[PATCH v3 11/17] y2038: xtensa: Extend sysvipc data structures

Arnd Bergmann
2018-04-19T14:37:31Z

xtensa, uses a nonstandard variation of the generic sysvipc
data structures, intended to have the padding moved around
so it can deal with big-endian 32-bit user space that has
64-bit time_t.

xtensa tries hard to define the structures so they work
in both big-endian and little-endian systems with padding
on the right side.
However, they only succeeded for for two of the three structures,
and their struct shmid64_ds ended up being defined in two
identical copies, and the big-endian one is wrong.

This takes just take the same approach here that we have for
the asm-generic headers and adds separate 32-bit fields for the
upper halves of the timestamps, to let libc deal with the mess
in user space.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
arch/xtensa/include/uapi/asm/msgbuf.h | 25 ++++++++++++-----------
arch/xtensa/include/uapi/asm/sembuf.h | 17 ++++++++--------
arch/xtensa/include/uapi/asm/shmbuf.h | 37 ++++++++---------------------------
3 files changed, 28 insertions(+), 51 deletions(-)

diff --git a/arch/xtensa/include/uapi/asm/msgbuf.h b/arch/xtensa/include/uapi/asm/msgbuf.h
index 36e2e103ca38..d6915e9f071c 100644
--- a/arch/xtensa/include/uapi/asm/msgbuf.h
+++ b/arch/xtensa/include/uapi/asm/msgbuf.h
@@ -7,7 +7,6 @@
* between kernel and user space.
*
* Pad space is left for:
- * - 64-bit time_t to solve y2038 problem
* - 2 miscellaneous 32-bit values
*
* This file is subject to the terms and conditions of the GNU General
@@ -21,19 +20,19 @@
struct msqid64_ds {
struct ipc64_perm msg_perm;
#ifdef __XTENSA_EB__
- unsigned int __unused1;
- __kernel_time_t msg_stime; /* last msgsnd time */
- unsigned int __unused2;
- __kernel_time_t msg_rtime; /* last msgrcv time */
- unsigned int __unused3;
- __kernel_time_t msg_ctime; /* last change time */
+ unsigned long msg_stime_high;
+ unsigned long msg_stime; /* last msgsnd time */
+ unsigned long msg_rtime_high;
+ unsigned long msg_rtime; /* last msgrcv time */
+ unsigned long msg_ctime_high;
+ unsigned long msg_ctime; /* last change time */
#elif defined(__XTENSA_EL__)
- __kernel_time_t msg_stime; /* last msgsnd time */
- unsigned int __unused1;
- __kernel_time_t msg_rtime; /* last msgrcv time */
- unsigned int __unused2;
- __kernel_time_t msg_ctime; /* last change time */
- unsigned int __unused3;
+ unsigned long msg_stime; /* last msgsnd time */
+ unsigned long msg_stime_high;
+ unsigned long msg_rtime; /* last msgrcv time */
+ unsigned long msg_rtime_high;
+ unsigned long msg_ctime; /* last change time */
+ unsigned long msg_ctime_high;
#else
# error processor byte order undefined!
#endif
diff --git a/arch/xtensa/include/uapi/asm/sembuf.h b/arch/xtensa/include/uapi/asm/sembuf.h
index f61b6331a10c..09f348d643f1 100644
--- a/arch/xtensa/include/uapi/asm/sembuf.h
+++ b/arch/xtensa/include/uapi/asm/sembuf.h
@@ -14,7 +14,6 @@
* between kernel and user space.
*
* Pad space is left for:
- * - 64-bit time_t to solve y2038 problem
* - 2 miscellaneous 32-bit values
*
*/
@@ -27,15 +26,15 @@
struct semid64_ds {
struct ipc64_perm sem_perm; /* permissions .. see ipc.h */
#ifdef __XTENSA_EL__
- __kernel_time_t sem_otime; /* last semop time */
- unsigned long __unused1;
- __kernel_time_t sem_ctime; /* last change time */
- unsigned long __unused2;
+ unsigned long sem_otime; /* last semop time */
+ unsigned long sem_otime_high;
+ unsigned long sem_ctime; /* last change time */
+ unsigned long sem_ctime_high;
#else
- unsigned long __unused1;
- __kernel_time_t sem_otime; /* last semop time */
- unsigned long __unused2;
- __kernel_time_t sem_ctime; /* last change time */
+ unsigned long sem_otime_high;
+ unsigned long sem_otime; /* last semop time */
+ unsigned long sem_ctime_high;
+ unsigned long sem_ctime; /* last change time */
#endif
unsigned long sem_nsems; /* no. of semaphores in array */
unsigned long __unused3;
diff --git a/arch/xtensa/include/uapi/asm/shmbuf.h b/arch/xtensa/include/uapi/asm/shmbuf.h
index 26550bdc8430..554a57a6a90f 100644
--- a/arch/xtensa/include/uapi/asm/shmbuf.h
+++ b/arch/xtensa/include/uapi/asm/shmbuf.h
@@ -4,10 +4,10 @@
*
* The shmid64_ds structure for Xtensa architecture.
* Note extra padding because this structure is passed back and forth
- * between kernel and user space.
+ * between kernel and user space, but the padding is on the wrong
+ * side for big-endian xtensa, for historic reasons.
*
* Pad space is left for:
- * - 64-bit time_t to solve y2038 problem
* - 2 miscellaneous 32-bit values
*
* This file is subject to the terms and conditions of the GNU General Public
@@ -20,42 +20,21 @@
#ifndef _XTENSA_SHMBUF_H
#define _XTENSA_SHMBUF_H

-#if defined (__XTENSA_EL__)
struct shmid64_ds {
struct ipc64_perm shm_perm; /* operation perms */
size_t shm_segsz; /* size of segment (bytes) */
- __kernel_time_t shm_atime; /* last attach time */
- unsigned long __unused1;
- __kernel_time_t shm_dtime; /* last detach time */
- unsigned long __unused2;
- __kernel_time_t shm_ctime; /* last change time */
- unsigned long __unused3;
+ unsigned long shm_atime; /* last attach time */
+ unsigned long shm_atime_high;
+ unsigned long shm_dtime; /* last detach time */
+ unsigned long shm_dtime_high;
+ unsigned long shm_ctime; /* last change time */
+ unsigned long shm_ctime_high;
__kernel_pid_t shm_cpid; /* pid of creator */
__kernel_pid_t shm_lpid; /* pid of last operator */
unsigned long shm_nattch; /* no. of current attaches */
unsigned long __unused4;
unsigned long __unused5;
};
-#elif defined (__XTENSA_EB__)
-struct shmid64_ds {
- struct ipc64_perm shm_perm; /* operation perms */
- size_t shm_segsz; /* size of segment (bytes) */
- __kernel_time_t shm_atime; /* last attach time */
- unsigned long __unused1;
- __kernel_time_t shm_dtime; /* last detach time */
- unsigned long __unused2;
- __kernel_time_t shm_ctime; /* last change time */
- unsigned long __unused3;
- __kernel_pid_t shm_cpid; /* pid of creator */
- __kernel_pid_t shm_lpid; /* pid of last operator */
- unsigned long shm_nattch; /* no. of current attaches */
- unsigned long __unused4;
- unsigned long __unused5;
-};
-#else
-# error endian order not defined
-#endif
-

struct shminfo64 {
unsigned long shmmax;
--
2.9.0