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authorDominik Brodowski <linux@dominikbrodowski.net>2018-03-20 20:00:39 +0100
committerDominik Brodowski <linux@dominikbrodowski.net>2018-04-02 20:15:22 +0200
commitd969c6fa7263c8fc1928f528bb68587872350b6c (patch)
treeea96ad301cb9b73b87838e925411bb7e4d111ce4
parent69894718a515fef7ff633cf354fcd7ed73a88891 (diff)
downloadlinux-d969c6fa7263c8fc1928f528bb68587872350b6c.tar.bz2
ipc: add semctl syscall/compat_syscall wrappers
Provide ksys_semctl() and compat_ksys_semctl() wrappers to avoid in-kernel calls to these syscalls. The ksys_ prefix denotes that these functions are meant as a drop-in replacement for the syscalls. In particular, they use the same calling convention as sys_semctl() and compat_sys_semctl(). This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
-rw-r--r--ipc/sem.c14
-rw-r--r--ipc/syscall.c4
-rw-r--r--ipc/util.h2
3 files changed, 16 insertions, 4 deletions
diff --git a/ipc/sem.c b/ipc/sem.c
index 2e5f7ec7a7db..1cf56279a84c 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -1581,7 +1581,7 @@ out_up:
return err;
}
-SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, unsigned long, arg)
+long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg)
{
int version;
struct ipc_namespace *ns;
@@ -1635,6 +1635,11 @@ SYSCALL_DEFINE4(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);
+}
+
#ifdef CONFIG_COMPAT
struct compat_semid_ds {
@@ -1683,7 +1688,7 @@ static int copy_compat_semid_to_user(void __user *buf, struct semid64_ds *in,
}
}
-COMPAT_SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, int, arg)
+long compat_ksys_semctl(int semid, int semnum, int cmd, int arg)
{
void __user *p = compat_ptr(arg);
struct ipc_namespace *ns;
@@ -1727,6 +1732,11 @@ COMPAT_SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, int, arg)
return -EINVAL;
}
}
+
+COMPAT_SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, int, arg)
+{
+ return compat_ksys_semctl(semid, semnum, cmd, arg);
+}
#endif
/* If the task doesn't already have a undo_list, then allocate one
diff --git a/ipc/syscall.c b/ipc/syscall.c
index 21fcdf0b4836..a536cca37661 100644
--- a/ipc/syscall.c
+++ b/ipc/syscall.c
@@ -42,7 +42,7 @@ SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
return -EINVAL;
if (get_user(arg, (unsigned long __user *) ptr))
return -EFAULT;
- return sys_semctl(first, second, third, arg);
+ return ksys_semctl(first, second, third, arg);
}
case MSGSND:
@@ -138,7 +138,7 @@ COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
return -EINVAL;
if (get_user(pad, (u32 __user *) compat_ptr(ptr)))
return -EFAULT;
- return compat_sys_semctl(first, second, third, pad);
+ return compat_ksys_semctl(first, second, third, pad);
case MSGSND:
return compat_sys_msgsnd(first, ptr, second, third);
diff --git a/ipc/util.h b/ipc/util.h
index 0f07056e5a73..1f1109b83437 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -241,12 +241,14 @@ long ksys_semtimedop(int semid, struct sembuf __user *tsops,
unsigned int nsops,
const struct timespec __user *timeout);
long ksys_semget(key_t key, int nsems, int semflg);
+long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg);
/* for CONFIG_ARCH_WANT_OLD_COMPAT_IPC */
#ifdef CONFIG_COMPAT
long compat_ksys_semtimedop(int semid, struct sembuf __user *tsems,
unsigned int nsops,
const struct compat_timespec __user *timeout);
+long compat_ksys_semctl(int semid, int semnum, int cmd, int arg);
#endif /* CONFIG_COMPAT */
#endif