linux-kernel - Re: [PATCH v2 13/43] m68k: Use set_current_blocked() and block

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Message-ID: <4E54804D.80005@snapgear.com>
Date:	Wed, 24 Aug 2011 14:38:37 +1000
From:	Greg Ungerer <gerg@...pgear.com>
To:	Matt Fleming <matt@...sole-pimps.org>
CC:	Oleg Nesterov <oleg@...hat.com>, <linux-kernel@...r.kernel.org>,
	Geert Uytterhoeven <geert@...ux-m68k.org>,
	Greg Ungerer <gerg@...inux.org>
Subject: Re: [PATCH v2 13/43] m68k: Use set_current_blocked() and block_sigmask()

Hi Matt,

On 20/08/11 02:46, Matt Fleming wrote:
> From: Matt Fleming<matt.fleming@...el.com>
>
> As described in e6fa16ab ("signal: sigprocmask() should do
> retarget_shared_pending()") the modification of current->blocked is
> incorrect as we need to check whether the signal we're about to block
> is pending in the shared queue.
>
> Also, use the new helper function block_sigmask() which centralises
> the code for updating current->blocked after successfully delivering a
> signal and reduces the amount of duplicate code across
> architectures. In the past some architectures got this code wrong, so
> using this helper function should stop that from happening again.
>
> Cc: Oleg Nesterov<oleg@...hat.com>
> Cc: Geert Uytterhoeven<geert@...ux-m68k.org>
> Cc: Greg Ungerer<gerg@...inux.org>
> Signed-off-by: Matt Fleming<matt.fleming@...el.com>

I don't see any problems. Fine by me.

Acked-by: Greg Ungerer <gerg@...inux.org>

Regards
Greg


> ---
>
> v2 of this patch depends on "[PATCH 01/43] signal: Add block_sigmask()
> for adding sigmask to current->blocked" so they need to go through the
> same tree but this patch would benefit from some maintainer ACK's.
>
>   arch/m68k/kernel/signal_mm.c |   22 +++++++++-------------
>   arch/m68k/kernel/signal_no.c |   28 +++++++++-------------------
>   2 files changed, 18 insertions(+), 32 deletions(-)
>
> diff --git a/arch/m68k/kernel/signal_mm.c b/arch/m68k/kernel/signal_mm.c
> index a0afc23..74ba0cf 100644
> --- a/arch/m68k/kernel/signal_mm.c
> +++ b/arch/m68k/kernel/signal_mm.c
> @@ -97,12 +97,13 @@ int handle_kernel_fault(struct pt_regs *regs)
>   asmlinkage int
>   sys_sigsuspend(int unused0, int unused1, old_sigset_t mask)
>   {
> -	mask&= _BLOCKABLE;
> -	spin_lock_irq(&current->sighand->siglock);
> +	sigset_t blocked;
> +
>   	current->saved_sigmask = current->blocked;
> -	siginitset(&current->blocked, mask);
> -	recalc_sigpending();
> -	spin_unlock_irq(&current->sighand->siglock);
> +
> +	mask&= _BLOCKABLE;
> +	siginitset(&blocked, mask);
> +	set_current_blocked(&blocked);
>
>   	current->state = TASK_INTERRUPTIBLE;
>   	schedule();
> @@ -465,8 +466,7 @@ asmlinkage int do_sigreturn(unsigned long __unused)
>   		goto badframe;
>
>   	sigdelsetmask(&set, ~_BLOCKABLE);
> -	current->blocked = set;
> -	recalc_sigpending();
> +	set_current_blocked(&set);
>
>   	if (restore_sigcontext(regs,&frame->sc, frame + 1))
>   		goto badframe;
> @@ -491,8 +491,7 @@ asmlinkage int do_rt_sigreturn(unsigned long __unused)
>   		goto badframe;
>
>   	sigdelsetmask(&set, ~_BLOCKABLE);
> -	current->blocked = set;
> -	recalc_sigpending();
> +	set_current_blocked(&set);
>
>   	if (rt_restore_ucontext(regs, sw,&frame->uc))
>   		goto badframe;
> @@ -965,10 +964,7 @@ handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info,
>   	if (err)
>   		return;
>
> -	sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
> -	if (!(ka->sa.sa_flags&  SA_NODEFER))
> -		sigaddset(&current->blocked,sig);
> -	recalc_sigpending();
> +	block_sigmask(ka, sig);
>
>   	if (test_thread_flag(TIF_DELAYED_TRACE)) {
>   		regs->sr&= ~0x8000;
> diff --git a/arch/m68k/kernel/signal_no.c b/arch/m68k/kernel/signal_no.c
> index 36a81bb..33e8bf5 100644
> --- a/arch/m68k/kernel/signal_no.c
> +++ b/arch/m68k/kernel/signal_no.c
> @@ -60,12 +60,13 @@ void ret_from_user_rt_signal(void);
>   asmlinkage int
>   sys_sigsuspend(int unused0, int unused1, old_sigset_t mask)
>   {
> -	mask&= _BLOCKABLE;
> -	spin_lock_irq(&current->sighand->siglock);
> +	sigset_t blocked;
> +
>   	current->saved_sigmask = current->blocked;
> -	siginitset(&current->blocked, mask);
> -	recalc_sigpending();
> -	spin_unlock_irq(&current->sighand->siglock);
> +
> +	mask&= _BLOCKABLE;
> +	siginitset(&blocked, mask);
> +	set_current_blocked(&blocked);
>
>   	current->state = TASK_INTERRUPTIBLE;
>   	schedule();
> @@ -343,10 +344,7 @@ asmlinkage int do_sigreturn(unsigned long __unused)
>   		goto badframe;
>
>   	sigdelsetmask(&set, ~_BLOCKABLE);
> -	spin_lock_irq(&current->sighand->siglock);
> -	current->blocked = set;
> -	recalc_sigpending();
> -	spin_unlock_irq(&current->sighand->siglock);
> +	set_current_blocked(&set);
>   	
>   	if (restore_sigcontext(regs,&frame->sc, frame + 1,&d0))
>   		goto badframe;
> @@ -372,10 +370,7 @@ asmlinkage int do_rt_sigreturn(unsigned long __unused)
>   		goto badframe;
>
>   	sigdelsetmask(&set, ~_BLOCKABLE);
> -	spin_lock_irq(&current->sighand->siglock);
> -	current->blocked = set;
> -	recalc_sigpending();
> -	spin_unlock_irq(&current->sighand->siglock);
> +	set_current_blocked(&set);
>   	
>   	if (rt_restore_ucontext(regs, sw,&frame->uc,&d0))
>   		goto badframe;
> @@ -708,12 +703,7 @@ handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info,
>   	if (err)
>   		return;
>
> -	spin_lock_irq(&current->sighand->siglock);
> -	sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
> -	if (!(ka->sa.sa_flags&  SA_NODEFER))
> -		sigaddset(&current->blocked,sig);
> -	recalc_sigpending();
> -	spin_unlock_irq(&current->sighand->siglock);
> +	block_sigmask(ka, sig);
>
>   	clear_thread_flag(TIF_RESTORE_SIGMASK);
>   }


-- 
------------------------------------------------------------------------
Greg Ungerer  --  Principal Engineer        EMAIL:     gerg@...pgear.com
SnapGear Group, McAfee                      PHONE:       +61 7 3435 2888
8 Gardner Close                             FAX:         +61 7 3217 5323
Milton, QLD, 4064, Australia                WEB: http://www.SnapGear.com
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