From c84d0791dfa7fe8f051082c09a558eb3e2d01931 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Tue, 20 Mar 2018 20:12:33 +0100 Subject: [PATCH] ipc: add shmctl syscall/compat_syscall wrappers Provide ksys_shmctl() and compat_ksys_shmctl() 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_shmctl() and compat_sys_shmctl(). 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 Cc: Andrew Morton Signed-off-by: Dominik Brodowski --- ipc/shm.c | 14 ++++++++++++-- ipc/syscall.c | 4 ++-- ipc/util.h | 2 ++ 3 files changed, 16 insertions(+), 4 deletions(-) diff --git a/ipc/shm.c b/ipc/shm.c index e5838e3328dc..0aae3e55bc56 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -1045,7 +1045,7 @@ out_unlock1: return err; } -SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf) +long ksys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf) { int err, version; struct ipc_namespace *ns; @@ -1099,6 +1099,11 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf) } } +SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf) +{ + return ksys_shmctl(shmid, cmd, buf); +} + #ifdef CONFIG_COMPAT struct compat_shmid_ds { @@ -1218,7 +1223,7 @@ static int copy_compat_shmid_from_user(struct shmid64_ds *out, void __user *buf, } } -COMPAT_SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, void __user *, uptr) +long compat_ksys_shmctl(int shmid, int cmd, void __user *uptr) { struct ipc_namespace *ns; struct shmid64_ds sem64; @@ -1273,6 +1278,11 @@ COMPAT_SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, void __user *, uptr) } return err; } + +COMPAT_SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, void __user *, uptr) +{ + return compat_ksys_shmctl(shmid, cmd, uptr); +} #endif /* diff --git a/ipc/syscall.c b/ipc/syscall.c index b3aa71564815..34bbabc9e672 100644 --- a/ipc/syscall.c +++ b/ipc/syscall.c @@ -94,7 +94,7 @@ SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second, case SHMGET: return ksys_shmget(first, second, third); case SHMCTL: - return sys_shmctl(first, second, + return ksys_shmctl(first, second, (struct shmid_ds __user *) ptr); default: return -ENOSYS; @@ -182,7 +182,7 @@ COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second, case SHMGET: return ksys_shmget(first, (unsigned int)second, third); case SHMCTL: - return compat_sys_shmctl(first, second, compat_ptr(ptr)); + return compat_ksys_shmctl(first, second, compat_ptr(ptr)); } return -ENOSYS; diff --git a/ipc/util.h b/ipc/util.h index 7770bcad1168..16e8b5b8c416 100644 --- a/ipc/util.h +++ b/ipc/util.h @@ -245,6 +245,7 @@ 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); +long ksys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf); /* for CONFIG_ARCH_WANT_OLD_COMPAT_IPC */ #ifdef CONFIG_COMPAT @@ -252,6 +253,7 @@ 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); +long compat_ksys_shmctl(int shmid, int cmd, void __user *uptr); #endif /* CONFIG_COMPAT */ #endif