glibc/sysdeps/unix/sysv/linux/shmctl.c
Adhemerval Zanella 9ebaabeaac sysvipc: Return EINVAL for invalid shmctl commands
It avoids regressions on possible future commands that might require
additional libc support.  The downside is new commands added by newer
kernels will need further glibc support.

Checked on x86_64-linux-gnu and i686-linux-gnu (Linux v4.15 and v5.4).
2020-10-14 11:49:55 -03:00

281 lines
7.9 KiB
C

/* Copyright (C) 1995-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, August 1995.
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/shm.h>
#include <stdarg.h>
#include <ipc_priv.h>
#include <sysdep.h>
#include <shlib-compat.h>
#include <errno.h>
#include <linux/posix_types.h> /* For __kernel_mode_t. */
/* POSIX states ipc_perm mode should have type of mode_t. */
_Static_assert (sizeof ((struct shmid_ds){0}.shm_perm.mode)
== sizeof (mode_t),
"sizeof (shmid_ds.shm_perm.mode) != sizeof (mode_t)");
#if __IPC_TIME64 == 0
typedef struct shmid_ds shmctl_arg_t;
#else
# include <struct_kernel_shmid64_ds.h>
static void
shmid64_to_kshmid64 (const struct __shmid64_ds *shmid64,
struct kernel_shmid64_ds *kshmid)
{
kshmid->shm_perm = shmid64->shm_perm;
kshmid->shm_segsz = shmid64->shm_segsz;
kshmid->shm_atime = shmid64->shm_atime;
kshmid->shm_atime_high = shmid64->shm_atime >> 32;
kshmid->shm_dtime = shmid64->shm_dtime;
kshmid->shm_dtime_high = shmid64->shm_dtime >> 32;
kshmid->shm_ctime = shmid64->shm_ctime;
kshmid->shm_ctime_high = shmid64->shm_ctime >> 32;
kshmid->shm_cpid = shmid64->shm_cpid;
kshmid->shm_lpid = shmid64->shm_lpid;
kshmid->shm_nattch = shmid64->shm_nattch;
}
static void
kshmid64_to_shmid64 (const struct kernel_shmid64_ds *kshmid,
struct __shmid64_ds *shmid64)
{
shmid64->shm_perm = kshmid->shm_perm;
shmid64->shm_segsz = kshmid->shm_segsz;
shmid64->shm_atime = kshmid->shm_atime
| ((__time64_t) kshmid->shm_atime_high << 32);
shmid64->shm_dtime = kshmid->shm_dtime
| ((__time64_t) kshmid->shm_dtime_high << 32);
shmid64->shm_ctime = kshmid->shm_ctime
| ((__time64_t) kshmid->shm_ctime_high << 32);
shmid64->shm_cpid = kshmid->shm_cpid;
shmid64->shm_lpid = kshmid->shm_lpid;
shmid64->shm_nattch = kshmid->shm_nattch;
}
typedef struct kernel_shmid64_ds shmctl_arg_t;
#endif
static int
shmctl_syscall (int shmid, int cmd, shmctl_arg_t *buf)
{
#ifdef __ASSUME_DIRECT_SYSVIPC_SYSCALLS
return INLINE_SYSCALL_CALL (shmctl, shmid, cmd | __IPC_64, buf);
#else
return INLINE_SYSCALL_CALL (ipc, IPCOP_shmctl, shmid, cmd | __IPC_64, 0,
buf);
#endif
}
/* Provide operations to control over shared memory segments. */
int
__shmctl64 (int shmid, int cmd, struct __shmid64_ds *buf)
{
#if __IPC_TIME64
struct kernel_shmid64_ds kshmid, *arg = NULL;
#else
shmctl_arg_t *arg;
#endif
switch (cmd)
{
case IPC_RMID:
case SHM_LOCK:
case SHM_UNLOCK:
arg = NULL;
break;
case IPC_SET:
case IPC_STAT:
case SHM_STAT:
case SHM_STAT_ANY:
#if __IPC_TIME64
if (buf != NULL)
{
shmid64_to_kshmid64 (buf, &kshmid);
arg = &kshmid;
}
# ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
if (cmd == IPC_SET)
arg->shm_perm.mode *= 0x10000U;
# endif
#else
arg = buf;
#endif
break;
case IPC_INFO:
case SHM_INFO:
/* This is a Linux extension where kernel expects either a
'struct shminfo' (IPC_INFO) or 'struct shm_info' (SHM_INFO). */
arg = (__typeof__ (arg)) buf;
break;
default:
__set_errno (EINVAL);
return -1;
}
int ret = shmctl_syscall (shmid, cmd, arg);
if (ret < 0)
return ret;
switch (cmd)
{
case IPC_STAT:
case SHM_STAT:
case SHM_STAT_ANY:
#ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
arg->shm_perm.mode >>= 16;
#else
/* Old Linux kernel versions might not clear the mode padding. */
if (sizeof ((struct shmid_ds){0}.shm_perm.mode)
!= sizeof (__kernel_mode_t))
arg->shm_perm.mode &= 0xFFFF;
#endif
#if __IPC_TIME64
kshmid64_to_shmid64 (arg, buf);
#endif
}
return ret;
}
#if __TIMESIZE != 64
libc_hidden_def (__shmctl64)
static void
shmid_to_shmid64 (struct __shmid64_ds *shm64, const struct shmid_ds *shm)
{
shm64->shm_perm = shm->shm_perm;
shm64->shm_segsz = shm->shm_segsz;
shm64->shm_atime = shm->shm_atime
| ((__time64_t) shm->__shm_atime_high << 32);
shm64->shm_dtime = shm->shm_dtime
| ((__time64_t) shm->__shm_dtime_high << 32);
shm64->shm_ctime = shm->shm_ctime
| ((__time64_t) shm->__shm_ctime_high << 32);
shm64->shm_cpid = shm->shm_cpid;
shm64->shm_lpid = shm->shm_lpid;
shm64->shm_nattch = shm->shm_nattch;
}
static void
shmid64_to_shmid (struct shmid_ds *shm, const struct __shmid64_ds *shm64)
{
shm->shm_perm = shm64->shm_perm;
shm->shm_segsz = shm64->shm_segsz;
shm->shm_atime = shm64->shm_atime;
shm->__shm_atime_high = 0;
shm->shm_dtime = shm64->shm_dtime;
shm->__shm_dtime_high = 0;
shm->shm_ctime = shm64->shm_ctime;
shm->__shm_ctime_high = 0;
shm->shm_cpid = shm64->shm_cpid;
shm->shm_lpid = shm64->shm_lpid;
shm->shm_nattch = shm64->shm_nattch;
}
int
__shmctl (int shmid, int cmd, struct shmid_ds *buf)
{
struct __shmid64_ds shmid64, *buf64 = NULL;
if (buf != NULL)
{
/* This is a Linux extension where kernel expects either a
'struct shminfo' (IPC_INFO) or 'struct shm_info' (SHM_INFO). */
if (cmd == IPC_INFO || cmd == SHM_INFO)
buf64 = (struct __shmid64_ds *) buf;
else
{
shmid_to_shmid64 (&shmid64, buf);
buf64 = &shmid64;
}
}
int ret = __shmctl64 (shmid, cmd, buf64);
if (ret < 0)
return ret;
switch (cmd)
{
case IPC_STAT:
case SHM_STAT:
case SHM_STAT_ANY:
shmid64_to_shmid (buf, buf64);
}
return ret;
}
#endif
#ifndef DEFAULT_VERSION
# ifndef __ASSUME_SYSVIPC_BROKEN_MODE_T
# define DEFAULT_VERSION GLIBC_2_2
# else
# define DEFAULT_VERSION GLIBC_2_31
# endif
#endif
versioned_symbol (libc, __shmctl, shmctl, DEFAULT_VERSION);
#if defined __ASSUME_SYSVIPC_BROKEN_MODE_T \
&& SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_31)
int
attribute_compat_text_section
__shmctl_mode16 (int shmid, int cmd, struct shmid_ds *buf)
{
return shmctl_syscall (shmid, cmd, (shmctl_arg_t *) buf);
}
compat_symbol (libc, __shmctl_mode16, shmctl, GLIBC_2_2);
#endif
#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
struct __old_shmid_ds
{
struct __old_ipc_perm shm_perm; /* operation permission struct */
int shm_segsz; /* size of segment in bytes */
__time_t shm_atime; /* time of last shmat() */
__time_t shm_dtime; /* time of last shmdt() */
__time_t shm_ctime; /* time of last change by shmctl() */
__ipc_pid_t shm_cpid; /* pid of creator */
__ipc_pid_t shm_lpid; /* pid of last shmop */
unsigned short int shm_nattch; /* number of current attaches */
unsigned short int __shm_npages; /* size of segment (pages) */
unsigned long int *__shm_pages; /* array of ptrs to frames -> SHMMAX */
struct vm_area_struct *__attaches; /* descriptors for attaches */
};
int
attribute_compat_text_section
__old_shmctl (int shmid, int cmd, struct __old_shmid_ds *buf)
{
#if defined __ASSUME_DIRECT_SYSVIPC_SYSCALLS \
&& !defined __ASSUME_SYSVIPC_DEFAULT_IPC_64
/* For architecture that have wire-up shmctl but also have __IPC_64 to a
value different than default (0x0), it means the compat symbol used the
__NR_ipc syscall. */
return INLINE_SYSCALL_CALL (shmctl, shmid, cmd, buf);
#else
return INLINE_SYSCALL_CALL (ipc, IPCOP_shmctl, shmid, cmd, 0, buf);
#endif
}
compat_symbol (libc, __old_shmctl, shmctl, GLIBC_2_0);
#endif