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Commit e9f92526 authored by Al Viro's avatar Al Viro
Browse files

microblaze: fix handling of multiple pending signals 



We need to keep building sigframes until no pending signals remain.
Wrap do_notify_resume() calls into loops; do _not_ allow syscall
restart logics to trigger after the first iteration.

Incidentally, comments about pending signals that should (somehow)
be in r18 are pure BS.  Doesn't work that way and cannot work that
way, sorry...

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 14203e19

arch/microblaze/kernel/entry-nommu.S

+11 −2
Original line number Diff line number Diff line
@@ -124,6 +124,7 @@ ret_from_intr: 
	lwi	r11, r1, PT_MODE

	bneid	r11, no_intr_resched



3:

	lwi	r6, r31, TS_THREAD_INFO	/* get thread info */

	lwi	r19, r6, TI_FLAGS	/* get flags in thread info */

				/* do an extra work if any bits are set */
@@ -132,11 +133,13 @@ ret_from_intr: 
	beqi	r11, 1f

	bralid	r15, schedule

	nop

	bri	3b

1:	andi	r11, r19, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME

	beqid	r11, no_intr_resched

	addk	r5, r1, r0

	bralid	r15, do_notify_resume

	addk	r6, r0, r0

	bri	3b



no_intr_resched:

	/* Disable interrupts, we are now committed to the state restore */
@@ -486,18 +489,24 @@ ENTRY(ret_from_kernel_thread) 
work_pending:

	lwi	r11, r1, PT_MODE

	bneid	r11, 2f

3:

	enable_irq



	andi	r11, r19, _TIF_NEED_RESCHED

	beqi	r11, 1f

	bralid	r15, schedule

	nop

	bri	4f

1:	andi	r11, r19, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME

	beqi	r11, no_work_pending

	addk	r5, r30, r0

	bralid	r15, do_notify_resume

	addik	r6, r0, 1

	bri	no_work_pending

	addk	r30, r0, r0	/* no restarts from now on */

4:

	disable_irq

	lwi	r6, r31, TS_THREAD_INFO /* get thread info */

	lwi	r19, r6, TI_FLAGS /* get flags in thread info */

	bri	3b



ENTRY(ret_to_user)

	disable_irq

arch/microblaze/kernel/entry.S

+31 −27
Original line number Diff line number Diff line
@@ -402,26 +402,27 @@ C_ENTRY(ret_from_trap): 
	 * trigger rescheduling. */

	/* get thread info from current task */

	lwi	r11, CURRENT_TASK, TS_THREAD_INFO;

	lwi	r11, r11, TI_FLAGS;		/* get flags in thread info */

	andi	r11, r11, _TIF_NEED_RESCHED;

	lwi	r19, r11, TI_FLAGS;		/* get flags in thread info */

	andi	r11, r19, _TIF_NEED_RESCHED;

	beqi	r11, 5f;



	bralid	r15, schedule;	/* Call scheduler */

	nop;				/* delay slot */

	bri	1b



	/* Maybe handle a signal */

5:	/* get thread info from current task*/

	lwi	r11, CURRENT_TASK, TS_THREAD_INFO;

	lwi	r11, r11, TI_FLAGS;	/* get flags in thread info */

	andi	r11, r11, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME;

	beqi	r11, 1f;		/* Signals to handle, handle them */

5:	

	andi	r11, r19, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME;

	beqi	r11, 4f;		/* Signals to handle, handle them */



	addik	r5, r1, 0;		/* Arg 1: struct pt_regs *regs */

	bralid	r15, do_notify_resume;	/* Handle any signals */

	add	r6, r30, r0;		/* Arg 2: int in_syscall */

	add	r30, r0, r0		/* no more restarts */

	bri	1b



/* Finally, return to user state.  */

1:	set_bip;			/*  Ints masked for state restore */

4:	set_bip;			/*  Ints masked for state restore */

	swi	CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */

	VM_OFF;

	tophys(r1,r1);
@@ -573,20 +574,20 @@ C_ENTRY(ret_from_exc): 


	/* We're returning to user mode, so check for various conditions that

	   trigger rescheduling. */

1:

	lwi	r11, CURRENT_TASK, TS_THREAD_INFO;	/* get thread info */

	lwi	r11, r11, TI_FLAGS;	/* get flags in thread info */

	andi	r11, r11, _TIF_NEED_RESCHED;

	lwi	r19, r11, TI_FLAGS;	/* get flags in thread info */

	andi	r11, r19, _TIF_NEED_RESCHED;

	beqi	r11, 5f;



/* Call the scheduler before returning from a syscall/trap. */

	bralid	r15, schedule;	/* Call scheduler */

	nop;				/* delay slot */

	bri	1b



	/* Maybe handle a signal */

5:	lwi	r11, CURRENT_TASK, TS_THREAD_INFO;	/* get thread info */

	lwi	r11, r11, TI_FLAGS;	/* get flags in thread info */

	andi	r11, r11, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME;

	beqi	r11, 1f;		/* Signals to handle, handle them */

5:	andi	r11, r19, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME;

	beqi	r11, 4f;		/* Signals to handle, handle them */



	/*

	 * Handle a signal return; Pending signals should be in r18.
@@ -602,9 +603,10 @@ C_ENTRY(ret_from_exc): 
	addik	r5, r1, 0;		/* Arg 1: struct pt_regs *regs */

	bralid	r15, do_notify_resume;	/* Handle any signals */

	addi	r6, r0, 0;		/* Arg 2: int in_syscall */

	bri	1b



/* Finally, return to user state.  */

1:	set_bip;			/* Ints masked for state restore */

4:	set_bip;			/* Ints masked for state restore */

	swi	CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */

	VM_OFF;

	tophys(r1,r1);
@@ -684,22 +686,23 @@ ret_from_irq: 
	lwi	r11, r1, PT_MODE;

	bnei	r11, 2f;



1:

	lwi	r11, CURRENT_TASK, TS_THREAD_INFO;

	lwi	r11, r11, TI_FLAGS; /* MS: get flags from thread info */

	andi	r11, r11, _TIF_NEED_RESCHED;

	lwi	r19, r11, TI_FLAGS; /* MS: get flags from thread info */

	andi	r11, r19, _TIF_NEED_RESCHED;

	beqi	r11, 5f

	bralid	r15, schedule;

	nop; /* delay slot */

	bri	1b



    /* Maybe handle a signal */

5:	lwi	r11, CURRENT_TASK, TS_THREAD_INFO; /* MS: get thread info */

	lwi	r11, r11, TI_FLAGS; /* get flags in thread info */

	andi	r11, r11, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME;

5:	andi	r11, r19, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME;

	beqid	r11, no_intr_resched

/* Handle a signal return; Pending signals should be in r18. */

	addik	r5, r1, 0; /* Arg 1: struct pt_regs *regs */

	bralid	r15, do_notify_resume;	/* Handle any signals */

	addi	r6, r0, 0; /* Arg 2: int in_syscall */

	bri	1b



/* Finally, return to user state. */

no_intr_resched:
@@ -817,28 +820,29 @@ dbtrap_call: /* Return point for kernel/user entry + 8 because of rtsd r15, 8 */ 
	lwi	r11, r1, PT_MODE;

	bnei	r11, 2f;

/* MS: Return to user space - gdb */

1:

	/* Get current task ptr into r11 */

	lwi	r11, CURRENT_TASK, TS_THREAD_INFO;	/* get thread info */

	lwi	r11, r11, TI_FLAGS;	/* get flags in thread info */

	andi	r11, r11, _TIF_NEED_RESCHED;

	lwi	r19, r11, TI_FLAGS;	/* get flags in thread info */

	andi	r11, r19, _TIF_NEED_RESCHED;

	beqi	r11, 5f;



	/* Call the scheduler before returning from a syscall/trap. */

	bralid	r15, schedule;	/* Call scheduler */

	nop;				/* delay slot */

	bri	1b



	/* Maybe handle a signal */

5:	lwi	r11, CURRENT_TASK, TS_THREAD_INFO;	/* get thread info */

	lwi	r11, r11, TI_FLAGS;	/* get flags in thread info */

	andi	r11, r11, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME;

	beqi	r11, 1f;		/* Signals to handle, handle them */

5:	andi	r11, r19, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME;

	beqi	r11, 4f;		/* Signals to handle, handle them */



	addik	r5, r1, 0;		/* Arg 1: struct pt_regs *regs */

	bralid	r15, do_notify_resume;	/* Handle any signals */

	addi  r6, r0, 0;	/* Arg 2: int in_syscall */

	bri	1b



/* Finally, return to user state.  */

1:	swi	CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */

4:	swi	CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */

	VM_OFF;

	tophys(r1,r1);

	/* MS: Restore all regs */