From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F3B65C2BA1A for ; Tue, 7 Apr 2020 03:11:42 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B63892072F for ; Tue, 7 Apr 2020 03:11:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="nbo1oYJS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B63892072F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 682CA8E0095; Mon, 6 Apr 2020 23:11:42 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 630E58E0062; Mon, 6 Apr 2020 23:11:42 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 51FD68E0095; Mon, 6 Apr 2020 23:11:42 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0002.hostedemail.com [216.40.44.2]) by kanga.kvack.org (Postfix) with ESMTP id 38BAD8E0062 for ; Mon, 6 Apr 2020 23:11:42 -0400 (EDT) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 0200FA74D for ; Tue, 7 Apr 2020 03:11:42 +0000 (UTC) X-FDA: 76679584044.06.hot29_ecf6398e2b0a X-HE-Tag: hot29_ecf6398e2b0a X-Filterd-Recvd-Size: 3956 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf14.hostedemail.com (Postfix) with ESMTP for ; Tue, 7 Apr 2020 03:11:41 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 41E1620716; Tue, 7 Apr 2020 03:11:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586229101; bh=5d3tPvXOsbIuVPgZlODBVuuIajFdjIMeiGu/jGbo8XY=; h=Date:From:To:Subject:In-Reply-To:From; b=nbo1oYJSgkZOm2peRn69yRATJYbv+5yI0lxW3CX3+8hSKLhgcOyKCghmqLDfQyjIh dDNl9CVOsJF/SIdxb3bBAhCc3CJaTyD524Rdiw6RDvnSQTvRnu36PVd/GfUFAkkBDk M8rYvyz6gfxwqx9/DUlBNkjpgJqYoun9pGFE4GP0= Date: Mon, 06 Apr 2020 20:11:39 -0700 From: Andrew Morton To: akpm@linux-foundation.org, ast@kernel.org, frederic@kernel.org, gregkh@linuxfoundation.org, hch@lst.de, joe.lawrence@redhat.com, linux-mm@kvack.org, mbenes@suse.cz, mhiramat@kernel.org, mm-commits@vger.kernel.org, pmladek@suse.com, prasad@linux.vnet.ibm.com, qperret@google.com, tglx@linutronix.de, torvalds@linux-foundation.org, will@kernel.org Subject: [patch 143/166] samples/hw_breakpoint: drop use of kallsyms_lookup_name() Message-ID: <20200407031139.af9PQo0A7%akpm@linux-foundation.org> In-Reply-To: <20200406200254.a69ebd9e08c4074e41ddebaf@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Will Deacon Subject: samples/hw_breakpoint: drop use of kallsyms_lookup_name() The 'data_breakpoint' test code is the only modular user of kallsyms_lookup_name(), which was exported as part of fixing the test in f60d24d2ad04 ("hw-breakpoints: Fix broken hw-breakpoint sample module"). In preparation for un-exporting this symbol, switch the test over to using __symbol_get(), which can be used to place breakpoints on exported symbols. Link: http://lkml.kernel.org/r/20200221114404.14641-3-will@kernel.org Signed-off-by: Will Deacon Reviewed-by: Christoph Hellwig Reviewed-by: Masami Hiramatsu Reviewed-by: Quentin Perret Cc: K.Prasad Cc: Thomas Gleixner Cc: Greg Kroah-Hartman Cc: Frederic Weisbecker Cc: Alexei Starovoitov Cc: Miroslav Benes Cc: Petr Mladek Cc: Joe Lawrence Signed-off-by: Andrew Morton --- samples/hw_breakpoint/data_breakpoint.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) --- a/samples/hw_breakpoint/data_breakpoint.c~samples-hw_breakpoint-drop-use-of-kallsyms_lookup_name +++ a/samples/hw_breakpoint/data_breakpoint.c @@ -23,7 +23,7 @@ struct perf_event * __percpu *sample_hbp; -static char ksym_name[KSYM_NAME_LEN] = "pid_max"; +static char ksym_name[KSYM_NAME_LEN] = "jiffies"; module_param_string(ksym, ksym_name, KSYM_NAME_LEN, S_IRUGO); MODULE_PARM_DESC(ksym, "Kernel symbol to monitor; this module will report any" " write operations on the kernel symbol"); @@ -41,9 +41,13 @@ static int __init hw_break_module_init(v { int ret; struct perf_event_attr attr; + void *addr = __symbol_get(ksym_name); + + if (!addr) + return -ENXIO; hw_breakpoint_init(&attr); - attr.bp_addr = kallsyms_lookup_name(ksym_name); + attr.bp_addr = (unsigned long)addr; attr.bp_len = HW_BREAKPOINT_LEN_4; attr.bp_type = HW_BREAKPOINT_W; @@ -66,6 +70,7 @@ fail: static void __exit hw_break_module_exit(void) { unregister_wide_hw_breakpoint(sample_hbp); + symbol_put(ksym_name); printk(KERN_INFO "HW Breakpoint for %s write uninstalled\n", ksym_name); } _