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
[off-list ref] wrote:

quoted

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 <redacted>

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