2023-05-12 16:37:38

by Marco Elver

[permalink] [raw]
Subject: Re: [PATCH 1/3] kcsan: Don't expect 64 bits atomic builtins from 32 bits architectures

On Fri, 12 May 2023 at 17:31, Christophe Leroy
<[email protected]> wrote:
>
> Activating KCSAN on a 32 bits architecture leads to the following
> link-time failure:
>
> LD .tmp_vmlinux.kallsyms1
> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_load':
> kernel/kcsan/core.c:1273: undefined reference to `__atomic_load_8'
> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_store':
> kernel/kcsan/core.c:1273: undefined reference to `__atomic_store_8'
> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_exchange':
> kernel/kcsan/core.c:1273: undefined reference to `__atomic_exchange_8'
> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_add':
> kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_add_8'
> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_sub':
> kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_sub_8'
> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_and':
> kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_and_8'
> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_or':
> kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_or_8'
> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_xor':
> kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_xor_8'
> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_nand':
> kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_nand_8'
> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_compare_exchange_strong':
> kernel/kcsan/core.c:1273: undefined reference to `__atomic_compare_exchange_8'
> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_compare_exchange_weak':
> kernel/kcsan/core.c:1273: undefined reference to `__atomic_compare_exchange_8'
> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_compare_exchange_val':
> kernel/kcsan/core.c:1273: undefined reference to `__atomic_compare_exchange_8'
>
> 32 bits architectures don't have 64 bits atomic builtins. Only
> include DEFINE_TSAN_ATOMIC_OPS(64) on 64 bits architectures.
>
> Fixes: 0f8ad5f2e934 ("kcsan: Add support for atomic builtins")
> Suggested-by: Marco Elver <[email protected]>
> Signed-off-by: Christophe Leroy <[email protected]>

Reviewed-by: Marco Elver <[email protected]>

Do you have your own tree to take this through with the other patches?

> ---
> kernel/kcsan/core.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/kernel/kcsan/core.c b/kernel/kcsan/core.c
> index 5a60cc52adc0..8a7baf4e332e 100644
> --- a/kernel/kcsan/core.c
> +++ b/kernel/kcsan/core.c
> @@ -1270,7 +1270,9 @@ static __always_inline void kcsan_atomic_builtin_memorder(int memorder)
> DEFINE_TSAN_ATOMIC_OPS(8);
> DEFINE_TSAN_ATOMIC_OPS(16);
> DEFINE_TSAN_ATOMIC_OPS(32);
> +#ifdef CONFIG_64BIT
> DEFINE_TSAN_ATOMIC_OPS(64);
> +#endif
>
> void __tsan_atomic_thread_fence(int memorder);
> void __tsan_atomic_thread_fence(int memorder)
> --
> 2.40.1
>


2023-05-12 19:15:38

by Christophe Leroy

[permalink] [raw]
Subject: Re: [PATCH 1/3] kcsan: Don't expect 64 bits atomic builtins from 32 bits architectures



Le 12/05/2023 à 18:09, Marco Elver a écrit :
> On Fri, 12 May 2023 at 17:31, Christophe Leroy
> <[email protected]> wrote:
>>
>> Activating KCSAN on a 32 bits architecture leads to the following
>> link-time failure:
>>
>> LD .tmp_vmlinux.kallsyms1
>> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_load':
>> kernel/kcsan/core.c:1273: undefined reference to `__atomic_load_8'
>> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_store':
>> kernel/kcsan/core.c:1273: undefined reference to `__atomic_store_8'
>> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_exchange':
>> kernel/kcsan/core.c:1273: undefined reference to `__atomic_exchange_8'
>> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_add':
>> kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_add_8'
>> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_sub':
>> kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_sub_8'
>> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_and':
>> kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_and_8'
>> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_or':
>> kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_or_8'
>> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_xor':
>> kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_xor_8'
>> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_nand':
>> kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_nand_8'
>> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_compare_exchange_strong':
>> kernel/kcsan/core.c:1273: undefined reference to `__atomic_compare_exchange_8'
>> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_compare_exchange_weak':
>> kernel/kcsan/core.c:1273: undefined reference to `__atomic_compare_exchange_8'
>> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_compare_exchange_val':
>> kernel/kcsan/core.c:1273: undefined reference to `__atomic_compare_exchange_8'
>>
>> 32 bits architectures don't have 64 bits atomic builtins. Only
>> include DEFINE_TSAN_ATOMIC_OPS(64) on 64 bits architectures.
>>
>> Fixes: 0f8ad5f2e934 ("kcsan: Add support for atomic builtins")
>> Suggested-by: Marco Elver <[email protected]>
>> Signed-off-by: Christophe Leroy <[email protected]>
>
> Reviewed-by: Marco Elver <[email protected]>
>
> Do you have your own tree to take this through with the other patches?

I don't have my own tree but I guess that it can be taken by Michael for
6.5 via powerpc tree with acks from you and Max.

Michael is that ok for you ?

Christophe

2023-06-09 13:20:11

by Michael Ellerman

[permalink] [raw]
Subject: Re: [PATCH 1/3] kcsan: Don't expect 64 bits atomic builtins from 32 bits architectures

Christophe Leroy <[email protected]> writes:
> Le 12/05/2023 à 18:09, Marco Elver a écrit :
>> On Fri, 12 May 2023 at 17:31, Christophe Leroy
>> <[email protected]> wrote:
>>>
>>> Activating KCSAN on a 32 bits architecture leads to the following
>>> link-time failure:
>>>
>>> LD .tmp_vmlinux.kallsyms1
>>> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_load':
>>> kernel/kcsan/core.c:1273: undefined reference to `__atomic_load_8'
>>> powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_store':
>>> kernel/kcsan/core.c:1273: undefined reference to `__atomic_store_8'
...
>>>
>>> 32 bits architectures don't have 64 bits atomic builtins. Only
>>> include DEFINE_TSAN_ATOMIC_OPS(64) on 64 bits architectures.
>>>
>>> Fixes: 0f8ad5f2e934 ("kcsan: Add support for atomic builtins")
>>> Suggested-by: Marco Elver <[email protected]>
>>> Signed-off-by: Christophe Leroy <[email protected]>
>>
>> Reviewed-by: Marco Elver <[email protected]>
>>
>> Do you have your own tree to take this through with the other patches?
>
> I don't have my own tree but I guess that it can be taken by Michael for
> 6.5 via powerpc tree with acks from you and Max.
>
> Michael is that ok for you ?

Yeah I can take it.

cheers