Commit 41f4f0e2 authored by Dominik Brodowski's avatar Dominik Brodowski

ipc: add semtimedop syscall/compat_syscall wrappers

Provide ksys_semtimedop() and compat_ksys_semtimedop() 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_semtimedop() and
compat_sys_semtimedop().

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 6df35465
......@@ -2120,8 +2120,8 @@ static long do_semtimedop(int semid, struct sembuf __user *tsops,
return error;
}
SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
unsigned, nsops, const struct timespec __user *, timeout)
long ksys_semtimedop(int semid, struct sembuf __user *tsops,
unsigned int nsops, const struct timespec __user *timeout)
{
if (timeout) {
struct timespec64 ts;
......@@ -2132,10 +2132,16 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
return do_semtimedop(semid, tsops, nsops, NULL);
}
SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
unsigned int, nsops, const struct timespec __user *, timeout)
{
return ksys_semtimedop(semid, tsops, nsops, timeout);
}
#ifdef CONFIG_COMPAT
COMPAT_SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsems,
unsigned, nsops,
const struct compat_timespec __user *, timeout)
long compat_ksys_semtimedop(int semid, struct sembuf __user *tsems,
unsigned int nsops,
const struct compat_timespec __user *timeout)
{
if (timeout) {
struct timespec64 ts;
......@@ -2145,6 +2151,13 @@ COMPAT_SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsems,
}
return do_semtimedop(semid, tsems, nsops, NULL);
}
COMPAT_SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsems,
unsigned int, nsops,
const struct compat_timespec __user *, timeout)
{
return compat_ksys_semtimedop(semid, tsems, nsops, timeout);
}
#endif
SYSCALL_DEFINE3(semop, int, semid, struct sembuf __user *, tsops,
......
......@@ -7,6 +7,9 @@
*/
#include <linux/unistd.h>
#include <linux/syscalls.h>
#include <linux/security.h>
#include <linux/ipc_namespace.h>
#include "util.h"
#ifdef __ARCH_WANT_SYS_IPC
#include <linux/errno.h>
......@@ -24,12 +27,12 @@ SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
switch (call) {
case SEMOP:
return sys_semtimedop(first, (struct sembuf __user *)ptr,
second, NULL);
return ksys_semtimedop(first, (struct sembuf __user *)ptr,
second, NULL);
case SEMTIMEDOP:
return sys_semtimedop(first, (struct sembuf __user *)ptr,
second,
(const struct timespec __user *)fifth);
return ksys_semtimedop(first, (struct sembuf __user *)ptr,
second,
(const struct timespec __user *)fifth);
case SEMGET:
return sys_semget(first, second, third);
......@@ -124,9 +127,9 @@ COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
switch (call) {
case SEMOP:
/* struct sembuf is the same on 32 and 64bit :)) */
return sys_semtimedop(first, compat_ptr(ptr), second, NULL);
return ksys_semtimedop(first, compat_ptr(ptr), second, NULL);
case SEMTIMEDOP:
return compat_sys_semtimedop(first, compat_ptr(ptr), second,
return compat_ksys_semtimedop(first, compat_ptr(ptr), second,
compat_ptr(fifth));
case SEMGET:
return sys_semget(first, second, third);
......
......@@ -235,4 +235,17 @@ static inline int compat_ipc_parse_version(int *cmd)
#endif
}
#endif
/* for __ARCH_WANT_SYS_IPC */
long ksys_semtimedop(int semid, struct sembuf __user *tsops,
unsigned int nsops,
const struct timespec __user *timeout);
/* 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);
#endif /* CONFIG_COMPAT */
#endif
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