From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752174AbbHEIYU (ORCPT ); Wed, 5 Aug 2015 04:24:20 -0400 Received: from mga02.intel.com ([134.134.136.20]:33077 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752110AbbHEIYP (ORCPT ); Wed, 5 Aug 2015 04:24:15 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.15,615,1432623600"; d="scan'208";a="762294036" From: Lv Zheng To: "Rafael J. Wysocki" , Len Brown Cc: Lv Zheng , Lv Zheng , , linux-acpi@vger.kernel.org Subject: [PATCH v2 3/4] ACPI / sysfs: Add support to allow leading "\" missing in trace_method_name. Date: Wed, 5 Aug 2015 16:23:57 +0800 Message-Id: <8fe4199b601436cf25ac3ba9e7e958bb4fc7b2a4.1438762804.git.lv.zheng@intel.com> X-Mailer: git-send-email 1.7.10 In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since _SB.PCI0 can be used as relative path from root and can be easily converted into internal trace_method_name format, we allow users to specify trace_method_name using relative paths from root. Note this is useful for grub2 for which users failed to pass "\" from the grub configuration file. Signed-off-by: Lv Zheng --- drivers/acpi/sysfs.c | 28 +++++++++++++--------------- 1 file changed, 13 insertions(+), 15 deletions(-) diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c index 8979e4a..40a4265 100644 --- a/drivers/acpi/sysfs.c +++ b/drivers/acpi/sysfs.c @@ -164,14 +164,18 @@ static const struct kernel_param_ops param_ops_debug_level = { module_param_cb(debug_layer, ¶m_ops_debug_layer, &acpi_dbg_layer, 0644); module_param_cb(debug_level, ¶m_ops_debug_level, &acpi_dbg_level, 0644); -static char* trace_method_name; -static bool trace_method_kmalloced; +static char trace_method_name[1024]; int param_set_trace_method_name(const char *val, const struct kernel_param *kp) { u32 saved_flags = 0; + bool is_abs_path = true; - if (strlen(val) > 1024) { + if (*val != '\\') + is_abs_path = false; + + if ((is_abs_path && strlen(val) > 1023) || + (!is_abs_path && strlen(val) > 1022)) { pr_err("%s: string parameter too long\n", kp->name); return -ENOSPC; } @@ -187,19 +191,13 @@ int param_set_trace_method_name(const char *val, const struct kernel_param *kp) acpi_gbl_trace_dbg_layer, 0); - if (trace_method_kmalloced) - kfree(trace_method_name); - trace_method_name = NULL; - trace_method_kmalloced = false; - /* This is a hack. We can't kmalloc in early boot. */ - if (slab_is_available()) { - trace_method_name = kstrdup(val, GFP_KERNEL); - if (!trace_method_name) - return -ENOMEM; - trace_method_kmalloced = true; - } else - trace_method_name = (char *)val; + if (is_abs_path) + strcpy(trace_method_name, val); + else { + trace_method_name[0] = '\\'; + strcpy(trace_method_name+1, val); + } /* Restore the original tracer state */ (void)acpi_debug_trace(trace_method_name, -- 1.7.10