ipc: fix sparc64 ipc() wrapper

Matt bisected a sparc64 specific issue with semctl, shmctl and msgctl
to a commit from my y2038 series in linux-5.1, as I missed the custom
sys_ipc() wrapper that sparc64 uses in place of the generic version that
I patched.

The problem is that the sys_{sem,shm,msg}ctl() functions in the kernel
now do not allow being called with the IPC_64 flag any more, resulting
in a -EINVAL error when they don't recognize the command.

Instead, the correct way to do this now is to call the internal
ksys_old_{sem,shm,msg}ctl() functions to select the API version.

As we generally move towards these functions anyway, change all of
sparc_ipc() to consistently use those in place of the sys_*() versions,
and move the required ksys_*() declarations into linux/syscalls.h

The IS_ENABLED(CONFIG_SYSVIPC) check is required to avoid link
errors when ipc is disabled.

Reported-by: Matt Turner <mattst88@gmail.com>
Fixes: 275f22148e87 ("ipc: rename old-style shmctl/semctl/msgctl syscalls")
Cc: stable@vger.kernel.org
Tested-by: Matt Turner <mattst88@gmail.com>
Tested-by: Anatoly Pugachev <matorola@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 18 insertions, 15 deletions

diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c
index ccc88926bc00..9f41a6f5a032 100644
--- a/arch/sparc/kernel/sys_sparc_64.c
+++ b/arch/sparc/kernel/sys_sparc_64.c
@@ -336,25 +336,28 @@ SYSCALL_DEFINE6(sparc_ipc, unsigned int, call, int, first, unsigned long, second
 {
 	long err;
 
+	if (!IS_ENABLED(CONFIG_SYSVIPC))
+		return -ENOSYS;
+
 	/* No need for backward compatibility. We can start fresh... */
 	if (call <= SEMTIMEDOP) {
 		switch (call) {
 		case SEMOP:
-			err = sys_semtimedop(first, ptr,
-					     (unsigned int)second, NULL);
+			err = ksys_semtimedop(first, ptr,
+					      (unsigned int)second, NULL);
 			goto out;
 		case SEMTIMEDOP:
-			err = sys_semtimedop(first, ptr, (unsigned int)second,
+			err = ksys_semtimedop(first, ptr, (unsigned int)second,
 				(const struct __kernel_timespec __user *)
-					     (unsigned long) fifth);
+					      (unsigned long) fifth);
 			goto out;
 		case SEMGET:
-			err = sys_semget(first, (int)second, (int)third);
+			err = ksys_semget(first, (int)second, (int)third);
 			goto out;
 		case SEMCTL: {
-			err = sys_semctl(first, second,
-					 (int)third | IPC_64,
-					 (unsigned long) ptr);
+			err = ksys_old_semctl(first, second,
+					      (int)third | IPC_64,
+					      (unsigned long) ptr);
 			goto out;
 		}
 		default:
@@ -365,18 +368,18 @@ SYSCALL_DEFINE6(sparc_ipc, unsigned int, call, int, first, unsigned long, second
 	if (call <= MSGCTL) {
 		switch (call) {
 		case MSGSND:
-			err = sys_msgsnd(first, ptr, (size_t)second,
+			err = ksys_msgsnd(first, ptr, (size_t)second,
 					 (int)third);
 			goto out;
 		case MSGRCV:
-			err = sys_msgrcv(first, ptr, (size_t)second, fifth,
+			err = ksys_msgrcv(first, ptr, (size_t)second, fifth,
 					 (int)third);
 			goto out;
 		case MSGGET:
-			err = sys_msgget((key_t)first, (int)second);
+			err = ksys_msgget((key_t)first, (int)second);
 			goto out;
 		case MSGCTL:
-			err = sys_msgctl(first, (int)second | IPC_64, ptr);
+			err = ksys_old_msgctl(first, (int)second | IPC_64, ptr);
 			goto out;
 		default:
 			err = -ENOSYS;
@@ -396,13 +399,13 @@ SYSCALL_DEFINE6(sparc_ipc, unsigned int, call, int, first, unsigned long, second
 			goto out;
 		}
 		case SHMDT:
-			err = sys_shmdt(ptr);
+			err = ksys_shmdt(ptr);
 			goto out;
 		case SHMGET:
-			err = sys_shmget(first, (size_t)second, (int)third);
+			err = ksys_shmget(first, (size_t)second, (int)third);
 			goto out;
 		case SHMCTL:
-			err = sys_shmctl(first, (int)second | IPC_64, ptr);
+			err = ksys_old_shmctl(first, (int)second | IPC_64, ptr);
 			goto out;
 		default:
 			err = -ENOSYS;