sysvipc: overhaul {sem,shm,msg}ctl for time64

being "ctl" functions that take command numbers, these will be handled
like ioctl/sockopt/etc., using new command numbers for the time64
variants with an "IPC_TIME64" bit added to their values. to obtain
such a reserved bit, we reuse the IPC_64 bit, 0x100, which served only
as part of the libc-to-kernel interface, not as a public interface of
the libc functions.

using new command numbers avoids the need for compat shims (in ABIs
doing time64 through symbol redirection and compat shims) and, by
virtue of having a fixed time64 bit for all commands, we can ensure
that libc can perform the appropriate translations, even if the
application is using new commands from a newer version of the libc
headers than the libc available at runtime.

for the vast majority of 32-bit archs, the kernel {sem,shm,msq}id64_ds
definitions left padding space intended for expanding their time_t
fields to 64 bits in-place, and it would have been really nice to be
able to do time64 support that way. however the padding was almost
always in little-endian order (except on powerpc, and for msqid_ds
only on mips, where it matched the arch's byte order), and more
importantly, the alignment was overlooked. in semid_ds and msqid_ds,
the time_t members were not suitably aligned to be expanded to 64-bit,
due to the ipc_perm header consisting of 9 32-bit words -- except on
powerpc where ipc_perm contains an extra padding word. in shmid_ds,
the time_t members were suitably aligned, except that mips
(accidentally?) omitted the padding for them alltogether.

as a result, we're stuck with adding new time_t fields on the end of
the structures, and assembling the 32-bit lo/hi parts (or 16-bit hi
parts, for mips shmid_ds, which lacked sufficient reserved space for
full 32-bit hi parts) to fill them in.

all of the functional changes here are conditional on the IPC_TIME64
macro having a nonzero definition, which will only happen when
IPC_STAT is redefined for 32-bit archs, and on time_t being larger
than long, so for now the new code is all dead code.

diff --git a/src/ipc/ipc.h b/src/ipc/ipc.h
index 36f3e2132455cc86ddeabbd1d33755df496d921b..746a905c986a02a4bca7f9dbd0db2c87e9f9c952 100644 (file)
--- a/src/ipc/ipc.h
+++ b/src/ipc/ipc.h
@@ -16,3 +16,9 @@
 #ifndef IPC_64
 #define IPC_64 0x100
 #endif
+
+#define IPC_TIME64 (IPC_STAT & 0x100)
+
+#define IPC_CMD(cmd) (((cmd) & ~IPC_TIME64) | IPC_64)
+
+#define IPC_HILO(b,t) ((b)->t = (b)->__##t##_lo | 0LL+(b)->__##t##_hi<<32)

diff --git a/src/ipc/msgctl.c b/src/ipc/msgctl.c
index 868197f61738ed9ead09929be86197926ae492ad..b043041a565a1c21bab03b616afb79c4e2a84e0d 100644 (file)
--- a/src/ipc/msgctl.c
+++ b/src/ipc/msgctl.c
@@ -18,17 +18,24 @@ int msgctl(int q, int cmd, struct msqid_ds *buf)
        }
 #endif
 #ifndef SYS_ipc
-       int r = __syscall(SYS_msgctl, q, cmd | IPC_64, buf);
+       int r = __syscall(SYS_msgctl, q, IPC_CMD(cmd), buf);
 #else
-       int r = __syscall(SYS_ipc, IPCOP_msgctl, q, cmd | IPC_64, 0, buf, 0);
+       int r = __syscall(SYS_ipc, IPCOP_msgctl, q, IPC_CMD(cmd), 0, buf, 0);
 #endif
 #ifdef SYSCALL_IPC_BROKEN_MODE
-       if (r >= 0) switch (cmd) {
+       if (r >= 0) switch (cmd | IPC_TIME64) {
        case IPC_STAT:
        case MSG_STAT:
        case MSG_STAT_ANY:
                buf->msg_perm.mode >>= 16;
        }
+#endif
+#if IPC_TIME64
+       if (r >= 0 && (cmd&IPC_TIME64)) {
+               IPC_HILO(buf, msg_stime);
+               IPC_HILO(buf, msg_rtime);
+               IPC_HILO(buf, msg_ctime);
+       }
 #endif
        return __syscall_ret(r);
 }

diff --git a/src/ipc/semctl.c b/src/ipc/semctl.c
index e5dd535919a1bbdecf0d5ad26e026b6795f08949..ed9827477aee81c032a0c7d29c9c8595ca64eed8 100644 (file)
--- a/src/ipc/semctl.c
+++ b/src/ipc/semctl.c
@@ -18,9 +18,12 @@ int semctl(int id, int num, int cmd, ...)
 {
        union semun arg = {0};
        va_list ap;
-       switch (cmd) {
-       case SETVAL: case GETALL: case SETALL: case IPC_STAT: case IPC_SET:
-       case IPC_INFO: case SEM_INFO: case SEM_STAT: case SEM_STAT_ANY:
+       switch (cmd & ~IPC_TIME64) {
+       case SETVAL: case GETALL: case SETALL: case IPC_SET:
+       case IPC_INFO: case SEM_INFO:
+       case IPC_STAT & ~IPC_TIME64:
+       case SEM_STAT & ~IPC_TIME64:
+       case SEM_STAT_ANY & ~IPC_TIME64:
                va_start(ap, cmd);
                arg = va_arg(ap, union semun);
                va_end(ap);
@@ -34,17 +37,23 @@ int semctl(int id, int num, int cmd, ...)
        }
 #endif
 #ifndef SYS_ipc
-       int r = __syscall(SYS_semctl, id, num, cmd | IPC_64, arg.buf);
+       int r = __syscall(SYS_semctl, id, num, IPC_CMD(cmd), arg.buf);
 #else
-       int r = __syscall(SYS_ipc, IPCOP_semctl, id, num, cmd | IPC_64, &arg.buf);
+       int r = __syscall(SYS_ipc, IPCOP_semctl, id, num, IPC_CMD(cmd), &arg.buf);
 #endif
 #ifdef SYSCALL_IPC_BROKEN_MODE
-       if (r >= 0) switch (cmd) {
+       if (r >= 0) switch (cmd | IPC_TIME64) {
        case IPC_STAT:
        case SEM_STAT:
        case SEM_STAT_ANY:
                arg.buf->sem_perm.mode >>= 16;
        }
+#endif
+#if IPC_TIME64
+       if (r >= 0 && (cmd&IPC_TIME64)) {
+               IPC_HILO(arg.buf, sem_otime);
+               IPC_HILO(arg.buf, sem_ctime);
+       }
 #endif
        return __syscall_ret(r);
 }

diff --git a/src/ipc/shmctl.c b/src/ipc/shmctl.c
index c2b2bb0d4c44fe68e9b2b4f5797e06573f0f2cd3..de3ce9d4d7d9f2cb1b15a5e9c29a33ce7c3716e8 100644 (file)
--- a/src/ipc/shmctl.c
+++ b/src/ipc/shmctl.c
@@ -18,17 +18,24 @@ int shmctl(int id, int cmd, struct shmid_ds *buf)
        }
 #endif
 #ifndef SYS_ipc
-       int r = __syscall(SYS_shmctl, id, cmd | IPC_64, buf);
+       int r = __syscall(SYS_shmctl, id, IPC_CMD(cmd), buf);
 #else
-       int r = __syscall(SYS_ipc, IPCOP_shmctl, id, cmd | IPC_64, 0, buf, 0);
+       int r = __syscall(SYS_ipc, IPCOP_shmctl, id, IPC_CMD(cmd), 0, buf, 0);
 #endif
 #ifdef SYSCALL_IPC_BROKEN_MODE
-       if (r >= 0) switch (cmd) {
+       if (r >= 0) switch (cmd | IPC_TIME64) {
        case IPC_STAT:
        case SHM_STAT:
        case SHM_STAT_ANY:
                buf->shm_perm.mode >>= 16;
        }
+#endif
+#if IPC_TIME64
+       if (r >= 0 && (cmd&IPC_TIME64)) {
+               IPC_HILO(buf, shm_atime);
+               IPC_HILO(buf, shm_dtime);
+               IPC_HILO(buf, shm_ctime);
+       }
 #endif
        return __syscall_ret(r);
 }