Date: 1 Apr 2004 15:57:26 -0000 From: "Christian S.J.Peron" <maneo@bsdpro.com> To: FreeBSD-gnats-submit@FreeBSD.org Subject: bin/65042: [patch] Minimize CPU cycles used by ls(1) when processing ACLs Message-ID: <20040401155726.82078.qmail@staff.seccuris.com> Resent-Message-ID: <200404011600.i31G0Zpd054154@freefall.freebsd.org>
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>Number: 65042
>Category: bin
>Synopsis: [patch] Minimize CPU cycles used by ls(1) when processing ACLs
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: change-request
>Submitter-Id: current-users
>Arrival-Date: Thu Apr 01 08:00:35 PST 2004
>Closed-Date:
>Last-Modified:
>Originator: Christian S.J. Peron
>Release: FreeBSD 5.2.1-RELEASE-p3 i386
>Organization:
>Environment:
System: FreeBSD dev 5.2.1-RELEASE-p3 FreeBSD 5.2.1-RELEASE-p3 #5: Tue Mar 23 00:19:58 GMT 2004 cperon@dev:/usr/src/sys/i386/compile/XOR i386
>Description:
Currently ls(1) will iterate through every ACL associated with a
file when it determines whether or not the file has implemented
extended ACLs.
In reality with access ACLs, (being an extension of
regular file permissions) the loop could terminate once it detects
greater than 3 ACLs for the file.
This makes the loop O(4) rather than O(n).
>How-To-Repeat:
N/A
>Fix:
--- bin/ls/print.c.bak Thu Apr 1 15:09:14 2004
+++ bin/ls/print.c Thu Apr 1 15:20:16 2004
@@ -694,11 +694,16 @@
*haveacls = 1;
if ((facl = acl_get_file(name, ACL_TYPE_ACCESS)) != NULL) {
if (acl_get_entry(facl, ACL_FIRST_ENTRY, &ae) == 1) {
- entries = 0;
- do
- entries++;
- while (acl_get_entry(facl, ACL_NEXT_ENTRY, &ae) == 1);
- if (entries != 3)
+ entries = 1;
+ while (acl_get_entry(facl, ACL_NEXT_ENTRY, &ae) == 1)
+ if (entries++ > 3)
+ break;
+ /*
+ * POSIX.1e requires that ACLs of type ACL_TYPE_ACCESS
+ * must have at least three entries owner, group and other.
+ * So anything with more than 3 ACLs looks interesting to us.
+ */
+ if (entries > 3)
buf[10] = '+';
}
acl_free(facl);
>Release-Note:
>Audit-Trail:
>Unformatted:
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