[4/9] y2038: x86: extend sysvipc data structures
Commit Message
This extends the x86 copy of the sysvipc data structures
to deal with 32-bit user space that has 64-bit time_t
and wants to see timestamps beyond 2038.
Fortunately, x86 has padding for this purpose in all the
data structures, so we can just add extra fields. For consistency
with big-endian architectures that copied the definitions from
x86 without moving around that padding, we however don't just
us a 64-bit value here, but instead use two unsigned 32-bit
fields, and expect the libc to provide a correct definition
to user space in a way that works across all architectures.
Interestingly, x86-64 is the only 64-bit architecture that
uses padding for 128-bit time_t, which seems to be have been
a mistake in the original x86_64 port. All other 64-bit
architectures have dropped those padding words.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
arch/x86/include/asm/compat.h | 32 ++++++++++-----------
arch/x86/include/uapi/asm/msgbuf.h | 41 ++++++++++++++++++++++++++-
arch/x86/include/uapi/asm/sembuf.h | 10 +++++++
arch/x86/include/uapi/asm/shmbuf.h | 58 +++++++++++++++++++++++++++++++++++++-
4 files changed, 123 insertions(+), 18 deletions(-)
@@ -205,10 +205,10 @@ struct compat_ipc64_perm {
struct compat_semid64_ds {
struct compat_ipc64_perm sem_perm;
- compat_time_t sem_otime;
- compat_ulong_t __unused1;
- compat_time_t sem_ctime;
- compat_ulong_t __unused2;
+ compat_ulong_t sem_otime;
+ compat_ulong_t sem_otime_high;
+ compat_ulong_t sem_ctime;
+ compat_ulong_t sem_ctime_high;
compat_ulong_t sem_nsems;
compat_ulong_t __unused3;
compat_ulong_t __unused4;
@@ -216,12 +216,12 @@ struct compat_semid64_ds {
struct compat_msqid64_ds {
struct compat_ipc64_perm msg_perm;
- compat_time_t msg_stime;
- compat_ulong_t __unused1;
- compat_time_t msg_rtime;
- compat_ulong_t __unused2;
- compat_time_t msg_ctime;
- compat_ulong_t __unused3;
+ compat_ulong_t msg_stime;
+ compat_ulong_t msg_stime_high;
+ compat_ulong_t msg_rtime;
+ compat_ulong_t msg_rtime_high;
+ compat_ulong_t msg_ctime;
+ compat_ulong_t msg_ctime_high;
compat_ulong_t msg_cbytes;
compat_ulong_t msg_qnum;
compat_ulong_t msg_qbytes;
@@ -234,12 +234,12 @@ struct compat_msqid64_ds {
struct compat_shmid64_ds {
struct compat_ipc64_perm shm_perm;
compat_size_t shm_segsz;
- compat_time_t shm_atime;
- compat_ulong_t __unused1;
- compat_time_t shm_dtime;
- compat_ulong_t __unused2;
- compat_time_t shm_ctime;
- compat_ulong_t __unused3;
+ compat_ulong_t shm_atime;
+ compat_ulong_t shm_atime_high;
+ compat_ulong_t shm_dtime;
+ compat_ulong_t shm_dtime_high;
+ compat_ulong_t shm_ctime;
+ compat_ulong_t shm_ctime_high;
compat_pid_t shm_cpid;
compat_pid_t shm_lpid;
compat_ulong_t shm_nattch;
@@ -1 +1,40 @@
-#include <asm-generic/msgbuf.h>
+/*
+ * x86 msqid64_ds structure.
+ *
+ * Note extra padding because this structure is passed back and forth
+ * between kernel and user space.
+ *
+ * msqid64_ds was originally meant to be architecture specific, but
+ * everyone just ended up making identical copies without specific
+ * optimizations, so we may just as well all use the same one.
+ *
+ * i386 uses the padding words to extend the time_t values, so user
+ * space must combine the two words. x32 and x86_64 have a 64-bit
+ * __kernel_time_t, so the data is already in the right place.
+ *
+ * Pad space is left for:
+ * - 2 miscellaneous 32-bit values
+ */
+
+struct msqid64_ds {
+ struct ipc64_perm msg_perm;
+#ifdef __i386__
+ 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
+ __kernel_time_t msg_stime; /* last msgsnd time */
+ __kernel_time_t msg_rtime; /* last msgrcv time */
+ __kernel_time_t msg_ctime; /* last change time */
+#endif
+ __kernel_ulong_t msg_cbytes; /* current number of bytes on queue */
+ __kernel_ulong_t msg_qnum; /* number of messages in queue */
+ __kernel_ulong_t msg_qbytes; /* max number of bytes on queue */
+ __kernel_pid_t msg_lspid; /* pid of last msgsnd */
+ __kernel_pid_t msg_lrpid; /* last receive pid */
+ __kernel_ulong_t __unused4;
+ __kernel_ulong_t __unused5;
+};
@@ -9,13 +9,23 @@
* Pad space is left for:
* - 64-bit time_t to solve y2038 problem
* - 2 miscellaneous 32-bit values
+ *
+ * x86_64 and x32 incorrectly added padding here, so the structures
+ * are still incompatible with the padding on x86.
*/
struct semid64_ds {
struct ipc64_perm sem_perm; /* permissions .. see ipc.h */
+#ifdef __i386__
+ 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
__kernel_time_t sem_otime; /* last semop time */
__kernel_ulong_t __unused1;
__kernel_time_t sem_ctime; /* last change time */
__kernel_ulong_t __unused2;
+#endif
__kernel_ulong_t sem_nsems; /* no. of semaphores in array */
__kernel_ulong_t __unused3;
__kernel_ulong_t __unused4;
@@ -1 +1,57 @@
-#include <asm-generic/shmbuf.h>
+#ifndef __ASM_GENERIC_SHMBUF_H
+#define __ASM_GENERIC_SHMBUF_H
+
+#include <asm/bitsperlong.h>
+
+/*
+ * The shmid64_ds structure for x86 architecture.
+ * Note extra padding because this structure is passed back and forth
+ * between kernel and user space.
+ *
+ * shmid64_ds was originally meant to be architecture specific, but
+ * everyone just ended up making identical copies without specific
+ * optimizations, so we may just as well all use the same one.
+ *
+ * i386 uses the padding for 64-bit time_t as it was originally designed,
+ * but uses two 'unsigned long' members to keep existing user space happy.
+ * x32 and x86_64 have a 64-bit __kernel_time_t.
+ *
+ * Pad space is left for:
+ * - 2 miscellaneous 32-bit values
+ */
+
+struct shmid64_ds {
+ struct ipc64_perm shm_perm; /* operation perms */
+ size_t shm_segsz; /* size of segment (bytes) */
+#ifdef __i386__
+ 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;
+#else
+ __kernel_time_t shm_atime; /* last attach time */
+ __kernel_time_t shm_dtime; /* last detach time */
+ __kernel_time_t shm_ctime; /* last change time */
+#endif
+ __kernel_pid_t shm_cpid; /* pid of creator */
+ __kernel_pid_t shm_lpid; /* pid of last operator */
+ __kernel_ulong_t shm_nattch; /* no. of current attaches */
+ __kernel_ulong_t __unused4;
+ __kernel_ulong_t __unused5;
+};
+
+struct shminfo64 {
+ __kernel_ulong_t shmmax;
+ __kernel_ulong_t shmmin;
+ __kernel_ulong_t shmmni;
+ __kernel_ulong_t shmseg;
+ __kernel_ulong_t shmall;
+ __kernel_ulong_t __unused1;
+ __kernel_ulong_t __unused2;
+ __kernel_ulong_t __unused3;
+ __kernel_ulong_t __unused4;
+};
+
+#endif /* __ASM_GENERIC_SHMBUF_H */