Commit d0420c83 authored by David Howells's avatar David Howells Committed by James Morris
Browse files

KEYS: Extend TIF_NOTIFY_RESUME to (almost) all architectures [try #6] 



Implement TIF_NOTIFY_RESUME for most of those architectures in which isn't yet
available, and, whilst we're at it, have it call the appropriate tracehook.

After this patch, blackfin, m68k* and xtensa still lack support and need
alteration of assembly code to make it work.

Resume notification can then be used (by a later patch) to install a new
session keyring on the parent of a process.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Acked-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>

cc: linux-arch@vger.kernel.org
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
parent 7b1b9164

arch/alpha/include/asm/thread_info.h

+4 −1
Original line number Diff line number Diff line
@@ -75,6 +75,7 @@ register struct thread_info *__current_thread_info __asm__("$8"); 
#define TIF_UAC_SIGBUS		7

#define TIF_MEMDIE		8

#define TIF_RESTORE_SIGMASK	9	/* restore signal mask in do_signal */

#define TIF_NOTIFY_RESUME	10	/* callback before returning to user */

#define TIF_FREEZE		16	/* is freezing for suspend */



#define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
@@ -82,10 +83,12 @@ register struct thread_info *__current_thread_info __asm__("$8"); 
#define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)

#define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)

#define _TIF_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)

#define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)

#define _TIF_FREEZE		(1<<TIF_FREEZE)



/* Work to do on interrupt/exception return.  */

#define _TIF_WORK_MASK		(_TIF_SIGPENDING | _TIF_NEED_RESCHED)

#define _TIF_WORK_MASK		(_TIF_SIGPENDING | _TIF_NEED_RESCHED | \

				 _TIF_NOTIFY_RESUME)



/* Work to do on any return to userspace.  */

#define _TIF_ALLWORK_MASK	(_TIF_WORK_MASK		\

arch/alpha/kernel/signal.c

+5 −0
Original line number Diff line number Diff line
@@ -683,4 +683,9 @@ do_notify_resume(struct pt_regs *regs, struct switch_stack *sw, 
{

	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))

		do_signal(regs, sw, r0, r19);



	if (thread_info_flags & _TIF_NOTIFY_RESUME) {

		clear_thread_flag(TIF_NOTIFY_RESUME);

		tracehook_notify_resume(regs);

	}

}

arch/arm/include/asm/thread_info.h

+3 −0
Original line number Diff line number Diff line
@@ -130,11 +130,13 @@ extern void vfp_sync_state(struct thread_info *thread); 
 *  TIF_SYSCALL_TRACE	- syscall trace active

 *  TIF_SIGPENDING	- signal pending

 *  TIF_NEED_RESCHED	- rescheduling necessary

 *  TIF_NOTIFY_RESUME	- callback before returning to user

 *  TIF_USEDFPU		- FPU was used by this task this quantum (SMP)

 *  TIF_POLLING_NRFLAG	- true if poll_idle() is polling TIF_NEED_RESCHED

 */

#define TIF_SIGPENDING		0

#define TIF_NEED_RESCHED	1

#define TIF_NOTIFY_RESUME	2	/* callback before returning to user */

#define TIF_SYSCALL_TRACE	8

#define TIF_POLLING_NRFLAG	16

#define TIF_USING_IWMMXT	17
@@ -143,6 +145,7 @@ extern void vfp_sync_state(struct thread_info *thread); 


#define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)

#define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)

#define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)

#define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)

#define _TIF_POLLING_NRFLAG	(1 << TIF_POLLING_NRFLAG)

#define _TIF_USING_IWMMXT	(1 << TIF_USING_IWMMXT)

arch/arm/kernel/entry-common.S

+1 −1
Original line number Diff line number Diff line
@@ -51,7 +51,7 @@ fast_work_pending: 
work_pending:

	tst	r1, #_TIF_NEED_RESCHED

	bne	work_resched

	tst	r1, #_TIF_SIGPENDING

	tst	r1, #_TIF_SIGPENDING|_TIF_NOTIFY_RESUME

	beq	no_work_pending

	mov	r0, sp				@ 'regs'

	mov	r2, why				@ 'syscall'

arch/arm/kernel/signal.c

+5 −0
Original line number Diff line number Diff line
@@ -707,4 +707,9 @@ do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall) 
{

	if (thread_flags & _TIF_SIGPENDING)

		do_signal(&current->blocked, regs, syscall);



	if (thread_flags & _TIF_NOTIFY_RESUME) {

		clear_thread_flag(TIF_NOTIFY_RESUME);

		tracehook_notify_resume(regs);

	}

}

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