From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754961Ab3BKJ5Z (ORCPT ); Mon, 11 Feb 2013 04:57:25 -0500 Received: from e7.ny.us.ibm.com ([32.97.182.137]:54134 "EHLO e7.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754417Ab3BKJ5Y (ORCPT ); Mon, 11 Feb 2013 04:57:24 -0500 Date: Mon, 11 Feb 2013 15:24:58 +0530 From: Srikar Dronamraju To: Oleg Nesterov Cc: Arnaldo Carvalho de Melo , Ingo Molnar , Peter Zijlstra , Steven Rostedt , Anton Arapov , Frank Eigler , Jiri Olsa , Josh Stone , Masami Hiramatsu , "Suzuki K. Poulose" , linux-kernel@vger.kernel.org Subject: Re: [PATCH 6/7] uprobes/perf: Teach trace_uprobe/perf code to use UPROBE_HANDLER_REMOVE Message-ID: <20130211095458.GH525@linux.vnet.ibm.com> Reply-To: Srikar Dronamraju References: <20130204190225.GA10840@redhat.com> <20130204190301.GA10885@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20130204190301.GA10885@redhat.com> User-Agent: Mutt/1.5.20 (2009-06-14) X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13021109-5806-0000-0000-00001F704493 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Oleg Nesterov [2013-02-04 20:03:01]: > Change uprobe_trace_func() and uprobe_perf_func() to return "int". Change > Change uprobe_dispatcher() to return "trace_ret | perf_ret" although this > is not really needed, currently TP_FLAG_TRACE/TP_FLAG_PROFILE are mutually > exclusive. > > The only functional change is that uprobe_perf_func() checks the filtering > too and returns UPROBE_HANDLER_REMOVE if nobody wants to trace current. > > Testing: > > # perf probe -x /lib/libc.so.6 syscall > > # perf record -e probe_libc:syscall -i perl -e 'fork; syscall -1 for 1..10; wait' > > # perf report --show-total-period > 100.00% 10 perl libc-2.8.so [.] syscall > > Before this patch: > > # cat /sys/kernel/debug/tracing/uprobe_profile > /lib/libc.so.6 syscall 20 > > A child process doesn't have a counter, but still it hits this breakoint > "copied" by dup_mmap(). > > After the patch: > > # cat /sys/kernel/debug/tracing/uprobe_profile > /lib/libc.so.6 syscall 11 > > The child process hits this int3 only once and does unapply_uprobe(). > > Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju > --- > kernel/trace/trace_uprobe.c | 21 ++++++++++++++------- > 1 files changed, 14 insertions(+), 7 deletions(-) > > diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c > index 5d5a261..1114619 100644 > --- a/kernel/trace/trace_uprobe.c > +++ b/kernel/trace/trace_uprobe.c > @@ -483,7 +483,7 @@ static const struct file_operations uprobe_profile_ops = { > }; > > /* uprobe handler */ > -static void uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs) > +static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs) > { > struct uprobe_trace_entry_head *entry; > struct ring_buffer_event *event; > @@ -501,7 +501,7 @@ static void uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs) > event = trace_current_buffer_lock_reserve(&buffer, call->event.type, > size, irq_flags, pc); > if (!event) > - return; > + return 0; > > entry = ring_buffer_event_data(event); > entry->ip = instruction_pointer(task_pt_regs(current)); > @@ -511,6 +511,8 @@ static void uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs) > > if (!filter_current_check_discard(buffer, call, entry, event)) > trace_buffer_unlock_commit(buffer, event, irq_flags, pc); > + > + return 0; > } > > /* Event entry printers */ > @@ -718,7 +720,7 @@ static bool uprobe_perf_filter(struct uprobe_consumer *uc, > } > > /* uprobe profile handler */ > -static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs) > +static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs) > { > struct ftrace_event_call *call = &tu->call; > struct uprobe_trace_entry_head *entry; > @@ -727,11 +729,14 @@ static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs) > int size, __size, i; > int rctx; > > + if (!uprobe_perf_filter(&tu->consumer, 0, current->mm)) > + return UPROBE_HANDLER_REMOVE; > + > __size = sizeof(*entry) + tu->size; > size = ALIGN(__size + sizeof(u32), sizeof(u64)); > size -= sizeof(u32); > if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough")) > - return; > + return 0; > > preempt_disable(); > > @@ -749,6 +754,7 @@ static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs) > > out: > preempt_enable(); > + return 0; > } > #endif /* CONFIG_PERF_EVENTS */ > > @@ -789,18 +795,19 @@ int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, > static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) > { > struct trace_uprobe *tu; > + int ret = 0; > > tu = container_of(con, struct trace_uprobe, consumer); > tu->nhit++; > > if (tu->flags & TP_FLAG_TRACE) > - uprobe_trace_func(tu, regs); > + ret |= uprobe_trace_func(tu, regs); > > #ifdef CONFIG_PERF_EVENTS > if (tu->flags & TP_FLAG_PROFILE) > - uprobe_perf_func(tu, regs); > + ret |= uprobe_perf_func(tu, regs); > #endif > - return 0; > + return ret; > } > > static struct trace_event_functions uprobe_funcs = { > -- > 1.5.5.1 > -- Thanks and Regards Srikar Dronamraju