Re: [PATCH] Smack: Simplified Mandatory Access Control Kernel

[Jan Engelhardt]

On Aug 11 2007 16:22, Casey Schaufler wrote:
>> >@@ -0,0 +1,8 @@
>> >+#
>> >+# Makefile for the SMACK LSM
>> >+#
>> >+
>> >+obj-$(CONFIG_SECURITY_SMACK) := smack.o
>> >+
>> >+smack-y := smack_lsm.o smack_access.o smackfs.o
>> 
>> smack-objs :=
>
>Added.

I should have added "replace it".

>> >+/*
>> >+ * 'ssssssss oooooooo mmmm\n\0' 
>> >+ */
>> 
>> I wonder why it's limited to 8 characters? Ah right.. sizeof(smack_t).
>> uhm.. are you trying to tell me that smack_t [typedef'ed to u64]
>> are actually meant as a char[8]? (/me scrathces head)
>
>Yes. "s == o" vs "strcmp(s,o) == 0".

Evil optimization ;-)
[ s == o is memcmp(s, o, sizeof(that)) == 0]

>> >+	char temp[80];
>> >+	ssize_t rc;
>> >+
>> >+	if (*ppos != 0)
>> >+		return 0;
>> >+
>> >+	sprintf(temp, "%d", smk_cipso_doi_value);
>> >+	rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp));
>> 
>> 80 is plenty for a 11 char string.
>> 
>> Look, they've got funny ideas! :)
>> net/ipv4/netfilter/nf_nat_irc.c:char buffer[sizeof("4294967296 65635")];

Proposal would have been: char temp[sizeof("4294967296")];

>> >+extern int smack_net_nltype;
>> >+extern int smack_cipso_direct;
>> >+extern struct smk_cipso_entry *smack_cipso;
>> 
>> for consistency reasons, add extern to the other vars too...
>
>the others?

There were some [or some function prototypes] above this point.

>> >+static int smack_task_movememory(struct task_struct *p)
>> >+{
>> >+	int rc;
>> >+
>> >+	rc = smk_curacc(smk_of_task(p), MAY_WRITE);
>> >+	return rc;
>> >+}
>> 
>> Uh...
>> 
>> {
>> 	return smk_curacc(smk_of_task(p), MAY_WRITE);
>> }
>> 
>> (also others)
>
>That was a little excessive, wasn't it?

How do you mean? I was just suggesting to collapse the three [four] lines into
one, getting rid of the tempotemporaries in a lot of these functions,
for example,

>> >+static int smack_task_kill(struct task_struct *p, struct siginfo *info,
>> >+			   int sig, u32 secid)
>> >+{
>> >+	smack_t *tsp = smk_of_task(p);
>> >+	int rc;
>> >+
>> >+	/*
>> >+	 * Sending a signal requires that the sender
>> >+	 * can write the receiver.
>> >+	 */
>> >+	rc = smk_curacc(tsp, MAY_WRITE);
>> >+
>> >+	return rc;
>> >+}

static int smack_task_kill(struct stask_struct *p, struct siginfo *info,
    int sig, u32 secid)
{
	/* Comment */
	return smk_curacc(smk_of_task(p), MAY_WRITE);
}



	Jan
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