[PATCH v8 06/12] landlock: Refactor landlock_add_rule() syscall

[Mickaël Salaün]

On 21/10/2022 17:26, Konstantin Meskhidze wrote:
> Modifies landlock_add_rule() syscall to support new rule types in future

Change the landlock_add_rule() syscall…


> Landlock versions. Adds add_rule_path_beneath() helper to support

Add the…

> current filesystem rules.
> 
> Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze at huawei.com>
> ---
> 
> Changes since v7:
> * None
> 
> Changes since v6:
> * None
> 
> Changes since v5:
> * Refactors syscall landlock_add_rule() and add_rule_path_beneath() helper
> to make argument check ordering consistent and get rid of partial revertings
> in following patches.
> * Rolls back refactoring base_test.c seltest.
> * Formats code with clang-format-14.
> 
> Changes since v4:
> * Refactors add_rule_path_beneath() and landlock_add_rule() functions
> to optimize code usage.
> * Refactors base_test.c seltest: adds LANDLOCK_RULE_PATH_BENEATH
> rule type in landlock_add_rule() call.
> 
> Changes since v3:
> * Split commit.
> * Refactors landlock_add_rule syscall.
> 
> ---
>   security/landlock/syscalls.c | 92 +++++++++++++++++++-----------------
>   1 file changed, 48 insertions(+), 44 deletions(-)
> 
> diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c
> index 71aca7f990bc..87389d7bfbf2 100644
> --- a/security/landlock/syscalls.c
> +++ b/security/landlock/syscalls.c
> @@ -274,6 +274,47 @@ static int get_path_from_fd(const s32 fd, struct path *const path)
>   	return err;
>   }
> 
> +static int add_rule_path_beneath(struct landlock_ruleset *const ruleset,
> +				 const void __user *const rule_attr)
> +{
> +	struct landlock_path_beneath_attr path_beneath_attr;
> +	struct path path;
> +	int res, err;
> +	u32 mask;

access_mask_t mask;