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[PATCH v3 3/3] sysv: linux: Pass 64-bit version of semctl syscall

From: Alistair Francis <alistair dot francis at wdc dot com>
To: libc-alpha at sourceware dot org
Cc: alistair23 at gmail dot com, Alistair Francis <alistair dot francis at wdc dot com>
Date: Wed, 4 Mar 2020 17:26:05 -0800
Subject: [PATCH v3 3/3] sysv: linux: Pass 64-bit version of semctl syscall
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References: <20200305012605.26870-1-alistair.francis@wdc.com>
Wdcironportexception: Internal

The semctl_syscall() function passes a union semun to the kernel. The
union includes struct semid_ds as a member. On 32-bit architectures the
Linux kernel provides a *_high version of the 32-bit sem_otime and
sem_ctime values. These can be combined to get a 64-bit version of the
time.

This patch adjusts the struct semid_ds to support the *_high versions
of sem_otime and sem_ctime. For 32-bit systems with a 64-bit time_t
this can be used to get a 64-bit time from the two 32-bit values.

We protect this new code via the __IPC_TIME64 marco, which is only true
for 32-bit architectures with a 64-bit time_t.
---
 bits/ipc.h                                    |  6 ++++-
 sysdeps/gnu/bits/ipc.h                        |  6 ++++-
 sysdeps/unix/sysv/linux/bits/ipc.h            |  6 ++++-
 sysdeps/unix/sysv/linux/bits/semid_ds_t.h     | 15 +++++++++++
 .../unix/sysv/linux/hppa/bits/semid_ds_t.h    | 15 +++++++++++
 .../unix/sysv/linux/mips/bits/semid_ds_t.h    | 13 ++++++++++
 .../unix/sysv/linux/powerpc/bits/semid_ds_t.h | 15 +++++++++++
 sysdeps/unix/sysv/linux/semctl.c              | 25 ++++++++++++++++---
 .../unix/sysv/linux/sparc/bits/semid_ds_t.h   | 15 +++++++++++
 sysdeps/unix/sysv/linux/x86/bits/semid_ds_t.h | 15 +++++++++++
 10 files changed, 124 insertions(+), 7 deletions(-)

diff --git a/bits/ipc.h b/bits/ipc.h
index e2981fd5c3..9ac8485193 100644
--- a/bits/ipc.h
+++ b/bits/ipc.h
@@ -29,7 +29,11 @@
 /* Control commands for `msgctl', `semctl', and `shmctl'.  */
 #define IPC_RMID	0		/* remove identifier */
 #define IPC_SET		1		/* set `ipc_perm' options */
-#define IPC_STAT	2		/* get `ipc_perm' options */
+#if __TIMESIZE == 64 && __WORDSIZE == 32
+# define IPC_STAT 0x102     /* Get `ipc_perm' options.  */
+#else
+# define IPC_STAT 2   /* Get `ipc_perm' options.  */
+#endif
 
 /* Special key values.  */
 #define IPC_PRIVATE	((key_t) 0)	/* private key */
diff --git a/sysdeps/gnu/bits/ipc.h b/sysdeps/gnu/bits/ipc.h
index 47df305e1c..328c11a0d7 100644
--- a/sysdeps/gnu/bits/ipc.h
+++ b/sysdeps/gnu/bits/ipc.h
@@ -29,7 +29,11 @@
 /* Control commands for `msgctl', `semctl', and `shmctl'.  */
 #define IPC_RMID	0		/* Remove identifier.  */
 #define IPC_SET		1		/* Set `ipc_perm' options.  */
-#define IPC_STAT	2		/* Get `ipc_perm' options.  */
+#if __TIMESIZE == 64 && __WORDSIZE == 32
+# define IPC_STAT 0x102     /* Get `ipc_perm' options.  */
+#else
+# define IPC_STAT 2   /* Get `ipc_perm' options.  */
+#endif
 #ifdef __USE_GNU
 # define IPC_INFO	3		/* See ipcs.  */
 #endif
diff --git a/sysdeps/unix/sysv/linux/bits/ipc.h b/sysdeps/unix/sysv/linux/bits/ipc.h
index 085dd628ac..44449de62f 100644
--- a/sysdeps/unix/sysv/linux/bits/ipc.h
+++ b/sysdeps/unix/sysv/linux/bits/ipc.h
@@ -29,7 +29,11 @@
 /* Control commands for `msgctl', `semctl', and `shmctl'.  */
 #define IPC_RMID	0		/* Remove identifier.  */
 #define IPC_SET		1		/* Set `ipc_perm' options.  */
-#define IPC_STAT	2		/* Get `ipc_perm' options.  */
+#if __TIMESIZE == 64 && __WORDSIZE == 32
+# define IPC_STAT 0x102     /* Get `ipc_perm' options.  */
+#else
+# define IPC_STAT	2		/* Get `ipc_perm' options.  */
+#endif
 #ifdef __USE_GNU
 # define IPC_INFO	3		/* See ipcs.  */
 #endif
diff --git a/sysdeps/unix/sysv/linux/bits/semid_ds_t.h b/sysdeps/unix/sysv/linux/bits/semid_ds_t.h
index d9d902ed0d..b135301356 100644
--- a/sysdeps/unix/sysv/linux/bits/semid_ds_t.h
+++ b/sysdeps/unix/sysv/linux/bits/semid_ds_t.h
@@ -20,6 +20,21 @@
 # error "Never include <bits/semid_ds_t.h> directly; use <sys/sem.h> instead."
 #endif
 
+#if __WORDSIZE == 32
+/* This is the "new" y2038 types defined after the 5.1 kernel. It allows
+ * the kernel to use {o,c}time{_high} values to support a 64-bit time_t.  */
+struct __semid_ds32 {
+  struct ipc_perm sem_perm;              /* operation permission struct */
+  __syscall_ulong_t   sem_otime;         /* last semop() time */
+  __syscall_ulong_t   sem_otime_high;    /* last semop() time high */
+  __syscall_ulong_t   sem_ctime;         /* last time changed by semctl() */
+  __syscall_ulong_t   sem_ctime_high;    /* last time changed by semctl() high */
+  __syscall_ulong_t   sem_nsems;         /* number of semaphores in set */
+  __syscall_ulong_t   __glibc_reserved3;
+  __syscall_ulong_t   __glibc_reserved4;
+};
+#endif
+
 /* Data structure describing a set of semaphores.  */
 #if __TIMESIZE == 32
 struct semid_ds
diff --git a/sysdeps/unix/sysv/linux/hppa/bits/semid_ds_t.h b/sysdeps/unix/sysv/linux/hppa/bits/semid_ds_t.h
index 39c0e53f38..3613c5ec94 100644
--- a/sysdeps/unix/sysv/linux/hppa/bits/semid_ds_t.h
+++ b/sysdeps/unix/sysv/linux/hppa/bits/semid_ds_t.h
@@ -20,6 +20,21 @@
 # error "Never include <bits/semid_ds_t.h> directly; use <sys/sem.h> instead."
 #endif
 
+#if __WORDSIZE == 32
+/* This is the "new" y2038 types defined after the 5.1 kernel. It allows
+ * the kernel to use {o,c}time{_high} values to support a 64-bit time_t.  */
+struct __semid_ds32 {
+  struct ipc_perm sem_perm;              /* operation permission struct */
+  __syscall_ulong_t   sem_otime_high;    /* last semop() time high */
+  __syscall_ulong_t   sem_otime;         /* last semop() time */
+  __syscall_ulong_t   sem_ctime_high;    /* last time changed by semctl() high */
+  __syscall_ulong_t   sem_ctime;         /* last time changed by semctl() */
+  __syscall_ulong_t   sem_nsems;         /* number of semaphores in set */
+  __syscall_ulong_t   __glibc_reserved3;
+  __syscall_ulong_t   __glibc_reserved4;
+};
+#endif
+
 /* Data structure describing a set of semaphores.  */
 #if __TIMESIZE == 32
 struct semid_ds
diff --git a/sysdeps/unix/sysv/linux/mips/bits/semid_ds_t.h b/sysdeps/unix/sysv/linux/mips/bits/semid_ds_t.h
index 1ab16492dd..e26906a67f 100644
--- a/sysdeps/unix/sysv/linux/mips/bits/semid_ds_t.h
+++ b/sysdeps/unix/sysv/linux/mips/bits/semid_ds_t.h
@@ -20,6 +20,19 @@
 # error "Never include <bits/semid_ds_t.h> directly; use <sys/sem.h> instead."
 #endif
 
+#if __WORDSIZE == 32
+/* This is the "new" y2038 types defined after the 5.1 kernel. It allows
+ * the kernel to use {o,c}time{_high} values to support a 64-bit time_t.  */
+struct __semid_ds32 {
+  struct ipc_perm sem_perm;              /* operation permission struct */
+  __syscall_ulong_t   sem_otime;          /* last semop time */
+  __syscall_ulong_t   sem_ctime;          /* last change time */
+  __syscall_ulong_t   sem_nsems;         /* number of semaphores in set */
+  __syscall_ulong_t   sem_otime_high;
+  __syscall_ulong_t   sem_ctime_high;
+};
+#endif
+
 /* Data structure describing a set of semaphores.  */
 struct semid_ds
 {
diff --git a/sysdeps/unix/sysv/linux/powerpc/bits/semid_ds_t.h b/sysdeps/unix/sysv/linux/powerpc/bits/semid_ds_t.h
index 79b4cba939..ec2ff552eb 100644
--- a/sysdeps/unix/sysv/linux/powerpc/bits/semid_ds_t.h
+++ b/sysdeps/unix/sysv/linux/powerpc/bits/semid_ds_t.h
@@ -20,6 +20,21 @@
 # error "Never include <bits/semid_ds_t.h> directly; use <sys/sem.h> instead."
 #endif
 
+#if __WORDSIZE == 32
+/* This is the "new" y2038 types defined after the 5.1 kernel. It allows
+ * the kernel to use {o,c}time{_high} values to support a 64-bit time_t.  */
+struct __semid_ds32 {
+  struct ipc_perm sem_perm;              /* operation permission struct */
+  __syscall_ulong_t   sem_otime_high;    /* last semop() time high */
+  __syscall_ulong_t   sem_otime;         /* last semop() time */
+  __syscall_ulong_t   sem_ctime_high;    /* last time changed by semctl() high */
+  __syscall_ulong_t   sem_ctime;         /* last time changed by semctl() */
+  __syscall_ulong_t   sem_nsems;         /* number of semaphores in set */
+  __syscall_ulong_t   __glibc_reserved3;
+  __syscall_ulong_t   __glibc_reserved4;
+};
+#endif
+
 /* Data structure describing a set of semaphores.  */
 #if __TIMESIZE == 32
 struct semid_ds
diff --git a/sysdeps/unix/sysv/linux/semctl.c b/sysdeps/unix/sysv/linux/semctl.c
index 0c3eb0932f..3ac6d01b84 100644
--- a/sysdeps/unix/sysv/linux/semctl.c
+++ b/sysdeps/unix/sysv/linux/semctl.c
@@ -23,11 +23,16 @@
 #include <shlib-compat.h>
 #include <errno.h>
 
+#define __IPC_TIME64 (IPC_STAT & __IPC_64)
+
 /* Define a `union semun' suitable for Linux here.  */
 union semun
 {
   int val;			/* value for SETVAL */
   struct semid_ds *buf;		/* buffer for IPC_STAT & IPC_SET */
+#if __WORDSIZE == 32
+  struct __semid_ds32 *buf32;   /* 32-bit buffer for IPC_STAT & IPC_SET */
+#endif
   unsigned short int *array;	/* array for GETALL & SETALL */
   struct seminfo *__buf;	/* buffer for IPC_INFO */
 };
@@ -43,13 +48,25 @@ union semun
 static int
 semctl_syscall (int semid, int semnum, int cmd, union semun arg)
 {
+  int ret;
 #ifdef __ASSUME_DIRECT_SYSVIPC_SYSCALLS
-  return INLINE_SYSCALL_CALL (semctl, semid, semnum, cmd | __IPC_64,
-			      arg.array);
+  ret = INLINE_SYSCALL_CALL (semctl, semid, semnum, cmd | __IPC_64,
+                             arg.array);
 #else
-  return INLINE_SYSCALL_CALL (ipc, IPCOP_semctl, semid, semnum, cmd | __IPC_64,
-			      SEMCTL_ARG_ADDRESS (arg));
+  ret = INLINE_SYSCALL_CALL (ipc, IPCOP_semctl, semid, semnum, cmd | __IPC_64,
+                             SEMCTL_ARG_ADDRESS (arg));
+#endif
+
+#if __IPC_TIME64
+  if (ret == 0 && (cmd & __IPC_TIME64))
+    {
+      arg.buf->sem_ctime = arg.buf32->sem_ctime |
+                               ((time_t) arg.buf32->sem_ctime_high << 32);
+      arg.buf->sem_otime = arg.buf32->sem_otime |
+                               ((time_t) arg.buf32->sem_otime_high << 32);
+    }
 #endif
+  return ret;
 }
 
 int
diff --git a/sysdeps/unix/sysv/linux/sparc/bits/semid_ds_t.h b/sysdeps/unix/sysv/linux/sparc/bits/semid_ds_t.h
index f8de676e79..b08fb8a79e 100644
--- a/sysdeps/unix/sysv/linux/sparc/bits/semid_ds_t.h
+++ b/sysdeps/unix/sysv/linux/sparc/bits/semid_ds_t.h
@@ -20,6 +20,21 @@
 # error "Never include <bits/semid_ds_t.h> directly; use <sys/sem.h> instead."
 #endif
 
+#if __WORDSIZE == 32
+/* This is the "new" y2038 types defined after the 5.1 kernel. It allows
+ * the kernel to use {o,c}time{_high} values to support a 64-bit time_t.  */
+struct __semid_ds32 {
+  struct ipc_perm sem_perm;              /* operation permission struct */
+  __syscall_ulong_t   sem_otime_high;    /* last semop() time high */
+  __syscall_ulong_t   sem_otime;         /* last semop() time */
+  __syscall_ulong_t   sem_ctime_high;    /* last time changed by semctl() high */
+  __syscall_ulong_t   sem_ctime;         /* last time changed by semctl() */
+  __syscall_ulong_t   sem_nsems;         /* number of semaphores in set */
+  __syscall_ulong_t   __glibc_reserved3;
+  __syscall_ulong_t   __glibc_reserved4;
+};
+#endif
+
 /* Data structure describing a set of semaphores.  */
 #if __TIMESIZE == 32
 struct semid_ds
diff --git a/sysdeps/unix/sysv/linux/x86/bits/semid_ds_t.h b/sysdeps/unix/sysv/linux/x86/bits/semid_ds_t.h
index 42694069d5..c7b9adce88 100644
--- a/sysdeps/unix/sysv/linux/x86/bits/semid_ds_t.h
+++ b/sysdeps/unix/sysv/linux/x86/bits/semid_ds_t.h
@@ -20,6 +20,21 @@
 # error "Never include <bits/semid_ds_t.h> directly; use <sys/sem.h> instead."
 #endif
 
+#if __WORDSIZE == 32
+/* This is the "new" y2038 types defined after the 5.1 kernel. It allows
+ * the kernel to use {o,c}time{_high} values to support a 64-bit time_t.  */
+struct __semid_ds32 {
+  struct ipc_perm sem_perm;              /* operation permission struct */
+  __syscall_ulong_t   sem_otime;         /* last semop() time */
+  __syscall_ulong_t   sem_otime_high;    /* last semop() time high */
+  __syscall_ulong_t   sem_ctime;         /* last time changed by semctl() */
+  __syscall_ulong_t   sem_ctime_high;    /* last time changed by semctl() high */
+  __syscall_ulong_t   sem_nsems;         /* number of semaphores in set */
+  __syscall_ulong_t   __glibc_reserved3;
+  __syscall_ulong_t   __glibc_reserved4;
+};
+#endif
+
 /* Data structure describing a set of semaphores.  */
 struct semid_ds
 {
-- 
2.25.1

Follow-Ups:
- Re: [PATCH v3 3/3] sysv: linux: Pass 64-bit version of semctl syscall
  - From: Andreas Schwab

References:
- [PATCH v3 0/3] Support y2038 semctl_syscall()
  - From: Alistair Francis

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