Subject: Re: [PATCH net-next v5 2/3] connector/cn_proc: Kunit tests for threads hash table

From: Stanislav Fomichev <[email-masked]>
Date: Thu, 17 Oct 2024 17:13:52 -0700

On 10/17, Anjali Kulkarni wrote:
> Kunit tests to test hash table add, delete, duplicate add and delete.
> Add following configs and compile kernel code:
> 
> CONFIG_CONNECTOR=y
> CONFIG_PROC_EVENTS=y
> CONFIG_NET=y
> CONFIG_KUNIT=m
> CONFIG_CN_HASH_KUNIT_TEST=m
> 
> To run kunit tests:
> sudo modprobe cn_hash_test
> 
> Output of kunit tests and hash table contents are displayed in
> /var/log/messages (at KERN_DEBUG level).
> 
> Signed-off-by: Anjali Kulkarni <[email-masked]>
> ---
>  drivers/connector/cn_hash.c   |  40 ++++++++
>  drivers/connector/connector.c |  12 +++
>  include/linux/connector.h     |   4 +
>  lib/Kconfig.debug             |  17 ++++
>  lib/Makefile                  |   1 +
>  lib/cn_hash_test.c            | 167 ++++++++++++++++++++++++++++++++++
>  lib/cn_hash_test.h            |  10 ++
>  7 files changed, 251 insertions(+)
>  create mode 100644 lib/cn_hash_test.c
>  create mode 100644 lib/cn_hash_test.h
> 
> diff --git a/drivers/connector/cn_hash.c b/drivers/connector/cn_hash.c
> index a079e9bcea6d..40099b5908ac 100644
> --- a/drivers/connector/cn_hash.c
> +++ b/drivers/connector/cn_hash.c
> @@ -170,6 +170,46 @@ int cn_hash_get_exval(struct cn_hash_dev *hdev, pid_t pid)
>  	return -EINVAL;
>  }
>  
> +int cn_hash_display_hlist(struct cn_hash_dev *hdev, pid_t pid, int max_len,
> +				int *hkey, int *key_display)
> +{
> +	struct uexit_pid_hnode *hnode;
> +	int key, count = 0;
> +
> +	mutex_lock(&hdev->uexit_hash_lock);
> +	key = hash_min(pid, HASH_BITS(hdev->uexit_pid_htable));
> +	pr_debug("Bucket: %d\n", key);
> +
> +	hlist_for_each_entry(hnode,
> +			&hdev->uexit_pid_htable[key],
> +			uexit_pid_hlist) {
> +		if (key_display[key] != 1) {
> +			if (hnode->uexit_pid_hlist.next == NULL)
> +				pr_debug("pid %d ", hnode->pid);
> +			else
> +				pr_debug("pid %d --> ", hnode->pid);
> +		}
> +		count++;
> +	}
> +
> +	mutex_unlock(&hdev->uexit_hash_lock);
> +
> +	if ((key_display[key] != 1) && !count)
> +		pr_debug("(empty)\n");
> +
> +	pr_debug("\n");
> +
> +	*hkey = key;
> +
> +	if (count > max_len) {
> +		pr_err("%d entries in hlist for key %d, expected %d\n",
> +				count, key, max_len);
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
>  bool cn_hash_table_empty(struct cn_hash_dev *hdev)
>  {
>  	bool is_empty;
> diff --git a/drivers/connector/connector.c b/drivers/connector/connector.c
> index c1c0dcec53c0..2be2fe1adc12 100644
> --- a/drivers/connector/connector.c
> +++ b/drivers/connector/connector.c
> @@ -304,6 +304,18 @@ int cn_get_exval(pid_t pid)
>  }
>  EXPORT_SYMBOL_GPL(cn_get_exval);
>  
> +int cn_display_hlist(pid_t pid, int max_len, int *hkey, int *key_display)
> +{
> +	struct cn_dev *dev = &cdev;
> +
> +	if (!cn_already_initialized)
> +		return 0;
> +
> +	return cn_hash_display_hlist(dev->hdev, pid, max_len,
> +					hkey, key_display);
> +}
> +EXPORT_SYMBOL_GPL(cn_display_hlist);
> +
>  bool cn_table_empty(void)
>  {
>  	struct cn_dev *dev = &cdev;
> diff --git a/include/linux/connector.h b/include/linux/connector.h
> index 5384e4bb98e8..a75c3fcf182a 100644
> --- a/include/linux/connector.h
> +++ b/include/linux/connector.h
> @@ -168,4 +168,8 @@ int cn_get_exval(pid_t pid);
>  bool cn_table_empty(void);
>  bool cn_hash_table_empty(struct cn_hash_dev *hdev);
>  
> +int cn_display_hlist(pid_t pid, int max_len, int *hkey, int *key_display);
> +int cn_hash_display_hlist(struct cn_hash_dev *hdev, pid_t pid, int max_len,
> +				int *hkey, int *key_display);
> +
>  #endif				/* __CONNECTOR_H */
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index 7315f643817a..290cf0a6befa 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -2705,6 +2705,23 @@ config HASHTABLE_KUNIT_TEST
>  
>  	  If unsure, say N.
>  
> +config CN_HASH_KUNIT_TEST
> +	tristate "KUnit Test for connector hashtable code" if !KUNIT_ALL_TESTS
> +	depends on KUNIT
> +	default KUNIT_ALL_TESTS
> +	help
> +	  This builds the hashtable KUnit test suite.
> +	  It tests the basic functionality of the API defined in
> +	  drivers/connector/cn_hash.c.
> +	  CONFIG_CONNECTOR=y, CONFIG_PROC_EVENTS=y and CONFIG_NET=y needs
> +	  to be enabled along with CONFIG_CN_HASH_KUNIT_TEST=m and
> +	  CONFIG_KUNIT=m in .config file to compile and then test as a kernel
> +	  module with "modprobe cn_hash_test".
> +	  For more information on KUnit and unit tests in general please
> +	  refer to the KUnit documentation in Documentation/dev-tools/kunit/.
> +
> +	  If unsure, say N.
> +

Looks like this needs to depend on CONFIG_CONNECTOR? Otherwise, the
existing kunit tester complains about the missing symbols (see below).
Please also hold off reposting for a couple of days to give people some
time to review.

ERROR:root:ld: vmlinux.o: in function `cn_hash_test_dup_del':
cn_hash_test.c:(.text+0x3e9dc3): undefined reference to `cn_del_get_exval'
ld: cn_hash_test.c:(.text+0x3e9dee): undefined reference to `cn_del_get_exval'
ld: cn_hash_test.c:(.text+0x3e9e22): undefined reference to `cn_table_empty'
ld: vmlinux.o: in function `cn_display_htable':
cn_hash_test.c:(.text+0x3e9f67): undefined reference to `cn_display_hlist'
ld: vmlinux.o: in function `cn_hash_test_del_get_exval':
cn_hash_test.c:(.text+0x3ea037): undefined reference to `cn_del_get_exval'
ld: cn_hash_test.c:(.text+0x3ea088): undefined reference to `cn_table_empty'
ld: vmlinux.o: in function `cn_hash_test_dup_add':
cn_hash_test.c:(.text+0x3ea176): undefined reference to `cn_add_elem'
ld: cn_hash_test.c:(.text+0x3ea19e): undefined reference to `cn_get_exval'
ld: cn_hash_test.c:(.text+0x3ea1dc): undefined reference to `cn_add_elem'
ld: cn_hash_test.c:(.text+0x3ea205): undefined reference to `cn_get_exval'
ld: vmlinux.o: in function `cn_hash_test_del':
cn_hash_test.c:(.text+0x3ea387): undefined reference to `cn_del_get_exval'
ld: cn_hash_test.c:(.text+0x3ea3ab): undefined reference to `cn_get_exval'
ld: cn_hash_test.c:(.text+0x3ea3fd): undefined reference to `cn_table_empty'
ld: vmlinux.o: in function `cn_hash_test_add':
cn_hash_test.c:(.text+0x3ea571): undefined reference to `cn_add_elem'
ld: cn_hash_test.c:(.text+0x3ea591): undefined reference to `cn_get_exval'
make[3]: *** [../scripts/Makefile.vmlinux:34: vmlinux] Error 1
make[2]: *** [/home/kunit/testing/Makefile:1166: vmlinux] Error 2
make[1]: *** [/home/kunit/testing/Makefile:224: __sub-make] Error 2
make: *** [Makefile:224: __sub-make] Error 2

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