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Subject: Re: [PATCH] security: mark expected switch fall-throughs
From:   "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To:     Casey Schaufler <casey@schaufler-ca.com>,
        John Johansen <john.johansen@canonical.com>,
        James Morris <jmorris@namei.org>,
        "Serge E. Hallyn" <serge@hallyn.com>,
        Mimi Zohar <zohar@linux.ibm.com>,
        Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc:     linux-security-module@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-integrity@vger.kernel.org
References: <20190125025639.GA13946@embeddedor>
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Message-ID: <f9ca33c7-2f96-ce1f-4fd2-587b991f2e85@embeddedor.com>
Date:   Thu, 24 Jan 2019 21:47:00 -0600
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On 1/24/19 9:29 PM, Gustavo A. R. Silva wrote:
> 
> 
> On 1/24/19 9:13 PM, Casey Schaufler wrote:
>> On 1/24/2019 6:56 PM, Gustavo A. R. Silva wrote:
>>> In preparation to enabling -Wimplicit-fallthrough, mark switch
>>> cases where we are expecting to fall through.
>>>
>>> This patch fixes the following warnings:
>>>
>>> security/integrity/ima/ima_appraise.c:116:26: warning: this statement may fall through [-Wimplicit-fallthrough=]
>>> security/integrity/ima/ima_template_lib.c:85:10: warning: this statement may fall through [-Wimplicit-fallthrough=]
>>> security/integrity/ima/ima_policy.c:940:18: warning: this statement may fall through [-Wimplicit-fallthrough=]
>>> security/integrity/ima/ima_policy.c:943:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
>>> security/integrity/ima/ima_policy.c:972:21: warning: this statement may fall through [-Wimplicit-fallthrough=]
>>> security/integrity/ima/ima_policy.c:974:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
>>> security/smack/smack_lsm.c:3391:9: warning: this statement may fall through [-Wimplicit-fallthrough=]
>>> security/apparmor/domain.c:569:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
>>>
>>> Warning level 3 was used: -Wimplicit-fallthrough=3
>>>
>>> This patch is part of the ongoing efforts to enabling -Wimplicit-fallthrough.
>>>
>>> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
>>
>> Acked-by: Casey Schaufler <casey@schaufler-ca.com>
>>

BTW, thanks, Casey.  I'll take this in my tree.

--
Gustavo

>> Ug. It can't be part of a greater comment? Grumble.
>>
> 
> Not like the one in this case.
> 
> It can be part of a one line comment like this:
> 
> /* fall through - ... */
> 
> and it has to be placed at the bottom of the case.
> 
> I know... I'd be great if this can be improved.
> 
>>> ---
>>>  security/apparmor/domain.c                | 2 +-
>>>  security/integrity/ima/ima_appraise.c     | 1 +
>>>  security/integrity/ima/ima_policy.c       | 4 ++++
>>>  security/integrity/ima/ima_template_lib.c | 1 +
>>>  security/smack/smack_lsm.c                | 3 +--
>>>  5 files changed, 8 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
>>> index 726910bba84b..c7c619578095 100644
>>> --- a/security/apparmor/domain.c
>>> +++ b/security/apparmor/domain.c
>>> @@ -572,7 +572,7 @@ static struct aa_label *x_to_label(struct aa_profile *profile,
>>>  			stack = NULL;
>>>  			break;
>>>  		}
>>> -		/* fall through to X_NAME */
>>> +		/* fall through - to X_NAME */
>>>  	case AA_X_NAME:
>>>  		if (xindex & AA_X_CHILD)
>>>  			/* released by caller */
>>> diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
>>> index a2baa85ea2f5..57daf30fb7d4 100644
>>> --- a/security/integrity/ima/ima_appraise.c
>>> +++ b/security/integrity/ima/ima_appraise.c
>>> @@ -114,6 +114,7 @@ static void ima_set_cache_status(struct integrity_iint_cache *iint,
>>>  		break;
>>>  	case CREDS_CHECK:
>>>  		iint->ima_creds_status = status;
>>> +		/* fall through */
>>>  	case FILE_CHECK:
>>>  	case POST_SETATTR:
>>>  		iint->ima_file_status = status;
>>> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
>>> index 8bc8a1c8cb3f..122797023bdb 100644
>>> --- a/security/integrity/ima/ima_policy.c
>>> +++ b/security/integrity/ima/ima_policy.c
>>> @@ -938,10 +938,12 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
>>>  		case Opt_uid_gt:
>>>  		case Opt_euid_gt:
>>>  			entry->uid_op = &uid_gt;
>>> +			/* fall through */
>>>  		case Opt_uid_lt:
>>>  		case Opt_euid_lt:
>>>  			if ((token == Opt_uid_lt) || (token == Opt_euid_lt))
>>>  				entry->uid_op = &uid_lt;
>>> +			/* fall through */
>>>  		case Opt_uid_eq:
>>>  		case Opt_euid_eq:
>>>  			uid_token = (token == Opt_uid_eq) ||
>>> @@ -970,9 +972,11 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
>>>  			break;
>>>  		case Opt_fowner_gt:
>>>  			entry->fowner_op = &uid_gt;
>>> +			/* fall through */
>>>  		case Opt_fowner_lt:
>>>  			if (token == Opt_fowner_lt)
>>>  				entry->fowner_op = &uid_lt;
>>> +			/* fall through */
>>>  		case Opt_fowner_eq:
>>>  			ima_log_string_op(ab, "fowner", args[0].from,
>>>  					  entry->fowner_op);
>>> diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c
>>> index 43752002c222..513b457ae900 100644
>>> --- a/security/integrity/ima/ima_template_lib.c
>>> +++ b/security/integrity/ima/ima_template_lib.c
>>> @@ -83,6 +83,7 @@ static void ima_show_template_data_ascii(struct seq_file *m,
>>>  		/* skip ':' and '\0' */
>>>  		buf_ptr += 2;
>>>  		buflen -= buf_ptr - field_data->data;
>>> +		/* fall through */
>>>  	case DATA_FMT_DIGEST:
>>>  	case DATA_FMT_HEX:
>>>  		if (!buflen)
>>> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
>>> index fa98394a40d0..127aa6c58e34 100644
>>> --- a/security/smack/smack_lsm.c
>>> +++ b/security/smack/smack_lsm.c
>>> @@ -3391,13 +3391,12 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
>>>  		 */
>>>  		final = &smack_known_star;
>>>  		/*
>>> -		 * Fall through.
>>> -		 *
>>>  		 * If a smack value has been set we want to use it,
>>>  		 * but since tmpfs isn't giving us the opportunity
>>>  		 * to set mount options simulate setting the
>>>  		 * superblock default.
>>>  		 */
>>> +		/* Fall through */
>>>  	default:
>>>  		/*
>>>  		 * This isn't an understood special case.