Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755734AbbBLM2X (ORCPT ); Thu, 12 Feb 2015 07:28:23 -0500 Received: from szxga01-in.huawei.com ([119.145.14.64]:36992 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755645AbbBLM2V (ORCPT ); Thu, 12 Feb 2015 07:28:21 -0500 From: Wang Nan To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , CC: , , , Subject: [RFC PATCH v2 07/26] ftrace: allow search ftrace addr before ftrace fully inited. Date: Thu, 12 Feb 2015 20:19:46 +0800 Message-ID: <1423743586-12310-1-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.4 In-Reply-To: <1423743476-11927-1-git-send-email-wangnan0@huawei.com> References: <1423743476-11927-1-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.107.197.247] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2283 Lines: 83 Signed-off-by: Wang Nan --- kernel/trace/ftrace.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index a6a6b09..79b3e88 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1539,6 +1539,8 @@ static unsigned long ftrace_location_range(unsigned long start, unsigned long en return 0; } +static unsigned long ftrace_search_mcount_ip(unsigned long ip); + /** * ftrace_location - return true if the ip giving is a traced location * @ip: the instruction pointer to check @@ -1550,6 +1552,9 @@ static unsigned long ftrace_location_range(unsigned long start, unsigned long en */ unsigned long ftrace_location(unsigned long ip) { + if (unlikely(!ftrace_pages_start)) + return ftrace_search_mcount_ip(ip); + return ftrace_location_range(ip, ip); } @@ -4733,6 +4738,18 @@ static int ftrace_cmp_ips(const void *a, const void *b) return 0; } +static int ftrace_cmp_ips_insn(const void *a, const void *b) +{ + const unsigned long *ipa = a; + const unsigned long *ipb = b; + + if (*ipa >= *ipb + MCOUNT_INSN_SIZE) + return 1; + if (*ipa < *ipb) + return -1; + return 0; +} + static void ftrace_swap_ips(void *a, void *b, int size) { unsigned long *ipa = a; @@ -4764,6 +4781,27 @@ static void ftrace_sort_mcount_area(void) } } +static unsigned long ftrace_search_mcount_ip(unsigned long ip) +{ + extern unsigned long __start_mcount_loc[]; + extern unsigned long __stop_mcount_loc[]; + + unsigned long *mcount_start = __start_mcount_loc; + unsigned long *mcount_end = __stop_mcount_loc; + unsigned long count = mcount_end - mcount_start; + unsigned long *retval; + + if (!mcount_sorted) + return 0; + + retval = bsearch(&ip, mcount_start, count, + sizeof(unsigned long), ftrace_cmp_ips_insn); + if (!retval) + return 0; + + return ftrace_call_adjust(ip); +} + static int ftrace_process_locs(struct module *mod, unsigned long *start, unsigned long *end) -- 1.8.4 -- 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/