[PATCH v9 06/12] landlock: Refactor _unmask_layers() and _init_layer_masks()

[Konstantin Meskhidze (A)]

2/10/2023 8:38 PM, Mickaël Salaün пишет:
> 
> On 16/01/2023 09:58, Konstantin Meskhidze wrote:
>> Add new key_type argument to the landlock_init_layer_masks() helper.
>> Add a masks_array_size argument to the landlock_unmask_layers() helper.
>> These modifications support implementing new rule types in the next
>> Landlock versions.
>> 
>> Signed-off-by: Mickaël Salaün <mic at digikod.net>
>> Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze at huawei.com>
>> ---
>> 
>> Changes since v8:
>> * None.
>> 
>> Changes since v7:
>> * Refactors commit message, adds a co-developer.
>> * Minor fixes.
>> 
>> Changes since v6:
>> * Removes masks_size attribute from init_layer_masks().
>> * Refactors init_layer_masks() with new landlock_key_type.
>> 
>> Changes since v5:
>> * Splits commit.
>> * Formats code with clang-format-14.
>> 
>> Changes since v4:
>> * Refactors init_layer_masks(), get_handled_accesses()
>> and unmask_layers() functions to support multiple rule types.
>> * Refactors landlock_get_fs_access_mask() function with
>> LANDLOCK_MASK_ACCESS_FS mask.
>> 
>> Changes since v3:
>> * Splits commit.
>> * Refactors landlock_unmask_layers functions.
>> 
>> ---
>>   security/landlock/fs.c      | 43 ++++++++++++++++--------------
>>   security/landlock/ruleset.c | 52 ++++++++++++++++++++++++++-----------
>>   security/landlock/ruleset.h | 17 ++++++------
>>   3 files changed, 70 insertions(+), 42 deletions(-)
>> 
>> diff --git a/security/landlock/fs.c b/security/landlock/fs.c
>> index 73a7399f93ba..a73dbd3f9ddb 100644
>> --- a/security/landlock/fs.c
>> +++ b/security/landlock/fs.c
>>
> 
> [...]
> 
>> @@ -658,10 +677,13 @@ access_mask_t landlock_init_layer_masks(
>>   		const unsigned long access_req = access_request;
>>   		unsigned long access_bit;
>>   
>> -		for_each_set_bit(access_bit, &access_req,
>> -				 ARRAY_SIZE(*layer_masks)) {
>> +		for_each_set_bit(access_bit, &access_req, num_access) {
>> +			/*
>> +			 * Artificially handles all initially denied by default
>> +			 * access rights.
>> +			 */
> 
> No need to re-add this old comment which was removed with patch 2/12.
> 
  Ok. Will be fixed.
> 
>>   			if (BIT_ULL(access_bit) &
>> -			    landlock_get_fs_access_mask(domain, layer_level)) {
>> +			    get_access_mask(domain, layer_level)) {
>>   				(*layer_masks)[access_bit] |=
>>   					BIT_ULL(layer_level);
>>   				handled_accesses |= BIT_ULL(access_bit);
>> diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h
>> index 60a3c4d4d961..77349764e111 100644
>> --- a/security/landlock/ruleset.h
>> +++ b/security/landlock/ruleset.h
>> @@ -266,14 +266,15 @@ landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset,
>>   	return landlock_get_raw_fs_access_mask(ruleset, layer_level) |
>>   	       ACCESS_FS_INITIALLY_DENIED;
>>   }
>> -bool landlock_unmask_layers(
>> -	const struct landlock_rule *const rule,
>> -	const access_mask_t access_request,
>> -	layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS]);
>> +bool landlock_unmask_layers(const struct landlock_rule *const rule,
>> +			    const access_mask_t access_request,
>> +			    layer_mask_t (*const layer_masks)[],
>> +			    const size_t masks_array_size);
>>   
>> -access_mask_t landlock_init_layer_masks(
>> -	const struct landlock_ruleset *const domain,
>> -	const access_mask_t access_request,
>> -	layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS]);
>> +access_mask_t
>> +landlock_init_layer_masks(const struct landlock_ruleset *const domain,
>> +			  const access_mask_t access_request,
>> +			  layer_mask_t (*const layer_masks)[],
>> +			  const enum landlock_key_type key_type);
>>   
>>   #endif /* _SECURITY_LANDLOCK_RULESET_H */
> .