From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932129Ab2LNR0k (ORCPT ); Fri, 14 Dec 2012 12:26:40 -0500 Received: from mx1.redhat.com ([209.132.183.28]:14614 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756604Ab2LNR0j (ORCPT ); Fri, 14 Dec 2012 12:26:39 -0500 Date: Fri, 14 Dec 2012 18:26:56 +0100 From: Oleg Nesterov To: Chris Metcalf Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] arch/tile: clean up tile-specific PTRACE_SETOPTIONS Message-ID: <20121214172656.GA21152@redhat.com> References: <20121213162710.GA20271@redhat.com> <201212122227.qBCMRiNg000851@farm-0002.internal.tilera.com> <20121212234307.GA7694@redhat.com> <50C9ECFF.6070708@tilera.com> <20121213154929.GA17421@redhat.com> <50C9FF11.2030303@tilera.com> <201212131643.qBDGh4L3018088@farm-0013.internal.tilera.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201212131643.qBDGh4L3018088@farm-0013.internal.tilera.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/13, Chris Metcalf wrote: > > Use the newer idioms for setting PTRACE_O_xxx and PT_TRACE_xxx flags. > Only set/clear tile-specific flags if the generic routine returns > success, since otherwise we want to avoid setting any flags at all. > Atomically update the ptrace flags with the new values. Eliminate > the PT_TRACE_MASK_TILE bitmask and just shift PTRACE_O_MASK_TILE. > Add a BUILD_BUG_ON to avoid overlapping with generic bits. > > Signed-off-by: Chris Metcalf Acked-by: Oleg Nesterov > --- > arch/tile/include/asm/ptrace.h | 3 +-- > arch/tile/include/uapi/asm/ptrace.h | 2 +- > arch/tile/kernel/ptrace.c | 10 +++++++--- > 3 files changed, 9 insertions(+), 6 deletions(-) > > diff --git a/arch/tile/include/asm/ptrace.h b/arch/tile/include/asm/ptrace.h > index 1a4fd9a..5ce052e 100644 > --- a/arch/tile/include/asm/ptrace.h > +++ b/arch/tile/include/asm/ptrace.h > @@ -24,8 +24,7 @@ typedef unsigned long pt_reg_t; > #include > > #define PTRACE_O_MASK_TILE (PTRACE_O_TRACEMIGRATE) > -#define PT_TRACE_MIGRATE 0x00080000 > -#define PT_TRACE_MASK_TILE (PT_TRACE_MIGRATE) > +#define PT_TRACE_MIGRATE PT_EVENT_FLAG(PTRACE_EVENT_MIGRATE) > > /* Flag bits in pt_regs.flags */ > #define PT_FLAGS_DISABLE_IRQ 1 /* on return to kernel, disable irqs */ > diff --git a/arch/tile/include/uapi/asm/ptrace.h b/arch/tile/include/uapi/asm/ptrace.h > index 0d22088..7757e19 100644 > --- a/arch/tile/include/uapi/asm/ptrace.h > +++ b/arch/tile/include/uapi/asm/ptrace.h > @@ -81,8 +81,8 @@ struct pt_regs { > #define PTRACE_SETFPREGS 15 > > /* Support TILE-specific ptrace options, with events starting at 16. */ > -#define PTRACE_O_TRACEMIGRATE 0x00010000 > #define PTRACE_EVENT_MIGRATE 16 > +#define PTRACE_O_TRACEMIGRATE (1 << PTRACE_EVENT_MIGRATE) > > /* > * Flag bits in pt_regs.flags that are part of the ptrace API. > diff --git a/arch/tile/kernel/ptrace.c b/arch/tile/kernel/ptrace.c > index 64ba102..b32bc3f 100644 > --- a/arch/tile/kernel/ptrace.c > +++ b/arch/tile/kernel/ptrace.c > @@ -151,12 +151,16 @@ long arch_ptrace(struct task_struct *child, long request, > > case PTRACE_SETOPTIONS: > /* Support TILE-specific ptrace options. */ > - child->ptrace &= ~PT_TRACE_MASK_TILE; > + BUILD_BUG_ON(PTRACE_O_MASK_TILE & PTRACE_O_MASK); > tmp = data & PTRACE_O_MASK_TILE; > data &= ~PTRACE_O_MASK_TILE; > ret = ptrace_request(child, request, addr, data); > - if (tmp & PTRACE_O_TRACEMIGRATE) > - child->ptrace |= PT_TRACE_MIGRATE; > + if (ret == 0) { > + unsigned int flags = child->ptrace; > + flags &= ~(PTRACE_O_MASK_TILE << PT_OPT_FLAG_SHIFT); > + flags |= (tmp << PT_OPT_FLAG_SHIFT); > + child->ptrace = flags; > + } > break; > > default: > -- > 1.7.10.3 >