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@xxxxxxxxxxxxxxxxxxxxxxxxxx Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx> --- ipc/sem.c | 23 ++++++++++++++++++----- ipc/syscall.c | 17 ++++++++++------- ipc/util.h | 13 +++++++++++++ 3 files changed, 41 insertions(+), 12 deletions(-) diff --git a/ipc/sem.c b/ipc/sem.c index a4af04979fd2..e21ceb8b4af1 100644 --- a/ipc/sem.c +++ b/ipc/sem.c @@ -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, diff --git a/ipc/syscall.c b/ipc/syscall.c index 3763b4293b74..84d6a7691baa 100644 --- a/ipc/syscall.c +++ b/ipc/syscall.c @@ -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); diff --git a/ipc/util.h b/ipc/util.h index 89b8ec176fc4..6deadf77547e 100644 --- a/ipc/util.h +++ b/ipc/util.h @@ -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 -- 2.16.3
