Provide ksys_shmdt() wrapper to avoid in-kernel calls to this syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_shmdt(). 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@xxxxxxxxxxxxxxxxxxxxxxxxxx Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx> --- ipc/shm.c | 7 ++++++- ipc/syscall.c | 4 ++-- ipc/util.h | 1 + 3 files changed, 9 insertions(+), 3 deletions(-) diff --git a/ipc/shm.c b/ipc/shm.c index 9f3cdb259a51..e5838e3328dc 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -1481,7 +1481,7 @@ COMPAT_SYSCALL_DEFINE3(shmat, int, shmid, compat_uptr_t, shmaddr, int, shmflg) * detach and kill segment if marked destroyed. * The work is done in shm_close. */ -SYSCALL_DEFINE1(shmdt, char __user *, shmaddr) +long ksys_shmdt(char __user *shmaddr) { struct mm_struct *mm = current->mm; struct vm_area_struct *vma; @@ -1588,6 +1588,11 @@ SYSCALL_DEFINE1(shmdt, char __user *, shmaddr) return retval; } +SYSCALL_DEFINE1(shmdt, char __user *, shmaddr) +{ + return ksys_shmdt(shmaddr); +} + #ifdef CONFIG_PROC_FS static int sysvipc_shm_proc_show(struct seq_file *s, void *it) { diff --git a/ipc/syscall.c b/ipc/syscall.c index 60bceb19b6f0..b3aa71564815 100644 --- a/ipc/syscall.c +++ b/ipc/syscall.c @@ -90,7 +90,7 @@ SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second, return -EINVAL; } case SHMDT: - return sys_shmdt((char __user *)ptr); + return ksys_shmdt((char __user *)ptr); case SHMGET: return ksys_shmget(first, second, third); case SHMCTL: @@ -178,7 +178,7 @@ COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second, return put_user(raddr, (compat_ulong_t __user *)compat_ptr(third)); } case SHMDT: - return sys_shmdt(compat_ptr(ptr)); + return ksys_shmdt(compat_ptr(ptr)); case SHMGET: return ksys_shmget(first, (unsigned int)second, third); case SHMCTL: diff --git a/ipc/util.h b/ipc/util.h index 51002c0b2a21..7770bcad1168 100644 --- a/ipc/util.h +++ b/ipc/util.h @@ -244,6 +244,7 @@ long ksys_semget(key_t key, int nsems, int semflg); long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg); long ksys_msgget(key_t key, int msgflg); long ksys_shmget(key_t key, size_t size, int shmflg); +long ksys_shmdt(char __user *shmaddr); /* for CONFIG_ARCH_WANT_OLD_COMPAT_IPC */ #ifdef CONFIG_COMPAT -- 2.16.3
