commit d57cdc1b5a52b5468b9259c0b9a215e22a1fa1f6

Author: Florian Weimer <fweimer@redhat.com>

Date:   Tue Nov 8 14:15:02 2022 +0100

    Linux: Support __IPC_64 in sysvctl *ctl command arguments (bug 29771)

    Old applications pass __IPC_64 as part of the command argument because

    old glibc did not check for unknown commands, and passed through the

    arguments directly to the kernel, without adding __IPC_64.

    Applications need to continue doing that for old glibc compatibility,

    so this commit enables this approach in current glibc.

    For msgctl and shmctl, if no translation is required, make

    direct system calls, as we did before the time64 changes.  If

    translation is required, mask __IPC_64 from the command argument.

    For semctl, the union-in-vararg argument handling means that

    translation is needed on all architectures.

    Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

    (cherry picked from commit 22a46dee24351fd5f4f188ad80554cad79c82524)

diff --git a/sysdeps/unix/sysv/linux/ipc_priv.h b/sysdeps/unix/sysv/linux/ipc_priv.h

index f9852367a466cea9..d4efb9f3483daa9f 100644

--- a/sysdeps/unix/sysv/linux/ipc_priv.h

+++ b/sysdeps/unix/sysv/linux/ipc_priv.h

@@ -63,4 +63,10 @@ struct __old_ipc_perm

 # define __IPC_TIME64 0

 #endif

+#if __IPC_TIME64 || defined __ASSUME_SYSVIPC_BROKEN_MODE_T

+# define IPC_CTL_NEED_TRANSLATION 1

+#else

+# define IPC_CTL_NEED_TRANSLATION 0

+#endif

+

 #include <ipc_ops.h>

diff --git a/sysdeps/unix/sysv/linux/msgctl.c b/sysdeps/unix/sysv/linux/msgctl.c

index 9f38c06d53936390..ba7b94c22d17bc7f 100644

--- a/sysdeps/unix/sysv/linux/msgctl.c

+++ b/sysdeps/unix/sysv/linux/msgctl.c

@@ -86,11 +86,19 @@ msgctl_syscall (int msqid, int cmd, msgctl_arg_t *buf)

 int

 __msgctl64 (int msqid, int cmd, struct __msqid64_ds *buf)

 {

-#if __IPC_TIME64

+#if IPC_CTL_NEED_TRANSLATION

+# if __IPC_TIME64

   struct kernel_msqid64_ds ksemid, *arg = NULL;

-#else

+# else

   msgctl_arg_t *arg;

-#endif

+# endif

+

+  /* Some applications pass the __IPC_64 flag in cmd, to invoke

+     previously unsupported commands back when there was no EINVAL

+     error checking in glibc.  Mask the flag for the switch statements

+     below.  msgctl_syscall adds back the __IPC_64 flag for the actual

+     system call.  */

+  cmd &= ~__IPC_64;

   switch (cmd)

     {

@@ -102,19 +110,19 @@ __msgctl64 (int msqid, int cmd, struct __msqid64_ds *buf)

     case IPC_STAT:

     case MSG_STAT:

     case MSG_STAT_ANY:

-#if __IPC_TIME64

+# if __IPC_TIME64

       if (buf != NULL)

 	{

 	  msqid64_to_kmsqid64 (buf, &ksemid);

 	  arg = &ksemid;

 	}

-# ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T

+#  ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T

       if (cmd == IPC_SET)

 	arg->msg_perm.mode *= 0x10000U;

-# endif

-#else

+#  endif

+# else

       arg = buf;

-#endif

+# endif

       break;

     case IPC_INFO:

@@ -138,21 +146,25 @@ __msgctl64 (int msqid, int cmd, struct __msqid64_ds *buf)

     case IPC_STAT:

     case MSG_STAT:

     case MSG_STAT_ANY:

-#ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T

+# ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T

       arg->msg_perm.mode >>= 16;

-#else

+# else

       /* Old Linux kernel versions might not clear the mode padding.  */

       if (sizeof ((struct msqid_ds){0}.msg_perm.mode)

           != sizeof (__kernel_mode_t))

 	arg->msg_perm.mode &= 0xFFFF;

-#endif

+# endif

-#if __IPC_TIME64

+# if __IPC_TIME64

       kmsqid64_to_msqid64 (arg, buf);

-#endif

+# endif

     }

   return ret;

+

+#else /* !IPC_CTL_NEED_TRANSLATION */

+  return msgctl_syscall (msqid, cmd, buf);

+#endif

 }

 #if __TIMESIZE != 64

 libc_hidden_def (__msgctl64)

diff --git a/sysdeps/unix/sysv/linux/semctl.c b/sysdeps/unix/sysv/linux/semctl.c

index bb2690d30f80bb22..97fa411547fdd81e 100644

--- a/sysdeps/unix/sysv/linux/semctl.c

+++ b/sysdeps/unix/sysv/linux/semctl.c

@@ -141,6 +141,13 @@ __semctl64 (int semid, int semnum, int cmd, ...)

   union semun64 arg64 = { 0 };

   va_list ap;

+  /* Some applications pass the __IPC_64 flag in cmd, to invoke

+     previously unsupported commands back when there was no EINVAL

+     error checking in glibc.  Mask the flag for the switch statements

+     below.  semctl_syscall adds back the __IPC_64 flag for the actual

+     system call.  */

+  cmd &= ~__IPC_64;

+

   /* Get the argument only if required.  */

   switch (cmd)

     {

diff --git a/sysdeps/unix/sysv/linux/shmctl.c b/sysdeps/unix/sysv/linux/shmctl.c

index f52018bfae4b3364..c44cbd6e4ac890a5 100644

--- a/sysdeps/unix/sysv/linux/shmctl.c

+++ b/sysdeps/unix/sysv/linux/shmctl.c

@@ -86,11 +86,19 @@ shmctl_syscall (int shmid, int cmd, shmctl_arg_t *buf)

 int

 __shmctl64 (int shmid, int cmd, struct __shmid64_ds *buf)

 {

-#if __IPC_TIME64

+#if IPC_CTL_NEED_TRANSLATION

+# if __IPC_TIME64

   struct kernel_shmid64_ds kshmid, *arg = NULL;

-#else

+# else

   shmctl_arg_t *arg;

-#endif

+# endif

+

+  /* Some applications pass the __IPC_64 flag in cmd, to invoke

+     previously unsupported commands back when there was no EINVAL

+     error checking in glibc.  Mask the flag for the switch statements

+     below.  shmctl_syscall adds back the __IPC_64 flag for the actual

+     system call.  */

+  cmd &= ~__IPC_64;

   switch (cmd)

     {

@@ -104,19 +112,19 @@ __shmctl64 (int shmid, int cmd, struct __shmid64_ds *buf)

     case IPC_STAT:

     case SHM_STAT:

     case SHM_STAT_ANY:

-#if __IPC_TIME64

+# if __IPC_TIME64

       if (buf != NULL)

 	{

 	  shmid64_to_kshmid64 (buf, &kshmid);

 	  arg = &kshmid;

 	}

-# ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T

+#  ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T

       if (cmd == IPC_SET)

         arg->shm_perm.mode *= 0x10000U;

-# endif

-#else

+#  endif

+# else

       arg = buf;

-#endif

+# endif

       break;

     case IPC_INFO:

@@ -141,21 +149,25 @@ __shmctl64 (int shmid, int cmd, struct __shmid64_ds *buf)

       case IPC_STAT:

       case SHM_STAT:

       case SHM_STAT_ANY:

-#ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T

+# ifdef __ASSUME_SYSVIPC_BROKEN_MODE_T

         arg->shm_perm.mode >>= 16;

-#else

+# else

       /* Old Linux kernel versions might not clear the mode padding.  */

       if (sizeof ((struct shmid_ds){0}.shm_perm.mode)

 	  != sizeof (__kernel_mode_t))

 	arg->shm_perm.mode &= 0xFFFF;

-#endif

+# endif

-#if __IPC_TIME64

+# if __IPC_TIME64

       kshmid64_to_shmid64 (arg, buf);

-#endif

+# endif

     }

   return ret;

+

+#else /* !IPC_CTL_NEED_TRANSLATION */

+  return shmctl_syscall (shmid, cmd, buf);

+#endif

 }

 #if __TIMESIZE != 64

 libc_hidden_def (__shmctl64)