 517ffce4e1
			
		
	
	
	517ffce4e1
	
	
	
		
			
			The Montgomery Multiply, Montgomery Square, and Multiple-Precision Multiply instructions work by loading a combination of the floating point and multiple register windows worth of integer registers with the inputs. These values are 64-bit. But for 32-bit userland processes we only save the low 32-bits of each integer register during a register spill. This is because the register window save area is in the user stack and has a fixed layout. Therefore, the only way to use these instruction in 32-bit mode is to perform the following sequence: 1) Load the top-32bits of a choosen integer register with a sentinel, say "-1". This will be in the outer-most register window. The idea is that we're trying to see if the outer-most register window gets spilled, and thus the 64-bit values were truncated. 2) Load all the inputs for the montmul/montsqr/mpmul instruction, down to the inner-most register window. 3) Execute the opcode. 4) Traverse back up to the outer-most register window. 5) Check the sentinel, if it's still "-1" store the results. Otherwise retry the entire sequence. This retry is extremely troublesome. If you're just unlucky and an interrupt or other trap happens, it'll push that outer-most window to the stack and clear the sentinel when we restore it. We could retry forever and never make forward progress if interrupts arrive at a fast enough rate (consider perf events as one example). So we have do limited retries and fallback to software which is extremely non-deterministic. Luckily it's very straightforward to provide a mechanism to let 32-bit applications use a 64-bit stack. Stacks in 64-bit mode are biased by 2047 bytes, which means that the lowest bit is set in the actual %sp register value. So if we see bit zero set in a 32-bit application's stack we treat it like a 64-bit stack. Runtime detection of such a facility is tricky, and cumbersome at best. For example, just trying to use a biased stack and seeing if it works is hard to recover from (the signal handler will need to use an alt stack, plus something along the lines of longjmp). Therefore, we add a system call to report a bitmask of arch specific features like this in a cheap and less hairy way. With help from Andy Polyakov. Signed-off-by: David S. Miller <davem@davemloft.net>
		
			
				
	
	
		
			310 lines
		
	
	
	
		
			6.3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			310 lines
		
	
	
	
		
			6.3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| #ifndef _ASM_SPARC64_COMPAT_H
 | |
| #define _ASM_SPARC64_COMPAT_H
 | |
| /*
 | |
|  * Architecture specific compatibility types
 | |
|  */
 | |
| #include <linux/types.h>
 | |
| 
 | |
| #define COMPAT_USER_HZ		100
 | |
| #define COMPAT_UTS_MACHINE	"sparc\0\0"
 | |
| 
 | |
| typedef u32		compat_size_t;
 | |
| typedef s32		compat_ssize_t;
 | |
| typedef s32		compat_time_t;
 | |
| typedef s32		compat_clock_t;
 | |
| typedef s32		compat_pid_t;
 | |
| typedef u16		__compat_uid_t;
 | |
| typedef u16		__compat_gid_t;
 | |
| typedef u32		__compat_uid32_t;
 | |
| typedef u32		__compat_gid32_t;
 | |
| typedef u16		compat_mode_t;
 | |
| typedef u32		compat_ino_t;
 | |
| typedef u16		compat_dev_t;
 | |
| typedef s32		compat_off_t;
 | |
| typedef s64		compat_loff_t;
 | |
| typedef s16		compat_nlink_t;
 | |
| typedef u16		compat_ipc_pid_t;
 | |
| typedef s32		compat_daddr_t;
 | |
| typedef u32		compat_caddr_t;
 | |
| typedef __kernel_fsid_t	compat_fsid_t;
 | |
| typedef s32		compat_key_t;
 | |
| typedef s32		compat_timer_t;
 | |
| 
 | |
| typedef s32		compat_int_t;
 | |
| typedef s32		compat_long_t;
 | |
| typedef s64		compat_s64;
 | |
| typedef u32		compat_uint_t;
 | |
| typedef u32		compat_ulong_t;
 | |
| typedef u64		compat_u64;
 | |
| typedef u32		compat_uptr_t;
 | |
| 
 | |
| struct compat_timespec {
 | |
| 	compat_time_t	tv_sec;
 | |
| 	s32		tv_nsec;
 | |
| };
 | |
| 
 | |
| struct compat_timeval {
 | |
| 	compat_time_t	tv_sec;
 | |
| 	s32		tv_usec;
 | |
| };
 | |
| 
 | |
| struct compat_stat {
 | |
| 	compat_dev_t	st_dev;
 | |
| 	compat_ino_t	st_ino;
 | |
| 	compat_mode_t	st_mode;
 | |
| 	compat_nlink_t	st_nlink;
 | |
| 	__compat_uid_t	st_uid;
 | |
| 	__compat_gid_t	st_gid;
 | |
| 	compat_dev_t	st_rdev;
 | |
| 	compat_off_t	st_size;
 | |
| 	compat_time_t	st_atime;
 | |
| 	compat_ulong_t	st_atime_nsec;
 | |
| 	compat_time_t	st_mtime;
 | |
| 	compat_ulong_t	st_mtime_nsec;
 | |
| 	compat_time_t	st_ctime;
 | |
| 	compat_ulong_t	st_ctime_nsec;
 | |
| 	compat_off_t	st_blksize;
 | |
| 	compat_off_t	st_blocks;
 | |
| 	u32		__unused4[2];
 | |
| };
 | |
| 
 | |
| struct compat_stat64 {
 | |
| 	unsigned long long	st_dev;
 | |
| 
 | |
| 	unsigned long long	st_ino;
 | |
| 
 | |
| 	unsigned int	st_mode;
 | |
| 	unsigned int	st_nlink;
 | |
| 
 | |
| 	unsigned int	st_uid;
 | |
| 	unsigned int	st_gid;
 | |
| 
 | |
| 	unsigned long long	st_rdev;
 | |
| 
 | |
| 	unsigned char	__pad3[8];
 | |
| 
 | |
| 	long long	st_size;
 | |
| 	unsigned int	st_blksize;
 | |
| 
 | |
| 	unsigned char	__pad4[8];
 | |
| 	unsigned int	st_blocks;
 | |
| 
 | |
| 	unsigned int	st_atime;
 | |
| 	unsigned int	st_atime_nsec;
 | |
| 
 | |
| 	unsigned int	st_mtime;
 | |
| 	unsigned int	st_mtime_nsec;
 | |
| 
 | |
| 	unsigned int	st_ctime;
 | |
| 	unsigned int	st_ctime_nsec;
 | |
| 
 | |
| 	unsigned int	__unused4;
 | |
| 	unsigned int	__unused5;
 | |
| };
 | |
| 
 | |
| struct compat_flock {
 | |
| 	short		l_type;
 | |
| 	short		l_whence;
 | |
| 	compat_off_t	l_start;
 | |
| 	compat_off_t	l_len;
 | |
| 	compat_pid_t	l_pid;
 | |
| 	short		__unused;
 | |
| };
 | |
| 
 | |
| #define F_GETLK64	12
 | |
| #define F_SETLK64	13
 | |
| #define F_SETLKW64	14
 | |
| 
 | |
| struct compat_flock64 {
 | |
| 	short		l_type;
 | |
| 	short		l_whence;
 | |
| 	compat_loff_t	l_start;
 | |
| 	compat_loff_t	l_len;
 | |
| 	compat_pid_t	l_pid;
 | |
| 	short		__unused;
 | |
| };
 | |
| 
 | |
| struct compat_statfs {
 | |
| 	int		f_type;
 | |
| 	int		f_bsize;
 | |
| 	int		f_blocks;
 | |
| 	int		f_bfree;
 | |
| 	int		f_bavail;
 | |
| 	int		f_files;
 | |
| 	int		f_ffree;
 | |
| 	compat_fsid_t	f_fsid;
 | |
| 	int		f_namelen;	/* SunOS ignores this field. */
 | |
| 	int		f_frsize;
 | |
| 	int		f_flags;
 | |
| 	int		f_spare[4];
 | |
| };
 | |
| 
 | |
| #define COMPAT_RLIM_INFINITY 0x7fffffff
 | |
| 
 | |
| typedef u32		compat_old_sigset_t;
 | |
| 
 | |
| #define _COMPAT_NSIG		64
 | |
| #define _COMPAT_NSIG_BPW	32
 | |
| 
 | |
| typedef u32		compat_sigset_word;
 | |
| 
 | |
| typedef union compat_sigval {
 | |
| 	compat_int_t	sival_int;
 | |
| 	compat_uptr_t	sival_ptr;
 | |
| } compat_sigval_t;
 | |
| 
 | |
| #define SI_PAD_SIZE32	(128/sizeof(int) - 3)
 | |
| 
 | |
| typedef struct compat_siginfo {
 | |
| 	int si_signo;
 | |
| 	int si_errno;
 | |
| 	int si_code;
 | |
| 
 | |
| 	union {
 | |
| 		int _pad[SI_PAD_SIZE32];
 | |
| 
 | |
| 		/* kill() */
 | |
| 		struct {
 | |
| 			compat_pid_t _pid;		/* sender's pid */
 | |
| 			unsigned int _uid;		/* sender's uid */
 | |
| 		} _kill;
 | |
| 
 | |
| 		/* POSIX.1b timers */
 | |
| 		struct {
 | |
| 			compat_timer_t _tid;		/* timer id */
 | |
| 			int _overrun;			/* overrun count */
 | |
| 			compat_sigval_t _sigval;	/* same as below */
 | |
| 			int _sys_private;	/* not to be passed to user */
 | |
| 		} _timer;
 | |
| 
 | |
| 		/* POSIX.1b signals */
 | |
| 		struct {
 | |
| 			compat_pid_t _pid;		/* sender's pid */
 | |
| 			unsigned int _uid;		/* sender's uid */
 | |
| 			compat_sigval_t _sigval;
 | |
| 		} _rt;
 | |
| 
 | |
| 		/* SIGCHLD */
 | |
| 		struct {
 | |
| 			compat_pid_t _pid;		/* which child */
 | |
| 			unsigned int _uid;		/* sender's uid */
 | |
| 			int _status;			/* exit code */
 | |
| 			compat_clock_t _utime;
 | |
| 			compat_clock_t _stime;
 | |
| 		} _sigchld;
 | |
| 
 | |
| 		/* SIGILL, SIGFPE, SIGSEGV, SIGBUS, SIGEMT */
 | |
| 		struct {
 | |
| 			u32 _addr; /* faulting insn/memory ref. */
 | |
| 			int _trapno;
 | |
| 		} _sigfault;
 | |
| 
 | |
| 		/* SIGPOLL */
 | |
| 		struct {
 | |
| 			int _band;	/* POLL_IN, POLL_OUT, POLL_MSG */
 | |
| 			int _fd;
 | |
| 		} _sigpoll;
 | |
| 	} _sifields;
 | |
| } compat_siginfo_t;
 | |
| 
 | |
| #define COMPAT_OFF_T_MAX	0x7fffffff
 | |
| #define COMPAT_LOFF_T_MAX	0x7fffffffffffffffL
 | |
| 
 | |
| /*
 | |
|  * A pointer passed in from user mode. This should not
 | |
|  * be used for syscall parameters, just declare them
 | |
|  * as pointers because the syscall entry code will have
 | |
|  * appropriately converted them already.
 | |
|  */
 | |
| 
 | |
| static inline void __user *compat_ptr(compat_uptr_t uptr)
 | |
| {
 | |
| 	return (void __user *)(unsigned long)uptr;
 | |
| }
 | |
| 
 | |
| static inline compat_uptr_t ptr_to_compat(void __user *uptr)
 | |
| {
 | |
| 	return (u32)(unsigned long)uptr;
 | |
| }
 | |
| 
 | |
| static inline void __user *arch_compat_alloc_user_space(long len)
 | |
| {
 | |
| 	struct pt_regs *regs = current_thread_info()->kregs;
 | |
| 	unsigned long usp = regs->u_regs[UREG_I6];
 | |
| 
 | |
| 	if (test_thread_64bit_stack(usp))
 | |
| 		usp += STACK_BIAS;
 | |
| 
 | |
| 	if (test_thread_flag(TIF_32BIT))
 | |
| 		usp &= 0xffffffffUL;
 | |
| 
 | |
| 	usp -= len;
 | |
| 	usp &= ~0x7UL;
 | |
| 
 | |
| 	return (void __user *) usp;
 | |
| }
 | |
| 
 | |
| struct compat_ipc64_perm {
 | |
| 	compat_key_t key;
 | |
| 	__compat_uid32_t uid;
 | |
| 	__compat_gid32_t gid;
 | |
| 	__compat_uid32_t cuid;
 | |
| 	__compat_gid32_t cgid;
 | |
| 	unsigned short __pad1;
 | |
| 	compat_mode_t mode;
 | |
| 	unsigned short __pad2;
 | |
| 	unsigned short seq;
 | |
| 	unsigned long __unused1;	/* yes they really are 64bit pads */
 | |
| 	unsigned long __unused2;
 | |
| };
 | |
| 
 | |
| struct compat_semid64_ds {
 | |
| 	struct compat_ipc64_perm sem_perm;
 | |
| 	unsigned int	__pad1;
 | |
| 	compat_time_t	sem_otime;
 | |
| 	unsigned int	__pad2;
 | |
| 	compat_time_t	sem_ctime;
 | |
| 	u32		sem_nsems;
 | |
| 	u32		__unused1;
 | |
| 	u32		__unused2;
 | |
| };
 | |
| 
 | |
| struct compat_msqid64_ds {
 | |
| 	struct compat_ipc64_perm msg_perm;
 | |
| 	unsigned int	__pad1;
 | |
| 	compat_time_t	msg_stime;
 | |
| 	unsigned int	__pad2;
 | |
| 	compat_time_t	msg_rtime;
 | |
| 	unsigned int	__pad3;
 | |
| 	compat_time_t	msg_ctime;
 | |
| 	unsigned int	msg_cbytes;
 | |
| 	unsigned int	msg_qnum;
 | |
| 	unsigned int	msg_qbytes;
 | |
| 	compat_pid_t	msg_lspid;
 | |
| 	compat_pid_t	msg_lrpid;
 | |
| 	unsigned int	__unused1;
 | |
| 	unsigned int	__unused2;
 | |
| };
 | |
| 
 | |
| struct compat_shmid64_ds {
 | |
| 	struct compat_ipc64_perm shm_perm;
 | |
| 	unsigned int	__pad1;
 | |
| 	compat_time_t	shm_atime;
 | |
| 	unsigned int	__pad2;
 | |
| 	compat_time_t	shm_dtime;
 | |
| 	unsigned int	__pad3;
 | |
| 	compat_time_t	shm_ctime;
 | |
| 	compat_size_t	shm_segsz;
 | |
| 	compat_pid_t	shm_cpid;
 | |
| 	compat_pid_t	shm_lpid;
 | |
| 	unsigned int	shm_nattch;
 | |
| 	unsigned int	__unused1;
 | |
| 	unsigned int	__unused2;
 | |
| };
 | |
| 
 | |
| static inline int is_compat_task(void)
 | |
| {
 | |
| 	return test_thread_flag(TIF_32BIT);
 | |
| }
 | |
| 
 | |
| #endif /* _ASM_SPARC64_COMPAT_H */
 |