From 574500a108be1d2a6a0dc97a075c9e0a98371aba Mon Sep 17 00:00:00 2001 From: "Dmitry V. Levin" Date: Tue, 29 Sep 2020 14:10:20 -0300 Subject: [PATCH] sysvipc: Fix SEM_STAT_ANY kernel argument pass [BZ #26637] 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 --- sysdeps/unix/sysv/linux/Makefile | 2 +- sysdeps/unix/sysv/linux/semctl.c | 6 + sysdeps/unix/sysv/linux/tst-sysvsem-linux.c | 184 ++++++++++++++++++++ sysvipc/test-sysvsem.c | 1 + 4 files changed, 192 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..45f19e2d37 --- /dev/null +++ b/sysdeps/unix/sysv/linux/tst-sysvsem-linux.c @@ -0,0 +1,184 @@ +/* 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 + . */ + +#include +#include +#include +#include +#include +#include + +#include +#include + +/* 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 void +read_sem_stat (struct test_seminfo *tseminfo) +{ + FILE *f = fopen ("/proc/sys/kernel/sem", "r"); + if (f == NULL) + FAIL_UNSUPPORTED ("/proc is not mounted or /proc/sys/kernel/sem is not " + "available"); + + int r = fscanf (f, "%d %d %d %d", + &tseminfo->semmsl, &tseminfo->semmns, &tseminfo->semopm, + &tseminfo->semmni); + TEST_VERIFY_EXIT (r == 4); + + fclose (f); +} + + +/* 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); + + TEST_COMPARE (seminfo.sem_perm.__key, key); + TEST_COMPARE (seminfo.sem_perm.mode, SEM_MODE); + TEST_COMPARE (seminfo.sem_nsems, 1); + + 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; + 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"); + + 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"); + + 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++) + { + /* 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 (check_seminfo (i, key, SEM_STAT)) + { + found = true; + break; + } + } + + 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 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 #include #include +#include #include #include #include