android_kernel_samsung_msm8976/arch/tile/kernel/compat.c
Chris Metcalf ce7f2a3967 arch/tile: make ptrace() work properly for TILE-Gx COMPAT mode
Previously, we tried to pass 64-bit arguments through the
"COMPAT" mode 32-bit syscall API, which turned out not to work
well.  Now we just use straight 32-bit arguments in COMPAT mode,
thus requiring individual registers to be read/written with
two syscalls.  Of course this is uncommon, since usually all
the registers are read or written at once.

The restructuring applies to all the tile platforms, but is
plausibly better than the original code in any case.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-15 15:39:44 -04:00

173 lines
5 KiB
C

/*
* Copyright 2010 Tilera Corporation. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*/
/* Adjust unistd.h to provide 32-bit numbers and functions. */
#define __SYSCALL_COMPAT
#include <linux/compat.h>
#include <linux/msg.h>
#include <linux/syscalls.h>
#include <linux/kdev_t.h>
#include <linux/fs.h>
#include <linux/fcntl.h>
#include <linux/smp_lock.h>
#include <linux/uaccess.h>
#include <linux/signal.h>
#include <asm/syscalls.h>
/*
* Syscalls that take 64-bit numbers traditionally take them in 32-bit
* "high" and "low" value parts on 32-bit architectures.
* In principle, one could imagine passing some register arguments as
* fully 64-bit on TILE-Gx in 32-bit mode, but it seems easier to
* adapt the usual convention.
*/
long compat_sys_truncate64(char __user *filename, u32 dummy, u32 low, u32 high)
{
return sys_truncate(filename, ((loff_t)high << 32) | low);
}
long compat_sys_ftruncate64(unsigned int fd, u32 dummy, u32 low, u32 high)
{
return sys_ftruncate(fd, ((loff_t)high << 32) | low);
}
long compat_sys_pread64(unsigned int fd, char __user *ubuf, size_t count,
u32 dummy, u32 low, u32 high)
{
return sys_pread64(fd, ubuf, count, ((loff_t)high << 32) | low);
}
long compat_sys_pwrite64(unsigned int fd, char __user *ubuf, size_t count,
u32 dummy, u32 low, u32 high)
{
return sys_pwrite64(fd, ubuf, count, ((loff_t)high << 32) | low);
}
long compat_sys_lookup_dcookie(u32 low, u32 high, char __user *buf, size_t len)
{
return sys_lookup_dcookie(((loff_t)high << 32) | low, buf, len);
}
long compat_sys_sync_file_range2(int fd, unsigned int flags,
u32 offset_lo, u32 offset_hi,
u32 nbytes_lo, u32 nbytes_hi)
{
return sys_sync_file_range(fd, ((loff_t)offset_hi << 32) | offset_lo,
((loff_t)nbytes_hi << 32) | nbytes_lo,
flags);
}
long compat_sys_fallocate(int fd, int mode,
u32 offset_lo, u32 offset_hi,
u32 len_lo, u32 len_hi)
{
return sys_fallocate(fd, mode, ((loff_t)offset_hi << 32) | offset_lo,
((loff_t)len_hi << 32) | len_lo);
}
long compat_sys_sched_rr_get_interval(compat_pid_t pid,
struct compat_timespec __user *interval)
{
struct timespec t;
int ret;
mm_segment_t old_fs = get_fs();
set_fs(KERNEL_DS);
ret = sys_sched_rr_get_interval(pid,
(struct timespec __force __user *)&t);
set_fs(old_fs);
if (put_compat_timespec(&t, interval))
return -EFAULT;
return ret;
}
/*
* The usual compat_sys_msgsnd() and _msgrcv() seem to be assuming
* some different calling convention than our normal 32-bit tile code.
*/
/* Already defined in ipc/compat.c, but we need it here. */
struct compat_msgbuf {
compat_long_t mtype;
char mtext[1];
};
long tile_compat_sys_msgsnd(int msqid,
struct compat_msgbuf __user *msgp,
size_t msgsz, int msgflg)
{
compat_long_t mtype;
if (get_user(mtype, &msgp->mtype))
return -EFAULT;
return do_msgsnd(msqid, mtype, msgp->mtext, msgsz, msgflg);
}
long tile_compat_sys_msgrcv(int msqid,
struct compat_msgbuf __user *msgp,
size_t msgsz, long msgtyp, int msgflg)
{
long err, mtype;
err = do_msgrcv(msqid, &mtype, msgp->mtext, msgsz, msgtyp, msgflg);
if (err < 0)
goto out;
if (put_user(mtype, &msgp->mtype))
err = -EFAULT;
out:
return err;
}
/* Provide the compat syscall number to call mapping. */
#undef __SYSCALL
#define __SYSCALL(nr, call) [nr] = (compat_##call),
/* The generic versions of these don't work for Tile. */
#define compat_sys_msgrcv tile_compat_sys_msgrcv
#define compat_sys_msgsnd tile_compat_sys_msgsnd
/* See comments in sys.c */
#define compat_sys_fadvise64 sys32_fadvise64
#define compat_sys_fadvise64_64 sys32_fadvise64_64
#define compat_sys_readahead sys32_readahead
#define compat_sys_sync_file_range compat_sys_sync_file_range2
/* The native 64-bit "struct stat" matches the 32-bit "struct stat64". */
#define compat_sys_stat64 sys_newstat
#define compat_sys_lstat64 sys_newlstat
#define compat_sys_fstat64 sys_newfstat
#define compat_sys_fstatat64 sys_newfstatat
/* The native sys_ptrace dynamically handles compat binaries. */
#define compat_sys_ptrace sys_ptrace
/* Call the trampolines to manage pt_regs where necessary. */
#define compat_sys_execve _compat_sys_execve
#define compat_sys_sigaltstack _compat_sys_sigaltstack
#define compat_sys_rt_sigreturn _compat_sys_rt_sigreturn
#define sys_clone _sys_clone
/*
* Note that we can't include <linux/unistd.h> here since the header
* guard will defeat us; <asm/unistd.h> checks for __SYSCALL as well.
*/
void *compat_sys_call_table[__NR_syscalls] = {
[0 ... __NR_syscalls-1] = sys_ni_syscall,
#include <asm/unistd.h>
};