Merge tag 'y2038-syscall-cleanup' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground into timers/2038

Pull preparatory work for y2038 changes from Arnd Bergmann:

System call unification and cleanup

The system call tables have diverged a bit over the years, and a number of
the recent additions never made it into all architectures, for one reason
or another.

This is an attempt to clean it up as far as we can without breaking
compatibility, doing a number of steps:

 - Add system calls that have not yet been integrated into all architectures
   but that we definitely want there. This includes {,f}statfs64() and
   get{eg,eu,g,p,u,pp}id() on alpha, which have been missing traditionally.

 - The s390 compat syscall handling is cleaned up to be more like what we
   do on other architectures, while keeping the 31-bit pointer
   extension. This was merged as a shared branch by the s390 maintainers
   and is included here in order to base the other patches on top.

 - Add the separate ipc syscalls on all architectures that traditionally
   only had sys_ipc(). This version is done without support for IPC_OLD
   that is we have in sys_ipc. The new semtimedop_time64 syscall will only
   be added here, not in sys_ipc

 - Add syscall numbers for a couple of syscalls that we probably don't need
   everywhere, in particular pkey_* and rseq, for the purpose of symmetry:
   if it's in asm-generic/unistd.h, it makes sense to have it everywhere. I
   expect that any future system calls will get assigned on all platforms
   together, even when they appear to be specific to a single architecture.

 - Prepare for having the same system call numbers for any future calls. In
   combination with the generated tables, this hopefully makes it easier to
   add new calls across all architectures together.

All of the above are technically separate from the y2038 work, but are done
as preparation before we add the new 64-bit time_t system calls everywhere,
providing a common baseline set of system calls.

I expect that glibc and other libraries that want to use 64-bit time_t will
require linux-5.1 kernel headers for building in the future, and at a much
later point may also require linux-5.1 or a later version as the minimum
kernel at runtime. Having a common baseline then allows the removal of many
architecture or kernel version specific workarounds.

1 files changed, 32 insertions, 7 deletions

diff --git a/ipc/sem.c b/ipc/sem.c
index 745dc6187e84..d1efff3a81bb 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -1634,9 +1634,8 @@ out_up:
 	return err;
 }
 
-long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg)
+static long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg, int version)
 {
-	int version;
 	struct ipc_namespace *ns;
 	void __user *p = (void __user *)arg;
 	struct semid64_ds semid64;
@@ -1645,7 +1644,6 @@ long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg)
 	if (semid < 0)
 		return -EINVAL;
 
-	version = ipc_parse_version(&cmd);
 	ns = current->nsproxy->ipc_ns;
 
 	switch (cmd) {
@@ -1691,9 +1689,23 @@ long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg)
 
 SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, unsigned long, arg)
 {
-	return ksys_semctl(semid, semnum, cmd, arg);
+	return ksys_semctl(semid, semnum, cmd, arg, IPC_64);
 }
 
+#ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
+long ksys_old_semctl(int semid, int semnum, int cmd, unsigned long arg)
+{
+	int version = ipc_parse_version(&cmd);
+
+	return ksys_semctl(semid, semnum, cmd, arg, version);
+}
+
+SYSCALL_DEFINE4(old_semctl, int, semid, int, semnum, int, cmd, unsigned long, arg)
+{
+	return ksys_old_semctl(semid, semnum, cmd, arg);
+}
+#endif
+
 #ifdef CONFIG_COMPAT
 
 struct compat_semid_ds {
@@ -1744,12 +1756,11 @@ static int copy_compat_semid_to_user(void __user *buf, struct semid64_ds *in,
 	}
 }
 
-long compat_ksys_semctl(int semid, int semnum, int cmd, int arg)
+static long compat_ksys_semctl(int semid, int semnum, int cmd, int arg, int version)
 {
 	void __user *p = compat_ptr(arg);
 	struct ipc_namespace *ns;
 	struct semid64_ds semid64;
-	int version = compat_ipc_parse_version(&cmd);
 	int err;
 
 	ns = current->nsproxy->ipc_ns;
@@ -1792,8 +1803,22 @@ long compat_ksys_semctl(int semid, int semnum, int cmd, int arg)
 
 COMPAT_SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, int, arg)
 {
-	return compat_ksys_semctl(semid, semnum, cmd, arg);
+	return compat_ksys_semctl(semid, semnum, cmd, arg, IPC_64);
 }
+
+#ifdef CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION
+long compat_ksys_old_semctl(int semid, int semnum, int cmd, int arg)
+{
+	int version = compat_ipc_parse_version(&cmd);
+
+	return compat_ksys_semctl(semid, semnum, cmd, arg, version);
+}
+
+COMPAT_SYSCALL_DEFINE4(old_semctl, int, semid, int, semnum, int, cmd, int, arg)
+{
+	return compat_ksys_old_semctl(semid, semnum, cmd, arg);
+}
+#endif
 #endif
 
 /* If the task doesn't already have a undo_list, then allocate one