diff mbox series

[3/6] sysvipc: Fix IPC_INFO and MSG_INFO handling [BZ #26639]

Message ID 20200928144556.239160-3-adhemerval.zanella@linaro.org
State Superseded
Headers show
Series [1/6] sysvipc: Fix SEM_STAT_ANY kernel argument pass [BZ #26637] | expand

Commit Message

Adhemerval Zanella Sept. 28, 2020, 2:45 p.m. UTC
Both commands are Linux exntesions where the third argument is a
'struct msginfo' instead of 'struct msqid_ds' and its information
does not contain any time related fields (so there is no need to
extra conversion for __IPC_TIME64.

The regression testcase checks for Linux specifix SysV ipc message
control extension.  For IPC_INFO/MSG_INFO it tries to match the values
against the tunable /proc values and for MSG_STAT/MSG_STAT_ANY it
check if the create message queue is within the global list returned
by the kernel.

Checked on x86_64-linux-gnu and on i686-linux-gnu (Linux v5.4 and on
Linux v4.15).
---
 sysdeps/unix/sysv/linux/Makefile            |   2 +-
 sysdeps/unix/sysv/linux/msgctl.c            |  22 ++-
 sysdeps/unix/sysv/linux/tst-sysvmsg-linux.c | 203 ++++++++++++++++++++
 3 files changed, 222 insertions(+), 5 deletions(-)
 create mode 100644 sysdeps/unix/sysv/linux/tst-sysvmsg-linux.c

Comments

Andreas Schwab Sept. 28, 2020, 2:55 p.m. UTC | #1
On Sep 28 2020, Adhemerval Zanella via Libc-alpha wrote:

> Both commands are Linux exntesions where the third argument is a

                          extensions

Andreas.
Florian Weimer Sept. 29, 2020, 7:57 a.m. UTC | #2
* Adhemerval Zanella via Libc-alpha:

> +static int
> +read_proc_file (const char *file)
> +{
> +  FILE *f = fopen (file, "r");
> +  if (f == NULL)
> +    return -1;
> +
> +  int v;
> +  int r = fscanf (f, "%d", & v);
> +  TEST_VERIFY_EXIT (r == 1);
> +
> +  fclose (f);
> +  return v;
> +}

You could use xfopen and xfclose.

> +/* Check if the message queue with IDX (index into the kernel's internal
> +   array) matches the one with KEY.  The CMD is either MSG_STAT or
> +   MSG_STAT_ANY.  */
> +
> +static bool
> +check_msginfo (int idx, key_t key, int cmd)
> +{
> +  struct msqid_ds msginfo;
> +  int mid = msgctl (idx, cmd, &msginfo);
> +  /* Ignore unused array slot returned by the kernel or information from
> +     unknown message queue.  */
> +  if ((mid == -1 && errno == EINVAL) || mid != msqid)
> +    return false;
> +
> +  if (mid == -1)
> +    FAIL_EXIT1 ("msgctl with %s failed: %m",
> +		cmd == MSG_STAT ? "MSG_STAT" : "MSG_STAT_ANY");
> +
> +  if (msginfo.msg_perm.__key != key)
> +    FAIL_EXIT1 ("msgid_ds::msg_perm::key (%d) != %d",
> +		(int) msginfo.msg_perm.__key, (int) key);
> +  if (msginfo.msg_perm.mode != MSGQ_MODE)
> +    FAIL_EXIT1 ("msgid_ds::msg_perm::mode (%o) != %o",
> +		msginfo.msg_perm.mode, MSGQ_MODE);
> +  if (msginfo.msg_qnum != 0)
> +    FAIL_EXIT1 ("msgid_ds::msg_qnum (%lu) != 0",
> +		(long unsigned) msginfo.msg_qnum);

As in the other patch, you might want to use TEST_COMPARE here.

Rest looks okay, I think.

Thanks,
Florian
Adhemerval Zanella Sept. 29, 2020, 12:37 p.m. UTC | #3
On 29/09/2020 04:57, Florian Weimer wrote:
> * Adhemerval Zanella via Libc-alpha:
> 
>> +static int
>> +read_proc_file (const char *file)
>> +{
>> +  FILE *f = fopen (file, "r");
>> +  if (f == NULL)
>> +    return -1;
>> +
>> +  int v;
>> +  int r = fscanf (f, "%d", & v);
>> +  TEST_VERIFY_EXIT (r == 1);
>> +
>> +  fclose (f);
>> +  return v;
>> +}
> 
> You could use xfopen and xfclose.

Indeed, I will change it.

> 
>> +/* Check if the message queue with IDX (index into the kernel's internal
>> +   array) matches the one with KEY.  The CMD is either MSG_STAT or
>> +   MSG_STAT_ANY.  */
>> +
>> +static bool
>> +check_msginfo (int idx, key_t key, int cmd)
>> +{
>> +  struct msqid_ds msginfo;
>> +  int mid = msgctl (idx, cmd, &msginfo);
>> +  /* Ignore unused array slot returned by the kernel or information from
>> +     unknown message queue.  */
>> +  if ((mid == -1 && errno == EINVAL) || mid != msqid)
>> +    return false;
>> +
>> +  if (mid == -1)
>> +    FAIL_EXIT1 ("msgctl with %s failed: %m",
>> +		cmd == MSG_STAT ? "MSG_STAT" : "MSG_STAT_ANY");
>> +
>> +  if (msginfo.msg_perm.__key != key)
>> +    FAIL_EXIT1 ("msgid_ds::msg_perm::key (%d) != %d",
>> +		(int) msginfo.msg_perm.__key, (int) key);
>> +  if (msginfo.msg_perm.mode != MSGQ_MODE)
>> +    FAIL_EXIT1 ("msgid_ds::msg_perm::mode (%o) != %o",
>> +		msginfo.msg_perm.mode, MSGQ_MODE);
>> +  if (msginfo.msg_qnum != 0)
>> +    FAIL_EXIT1 ("msgid_ds::msg_qnum (%lu) != 0",
>> +		(long unsigned) msginfo.msg_qnum);
> 
> As in the other patch, you might want to use TEST_COMPARE here.

Yes, I changed it as well from the other patch review.

> 
> Rest looks okay, I think.
> 
> Thanks,
> Florian
>
Adhemerval Zanella Sept. 29, 2020, 12:58 p.m. UTC | #4
On 29/09/2020 09:37, Adhemerval Zanella wrote:
> 
> 
> On 29/09/2020 04:57, Florian Weimer wrote:
>> * Adhemerval Zanella via Libc-alpha:
>>
>>> +static int
>>> +read_proc_file (const char *file)
>>> +{
>>> +  FILE *f = fopen (file, "r");
>>> +  if (f == NULL)
>>> +    return -1;
>>> +
>>> +  int v;
>>> +  int r = fscanf (f, "%d", & v);
>>> +  TEST_VERIFY_EXIT (r == 1);
>>> +
>>> +  fclose (f);
>>> +  return v;
>>> +}
>>
>> You could use xfopen and xfclose.
> 
> Indeed, I will change it.

In fact I though about it before and for this test we do want to 
check if the /proc file is accessible and just check against the 
tunable value if it were the case.  Otherwise the test will always
fail if /proc is not mounted (not really the expected scenario I 
give you).
Florian Weimer Sept. 29, 2020, 1:01 p.m. UTC | #5
* Adhemerval Zanella:

> On 29/09/2020 09:37, Adhemerval Zanella wrote:
>> 
>> 
>> On 29/09/2020 04:57, Florian Weimer wrote:
>>> * Adhemerval Zanella via Libc-alpha:
>>>
>>>> +static int
>>>> +read_proc_file (const char *file)
>>>> +{
>>>> +  FILE *f = fopen (file, "r");
>>>> +  if (f == NULL)
>>>> +    return -1;
>>>> +
>>>> +  int v;
>>>> +  int r = fscanf (f, "%d", & v);
>>>> +  TEST_VERIFY_EXIT (r == 1);
>>>> +
>>>> +  fclose (f);
>>>> +  return v;
>>>> +}
>>>
>>> You could use xfopen and xfclose.
>> 
>> Indeed, I will change it.
>
> In fact I though about it before and for this test we do want to 
> check if the /proc file is accessible and just check against the 
> tunable value if it were the case.  Otherwise the test will always
> fail if /proc is not mounted (not really the expected scenario I 
> give you).

Maybe add FAIL_UNSUPPORTED for this case at the start of the test?

Thanks,
Florian
Adhemerval Zanella Sept. 29, 2020, 1:04 p.m. UTC | #6
On 29/09/2020 10:01, Florian Weimer wrote:
> * Adhemerval Zanella:
> 
>> On 29/09/2020 09:37, Adhemerval Zanella wrote:
>>>
>>>
>>> On 29/09/2020 04:57, Florian Weimer wrote:
>>>> * Adhemerval Zanella via Libc-alpha:
>>>>
>>>>> +static int
>>>>> +read_proc_file (const char *file)
>>>>> +{
>>>>> +  FILE *f = fopen (file, "r");
>>>>> +  if (f == NULL)
>>>>> +    return -1;
>>>>> +
>>>>> +  int v;
>>>>> +  int r = fscanf (f, "%d", & v);
>>>>> +  TEST_VERIFY_EXIT (r == 1);
>>>>> +
>>>>> +  fclose (f);
>>>>> +  return v;
>>>>> +}
>>>>
>>>> You could use xfopen and xfclose.
>>>
>>> Indeed, I will change it.
>>
>> In fact I though about it before and for this test we do want to 
>> check if the /proc file is accessible and just check against the 
>> tunable value if it were the case.  Otherwise the test will always
>> fail if /proc is not mounted (not really the expected scenario I 
>> give you).
> 
> Maybe add FAIL_UNSUPPORTED for this case at the start of the test?

I don't have a strong opinion, I will add the FAIL_UNSUPPORTED for
case /proc is not accessible then.
diff mbox series

Patch

diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 4a4ed3cb5d..a54eb75d74 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -101,7 +101,7 @@  tests += tst-clone tst-clone2 tst-clone3 tst-fanotify tst-personality \
 	 tst-quota tst-sync_file_range tst-sysconf-iov_max tst-ttyname \
 	 test-errno-linux tst-memfd_create tst-mlock2 tst-pkey \
 	 tst-rlimit-infinity tst-ofdlocks tst-gettid tst-gettid-kill \
-	 tst-tgkill tst-sysvsem-linux
+	 tst-tgkill tst-sysvsem-linux tst-sysvmsg-linux
 tests-internal += tst-ofdlocks-compat tst-sigcontext-get_pc
 
 CFLAGS-tst-sigcontext-get_pc.c = -fasynchronous-unwind-tables
diff --git a/sysdeps/unix/sysv/linux/msgctl.c b/sysdeps/unix/sysv/linux/msgctl.c
index 0776472d5e..a1f24ab242 100644
--- a/sysdeps/unix/sysv/linux/msgctl.c
+++ b/sysdeps/unix/sysv/linux/msgctl.c
@@ -90,8 +90,15 @@  __msgctl64 (int msqid, int cmd, struct __msqid64_ds *buf)
   struct kernel_msqid64_ds ksemid, *arg = NULL;
   if (buf != NULL)
     {
-      msqid64_to_kmsqid64 (buf, &ksemid);
-      arg = &ksemid;
+      /* This is a Linux extension where kernel returns a 'struct msginfo'
+	 instead.  */
+      if (cmd == IPC_INFO || cmd == MSG_INFO)
+	arg = (struct kernel_msqid64_ds *) buf;
+      else
+	{
+	  msqid64_to_kmsqid64 (buf, &ksemid);
+	  arg = &ksemid;
+	}
     }
 # ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
   if (cmd == IPC_SET)
@@ -169,8 +176,15 @@  __msgctl (int msqid, int cmd, struct msqid_ds *buf)
   struct __msqid64_ds msqid64, *buf64 = NULL;
   if (buf != NULL)
     {
-      msqid_to_msqid64 (&msqid64, buf);
-      buf64 = &msqid64;
+      /* This is a Linux extension where kernel returns a 'struct msginfo'
+	 instead.  */
+      if (cmd == IPC_INFO || cmd == MSG_INFO)
+	buf64 = (struct __msqid64_ds *) buf;
+      else
+	{
+	  msqid_to_msqid64 (&msqid64, buf);
+	  buf64 = &msqid64;
+	}
     }
 
   int ret = __msgctl64 (msqid, cmd, buf64);
diff --git a/sysdeps/unix/sysv/linux/tst-sysvmsg-linux.c b/sysdeps/unix/sysv/linux/tst-sysvmsg-linux.c
new file mode 100644
index 0000000000..79a94b3d44
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-sysvmsg-linux.c
@@ -0,0 +1,203 @@ 
+/* Basic tests for Linux SYSV message queue extensions.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <sys/ipc.h>
+#include <sys/msg.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <stdio.h>
+
+#include <support/check.h>
+#include <support/temp_file.h>
+
+#define MSGQ_MODE 0644
+
+/* These are for the temporary file we generate.  */
+static char *name;
+static int msqid;
+
+static void
+remove_msq (void)
+{
+  /* Enforce message queue removal in case of early test failure.
+     Ignore error since the msg may already have being removed.  */
+  msgctl (msqid, IPC_RMID, NULL);
+}
+
+static void
+do_prepare (int argc, char *argv[])
+{
+  TEST_VERIFY_EXIT (create_temp_file ("tst-sysvmsg.", &name) != -1);
+}
+
+#define PREPARE do_prepare
+
+struct test_msginfo
+{
+  int msgmax;
+  int msgmnb;
+  int msgmni;
+};
+
+/* It tries to obtain some system-wide SysV messsage queue information from
+   /proc to check against IPC_INFO/MSG_INFO.  The /proc only returns the
+   tunables value of MSGMAX, MSGMNB, and MSGMNI.
+
+   The kernel also returns constant value for MSGSSZ, MSGSEG and also MSGMAP,
+   MSGPOOL, and MSGTQL (for IPC_INFO).  The issue to check them is they might
+   change over kernel releases.  */
+
+static int
+read_proc_file (const char *file)
+{
+  FILE *f = fopen (file, "r");
+  if (f == NULL)
+    return -1;
+
+  int v;
+  int r = fscanf (f, "%d", & v);
+  TEST_VERIFY_EXIT (r == 1);
+
+  fclose (f);
+  return v;
+}
+
+static bool
+read_msg_stat (struct test_msginfo *tmsginfo)
+{
+  tmsginfo->msgmax = read_proc_file ("/proc/sys/kernel/msgmax");
+  if (tmsginfo->msgmax == -1)
+    return false;
+  tmsginfo->msgmnb = read_proc_file ("/proc/sys/kernel/msgmnb");
+  if (tmsginfo->msgmnb == -1)
+    return false;
+  tmsginfo->msgmni = read_proc_file ("/proc/sys/kernel/msgmni");
+  if (tmsginfo->msgmni == -1)
+    return false;
+  return true;
+}
+
+
+/* Check if the message queue with IDX (index into the kernel's internal
+   array) matches the one with KEY.  The CMD is either MSG_STAT or
+   MSG_STAT_ANY.  */
+
+static bool
+check_msginfo (int idx, key_t key, int cmd)
+{
+  struct msqid_ds msginfo;
+  int mid = msgctl (idx, cmd, &msginfo);
+  /* Ignore unused array slot returned by the kernel or information from
+     unknown message queue.  */
+  if ((mid == -1 && errno == EINVAL) || mid != msqid)
+    return false;
+
+  if (mid == -1)
+    FAIL_EXIT1 ("msgctl with %s failed: %m",
+		cmd == MSG_STAT ? "MSG_STAT" : "MSG_STAT_ANY");
+
+  if (msginfo.msg_perm.__key != key)
+    FAIL_EXIT1 ("msgid_ds::msg_perm::key (%d) != %d",
+		(int) msginfo.msg_perm.__key, (int) key);
+  if (msginfo.msg_perm.mode != MSGQ_MODE)
+    FAIL_EXIT1 ("msgid_ds::msg_perm::mode (%o) != %o",
+		msginfo.msg_perm.mode, MSGQ_MODE);
+  if (msginfo.msg_qnum != 0)
+    FAIL_EXIT1 ("msgid_ds::msg_qnum (%lu) != 0",
+		(long unsigned) msginfo.msg_qnum);
+
+  return true;
+}
+
+static int
+do_test (void)
+{
+  atexit (remove_msq);
+
+  key_t key = ftok (name, 'G');
+  if (key == -1)
+    FAIL_EXIT1 ("ftok failed: %m");
+
+  msqid = msgget (key, MSGQ_MODE | IPC_CREAT);
+  if (msqid == -1)
+    FAIL_EXIT1 ("msgget failed: %m");
+
+  struct test_msginfo tipcinfo;
+  bool tipcget = read_msg_stat (&tipcinfo);
+
+  int msqidx;
+
+  {
+    struct msginfo ipcinfo;
+    msqidx = msgctl (msqid, IPC_INFO, (struct msqid_ds *) &ipcinfo);
+    if (msqidx == -1)
+      FAIL_EXIT1 ("msgctl with IPC_INFO failed: %m");
+
+    /* We only check if /proc is mounted.  */
+    if (tipcget)
+      {
+	TEST_COMPARE (ipcinfo.msgmax, tipcinfo.msgmax);
+	TEST_COMPARE (ipcinfo.msgmnb, tipcinfo.msgmnb);
+	TEST_COMPARE (ipcinfo.msgmni, tipcinfo.msgmni);
+      }
+  }
+
+  /* Same as before but with MSG_INFO.  */
+  {
+    struct msginfo ipcinfo;
+    msqidx = msgctl (msqid, MSG_INFO, (struct msqid_ds *) &ipcinfo);
+    if (msqidx == -1)
+      FAIL_EXIT1 ("msgctl with IPC_INFO failed: %m");
+
+    if (tipcget)
+      {
+	TEST_COMPARE (ipcinfo.msgmax, tipcinfo.msgmax);
+	TEST_COMPARE (ipcinfo.msgmnb, tipcinfo.msgmnb);
+	TEST_COMPARE (ipcinfo.msgmni, tipcinfo.msgmni);
+      }
+  }
+
+  /* We check if the created message queue shows in global list.  */
+  bool found = false;
+  for (int i = 0; i <= msqidx; i++)
+    {
+      if (check_msginfo (i, key, MSG_STAT))
+	{
+	  found = true;
+	  break;
+	}
+
+      /* We can't tell apart if MSG_STAT_ANY is not supported (kernel older
+	 than 4.17) or if the index used is invalid.  So it just check if the
+	 value returned from a valid call matches the created message
+	 queue.  */
+      check_msginfo (i, key, MSG_STAT_ANY);
+    }
+
+  if (!found)
+    FAIL_EXIT1 ("msgctl with MSG_STAT/MSG_STAT_ANY could not find the "
+		"created message queue");
+
+  if (msgctl (msqid, IPC_RMID, NULL) == -1)
+    FAIL_EXIT1 ("msgctl failed");
+
+  return 0;
+}
+
+#include <support/test-driver.c>