[PATCH 1/6] sysvipc: Fix SEM_STAT_ANY kernel argument pass [BZ #26637]
Adhemerval Zanella
adhemerval.zanella@linaro.org
Mon Sep 28 14:45:51 GMT 2020
From: "Dmitry V. Levin" <ldv@altlinux.org>
Handle SEM_STAT_ANY the same way as SEM_STAT so that the buffer argument
of SEM_STAT_ANY is properly passed to the kernel and back.
The regression testcase checks for Linux specifix SysV ipc message
control extension. For IPC_INFO/SEM_INFO it tries to match the values
against the tunable /proc values and for SEM_STAT/SEM_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).
Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
---
sysdeps/unix/sysv/linux/Makefile | 2 +-
sysdeps/unix/sysv/linux/semctl.c | 6 +
sysdeps/unix/sysv/linux/tst-sysvsem-linux.c | 198 ++++++++++++++++++++
sysvipc/test-sysvsem.c | 1 +
4 files changed, 206 insertions(+), 1 deletion(-)
create mode 100644 sysdeps/unix/sysv/linux/tst-sysvsem-linux.c
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 3bd3106ef9..4a4ed3cb5d 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-tgkill tst-sysvsem-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/semctl.c b/sysdeps/unix/sysv/linux/semctl.c
index f131a26fc7..1cdabde8f2 100644
--- a/sysdeps/unix/sysv/linux/semctl.c
+++ b/sysdeps/unix/sysv/linux/semctl.c
@@ -102,6 +102,7 @@ semun64_to_ksemun64 (int cmd, union semun64 semun64,
r.array = semun64.array;
break;
case SEM_STAT:
+ case SEM_STAT_ANY:
case IPC_STAT:
case IPC_SET:
r.buf = buf;
@@ -150,6 +151,7 @@ __semctl64 (int semid, int semnum, int cmd, ...)
case IPC_STAT: /* arg.buf */
case IPC_SET:
case SEM_STAT:
+ case SEM_STAT_ANY:
case IPC_INFO: /* arg.__buf */
case SEM_INFO:
va_start (ap, cmd);
@@ -238,6 +240,7 @@ semun_to_semun64 (int cmd, union semun semun, struct __semid64_ds *semid64)
r.array = semun.array;
break;
case SEM_STAT:
+ case SEM_STAT_ANY:
case IPC_STAT:
case IPC_SET:
r.buf = semid64;
@@ -267,6 +270,7 @@ __semctl (int semid, int semnum, int cmd, ...)
case IPC_STAT: /* arg.buf */
case IPC_SET:
case SEM_STAT:
+ case SEM_STAT_ANY:
case IPC_INFO: /* arg.__buf */
case SEM_INFO:
va_start (ap, cmd);
@@ -321,6 +325,7 @@ __semctl_mode16 (int semid, int semnum, int cmd, ...)
case IPC_STAT: /* arg.buf */
case IPC_SET:
case SEM_STAT:
+ case SEM_STAT_ANY:
case IPC_INFO: /* arg.__buf */
case SEM_INFO:
va_start (ap, cmd);
@@ -354,6 +359,7 @@ __old_semctl (int semid, int semnum, int cmd, ...)
case IPC_STAT: /* arg.buf */
case IPC_SET:
case SEM_STAT:
+ case SEM_STAT_ANY:
case IPC_INFO: /* arg.__buf */
case SEM_INFO:
va_start (ap, cmd);
diff --git a/sysdeps/unix/sysv/linux/tst-sysvsem-linux.c b/sysdeps/unix/sysv/linux/tst-sysvsem-linux.c
new file mode 100644
index 0000000000..12a3946d98
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-sysvsem-linux.c
@@ -0,0 +1,198 @@
+/* Basic tests for Linux SYSV semaphore 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/sem.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <stdio.h>
+
+#include <support/check.h>
+#include <support/temp_file.h>
+
+/* These are for the temporary file we generate. */
+static char *name;
+static int semid;
+
+static void
+remove_sem (void)
+{
+ /* Enforce message queue removal in case of early test failure.
+ Ignore error since the sem may already have being removed. */
+ semctl (semid, 0, IPC_RMID, 0);
+}
+
+static void
+do_prepare (int argc, char *argv[])
+{
+ TEST_VERIFY_EXIT (create_temp_file ("tst-sysvsem.", &name) != -1);
+}
+
+#define PREPARE do_prepare
+
+#define SEM_MODE 0644
+
+union semun
+{
+ int val;
+ struct semid_ds *buf;
+ unsigned short *array;
+ struct seminfo *__buf;
+};
+
+struct test_seminfo
+{
+ int semmsl;
+ int semmns;
+ int semopm;
+ int semmni;
+};
+
+/* It tries to obtain some system-wide SysV semaphore information from /proc
+ to check against IPC_INFO/SEM_INFO. The /proc only returns the tunables
+ value of SEMMSL, SEMMNS, SEMOPM, and SEMMNI.
+
+ The kernel also returns constant value for SEMVMX, SEMMNU, SEMMAP, SEMUME,
+ and also SEMUSZ and SEMAEM (for IPC_INFO). The issue to check them is they
+ might change over kernel releases. */
+
+static bool
+read_sem_stat (struct test_seminfo *tseminfo)
+{
+ FILE *f = fopen ("/proc/sys/kernel/sem", "r");
+ if (f == NULL)
+ return false;
+
+ int r = fscanf (f, "%d %d %d %d",
+ &tseminfo->semmsl, &tseminfo->semmns, &tseminfo->semopm,
+ &tseminfo->semmni);
+ TEST_VERIFY_EXIT (r == 4);
+
+ fclose (f);
+
+ return 0;
+}
+
+
+/* Check if the semaphore with IDX (index into the kernel's internal array)
+ matches the one with KEY. The CMD is either SEM_STAT or SEM_STAT_ANY. */
+
+static bool
+check_seminfo (int idx, key_t key, int cmd)
+{
+ struct semid_ds seminfo;
+ int sid = semctl (idx, 0, cmd, (union semun) { .buf = &seminfo });
+ /* Ignore unused array slot returned by the kernel or information from
+ unknown semaphores. */
+ if ((sid == -1 && errno == EINVAL) || sid != semid)
+ return false;
+
+ if (sid == -1)
+ FAIL_EXIT1 ("semctl with SEM_STAT failed (errno=%d)", errno);
+
+ if (seminfo.sem_perm.__key != key)
+ FAIL_EXIT1 ("semid_ds::sem_perm::key (%d) != %d",
+ (int) seminfo.sem_perm.__key, (int) key);
+ if (seminfo.sem_perm.mode != SEM_MODE)
+ FAIL_EXIT1 ("semid_ds::sem_perm::mode (%o) != %o",
+ seminfo.sem_perm.mode, SEM_MODE);
+ if (seminfo.sem_nsems != 1)
+ FAIL_EXIT1 ("semid_ds::sem_nsems (%lu) != 1",
+ (long unsigned) seminfo.sem_nsems);
+
+ return true;
+}
+
+static int
+do_test (void)
+{
+ atexit (remove_sem);
+
+ key_t key = ftok (name, 'G');
+ if (key == -1)
+ FAIL_EXIT1 ("ftok failed: %m");
+
+ semid = semget (key, 1, IPC_CREAT | IPC_EXCL | SEM_MODE);
+ if (semid == -1)
+ FAIL_EXIT1 ("semget failed: %m");
+
+ struct test_seminfo tipcinfo;
+ bool tipcget = read_sem_stat (&tipcinfo);
+
+ int semidx;
+
+ {
+ struct seminfo ipcinfo;
+ semidx = semctl (semid, 0, IPC_INFO, (union semun) { .__buf = &ipcinfo });
+ if (semidx == -1)
+ FAIL_EXIT1 ("semctl with IPC_INFO failed: %m");
+
+ /* We only check if /proc is mounted. */
+ if (tipcget)
+ {
+ TEST_COMPARE (ipcinfo.semmsl, tipcinfo.semmsl);
+ TEST_COMPARE (ipcinfo.semmns, tipcinfo.semmns);
+ TEST_COMPARE (ipcinfo.semopm, tipcinfo.semopm);
+ TEST_COMPARE (ipcinfo.semmni, tipcinfo.semmni);
+ }
+ }
+
+ /* Same as before but with SEM_INFO. */
+ {
+ struct seminfo ipcinfo;
+ semidx = semctl (semid, 0, SEM_INFO, (union semun) { .__buf = &ipcinfo });
+ if (semidx == -1)
+ FAIL_EXIT1 ("semctl with IPC_INFO failed: %m");
+
+ if (tipcget)
+ {
+ TEST_COMPARE (ipcinfo.semmsl, tipcinfo.semmsl);
+ TEST_COMPARE (ipcinfo.semmns, tipcinfo.semmns);
+ TEST_COMPARE (ipcinfo.semopm, tipcinfo.semopm);
+ TEST_COMPARE (ipcinfo.semmni, tipcinfo.semmni);
+ }
+ }
+
+ /* We check if the created semaphore shows in the system-wide status. */
+ bool found = false;
+ for (int i = 0; i <= semidx; i++)
+ {
+ if (check_seminfo (i, key, SEM_STAT))
+ {
+ found = true;
+ break;
+ }
+
+ /* We can't tell apart if SEM_STAT_ANY is not supported (kernel older
+ than 4.17) or if the index used is invalid. So it just check if
+ value returned from a valid call matches the created semaphore. */
+ check_seminfo (i, key, SEM_STAT_ANY);
+ }
+
+ if (!found)
+ FAIL_EXIT1 ("semctl with SEM_STAT/SEM_STAT_ANY could not find the "
+ "created semaphore");
+
+ if (semctl (semid, 0, IPC_RMID, 0) == -1)
+ FAIL_EXIT1 ("semctl failed: %m");
+
+ return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/sysvipc/test-sysvsem.c b/sysvipc/test-sysvsem.c
index 01dbff343a..b7284e0b48 100644
--- a/sysvipc/test-sysvsem.c
+++ b/sysvipc/test-sysvsem.c
@@ -20,6 +20,7 @@
#include <stdlib.h>
#include <errno.h>
#include <string.h>
+#include <stdbool.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
--
2.25.1
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