Prepare for the removal of 'usersp', by simplifying PER_CPU(old_rsp) usage:
  - use it only as temp storage
  - store the userspace stack pointer immediately in pt_regs->sp
    on syscall entry, instead of using it later, on syscall exit.
  - change C code to use pt_regs->sp only, instead of PER_CPU(old_rsp)
    and task->thread.usersp.
FIXUP/RESTORE_TOP_OF_STACK are simplified as well.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1425926364-9526-4-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
		
	
			
		
			
				
	
	
		
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			324 lines
		
	
	
	
		
			7.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
#ifndef _ASM_X86_COMPAT_H
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#define _ASM_X86_COMPAT_H
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/*
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 * Architecture specific compatibility types
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 */
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#include <linux/types.h>
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#include <linux/sched.h>
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#include <asm/processor.h>
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#include <asm/user32.h>
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#include <asm/unistd.h>
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#define COMPAT_USER_HZ		100
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#define COMPAT_UTS_MACHINE	"i686\0\0"
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typedef u32		compat_size_t;
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typedef s32		compat_ssize_t;
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typedef s32		compat_time_t;
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typedef s32		compat_clock_t;
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typedef s32		compat_pid_t;
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typedef u16		__compat_uid_t;
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typedef u16		__compat_gid_t;
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typedef u32		__compat_uid32_t;
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typedef u32		__compat_gid32_t;
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typedef u16		compat_mode_t;
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typedef u32		compat_ino_t;
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typedef u16		compat_dev_t;
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typedef s32		compat_off_t;
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typedef s64		compat_loff_t;
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typedef u16		compat_nlink_t;
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typedef u16		compat_ipc_pid_t;
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typedef s32		compat_daddr_t;
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typedef u32		compat_caddr_t;
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typedef __kernel_fsid_t	compat_fsid_t;
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typedef s32		compat_timer_t;
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typedef s32		compat_key_t;
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typedef s32		compat_int_t;
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typedef s32		compat_long_t;
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typedef s64 __attribute__((aligned(4))) compat_s64;
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typedef u32		compat_uint_t;
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typedef u32		compat_ulong_t;
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typedef u64 __attribute__((aligned(4))) compat_u64;
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typedef u32		compat_uptr_t;
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struct compat_timespec {
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	compat_time_t	tv_sec;
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	s32		tv_nsec;
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};
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struct compat_timeval {
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	compat_time_t	tv_sec;
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	s32		tv_usec;
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};
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struct compat_stat {
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	compat_dev_t	st_dev;
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	u16		__pad1;
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	compat_ino_t	st_ino;
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	compat_mode_t	st_mode;
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	compat_nlink_t	st_nlink;
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	__compat_uid_t	st_uid;
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	__compat_gid_t	st_gid;
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	compat_dev_t	st_rdev;
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	u16		__pad2;
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	u32		st_size;
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	u32		st_blksize;
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	u32		st_blocks;
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	u32		st_atime;
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	u32		st_atime_nsec;
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	u32		st_mtime;
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	u32		st_mtime_nsec;
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	u32		st_ctime;
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	u32		st_ctime_nsec;
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	u32		__unused4;
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	u32		__unused5;
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};
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struct compat_flock {
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	short		l_type;
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	short		l_whence;
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	compat_off_t	l_start;
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	compat_off_t	l_len;
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	compat_pid_t	l_pid;
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};
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#define F_GETLK64	12	/*  using 'struct flock64' */
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#define F_SETLK64	13
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#define F_SETLKW64	14
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/*
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 * IA32 uses 4 byte alignment for 64 bit quantities,
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 * so we need to pack this structure.
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 */
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struct compat_flock64 {
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	short		l_type;
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	short		l_whence;
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	compat_loff_t	l_start;
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	compat_loff_t	l_len;
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	compat_pid_t	l_pid;
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} __attribute__((packed));
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struct compat_statfs {
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	int		f_type;
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	int		f_bsize;
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	int		f_blocks;
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	int		f_bfree;
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	int		f_bavail;
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	int		f_files;
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	int		f_ffree;
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	compat_fsid_t	f_fsid;
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	int		f_namelen;	/* SunOS ignores this field. */
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	int		f_frsize;
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	int		f_flags;
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	int		f_spare[4];
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};
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#define COMPAT_RLIM_OLD_INFINITY	0x7fffffff
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#define COMPAT_RLIM_INFINITY		0xffffffff
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typedef u32		compat_old_sigset_t;	/* at least 32 bits */
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#define _COMPAT_NSIG		64
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#define _COMPAT_NSIG_BPW	32
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typedef u32               compat_sigset_word;
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typedef union compat_sigval {
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	compat_int_t	sival_int;
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	compat_uptr_t	sival_ptr;
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} compat_sigval_t;
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typedef struct compat_siginfo {
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	int si_signo;
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	int si_errno;
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	int si_code;
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	union {
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		int _pad[128/sizeof(int) - 3];
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		/* kill() */
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		struct {
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			unsigned int _pid;	/* sender's pid */
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			unsigned int _uid;	/* sender's uid */
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		} _kill;
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		/* POSIX.1b timers */
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		struct {
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			compat_timer_t _tid;	/* timer id */
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			int _overrun;		/* overrun count */
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			compat_sigval_t _sigval;	/* same as below */
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			int _sys_private;	/* not to be passed to user */
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			int _overrun_incr;	/* amount to add to overrun */
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		} _timer;
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		/* POSIX.1b signals */
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		struct {
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			unsigned int _pid;	/* sender's pid */
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			unsigned int _uid;	/* sender's uid */
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			compat_sigval_t _sigval;
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		} _rt;
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		/* SIGCHLD */
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		struct {
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			unsigned int _pid;	/* which child */
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			unsigned int _uid;	/* sender's uid */
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			int _status;		/* exit code */
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			compat_clock_t _utime;
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			compat_clock_t _stime;
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		} _sigchld;
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		/* SIGCHLD (x32 version) */
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		struct {
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			unsigned int _pid;	/* which child */
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			unsigned int _uid;	/* sender's uid */
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			int _status;		/* exit code */
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			compat_s64 _utime;
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			compat_s64 _stime;
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		} _sigchld_x32;
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		/* SIGILL, SIGFPE, SIGSEGV, SIGBUS */
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		struct {
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			unsigned int _addr;	/* faulting insn/memory ref. */
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		} _sigfault;
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		/* SIGPOLL */
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		struct {
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			int _band;	/* POLL_IN, POLL_OUT, POLL_MSG */
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			int _fd;
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		} _sigpoll;
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		struct {
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			unsigned int _call_addr; /* calling insn */
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			int _syscall;	/* triggering system call number */
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			unsigned int _arch;	/* AUDIT_ARCH_* of syscall */
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		} _sigsys;
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	} _sifields;
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} compat_siginfo_t;
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#define COMPAT_OFF_T_MAX	0x7fffffff
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#define COMPAT_LOFF_T_MAX	0x7fffffffffffffffL
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struct compat_ipc64_perm {
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	compat_key_t key;
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	__compat_uid32_t uid;
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	__compat_gid32_t gid;
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	__compat_uid32_t cuid;
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	__compat_gid32_t cgid;
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	unsigned short mode;
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	unsigned short __pad1;
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	unsigned short seq;
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	unsigned short __pad2;
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	compat_ulong_t unused1;
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	compat_ulong_t unused2;
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};
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struct compat_semid64_ds {
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	struct compat_ipc64_perm sem_perm;
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	compat_time_t  sem_otime;
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	compat_ulong_t __unused1;
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	compat_time_t  sem_ctime;
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	compat_ulong_t __unused2;
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	compat_ulong_t sem_nsems;
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	compat_ulong_t __unused3;
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	compat_ulong_t __unused4;
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};
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struct compat_msqid64_ds {
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	struct compat_ipc64_perm msg_perm;
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	compat_time_t  msg_stime;
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	compat_ulong_t __unused1;
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	compat_time_t  msg_rtime;
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	compat_ulong_t __unused2;
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	compat_time_t  msg_ctime;
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	compat_ulong_t __unused3;
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	compat_ulong_t msg_cbytes;
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	compat_ulong_t msg_qnum;
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	compat_ulong_t msg_qbytes;
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	compat_pid_t   msg_lspid;
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	compat_pid_t   msg_lrpid;
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	compat_ulong_t __unused4;
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	compat_ulong_t __unused5;
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};
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struct compat_shmid64_ds {
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	struct compat_ipc64_perm shm_perm;
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	compat_size_t  shm_segsz;
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	compat_time_t  shm_atime;
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	compat_ulong_t __unused1;
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	compat_time_t  shm_dtime;
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	compat_ulong_t __unused2;
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	compat_time_t  shm_ctime;
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	compat_ulong_t __unused3;
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	compat_pid_t   shm_cpid;
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	compat_pid_t   shm_lpid;
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	compat_ulong_t shm_nattch;
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	compat_ulong_t __unused4;
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	compat_ulong_t __unused5;
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};
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/*
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 * The type of struct elf_prstatus.pr_reg in compatible core dumps.
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 */
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#ifdef CONFIG_X86_X32_ABI
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typedef struct user_regs_struct compat_elf_gregset_t;
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#define PR_REG_SIZE(S) (test_thread_flag(TIF_IA32) ? 68 : 216)
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#define PRSTATUS_SIZE(S) (test_thread_flag(TIF_IA32) ? 144 : 296)
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#define SET_PR_FPVALID(S,V) \
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  do { *(int *) (((void *) &((S)->pr_reg)) + PR_REG_SIZE(0)) = (V); } \
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  while (0)
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#define COMPAT_USE_64BIT_TIME \
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	(!!(task_pt_regs(current)->orig_ax & __X32_SYSCALL_BIT))
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#else
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typedef struct user_regs_struct32 compat_elf_gregset_t;
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#endif
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/*
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 * A pointer passed in from user mode. This should not
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 * be used for syscall parameters, just declare them
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 * as pointers because the syscall entry code will have
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 * appropriately converted them already.
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 */
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static inline void __user *compat_ptr(compat_uptr_t uptr)
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{
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	return (void __user *)(unsigned long)uptr;
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}
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static inline compat_uptr_t ptr_to_compat(void __user *uptr)
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{
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	return (u32)(unsigned long)uptr;
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}
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static inline void __user *arch_compat_alloc_user_space(long len)
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{
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	compat_uptr_t sp;
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	if (test_thread_flag(TIF_IA32)) {
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		sp = task_pt_regs(current)->sp;
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	} else {
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		/* -128 for the x32 ABI redzone */
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		sp = task_pt_regs(current)->sp - 128;
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	}
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	return (void __user *)round_down(sp - len, 16);
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}
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static inline bool is_x32_task(void)
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{
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#ifdef CONFIG_X86_X32_ABI
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	if (task_pt_regs(current)->orig_ax & __X32_SYSCALL_BIT)
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		return true;
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#endif
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	return false;
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}
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static inline bool is_compat_task(void)
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{
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	return is_ia32_task() || is_x32_task();
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}
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#endif /* _ASM_X86_COMPAT_H */
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