Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754765Ab3HEITy (ORCPT ); Mon, 5 Aug 2013 04:19:54 -0400 Received: from mail9.hitachi.co.jp ([133.145.228.44]:57136 "EHLO mail9.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754371Ab3HEITw (ORCPT ); Mon, 5 Aug 2013 04:19:52 -0400 Message-ID: <51FF6026.7090409@hitachi.com> Date: Mon, 05 Aug 2013 17:19:50 +0900 From: Masami Hiramatsu Organization: Hitachi, Ltd., Japan User-Agent: Mozilla/5.0 (Windows NT 5.2; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: Namhyung Kim Cc: Steven Rostedt , Namhyung Kim , Hyeoncheol Lee , LKML , Srikar Dronamraju , Oleg Nesterov , "zhangwei(Jovi)" , Arnaldo Carvalho de Melo Subject: Re: [PATCH 02/13] tracing/kprobes: Add fetch{,_size} member into symbol and deref fetch method References: <1375261410-11219-1-git-send-email-namhyung@kernel.org> <1375261410-11219-3-git-send-email-namhyung@kernel.org> In-Reply-To: <1375261410-11219-3-git-send-email-namhyung@kernel.org> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4802 Lines: 149 (2013/07/31 18:03), Namhyung Kim wrote: > From: Hyeoncheol Lee > > Those symbol and deref fetch methods access a memory region but they > assume it's a kernel memory since uprobes does not support them. > > Add ->fetch and ->fetch_size member in order to provide a proper > access method for supporting uprobes. It looks symbol cache is not used by uprobes. I think it it enough to add fetch/fetch_size to only deref, isn't it? Thank you, > > Cc: Masami Hiramatsu > Cc: Srikar Dronamraju > Cc: Oleg Nesterov > Cc: zhangwei(Jovi) > Cc: Arnaldo Carvalho de Melo > Signed-off-by: Hyeoncheol Lee > [namhyung@kernel.org: Split original patch into pieces as requested] > Signed-off-by: Namhyung Kim > --- > kernel/trace/trace_probe.c | 48 ++++++++++++++++++++++++++++++++++++++++------ > 1 file changed, 42 insertions(+), 6 deletions(-) > > diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c > index c58c25d81591..c123a890c5b1 100644 > --- a/kernel/trace/trace_probe.c > +++ b/kernel/trace/trace_probe.c > @@ -93,6 +93,8 @@ struct symbol_cache { > char *symbol; > long offset; > unsigned long addr; > + fetch_func_t fetch; > + fetch_func_t fetch_size; > }; > > static unsigned long update_symbol_cache(struct symbol_cache *sc) > @@ -139,18 +141,29 @@ __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, \ > { \ > struct symbol_cache *sc = data; \ > if (sc->addr) \ > - fetch_memory_##type(regs, (void *)sc->addr, dest); \ > + sc->fetch(regs, (void *)sc->addr, dest); \ > else \ > *(type *)dest = 0; \ > } > DEFINE_BASIC_FETCH_FUNCS(symbol) > DEFINE_FETCH_symbol(string) > -DEFINE_FETCH_symbol(string_size) > + > +__kprobes void FETCH_FUNC_NAME(symbol, string_size)(struct pt_regs *regs, > + void *data, void *dest) > +{ > + struct symbol_cache *sc = data; > + if (sc->addr && sc->fetch_size) > + sc->fetch_size(regs, (void *)sc->addr, dest); > + else > + *(string_size *)dest = 0; > +} > > /* Dereference memory access function */ > struct deref_fetch_param { > struct fetch_param orig; > long offset; > + fetch_func_t fetch; > + fetch_func_t fetch_size; > }; > > #define DEFINE_FETCH_deref(type) \ > @@ -162,13 +175,26 @@ __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \ > call_fetch(&dprm->orig, regs, &addr); \ > if (addr) { \ > addr += dprm->offset; \ > - fetch_memory_##type(regs, (void *)addr, dest); \ > + dprm->fetch(regs, (void *)addr, dest); \ > } else \ > *(type *)dest = 0; \ > } > DEFINE_BASIC_FETCH_FUNCS(deref) > DEFINE_FETCH_deref(string) > -DEFINE_FETCH_deref(string_size) > + > +__kprobes void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs, > + void *data, void *dest) > +{ > + struct deref_fetch_param *dprm = data; > + unsigned long addr; > + > + call_fetch(&dprm->orig, regs, &addr); > + if (addr && dprm->fetch_size) { > + addr += dprm->offset; > + dprm->fetch_size(regs, (void *)addr, dest); > + } else > + *(string_size *)dest = 0; > +} > > static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data) > { > @@ -410,13 +436,20 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, > f->fn = t->fetch[FETCH_MTD_memory]; > f->data = (void *)param; > } else { > + struct symbol_cache *sc; > + > ret = traceprobe_split_symbol_offset(arg + 1, &offset); > if (ret) > break; > > - f->data = alloc_symbol_cache(arg + 1, offset); > - if (f->data) > + sc = alloc_symbol_cache(arg + 1, offset); > + if (sc) { > f->fn = t->fetch[FETCH_MTD_symbol]; > + sc->fetch = t->fetch[FETCH_MTD_memory]; > + sc->fetch_size = get_fetch_size_function(t, > + sc->fetch, ttbl); > + f->data = sc; > + } > } > break; > > @@ -448,6 +481,9 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, > return -ENOMEM; > > dprm->offset = offset; > + dprm->fetch = t->fetch[FETCH_MTD_memory]; > + dprm->fetch_size = get_fetch_size_function(t, > + dprm->fetch, ttbl); > ret = parse_probe_arg(arg, t2, &dprm->orig, is_return, > is_kprobe); > if (ret) > -- Masami HIRAMATSU IT Management Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/