Commit 31c213f2 authored by Dominik Brodowski's avatar Dominik Brodowski

ipc: add msgsnd syscall/compat_syscall wrappers

Provide ksys_msgsnd() and compat_ksys_msgsnd() 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_msgsnd() and compat_sys_msgsnd().

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: default avatarDominik Brodowski <linux@dominikbrodowski.net>
parent 078faac9
...@@ -867,8 +867,8 @@ static long do_msgsnd(int msqid, long mtype, void __user *mtext, ...@@ -867,8 +867,8 @@ static long do_msgsnd(int msqid, long mtype, void __user *mtext,
return err; return err;
} }
SYSCALL_DEFINE4(msgsnd, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz, long ksys_msgsnd(int msqid, struct msgbuf __user *msgp, size_t msgsz,
int, msgflg) int msgflg)
{ {
long mtype; long mtype;
...@@ -877,6 +877,12 @@ SYSCALL_DEFINE4(msgsnd, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz, ...@@ -877,6 +877,12 @@ SYSCALL_DEFINE4(msgsnd, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
return do_msgsnd(msqid, mtype, msgp->mtext, msgsz, msgflg); return do_msgsnd(msqid, mtype, msgp->mtext, msgsz, msgflg);
} }
SYSCALL_DEFINE4(msgsnd, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
int, msgflg)
{
return ksys_msgsnd(msqid, msgp, msgsz, msgflg);
}
#ifdef CONFIG_COMPAT #ifdef CONFIG_COMPAT
struct compat_msgbuf { struct compat_msgbuf {
...@@ -884,8 +890,8 @@ struct compat_msgbuf { ...@@ -884,8 +890,8 @@ struct compat_msgbuf {
char mtext[1]; char mtext[1];
}; };
COMPAT_SYSCALL_DEFINE4(msgsnd, int, msqid, compat_uptr_t, msgp, long compat_ksys_msgsnd(int msqid, compat_uptr_t msgp,
compat_ssize_t, msgsz, int, msgflg) compat_ssize_t msgsz, int msgflg)
{ {
struct compat_msgbuf __user *up = compat_ptr(msgp); struct compat_msgbuf __user *up = compat_ptr(msgp);
compat_long_t mtype; compat_long_t mtype;
...@@ -894,6 +900,12 @@ COMPAT_SYSCALL_DEFINE4(msgsnd, int, msqid, compat_uptr_t, msgp, ...@@ -894,6 +900,12 @@ COMPAT_SYSCALL_DEFINE4(msgsnd, int, msqid, compat_uptr_t, msgp,
return -EFAULT; return -EFAULT;
return do_msgsnd(msqid, mtype, up->mtext, (ssize_t)msgsz, msgflg); return do_msgsnd(msqid, mtype, up->mtext, (ssize_t)msgsz, msgflg);
} }
COMPAT_SYSCALL_DEFINE4(msgsnd, int, msqid, compat_uptr_t, msgp,
compat_ssize_t, msgsz, int, msgflg)
{
return compat_ksys_msgsnd(msqid, msgp, msgsz, msgflg);
}
#endif #endif
static inline int convert_mode(long *msgtyp, int msgflg) static inline int convert_mode(long *msgtyp, int msgflg)
......
...@@ -46,7 +46,7 @@ SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second, ...@@ -46,7 +46,7 @@ SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
} }
case MSGSND: case MSGSND:
return sys_msgsnd(first, (struct msgbuf __user *) ptr, return ksys_msgsnd(first, (struct msgbuf __user *) ptr,
second, third); second, third);
case MSGRCV: case MSGRCV:
switch (version) { switch (version) {
...@@ -142,7 +142,7 @@ COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second, ...@@ -142,7 +142,7 @@ COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
return compat_ksys_semctl(first, second, third, pad); return compat_ksys_semctl(first, second, third, pad);
case MSGSND: case MSGSND:
return compat_sys_msgsnd(first, ptr, second, third); return compat_ksys_msgsnd(first, ptr, second, third);
case MSGRCV: { case MSGRCV: {
void __user *uptr = compat_ptr(ptr); void __user *uptr = compat_ptr(ptr);
......
...@@ -246,6 +246,8 @@ long ksys_msgget(key_t key, int msgflg); ...@@ -246,6 +246,8 @@ long ksys_msgget(key_t key, int msgflg);
long ksys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf); long ksys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf);
long ksys_msgrcv(int msqid, struct msgbuf __user *msgp, size_t msgsz, long ksys_msgrcv(int msqid, struct msgbuf __user *msgp, size_t msgsz,
long msgtyp, int msgflg); long msgtyp, int msgflg);
long ksys_msgsnd(int msqid, struct msgbuf __user *msgp, size_t msgsz,
int msgflg);
long ksys_shmget(key_t key, size_t size, int shmflg); long ksys_shmget(key_t key, size_t size, int shmflg);
long ksys_shmdt(char __user *shmaddr); long ksys_shmdt(char __user *shmaddr);
long ksys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf); long ksys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf);
...@@ -259,6 +261,8 @@ long compat_ksys_semctl(int semid, int semnum, int cmd, int arg); ...@@ -259,6 +261,8 @@ long compat_ksys_semctl(int semid, int semnum, int cmd, int arg);
long compat_ksys_msgctl(int msqid, int cmd, void __user *uptr); long compat_ksys_msgctl(int msqid, int cmd, void __user *uptr);
long compat_ksys_msgrcv(int msqid, compat_uptr_t msgp, compat_ssize_t msgsz, long compat_ksys_msgrcv(int msqid, compat_uptr_t msgp, compat_ssize_t msgsz,
compat_long_t msgtyp, int msgflg); compat_long_t msgtyp, int msgflg);
long compat_ksys_msgsnd(int msqid, compat_uptr_t msgp,
compat_ssize_t msgsz, int msgflg);
long compat_ksys_shmctl(int shmid, int cmd, void __user *uptr); long compat_ksys_shmctl(int shmid, int cmd, void __user *uptr);
#endif /* CONFIG_COMPAT */ #endif /* CONFIG_COMPAT */
......
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