[PATCH v3 07/17] y2038: x86: Extend sysvipc data structures

Arnd Bergmann
2018-04-19T14:37:27Z

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. With msgid64_ds and shmid64_ds, the
data structure is identical to the asm-generic version, which we have
already extended.

For some reason however, the 64-bit version of semid64_ds ended up with
extra padding, so I'm implementing the same approach as the asm-generic
version here, by using separate fields for the upper and lower halves
of the two timestamps.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
arch/x86/include/asm/compat.h | 32 ++++++++++++++++----------------
arch/x86/include/uapi/asm/Kbuild | 5 ++++-
arch/x86/include/uapi/asm/msgbuf.h | 1 -
arch/x86/include/uapi/asm/sembuf.h | 11 ++++++++++-
arch/x86/include/uapi/asm/shmbuf.h | 1 -
5 files changed, 30 insertions(+), 20 deletions(-)
delete mode 100644 arch/x86/include/uapi/asm/msgbuf.h
delete mode 100644 arch/x86/include/uapi/asm/shmbuf.h

diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h
index 7cd314b71c51..fb97cf7c4137 100644
--- a/arch/x86/include/asm/compat.h
+++ b/arch/x86/include/asm/compat.h
@@ -134,10 +134,10 @@ 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;
@@ -145,12 +145,12 @@ 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;
@@ -163,12 +163,12 @@ 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;
diff --git a/arch/x86/include/uapi/asm/Kbuild b/arch/x86/include/uapi/asm/Kbuild
index 322681622d1e..d1d883e304f7 100644
--- a/arch/x86/include/uapi/asm/Kbuild
+++ b/arch/x86/include/uapi/asm/Kbuild
@@ -2,7 +2,10 @@
include include/uapi/asm-generic/Kbuild.asm

generic-y += bpf_perf_event.h
+generic-y += msgbuf.h
+generic-y += poll.h
+generic-y += shmbuf.h
+
generated-y += unistd_32.h
generated-y += unistd_64.h
generated-y += unistd_x32.h
-generic-y += poll.h
diff --git a/arch/x86/include/uapi/asm/msgbuf.h b/arch/x86/include/uapi/asm/msgbuf.h
deleted file mode 100644
index 809134c644a6..000000000000
--- a/arch/x86/include/uapi/asm/msgbuf.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <asm-generic/msgbuf.h>
diff --git a/arch/x86/include/uapi/asm/sembuf.h b/arch/x86/include/uapi/asm/sembuf.h
index cabd7476bd6c..89de6cd9f0a7 100644
--- a/arch/x86/include/uapi/asm/sembuf.h
+++ b/arch/x86/include/uapi/asm/sembuf.h
@@ -8,15 +8,24 @@
* between kernel and user space.
*
* 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;
diff --git a/arch/x86/include/uapi/asm/shmbuf.h b/arch/x86/include/uapi/asm/shmbuf.h
deleted file mode 100644
index 83c05fc2de38..000000000000
--- a/arch/x86/include/uapi/asm/shmbuf.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <asm-generic/shmbuf.h>
--
2.9.0