Skip to contentSkip to conversation

syscalls/munlockall02: fix the outdated TCONF message

PATCH New Junchi Chen 2 participants 2 messages Aug 28, 2018

lore
Share & tools
lore

Junchi Chen

author
#0 lore raw

PATCH 1/1 syscalls/munlockall02: fix the outdated TCONF message

ISSUE:
This TCONF message: "Some distros... support
non-superuser munlockall calls."
has unnecessarily shown for years.

REASON：
EPERM is the error expected, which, by man page, is occurring due
to the lack of privilege (CAP_IPC_LOCK).
The intersection of munlockall syscall and CAP_IPC_LOCK macro is only in /mm/mlock.c file.

From v2.6, in /mm/mlock.c, there are no privilege check when using
munlockall syscall.
- For older version, the execution of do_mlockall()
with flag 0 is done right after the request for the semlock. By comparison, mlockall syscall checked via capable(CAP_IPC_LOCK) before do_mlockall() with flags.
- For newer version, apply_mlockall_flags()
substituted do_mlockall(), but nothing changed regarding privilege check.

ACTION:
Add tst_kvercmp() to test kernel version.

Signed-off-by Junchi Chen <[email protected]>
---
 .../kernel/syscalls/munlockall/munlockall02.c | 30 ++++++++++++++-----
 1 file changed, 23 insertions(+), 7 deletions(-)
testcases/kernel/syscalls/munlockall/munlockall02.c +23 -7
index f97905473..2e2695c52 100644
@@ -48,6 +48,8 @@
  *	 otherwise,
  *	  Issue sys call fails with unexpected errno.
  *
+ *	 Since V2.6.11, the mainline kernel support none-superuser
+ *	  munlockall calls. So the test pass with a success.
  *
  * 	Cleanup:
  *      change effective user id to root

@@ -69,6 +71,7 @@
 #include <errno.h>
 #include <pwd.h>
 #include <sys/mman.h>
+#include "tst_kvercmp.h"
 #include "test.h"
 #include "safe_macros.h"
 

@@ -98,14 +101,27 @@ int main(int ac, char **av)
 
 		TEST(munlockall());
 		/* check return code */
-		if ((TEST_RETURN == -1) && (TEST_ERRNO == EPERM)) {
-			tst_resm(TPASS, "munlockall() failed"
-				 " as expected for non-superuser" ":GOT EPERM");
+		if (tst_kvercmp(2, 6, 11) < 0) {
+			if ((TEST_RETURN == -1) && (TEST_ERRNO == EPERM)) {
+				tst_resm(TPASS, "munlockall() failed"
+						" as expected for non-superuser"
+						":GOT EPERM");
+			} else {
+				tst_resm(TCONF, "munlockall() failed to produce "
+						"expected errno :%d Got : %d, %s. ***Some distros, "
+						"such as Red Hat Enterprise Linux, support "
+						"non-superuser munlockall calls.***",
+						EPERM, TEST_ERRNO, strerror(TEST_ERRNO));
+			}
 		} else {
-			tst_resm(TCONF, "munlockall() failed to produce "
-				 "expected errno :%d Got : %d, %s. ***Some distros, such as Red Hat Enterprise Linux, support non-superuser munlockall calls.***",
-				 EPERM, TEST_ERRNO, strerror(TEST_ERRNO));
-
+			if (TEST_RETURN == 0) {
+				tst_resm(TPASS, "munlockall() succeeded"
+						" as expected for non-superuser");
+			} else {
+				tst_resm(TFAIL, "munlockall() failed to run"
+						" as non-superuser, Got : %d, %s.",
+						TEST_ERRNO, strerror(TEST_ERRNO));
+			}
 		}
 	}
Signature · 1 line
2.17.1
#1 lore raw

PATCH 1/1 syscalls/munlockall02: fix the outdated TCONF message

Hi!
Given that 2.6.11 is quite old, 13 years to be exact I would be in favor for dropping this particular EPERM test completely.

Signature · 2 lines
Cyril Hrubis
[email protected]