linux/overflow.h:254:13: error: undefined identifier '__builtin_mul_overflow'
>> ./include/linux/overflow.h:254:13: error: incorrect type in conditional
>> ./include/linux/overflow.h:254:13: got void
>> ./include/linux/overflow.h:256:13: error: undefined identifier '__builtin_add_overflow'
>> ./include/linux/overflow.h:256:13: error: incorrect type in conditional
>> ./include/linux/overflow.h:256:13: got void
>>
>> This hunk obviously fixes it, but I'm really not sure if it is a proper
>> fix.
>>
>> diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
>> index f1a7492a5cc8..15e55b89e952 100644
>> --- a/include/linux/compiler-gcc.h
>> +++ b/include/linux/compiler-gcc.h
>> @@ -344,6 +344,6 @@
>> */
>> #define uninitialized_var(x) x = x
>>
>> -#if GCC_VERSION >= 50100
>> +#if GCC_VERSION >= 50100 && !defined(__CHECKER__)
>> #define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
>> #endif
>>
>> Any idea?
>
> Hi! Yeah, that's probably the correct approach. If the checker doesn't
> have it, the builtins need to be disabled. :)
IIRC, the problem is that sparse pretends to be the gcc sparse itself
was built with, which is obviously entirely unrelated to the C dialect
that that particular sparse version groks. Sigh. Ack to the fix above.
Rasmus
On Thu, Jun 07, 2018 at 09:25:09PM +0200, Rasmus Villemoes wrote:
>
> IIRC, the problem is that sparse pretends to be the gcc sparse itself
> was built with, which is obviously entirely unrelated to the C dialect
> that that particular sparse version groks. Sigh. Ack to the fix above.
Yes, indeed, and it is sometimes a problem.
Ideal would be that sparse would pretend to be same GCC as the one used
to compile the code being checked *and* to have exactly the same features.
Pretending to be an older version of GCC would maybe solve the present
problem it's not really a general solution.
One good thing would be to not depend on GCC versions to enable some
features (but GCC offers few facilities helping here).
Best regards,
-- Luc Van Oostenryck
sparse errors out with
./include/linux/overflow.h:254:13: error: undefined identifier '__builtin_mul_overflow'
./include/linux/overflow.h:254:13: error: incorrect type in conditional
./include/linux/overflow.h:254:13: got void
./include/linux/overflow.h:256:13: error: undefined identifier '__builtin_add_overflow'
./include/linux/overflow.h:256:13: error: incorrect type in conditional
./include/linux/overflow.h:256:13: got void
Sparse has not acquired generic overflow builtins yet, so don't set
COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW for it.
Signed-off-by: Miroslav Benes <[email protected]>
Acked-by: Rasmus Villemoes <[email protected]>
---
include/linux/compiler-gcc.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index f1a7492a5cc8..15e55b89e952 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -344,6 +344,6 @@
*/
#define uninitialized_var(x) x = x
-#if GCC_VERSION >= 50100
+#if GCC_VERSION >= 50100 && !defined(__CHECKER__)
#define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
#endif
--
2.17.0