From 687ad0191488a067b3b3cc94f670cc21f93811e1 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Sat, 14 Jan 2006 16:35:31 +0000 Subject: [ARM] 3109/1: old ABI compat: syscall wrappers for ABI impedance matching Patch from Nicolas Pitre The difference between EABI and the legacy ABI may affect either structure member alignment and/or argument register selection. The patch has the details. Included are wrappers for the following syscalls: sys_stat64 sys_lstat64 sys_fstat64 sys_fcntl64 sys_epoll_ctl sys_epoll_wait sys_ipc sys_semop sys_semtimedop sys_pread64 sys_pwrite64 sys_truncate64 sys_ftruncate64 sys_readahead Signed-off-by: Nicolas Pitre Signed-off-by: Russell King --- arch/arm/kernel/Makefile | 1 + arch/arm/kernel/entry-common.S | 32 ++++ arch/arm/kernel/sys_oabi-compat.c | 339 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 372 insertions(+) create mode 100644 arch/arm/kernel/sys_oabi-compat.c (limited to 'arch/arm') diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index de94b0f3ee2..2ce0e3a27a4 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -20,6 +20,7 @@ obj-$(CONFIG_ARTHUR) += arthur.o obj-$(CONFIG_ISA_DMA) += dma-isa.o obj-$(CONFIG_PCI) += bios32.o obj-$(CONFIG_SMP) += smp.o +obj-$(CONFIG_OABI_COMPAT) += sys_oabi-compat.o obj-$(CONFIG_IWMMXT) += iwmmxt.o AFLAGS_iwmmxt.o := -Wa,-mcpu=iwmmxt diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index ee63ee78d84..59ce1bcec42 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -288,3 +288,35 @@ sys_mmap2: str r5, [sp, #4] b do_mmap2 #endif + +#ifdef CONFIG_OABI_COMPAT +/* + * These are syscalls with argument register differences + */ + +sys_oabi_pread64: + stmia sp, {r3, r4} + b sys_pread64 + +sys_oabi_pwrite64: + stmia sp, {r3, r4} + b sys_pwrite64 + +sys_oabi_truncate64: + mov r3, r2 + mov r2, r1 + b sys_truncate64 + +sys_oabi_ftruncate64: + mov r3, r2 + mov r2, r1 + b sys_ftruncate64 + +sys_oabi_readahead: + str r3, [sp] + mov r3, r2 + mov r2, r1 + b sys_readahead + +#endif + diff --git a/arch/arm/kernel/sys_oabi-compat.c b/arch/arm/kernel/sys_oabi-compat.c new file mode 100644 index 00000000000..eafa8e5284a --- /dev/null +++ b/arch/arm/kernel/sys_oabi-compat.c @@ -0,0 +1,339 @@ +/* + * arch/arm/kernel/sys_oabi-compat.c + * + * Compatibility wrappers for syscalls that are used from + * old ABI user space binaries with an EABI kernel. + * + * Author: Nicolas Pitre + * Created: Oct 7, 2005 + * Copyright: MontaVista Software, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +/* + * The legacy ABI and the new ARM EABI have different rules making some + * syscalls incompatible especially with structure arguments. + * Most notably, Eabi says 64-bit members should be 64-bit aligned instead of + * simply word aligned. EABI also pads structures to the size of the largest + * member it contains instead of the invariant 32-bit. + * + * The following syscalls are affected: + * + * sys_stat64: + * sys_lstat64: + * sys_fstat64: + * + * struct stat64 has different sizes and some members are shifted + * Compatibility wrappers are needed for them and provided below. + * + * sys_fcntl64: + * + * struct flock64 has different sizes and some members are shifted + * A compatibility wrapper is needed and provided below. + * + * sys_statfs64: + * sys_fstatfs64: + * + * struct statfs64 has extra padding with EABI growing its size from + * 84 to 88. This struct is now __attribute__((packed,aligned(4))) + * with a small assembly wrapper to force the sz argument to 84 if it is 88 + * to avoid copying the extra padding over user space unexpecting it. + * + * sys_newuname: + * + * struct new_utsname has no padding with EABI. No problem there. + * + * sys_epoll_ctl: + * sys_epoll_wait: + * + * struct epoll_event has its second member shifted also affecting the + * structure size. Compatibility wrappers are needed and provided below. + * + * sys_ipc: + * sys_semop: + * sys_semtimedop: + * + * struct sembuf loses its padding with EABI. Since arrays of them are + * used they have to be copyed to remove the padding. Compatibility wrappers + * provided below. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +struct oldabi_stat64 { + unsigned long long st_dev; + unsigned int __pad1; + unsigned long __st_ino; + unsigned int st_mode; + unsigned int st_nlink; + + unsigned long st_uid; + unsigned long st_gid; + + unsigned long long st_rdev; + unsigned int __pad2; + + long long st_size; + unsigned long st_blksize; + unsigned long long st_blocks; + + unsigned long st_atime; + unsigned long st_atime_nsec; + + unsigned long st_mtime; + unsigned long st_mtime_nsec; + + unsigned long st_ctime; + unsigned long st_ctime_nsec; + + unsigned long long st_ino; +} __attribute__ ((packed,aligned(4))); + +static long cp_oldabi_stat64(struct kstat *stat, + struct oldabi_stat64 __user *statbuf) +{ + struct oldabi_stat64 tmp; + + tmp.st_dev = huge_encode_dev(stat->dev); + tmp.__pad1 = 0; + tmp.__st_ino = stat->ino; + tmp.st_mode = stat->mode; + tmp.st_nlink = stat->nlink; + tmp.st_uid = stat->uid; + tmp.st_gid = stat->gid; + tmp.st_rdev = huge_encode_dev(stat->rdev); + tmp.st_size = stat->size; + tmp.st_blocks = stat->blocks; + tmp.__pad2 = 0; + tmp.st_blksize = stat->blksize; + tmp.st_atime = stat->atime.tv_sec; + tmp.st_atime_nsec = stat->atime.tv_nsec; + tmp.st_mtime = stat->mtime.tv_sec; + tmp.st_mtime_nsec = stat->mtime.tv_nsec; + tmp.st_ctime = stat->ctime.tv_sec; + tmp.st_ctime_nsec = stat->ctime.tv_nsec; + tmp.st_ino = stat->ino; + return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; +} + +asmlinkage long sys_oabi_stat64(char __user * filename, + struct oldabi_stat64 __user * statbuf) +{ + struct kstat stat; + int error = vfs_stat(filename, &stat); + if (!error) + error = cp_oldabi_stat64(&stat, statbuf); + return error; +} + +asmlinkage long sys_oabi_lstat64(char __user * filename, + struct oldabi_stat64 __user * statbuf) +{ + struct kstat stat; + int error = vfs_lstat(filename, &stat); + if (!error) + error = cp_oldabi_stat64(&stat, statbuf); + return error; +} + +asmlinkage long sys_oabi_fstat64(unsigned long fd, + struct oldabi_stat64 __user * statbuf) +{ + struct kstat stat; + int error = vfs_fstat(fd, &stat); + if (!error) + error = cp_oldabi_stat64(&stat, statbuf); + return error; +} + +struct oabi_flock64 { + short l_type; + short l_whence; + loff_t l_start; + loff_t l_len; + pid_t l_pid; +} __attribute__ ((packed,aligned(4))); + +asmlinkage long sys_oabi_fcntl64(unsigned int fd, unsigned int cmd, + unsigned long arg) +{ + struct oabi_flock64 user; + struct flock64 kernel; + mm_segment_t fs = USER_DS; /* initialized to kill a warning */ + unsigned long local_arg = arg; + int ret; + + switch (cmd) { + case F_GETLK64: + case F_SETLK64: + case F_SETLKW64: + if (copy_from_user(&user, (struct oabi_flock64 __user *)arg, + sizeof(user))) + return -EFAULT; + kernel.l_type = user.l_type; + kernel.l_whence = user.l_whence; + kernel.l_start = user.l_start; + kernel.l_len = user.l_len; + kernel.l_pid = user.l_pid; + local_arg = (unsigned long)&kernel; + fs = get_fs(); + set_fs(KERNEL_DS); + } + + ret = sys_fcntl64(fd, cmd, local_arg); + + switch (cmd) { + case F_GETLK64: + if (!ret) { + user.l_type = kernel.l_type; + user.l_whence = kernel.l_whence; + user.l_start = kernel.l_start; + user.l_len = kernel.l_len; + user.l_pid = kernel.l_pid; + if (copy_to_user((struct oabi_flock64 __user *)arg, + &user, sizeof(user))) + ret = -EFAULT; + } + case F_SETLK64: + case F_SETLKW64: + set_fs(fs); + } + + return ret; +} + +struct oabi_epoll_event { + __u32 events; + __u64 data; +} __attribute__ ((packed,aligned(4))); + +asmlinkage long sys_oabi_epoll_ctl(int epfd, int op, int fd, + struct oabi_epoll_event __user *event) +{ + struct oabi_epoll_event user; + struct epoll_event kernel; + mm_segment_t fs; + long ret; + + if (op == EPOLL_CTL_DEL) + return sys_epoll_ctl(epfd, op, fd, NULL); + if (copy_from_user(&user, event, sizeof(user))) + return -EFAULT; + kernel.events = user.events; + kernel.data = user.data; + fs = get_fs(); + set_fs(KERNEL_DS); + ret = sys_epoll_ctl(epfd, op, fd, &kernel); + set_fs(fs); + return ret; +} + +asmlinkage long sys_oabi_epoll_wait(int epfd, + struct oabi_epoll_event __user *events, + int maxevents, int timeout) +{ + struct epoll_event *kbuf; + mm_segment_t fs; + long ret, err, i; + + if (maxevents <= 0 || maxevents > (INT_MAX/sizeof(struct epoll_event))) + return -EINVAL; + kbuf = kmalloc(sizeof(*kbuf) * maxevents, GFP_KERNEL); + if (!kbuf) + return -ENOMEM; + fs = get_fs(); + set_fs(KERNEL_DS); + ret = sys_epoll_wait(epfd, kbuf, maxevents, timeout); + set_fs(fs); + err = 0; + for (i = 0; i < ret; i++) { + __put_user_error(kbuf[i].events, &events->events, err); + __put_user_error(kbuf[i].data, &events->data, err); + events++; + } + kfree(kbuf); + return err ? -EFAULT : ret; +} + +struct oabi_sembuf { + unsigned short sem_num; + short sem_op; + short sem_flg; + unsigned short __pad; +}; + +asmlinkage long sys_oabi_semtimedop(int semid, + struct oabi_sembuf __user *tsops, + unsigned nsops, + const struct timespec __user *timeout) +{ + struct sembuf *sops; + struct timespec local_timeout; + long err; + int i; + + if (nsops < 1) + return -EINVAL; + sops = kmalloc(sizeof(*sops) * nsops, GFP_KERNEL); + if (!sops) + return -ENOMEM; + err = 0; + for (i = 0; i < nsops; i++) { + __get_user_error(sops[i].sem_num, &tsops->sem_num, err); + __get_user_error(sops[i].sem_op, &tsops->sem_op, err); + __get_user_error(sops[i].sem_flg, &tsops->sem_flg, err); + tsops++; + } + if (timeout) { + /* copy this as well before changing domain protection */ + err |= copy_from_user(&local_timeout, timeout, sizeof(*timeout)); + timeout = &local_timeout; + } + if (err) { + err = -EFAULT; + } else { + mm_segment_t fs = get_fs(); + set_fs(KERNEL_DS); + err = sys_semtimedop(semid, sops, nsops, timeout); + set_fs(fs); + } + kfree(sops); + return err; +} + +asmlinkage long sys_oabi_semop(int semid, struct oabi_sembuf __user *tsops, + unsigned nsops) +{ + return sys_oabi_semtimedop(semid, tsops, nsops, NULL); +} + +extern asmlinkage int sys_ipc(uint call, int first, int second, int third, + void __user *ptr, long fifth); + +asmlinkage int sys_oabi_ipc(uint call, int first, int second, int third, + void __user *ptr, long fifth) +{ + switch (call & 0xffff) { + case SEMOP: + return sys_oabi_semtimedop(first, + (struct oabi_sembuf __user *)ptr, + second, NULL); + case SEMTIMEDOP: + return sys_oabi_semtimedop(first, + (struct oabi_sembuf __user *)ptr, + second, + (const struct timespec __user *)fifth); + default: + return sys_ipc(call, first, second, third, ptr, fifth); + } +} -- cgit v1.2.3-70-g09d2