Commit 2c680514 authored by Daniel Palmer's avatar Daniel Palmer Committed by Greg Ungerer
Browse files

m68k: Fix task info flags handling for 68000 



The logic for deciding what to do after a syscall should be checking
if any of the lower byte bits are set and then checking if the reschedule
bit is set.

Currently we are loading the top word, checking if any bits are set
(which never seems to be true) and thus jumping over loading the
whole long and checking if the reschedule bit is set.

We get the thread info in two places so split that logic out in
a macro and then fix the code so that it loads the byte of the flags
we need to check, checks if anything is set and then checks if
the reschedule bit in particular is set.

Reported-by: default avatarChristoph Plattner <christoph.plattner@gmx.at>
Signed-off-by: default avatarDaniel Palmer <daniel@0x0f.com>
Signed-off-by: default avatarGreg Ungerer <gerg@kernel.org>
parent 591cd656

arch/m68k/68000/entry.S

+13 −8
Original line number Diff line number Diff line
@@ -18,6 +18,13 @@ 


.text



/* get thread_info pointer into a2 */

 .macro getthreadinfo

	movel	%sp,%d1

	andl	#-THREAD_SIZE,%d1

	movel	%d1,%a2

 .endm



.globl system_call

.globl resume

.globl ret_from_exception
@@ -70,9 +77,8 @@ ENTRY(system_call) 


	movel	%sp@(PT_OFF_ORIG_D0),%d0



	movel	%sp,%d1			/* get thread_info pointer */

	andl	#-THREAD_SIZE,%d1

	movel	%d1,%a2

	/* Doing a trace ? */

	getthreadinfo

	btst	#(TIF_SYSCALL_TRACE%8),%a2@(TINFO_FLAGS+(31-TIF_SYSCALL_TRACE)/8)

	jne	do_trace

	cmpl	#NR_syscalls,%d0
@@ -96,16 +102,15 @@ Luser_return: 
	/* heavy interrupt load*/

	andw	#ALLOWINT,%sr



	movel	%sp,%d1			/* get thread_info pointer */

	andl	#-THREAD_SIZE,%d1

	movel	%d1,%a2

	getthreadinfo

1:

	move	%a2@(TINFO_FLAGS),%d1	/* thread_info->flags */

	/* check if any of the flags are set */

	moveb	%a2@(TINFO_FLAGS + 3),%d1	/* thread_info->flags (low 8 bits) */

	jne	Lwork_to_do

	RESTORE_ALL



Lwork_to_do:

	movel	%a2@(TINFO_FLAGS),%d1	/* thread_info->flags */

	/* check if reschedule needs to be called */

	btst	#TIF_NEED_RESCHED,%d1

	jne	reschedule