Commit 66285217 authored by Al Viro's avatar Al Viro Committed by Russell King
Browse files

ARM: 7474/1: get rid of TIF_SYSCALL_RESTARTSYS 



just let do_work_pending() return 1 on normal local restarts and
-1 on those that had been caused by ERESTART_RESTARTBLOCK (and 0
is still "all done, sod off to userland now").  And let the asm
glue flip scno to restart_syscall(2) one if it got negative from
us...

[will: resolved conflicts with audit fixes]

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 81783786

arch/arm/include/asm/thread_info.h

+1 −4
Original line number Diff line number Diff line
@@ -148,7 +148,6 @@ extern int vfp_restore_user_hwstate(struct user_vfp __user *, 
#define TIF_NOTIFY_RESUME	2	/* callback before returning to user */

#define TIF_SYSCALL_TRACE	8

#define TIF_SYSCALL_AUDIT	9

#define TIF_SYSCALL_RESTARTSYS	10

#define TIF_POLLING_NRFLAG	16

#define TIF_USING_IWMMXT	17

#define TIF_MEMDIE		18	/* is terminating due to OOM killer */
@@ -164,11 +163,9 @@ extern int vfp_restore_user_hwstate(struct user_vfp __user *, 
#define _TIF_POLLING_NRFLAG	(1 << TIF_POLLING_NRFLAG)

#define _TIF_USING_IWMMXT	(1 << TIF_USING_IWMMXT)

#define _TIF_SECCOMP		(1 << TIF_SECCOMP)

#define _TIF_SYSCALL_RESTARTSYS	(1 << TIF_SYSCALL_RESTARTSYS)



/* Checks for any syscall work in entry-common.S */

#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \

			   _TIF_SYSCALL_RESTARTSYS)

#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT)



/*

 * Change these and you break ASM code in entry-common.S

arch/arm/kernel/entry-common.S

+2 −1
Original line number Diff line number Diff line
@@ -54,8 +54,9 @@ work_pending: 
	mov	r0, sp				@ 'regs'

	mov	r2, why				@ 'syscall'

	bl	do_work_pending

	tst	r0, #1

	cmp	r0, #0

	beq	no_work_pending

	movlt	scno, #(__NR_restart_syscall - __NR_SYSCALL_BASE)

	ldmia	sp, {r0 - r6}			@ have to reload r0 - r6

	b	local_restart			@ ... and off we go

arch/arm/kernel/ptrace.c

+1 −6
Original line number Diff line number Diff line
@@ -941,12 +941,7 @@ static int ptrace_syscall_trace(struct pt_regs *regs, int scno, 


asmlinkage int syscall_trace_enter(struct pt_regs *regs, int scno)

{

	int ret;



	if (test_and_clear_thread_flag(TIF_SYSCALL_RESTARTSYS))

		scno = __NR_restart_syscall - __NR_SYSCALL_BASE;



	ret = ptrace_syscall_trace(regs, scno, PTRACE_SYSCALL_ENTER);

	int ret = ptrace_syscall_trace(regs, scno, PTRACE_SYSCALL_ENTER);

	audit_syscall_entry(AUDIT_ARCH_ARM, scno, regs->ARM_r0, regs->ARM_r1,

			    regs->ARM_r2, regs->ARM_r3);

	return ret;

arch/arm/kernel/signal.c

+6 −9
Original line number Diff line number Diff line
@@ -591,7 +591,7 @@ static int do_signal(struct pt_regs *regs, int syscall) 
		 */

		switch (retval) {

		case -ERESTART_RESTARTBLOCK:

			restart++;

			restart -= 2;

		case -ERESTARTNOHAND:

		case -ERESTARTSYS:

		case -ERESTARTNOINTR:
@@ -629,13 +629,9 @@ static int do_signal(struct pt_regs *regs, int syscall) 
		return 0;

	}



	if (unlikely(restart)) {

		if (restart > 1)

			set_thread_flag(TIF_SYSCALL_RESTARTSYS);

		regs->ARM_pc = continue_addr;

	}



	restore_saved_sigmask();

	if (unlikely(restart))

		regs->ARM_pc = continue_addr;

	return restart;

}
@@ -650,13 +646,14 @@ do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall) 
				return 0;

			local_irq_enable();

			if (thread_flags & _TIF_SIGPENDING) {

				if (unlikely(do_signal(regs, syscall))) {

				int restart = do_signal(regs, syscall);

				if (unlikely(restart)) {

					/*

					 * Restart without handlers.

					 * Deal with it without leaving

					 * the kernel space.

					 */

					return 1;

					return restart;

				}

				syscall = 0;

			} else {

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