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sysv: linux: Add 64-bit time_t variant for msgctl

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To provide a y2038 safe interface a new symbol __msgctl64 is added
and __msgctl is change to call it instead (it adds some extra buffer
coping for the 32 bit time_t implementation).

Two new structures are added:

  1. kernel_msqid64_ds: used internally only on 32-bit architectures
     to issue the syscall.  A handful of architectures (hppa, i386, mips,
     powerpc32, and sparc32) require specific implementations due to
     their kernel ABI.

  2. msqid_ds64: this is only for __TIMESIZE != 64 to use along with
     the 64-bit msgctl.  It is different than the kernel struct because
     the exported 64-bit time_t might require different alignment
     depending on the architecture ABI.

So the resulting implementation does:

  1. For 64-bit architectures it assumes msqid_ds already contains
     64-bit time_t fields and will result in just the __msgctl symbol
     using the __msgctl64 code.  The msgid_ds argument is passed as-is
     to the syscall.

  2. For 32-bit architectures with default 64-bit time_t (newer ABIs
     such riscv32 or arc), it will also result in only one exported
     symbol but with the required high/low time handling.

  3. Finally for 32-bit architecture with both 32-bit and 64-bit time_t
     support we follow the already set way to provide one symbol with
     64-bit time_t support and implement the 32-bit time_t support using
     the 64-bit time_t.

     The default 32-bit symbol will allocate and copy the msqid_ds
     over multiple buffers, but this should be deprecated in favor
     of the __msgctl64 anyway.

Checked on i686-linux-gnu and x86_64-linux-gnu.  I also did some sniff
tests on powerpc, powerpc64, mips, mips64, armhf, sparcv9, and
sparc64.

Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Tested-by: Alistair Francis <alistair.francis@wdc.com>
This commit is contained in:
Adhemerval Zanella
2020-06-30 09:20:48 -03:00
parent 915b9fe312
commit 3283f71113
15 changed files with 355 additions and 68 deletions
Download Patch File Download Diff File Expand all files Collapse all files

192
sysdeps/unix/sysv/linux/msgctl.c
View File

@ -23,16 +23,57 @@
#include <errno.h>
#include <linux/posix_types.h> /* For __kernel_mode_t. */
#ifndef DEFAULT_VERSION
# ifndef __ASSUME_SYSVIPC_BROKEN_MODE_T
# define DEFAULT_VERSION GLIBC_2_2
# else
# define DEFAULT_VERSION GLIBC_2_31
# endif
/* POSIX states ipc_perm mode should have type of mode_t. */
_Static_assert (sizeof ((struct msqid_ds){0}.msg_perm.mode)
== sizeof (mode_t),
"sizeof (msqid_ds.msg_perm.mode) != sizeof (mode_t)");
#if __IPC_TIME64 == 0
typedef struct msqid_ds msgctl_arg_t;
#else
# include <struct_kernel_msqid64_ds.h>
static void
msqid64_to_kmsqid64 (const struct __msqid64_ds *msqid64,
struct kernel_msqid64_ds *kmsqid)
{
kmsqid->msg_perm = msqid64->msg_perm;
kmsqid->msg_stime = msqid64->msg_stime;
kmsqid->msg_stime_high = msqid64->msg_stime >> 32;
kmsqid->msg_rtime = msqid64->msg_rtime;
kmsqid->msg_rtime_high = msqid64->msg_rtime >> 32;
kmsqid->msg_ctime = msqid64->msg_ctime;
kmsqid->msg_ctime_high = msqid64->msg_ctime >> 32;
kmsqid->msg_cbytes = msqid64->msg_cbytes;
kmsqid->msg_qnum = msqid64->msg_qnum;
kmsqid->msg_qbytes = msqid64->msg_qbytes;
kmsqid->msg_lspid = msqid64->msg_lspid;
kmsqid->msg_lrpid = msqid64->msg_lrpid;
}
static void
kmsqid64_to_msqid64 (const struct kernel_msqid64_ds *kmsqid,
struct __msqid64_ds *msqid64)
{
msqid64->msg_perm = kmsqid->msg_perm;
msqid64->msg_stime = kmsqid->msg_stime
| ((__time64_t) kmsqid->msg_stime_high << 32);
msqid64->msg_rtime = kmsqid->msg_rtime
| ((__time64_t) kmsqid->msg_rtime_high << 32);
msqid64->msg_ctime = kmsqid->msg_ctime
| ((__time64_t) kmsqid->msg_ctime_high << 32);
msqid64->msg_cbytes = kmsqid->msg_cbytes;
msqid64->msg_qnum = kmsqid->msg_qnum;
msqid64->msg_qbytes = kmsqid->msg_qbytes;
msqid64->msg_lspid = kmsqid->msg_lspid;
msqid64->msg_lrpid = kmsqid->msg_lrpid;
}
typedef struct kernel_msqid64_ds msgctl_arg_t;
#endif
static int
msgctl_syscall (int msqid, int cmd, struct msqid_ds *buf)
msgctl_syscall (int msqid, int cmd, msgctl_arg_t *buf)
{
#ifdef __ASSUME_DIRECT_SYSVIPC_SYSCALLS
return INLINE_SYSCALL_CALL (msgctl, msqid, cmd | __IPC_64, buf);
@ -43,46 +84,119 @@ msgctl_syscall (int msqid, int cmd, struct msqid_ds *buf)
}
int
__new_msgctl (int msqid, int cmd, struct msqid_ds *buf)
__msgctl64 (int msqid, int cmd, struct __msqid64_ds *buf)
{
/* POSIX states ipc_perm mode should have type of mode_t. */
_Static_assert (sizeof ((struct msqid_ds){0}.msg_perm.mode)
== sizeof (mode_t),
"sizeof (msqid_ds.msg_perm.mode) != sizeof (mode_t)");
#ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
struct msqid_ds tmpds;
if (cmd == IPC_SET)
#if __IPC_TIME64
struct kernel_msqid64_ds ksemid, *arg = NULL;
if (buf != NULL)
{
tmpds = *buf;
tmpds.msg_perm.mode *= 0x10000U;
buf = &tmpds;
msqid64_to_kmsqid64 (buf, &ksemid);
arg = &ksemid;
}
#endif
int ret = msgctl_syscall (msqid, cmd, buf);
if (ret >= 0)
{
switch (cmd)
{
case IPC_STAT:
case MSG_STAT:
case MSG_STAT_ANY:
#ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
buf->msg_perm.mode >>= 16;
# ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
if (cmd == IPC_SET)
arg->msg_perm.mode *= 0x10000U;
# endif
#else
/* Old Linux kernel versions might not clear the mode padding. */
if (sizeof ((struct msqid_ds){0}.msg_perm.mode)
!= sizeof (__kernel_mode_t))
buf->msg_perm.mode &= 0xFFFF;
msgctl_arg_t *arg = buf;
#endif
int ret = msgctl_syscall (msqid, cmd, arg);
if (ret < 0)
return ret;
switch (cmd)
{
case IPC_STAT:
case MSG_STAT:
case MSG_STAT_ANY:
#ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T
arg->msg_perm.mode >>= 16;
#else
/* Old Linux kernel versions might not clear the mode padding. */
if (sizeof ((struct msqid_ds){0}.msg_perm.mode)
!= sizeof (__kernel_mode_t))
arg->msg_perm.mode &= 0xFFFF;
#endif
#if __IPC_TIME64
kmsqid64_to_msqid64 (arg, buf);
#endif
}
}
return ret;
}
versioned_symbol (libc, __new_msgctl, msgctl, DEFAULT_VERSION);
#if __TIMESIZE != 64
libc_hidden_def (__msgctl64)
static void
msqid_to_msqid64 (struct __msqid64_ds *mq64, const struct msqid_ds *mq)
{
mq64->msg_perm = mq->msg_perm;
mq64->msg_stime = mq->msg_stime
| ((__time64_t) mq->__msg_stime_high << 32);
mq64->msg_rtime = mq->msg_rtime
| ((__time64_t) mq->__msg_rtime_high << 32);
mq64->msg_ctime = mq->msg_ctime
| ((__time64_t) mq->__msg_ctime_high << 32);
mq64->msg_cbytes = mq->msg_cbytes;
mq64->msg_qnum = mq->msg_qnum;
mq64->msg_qbytes = mq->msg_qbytes;
mq64->msg_lspid = mq->msg_lspid;
mq64->msg_lrpid = mq->msg_lrpid;
}
static void
msqid64_to_msqid (struct msqid_ds *mq, const struct __msqid64_ds *mq64)
{
mq->msg_perm = mq64->msg_perm;
mq->msg_stime = mq64->msg_stime;
mq->__msg_stime_high = 0;
mq->msg_rtime = mq64->msg_rtime;
mq->__msg_rtime_high = 0;
mq->msg_ctime = mq64->msg_ctime;
mq->__msg_ctime_high = 0;
mq->msg_cbytes = mq64->msg_cbytes;
mq->msg_qnum = mq64->msg_qnum;
mq->msg_qbytes = mq64->msg_qbytes;
mq->msg_lspid = mq64->msg_lspid;
mq->msg_lrpid = mq64->msg_lrpid;
}
int
__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;
}
int ret = __msgctl64 (msqid, cmd, buf64);
if (ret < 0)
return ret;
switch (cmd)
{
case IPC_STAT:
case MSG_STAT:
case MSG_STAT_ANY:
msqid64_to_msqid (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, __msgctl, msgctl, DEFAULT_VERSION);
#if defined __ASSUME_SYSVIPC_BROKEN_MODE_T \
&& SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_31)
@ -90,7 +204,7 @@ int
attribute_compat_text_section
__msgctl_mode16 (int msqid, int cmd, struct msqid_ds *buf)
{
return msgctl_syscall (msqid, cmd, buf);
return msgctl_syscall (msqid, cmd, (msgctl_arg_t *) buf);
}
compat_symbol (libc, __msgctl_mode16, msgctl, GLIBC_2_2);
#endif