From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757402Ab3KYRUl (ORCPT ); Mon, 25 Nov 2013 12:20:41 -0500 Received: from mx1.redhat.com ([209.132.183.28]:58687 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754433Ab3KYRUi (ORCPT ); Mon, 25 Nov 2013 12:20:38 -0500 Date: Mon, 25 Nov 2013 18:21:45 +0100 From: Oleg Nesterov To: Steven Rostedt , Namhyung Kim , Masami Hiramatsu , Frederic Weisbecker , Ingo Molnar , Jiri Olsa Cc: linux-kernel@vger.kernel.org Subject: [RFC PATCH 2/3] tracing: introduce {calc,parse}_probe_offset() for FETCH_MTD_{symbol,deref} Message-ID: <20131125172145.GC14516@redhat.com> References: <20131123201543.GA22148@redhat.com> <20131125172106.GA14516@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131125172106.GA14516@redhat.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 Preparation to simplify the review of the next patch. Add 2 "dummy" helpers used by FETCH_MTD_{symbol,deref} parse/fetch code: calc_probe_offset(offset) which currently simply returns its arg, and parse_probe_offset(name, offset) which calls kstrtol(). Signed-off-by: Oleg Nesterov --- kernel/trace/trace_probe.c | 27 +++++++++++++++++++++------ 1 files changed, 21 insertions(+), 6 deletions(-) diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index dcf7780..723e6e9 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -263,12 +263,14 @@ static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) return sc; } +static long calc_probe_offset(unsigned long offset); + #define DEFINE_FETCH_symbol(type) \ static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\ void *data, void *dest) \ { \ struct symbol_cache *sc = data; \ - long off = sc->offset; \ + long off = calc_probe_offset(sc->offset); \ if (sc->addr) \ fetch_memory_##type(regs, (void *)sc->addr + off, dest);\ else \ @@ -292,7 +294,7 @@ static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\ unsigned long addr; \ call_fetch(&dprm->orig, regs, &addr); \ if (addr) { \ - addr += dprm->offset; \ + addr += calc_probe_offset(dprm->offset); \ fetch_memory_##type(regs, (void *)addr, dest); \ } else \ *(type *)dest = 0; \ @@ -487,6 +489,8 @@ static fetch_func_t get_fetch_size_function(const struct fetch_type *type, return NULL; } +static int parse_probe_offset(const char *name, unsigned long *offset); + /* Split symbol and offset. */ int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset) { @@ -495,8 +499,7 @@ int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset) tmp = strchr(symbol, '+'); if (tmp) { - /* skip sign because kstrtoul doesn't accept '+' */ - ret = kstrtoul(tmp + 1, 0, offset); + ret = parse_probe_offset(tmp, offset); if (ret) return ret; @@ -588,6 +591,19 @@ static int pseudo_reg_query_offset(const char *name) return -EINVAL; } +static long calc_probe_offset(unsigned long offset) +{ + return offset; +} + +static int parse_probe_offset(const char *name, unsigned long *offset) +{ + if (name[0] == '+') /* kstrtol() rejects '+' */ + name++; + + return kstrtol(name, 0, offset); +} + /* Recursive argument parser */ static int parse_probe_arg(char *arg, const struct fetch_type *t, struct fetch_param *f, bool is_return, bool is_kprobe) @@ -641,14 +657,13 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, break; case '+': /* deref memory */ - arg++; /* Skip '+', because kstrtol() rejects it. */ case '-': tmp = strchr(arg, '('); if (!tmp) break; *tmp = '\0'; - ret = kstrtol(arg, 0, &offset); + ret = parse_probe_offset(arg, &offset); if (ret) break; -- 1.5.5.1