From patchwork Mon Nov 27 22:30:19 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Tobin C. Harding" X-Patchwork-Id: 841883 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=tobin.cc header.i=@tobin.cc header.b="NUpUkZ2H"; dkim=pass (2048-bit key; unprotected) header.d=messagingengine.com header.i=@messagingengine.com header.b="XjKG2gUy"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3ym1jK61QGz9ryv for ; Tue, 28 Nov 2017 09:31:01 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753153AbdK0Wat (ORCPT ); Mon, 27 Nov 2017 17:30:49 -0500 Received: from out4-smtp.messagingengine.com ([66.111.4.28]:60785 "EHLO out4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753014AbdK0War (ORCPT ); Mon, 27 Nov 2017 17:30:47 -0500 Received: from compute5.internal (compute5.nyi.internal [10.202.2.45]) by mailout.nyi.internal (Postfix) with ESMTP id 5852120C0E; Mon, 27 Nov 2017 17:30:46 -0500 (EST) Received: from frontend2 ([10.202.2.161]) by compute5.internal (MEProxy); Mon, 27 Nov 2017 17:30:46 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tobin.cc; h=cc :date:from:in-reply-to:message-id:references:subject:to :x-me-sender:x-me-sender:x-sasl-enc; s=fm1; bh=zxNtm9gAUcU/benW0 zdQ3UnutO1bdXMPyHB3RmH7zG0=; b=NUpUkZ2H8jAIbhu61dQpZfOayCFn/X+xg bwdUtLSV7ho6cQ+H+3yv1wDCK81N1c7/C6dc7dkjJPk0lwUaf/ZbQbR+YNsmj+Ig 72CLxY0dQKs5vOlnpWfG0kpDPBGm3wmW6cQmOhNMPODLtRdKlUUbcb8433KlvgDE 5Jmo7CoF8IwRANt/2tRH3wQlbcP0S82cC3e1eeRfRdyAd1oN8C25iVrnrBplvFaJ PlclFqnYdyTdNj4oFP6gveAiYZgi5CWVkDe+BXEJ6pFKrGzMoEjn+5die+chIuCu Bp5lg/fFos37VvxYaT6Nu+AJgPGgQAxC7t5/Y+YrApaY5qFjSDz4g== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:date:from:in-reply-to:message-id :references:subject:to:x-me-sender:x-me-sender:x-sasl-enc; s= fm1; bh=zxNtm9gAUcU/benW0zdQ3UnutO1bdXMPyHB3RmH7zG0=; b=XjKG2gUy QAp1Mhb8jEjjx23/R6ENIWRrwIVbYn2nbgNjKYmCmSVcU5dfNZlLrKfLpu/TWzNg B8yAZcER8/yf3EyGKSQKHlkcsmGM8DLDkCOZ5RvtCbMA/AsixCBBn2ozgZQ5WzOq bptRY8kpDePt4fQDV36OiljAUCgImFw1QHH9kLX3vawqGrZgDHXAHJdXNVbwPtIJ r6wYGiyxUV043al0fd8XWVakcVtbfYML2vh3/koN510V6H5yYjETt7NKkEMgKDqI CQNhFw197aFZDGJbSoanBsM0u+5AJpG1QNy/XmKhvakN4ffCDA+r3d1w+DRJSmJ1 kmUaRtMDcsttdQ== X-ME-Sender: Received: from localhost (202-159-174-127.dyn.iinet.net.au [202.159.174.127]) by mail.messagingengine.com (Postfix) with ESMTPA id 9E496246AC; Mon, 27 Nov 2017 17:30:45 -0500 (EST) From: "Tobin C. Harding" To: kernel-hardening@lists.openwall.com Cc: "Tobin C. Harding" , linux-kernel@vger.kernel.org, Network Development , Steven Rostedt , Tycho Andersen , Ingo Molnar Subject: [RFC 3/3] trace: print address if symbol not found Date: Tue, 28 Nov 2017 09:30:19 +1100 Message-Id: <1511821819-5496-4-git-send-email-me@tobin.cc> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1511821819-5496-1-git-send-email-me@tobin.cc> References: <1511821819-5496-1-git-send-email-me@tobin.cc> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Fixes behaviour modified by: commit bd6b239cdbb2 ("kallsyms: don't leak address when symbol not found") Previous patch changed behaviour of kallsyms function sprint_symbol() to return an error code instead of printing the address if a symbol was not found. Ftrace relies on the original behaviour. We should not break tracing when applying the previous patch. We can maintain the original behaviour by checking the return code on calls to sprint_symbol() and friends. Check return code and print actual address on error (i.e symbol not found). Signed-off-by: Tobin C. Harding --- kernel/trace/trace.h | 24 ++++++++++++++++++++++++ kernel/trace/trace_events_hist.c | 6 +++--- 2 files changed, 27 insertions(+), 3 deletions(-) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 2a6d0325a761..881b1a577d75 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1814,4 +1814,28 @@ static inline void trace_event_eval_update(struct trace_eval_map **map, int len) extern struct trace_iterator *tracepoint_print_iter; +static inline int +trace_sprint_symbol(char *buffer, unsigned long address) +{ + int ret; + + ret = sprint_symbol(buffer, address); + if (ret == -1) + ret = sprintf(buffer, "0x%lx", address); + + return ret; +} + +static inline int +trace_sprint_symbol_no_offset(char *buffer, unsigned long address) +{ + int ret; + + ret = sprint_symbol_no_offset(buffer, address); + if (ret == -1) + ret = sprintf(buffer, "0x%lx", address); + + return ret; +} + #endif /* _LINUX_KERNEL_TRACE_H */ diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 1e1558c99d56..3e28522a76f4 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -982,7 +982,7 @@ static void hist_trigger_stacktrace_print(struct seq_file *m, return; seq_printf(m, "%*c", 1 + spaces, ' '); - sprint_symbol(str, stacktrace_entries[i]); + trace_sprint_symbol_addr(str, stacktrace_entries[i]); seq_printf(m, "%s\n", str); } } @@ -1014,12 +1014,12 @@ hist_trigger_entry_print(struct seq_file *m, seq_printf(m, "%s: %llx", field_name, uval); } else if (key_field->flags & HIST_FIELD_FL_SYM) { uval = *(u64 *)(key + key_field->offset); - sprint_symbol_no_offset(str, uval); + trace_sprint_symbol_no_offset(str, uval); seq_printf(m, "%s: [%llx] %-45s", field_name, uval, str); } else if (key_field->flags & HIST_FIELD_FL_SYM_OFFSET) { uval = *(u64 *)(key + key_field->offset); - sprint_symbol(str, uval); + trace_sprint_symbol(str, uval); seq_printf(m, "%s: [%llx] %-55s", field_name, uval, str); } else if (key_field->flags & HIST_FIELD_FL_EXECNAME) {