Provide ksys_shmget() 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_shmget(). 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 4643865e9171..9f3cdb259a51 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -656,7 +656,7 @@ static inline int shm_more_checks(struct kern_ipc_perm *ipcp, return 0; } -SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg) +long ksys_shmget(key_t key, size_t size, int shmflg) { struct ipc_namespace *ns; static const struct ipc_ops shm_ops = { @@ -675,6 +675,11 @@ SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg) return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params); } +SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg) +{ + return ksys_shmget(key, size, shmflg); +} + static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version) { switch (version) { diff --git a/ipc/syscall.c b/ipc/syscall.c index 355c4a644bbf..60bceb19b6f0 100644 --- a/ipc/syscall.c +++ b/ipc/syscall.c @@ -92,7 +92,7 @@ SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second, case SHMDT: return sys_shmdt((char __user *)ptr); case SHMGET: - return sys_shmget(first, second, third); + return ksys_shmget(first, second, third); case SHMCTL: return sys_shmctl(first, second, (struct shmid_ds __user *) ptr); @@ -180,7 +180,7 @@ COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second, case SHMDT: return sys_shmdt(compat_ptr(ptr)); case SHMGET: - return sys_shmget(first, (unsigned)second, third); + return ksys_shmget(first, (unsigned int)second, third); case SHMCTL: return compat_sys_shmctl(first, second, compat_ptr(ptr)); } diff --git a/ipc/util.h b/ipc/util.h index b35c0dfe3bc3..51002c0b2a21 100644 --- a/ipc/util.h +++ b/ipc/util.h @@ -243,6 +243,7 @@ long ksys_semtimedop(int semid, struct sembuf __user *tsops, 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); /* for CONFIG_ARCH_WANT_OLD_COMPAT_IPC */ #ifdef CONFIG_COMPAT -- 2.16.3
