On Thu, Oct 17, 2024 at 11:14:36AM -0700, Anjali Kulkarni wrote:
> Test to check if setting PROC_CN_MCAST_NOTIFY in proc connector API, allows
> a thread's non-zero exit status to be returned to proc_filter.
>
> The threads.c program creates 2 child threads. 1st thread handles signal
> SIGSEGV, and 2nd thread needs to indicate some error condition (value 1)
> to the kernel, instead of using pthread_exit() with 1.
>
> In both cases, child sends notify_netlink_thread_exit(exit_code) to kernel,
> to let kernel know it has exited abnormally with exit_code.
>
> Compile:
> make thread
> make proc_filter
> Run:
> ./threads
>
> Signed-off-by: Anjali Kulkarni <anjali.k.kulkarni@xxxxxxxxxx>
> ---
> tools/testing/selftests/connector/Makefile | 23 +-
> .../testing/selftests/connector/proc_filter.c | 34 ++-
> tools/testing/selftests/connector/thread.c | 232 ++++++++++++++++++
> .../selftests/connector/thread_filter.c | 96 ++++++++
> 4 files changed, 378 insertions(+), 7 deletions(-)
> create mode 100644 tools/testing/selftests/connector/thread.c
> create mode 100644 tools/testing/selftests/connector/thread_filter.c
>
> diff --git a/tools/testing/selftests/connector/Makefile b/tools/testing/selftests/connector/Makefile
> index 92188b9bac5c..bf335826bc3b 100644
> --- a/tools/testing/selftests/connector/Makefile
> +++ b/tools/testing/selftests/connector/Makefile
> @@ -1,5 +1,26 @@
> # SPDX-License-Identifier: GPL-2.0
> -CFLAGS += -Wall $(KHDR_INCLUDES)
> +KERNEL="../../../.."
> +
> +CFLAGS += -Wall $(KHDR_INCLUDES) -I $(KERNEL)/include/uapi -I $(KERNEL)/include
> +
> +proc_filter: proc_filter.o
> + cc proc_filter.o -o proc_filter
> +
> +proc_filter.o: proc_filter.c
> + cc -c proc_filter.c -o proc_filter.o $(CFLAGS)
> +
> +thread: thread.o thread_filter.o
> + cc thread.o thread_filter.o -o thread
> +
> +thread.o: thread.c $(DEPS)
> + cc -c thread.c -o thread.o $(CFLAGS)
> +
> +thread_filter.o: thread_filter.c
> + cc -c thread_filter.c -o thread_filter.o $(CFLAGS)
> +
> +define EXTRA_CLEAN
> + rm *.o thread
> +endef
>
> TEST_GEN_PROGS = proc_filter
>
I am a little confused by this, as it seems to result in user-space
code using kernel headers. Is that expected?
$ make -C tools/testing/selftests/connector
...
cc -c proc_filter.c -o proc_filter.o -Wall -isystem /home/horms/projects/linux/linux/tools/testing/selftests/../../../usr/include -I "../../../.."/include/uapi -I "../../../.."/include -D_GNU_SOURCE=
In file included from ../../../../include/uapi/linux/netlink.h:7,
from proc_filter.c:11:
../../../../include/uapi/linux/types.h:10:2: warning: #warning "Attempt to use kernel headers from user space, see https://kernelnewbies.org/KernelHeaders"; [-Wcpp]
10 | #warning "Attempt to use kernel headers from user space, see https://kernelnewbies.org/KernelHeaders";
| ^~~~~~~
...
> diff --git a/tools/testing/selftests/connector/thread.c b/tools/testing/selftests/connector/thread.c
...
> +static inline void init_threads(pthread_attr_t *attr)
Please don't use inline in .c files unless there is a demonstrable,
usually performance, reason to do so.
Likewise twice more in this patch and once in patch 1/3.
> +{
> + int ret;
> +
> + ret = pthread_attr_init(attr);
> + if (ret != 0) {
> + perror("pthread_attr_init failed");
> + exit(ret);
> + }
> +
> + ret = pthread_attr_setdetachstate(attr, PTHREAD_CREATE_DETACHED);
> + if (ret != 0) {
> + perror("pthread_attr_setdetachstate failed");
> + exit(ret);
> + }
> +}
...
