Commit 3185bd26 authored by Al Viro's avatar Al Viro Committed by Linus Torvalds
Browse files

alpha: separate thread-synchronous flags 



... and fix the race in updating unaligned control ones

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3d0ceac1

arch/alpha/include/asm/thread_info.h

+54 −26
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
#include <asm/processor.h>

#include <asm/types.h>

#include <asm/hwrpb.h>

#include <asm/sysinfo.h>

#endif



#ifndef __ASSEMBLY__
@@ -21,6 +22,7 @@ struct thread_info { 
	mm_segment_t		addr_limit;	/* thread address space */

	unsigned		cpu;		/* current CPU */

	int			preempt_count; /* 0 => preemptable, <0 => BUG */

	unsigned int		status;		/* thread-synchronous flags */



	int bpt_nsaved;

	unsigned long bpt_addr[2];		/* breakpoint handling  */
@@ -63,8 +65,6 @@ register struct thread_info *__current_thread_info __asm__("$8"); 
 * - these are process state flags and used from assembly

 * - pending work-to-be-done flags come first and must be assigned to be

 *   within bits 0 to 7 to fit in and immediate operand.

 * - ALPHA_UAC_SHIFT below must be kept consistent with the unaligned

 *   control flags.

 *

 * TIF_SYSCALL_TRACE is known to be 0 via blbs.

 */
@@ -72,18 +72,12 @@ register struct thread_info *__current_thread_info __asm__("$8"); 
#define TIF_NOTIFY_RESUME	1	/* callback before returning to user */

#define TIF_SIGPENDING		2	/* signal pending */

#define TIF_NEED_RESCHED	3	/* rescheduling necessary */

#define TIF_POLLING_NRFLAG	8	/* poll_idle is polling NEED_RESCHED */

#define TIF_DIE_IF_KERNEL	9	/* dik recursion lock */

#define TIF_UAC_NOPRINT		10	/* ! Preserve sequence of following */

#define TIF_UAC_NOFIX		11	/* ! flags as they match            */

#define TIF_UAC_SIGBUS		12	/* ! userspace part of 'osf_sysinfo' */

#define TIF_MEMDIE		13	/* is terminating due to OOM killer */

#define TIF_RESTORE_SIGMASK	14	/* restore signal mask in do_signal */



#define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)

#define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)

#define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)

#define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)

#define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)



/* Work to do on interrupt/exception return.  */
@@ -94,29 +88,63 @@ register struct thread_info *__current_thread_info __asm__("$8"); 
#define _TIF_ALLWORK_MASK	(_TIF_WORK_MASK		\

				 | _TIF_SYSCALL_TRACE)



#define ALPHA_UAC_SHIFT		TIF_UAC_NOPRINT

#define ALPHA_UAC_MASK		(1 << TIF_UAC_NOPRINT | 1 << TIF_UAC_NOFIX | \

				 1 << TIF_UAC_SIGBUS)

#define TS_UAC_NOPRINT		0x0001	/* ! Preserve the following three */

#define TS_UAC_NOFIX		0x0002	/* ! flags as they match          */

#define TS_UAC_SIGBUS		0x0004	/* ! userspace part of 'osf_sysinfo' */

#define TS_RESTORE_SIGMASK	0x0008	/* restore signal mask in do_signal() */

#define TS_POLLING		0x0010	/* idle task polling need_resched,

					   skip sending interrupt */



#define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)



#ifndef __ASSEMBLY__

#define HAVE_SET_RESTORE_SIGMASK	1

static inline void set_restore_sigmask(void)

{

	struct thread_info *ti = current_thread_info();

	ti->status |= TS_RESTORE_SIGMASK;

	WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags));

}

static inline void clear_restore_sigmask(void)

{

	current_thread_info()->status &= ~TS_RESTORE_SIGMASK;

}

static inline bool test_restore_sigmask(void)

{

	return current_thread_info()->status & TS_RESTORE_SIGMASK;

}

static inline bool test_and_clear_restore_sigmask(void)

{

	struct thread_info *ti = current_thread_info();

	if (!(ti->status & TS_RESTORE_SIGMASK))

		return false;

	ti->status &= ~TS_RESTORE_SIGMASK;

	return true;

}

#endif



#define SET_UNALIGN_CTL(task,value)	({				\

	task_thread_info(task)->flags = ((task_thread_info(task)->flags &    \

		~ALPHA_UAC_MASK)					     \

		| (((value) << ALPHA_UAC_SHIFT)       & (1<<TIF_UAC_NOPRINT))\

		| (((value) << (ALPHA_UAC_SHIFT + 1)) & (1<<TIF_UAC_SIGBUS)) \

		| (((value) << (ALPHA_UAC_SHIFT - 1)) & (1<<TIF_UAC_NOFIX)));\

	__u32 status = task_thread_info(task)->status & ~UAC_BITMASK;	\

	if (value & PR_UNALIGN_NOPRINT)					\

		status |= TS_UAC_NOPRINT;				\

	if (value & PR_UNALIGN_SIGBUS)					\

		status |= TS_UAC_SIGBUS;				\

	if (value & 4)	/* alpha-specific */				\

		status |= TS_UAC_NOFIX;					\

	task_thread_info(task)->status = status;			\

	0; })



#define GET_UNALIGN_CTL(task,value)	({				\

	put_user((task_thread_info(task)->flags & (1 << TIF_UAC_NOPRINT))\

		  >> ALPHA_UAC_SHIFT					\

		 | (task_thread_info(task)->flags & (1 << TIF_UAC_SIGBUS))\

		 >> (ALPHA_UAC_SHIFT + 1)				\

		 | (task_thread_info(task)->flags & (1 << TIF_UAC_NOFIX))\

		 >> (ALPHA_UAC_SHIFT - 1),				\

		 (int __user *)(value));				\

	__u32 status = task_thread_info(task)->status & ~UAC_BITMASK;	\

	__u32 res = 0;							\

	if (status & TS_UAC_NOPRINT)					\

		res |= PR_UNALIGN_NOPRINT;				\

	if (status & TS_UAC_SIGBUS)					\

		res |= PR_UNALIGN_SIGBUS;				\

	if (status & TS_UAC_NOFIX)					\

		res |= 4;						\

	put_user(res, (int __user *)(value));				\

	})



#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)



#endif /* __KERNEL__ */

#endif /* _ALPHA_THREAD_INFO_H */

arch/alpha/kernel/osf_sys.c

+10 −15
Original line number Diff line number Diff line
@@ -793,8 +793,7 @@ SYSCALL_DEFINE5(osf_getsysinfo, unsigned long, op, void __user *, buffer, 
 	case GSI_UACPROC:

		if (nbytes < sizeof(unsigned int))

			return -EINVAL;

		w = (current_thread_info()->flags >> ALPHA_UAC_SHIFT) &

			UAC_BITMASK;

		w = current_thread_info()->status & UAC_BITMASK;

		if (put_user(w, (unsigned int __user *)buffer))

			return -EFAULT;

 		return 1;
@@ -904,24 +903,20 @@ SYSCALL_DEFINE5(osf_setsysinfo, unsigned long, op, void __user *, buffer, 
		break;



 	case SSI_NVPAIRS: {

		unsigned long v, w, i;

		unsigned int old, new;

		unsigned __user *p = buffer;

		unsigned i;

		

 		for (i = 0; i < nbytes; ++i) {

		for (i = 0, p = buffer; i < nbytes; ++i, p += 2) {

			unsigned v, w, status;



 			if (get_user(v, 2*i + (unsigned int __user *)buffer))

 				return -EFAULT;

 			if (get_user(w, 2*i + 1 + (unsigned int __user *)buffer))

			if (get_user(v, p) || get_user(w, p + 1))

 				return -EFAULT;

 			switch (v) {

 			case SSIN_UACPROC:

			again:

				old = current_thread_info()->flags;

				new = old & ~(UAC_BITMASK << ALPHA_UAC_SHIFT);

				new = new | (w & UAC_BITMASK) << ALPHA_UAC_SHIFT;

				if (cmpxchg(&current_thread_info()->flags,

					    old, new) != old)

					goto again;

				w &= UAC_BITMASK;

				status = current_thread_info()->status;

				status = (status & ~UAC_BITMASK) | w;

				current_thread_info()->status = status;

 				break;

 

 			default:

arch/alpha/kernel/process.c

+1 −1
Original line number Diff line number Diff line
@@ -49,7 +49,7 @@ EXPORT_SYMBOL(pm_power_off); 
void

cpu_idle(void)

{

	set_thread_flag(TIF_POLLING_NRFLAG);

	current_thread_info()->status |= TS_POLLING;



	while (1) {

		/* FIXME -- EV6 and LCA45 know how to power down

arch/alpha/kernel/traps.c

+3 −3
Original line number Diff line number Diff line
@@ -780,17 +780,17 @@ do_entUnaUser(void __user * va, unsigned long opcode, 
	/* Check the UAC bits to decide what the user wants us to do

	   with the unaliged access.  */



	if (!test_thread_flag (TIF_UAC_NOPRINT)) {

	if (!(current_thread_info()->status & TS_UAC_NOPRINT)) {

		if (__ratelimit(&ratelimit)) {

			printk("%s(%d): unaligned trap at %016lx: %p %lx %ld\n",

			       current->comm, task_pid_nr(current),

			       regs->pc - 4, va, opcode, reg);

		}

	}

	if (test_thread_flag (TIF_UAC_SIGBUS))

	if ((current_thread_info()->status & TS_UAC_SIGBUS))

		goto give_sigbus;

	/* Not sure why you'd want to use this, but... */

	if (test_thread_flag (TIF_UAC_NOFIX))

	if ((current_thread_info()->status & TS_UAC_NOFIX))

		return;



	/* Don't bother reading ds in the access check since we already