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

[Christophe Leroy <christophe.leroy@csgroup.eu>]

Le 12/05/2023 à 18:09, Marco Elver a écrit :
> On Fri, 12 May 2023 at 17:31, Christophe Leroy
> <christophe.leroy@csgroup.eu> 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 <elver@google.com>
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> 
> Reviewed-by: Marco Elver <elver@google.com>
> 
> 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