From patchwork Tue Sep 19 23:33:17 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mirsad Todorovac X-Patchwork-Id: 13392014 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8DCE4CE79A9 for ; Tue, 19 Sep 2023 23:34:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229748AbjISXeb (ORCPT ); Tue, 19 Sep 2023 19:34:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50456 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229521AbjISXea (ORCPT ); Tue, 19 Sep 2023 19:34:30 -0400 Received: from domac.alu.hr (domac.alu.unizg.hr [161.53.235.3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EBF03C4; Tue, 19 Sep 2023 16:34:22 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by domac.alu.hr (Postfix) with ESMTP id E916460157; Wed, 20 Sep 2023 01:34:09 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=alu.unizg.hr; s=mail; t=1695166449; bh=zaMLddCalyQnI1zjdeSAxREZqo19txmGC6/R4+XOaUY=; h=From:To:Cc:Subject:Date:From; b=ZVFVWdlZmCCHvCNhq27Htp9JVHD8RO3ejZHWuhnmkXEH3LNNkFuSZUO58zgmKaRZO aTQMSKPF36m+F0OQlZLFt+x1/2Sdss+N1yYPRfkgKZtyASgqd397QLXOt+OghmtGlB /2kKaDMYR1Qd1UjrI8KK3vMkJ2JaDoDysKQAfQJotaCDb+nmafU/KgtIGuoWqtiO75 DKB1YCM81iYig4ir5zBg6ZNzgnpQUaMKMQgHVcPBMwqomMLd9DL8PD32qLQPXNrgsq P5c0cZe873lyfFq3QcDnPxZ9xLel4bgYFGIeFICWUtOAOa6tlRvnVOn9AKOrryAzNC 5zIm5qwCmVMTQ== X-Virus-Scanned: Debian amavisd-new at domac.alu.hr Received: from domac.alu.hr ([127.0.0.1]) by localhost (domac.alu.hr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id eMLC9_jQgw-G; Wed, 20 Sep 2023 01:34:07 +0200 (CEST) Received: from defiant.home (78-0-136-157.adsl.net.t-com.hr [78.0.136.157]) by domac.alu.hr (Postfix) with ESMTPSA id 2A3E460152; Wed, 20 Sep 2023 01:34:06 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=alu.unizg.hr; s=mail; t=1695166447; bh=zaMLddCalyQnI1zjdeSAxREZqo19txmGC6/R4+XOaUY=; h=From:To:Cc:Subject:Date:From; b=CZ66NEpRZc72ipqhL6eK/bKEOkxq8BYOvBkzgzxZVKGRxdiuGUKZEns84WitxJjkh ZNsAWcKhwktBUlCAhJuMqcnxQ0l8V5As9KZ34KnKjsZbXFvlhxC4dWYaux2kEVWdkd Bs0+hMjdUB2FKu7TMgzOHTrAy1W0pX+E12XMso3VInSQRJy6H6KCDCRgztOtwWwzSa qzkj6ZA7K3oYwqzSheVXtgyshm1j3uNPFHXU/Xc4zEHVuIfGQux07jxDINyfYyktba qeCvfK4qOgluH3cGe2yK/h8hpWT8dKcTxcRKdcgLKb+pD8JR8hlX1V78HXKxTCpppp 1o4AYNj9nVXIQ== From: Mirsad Goran Todorovac To: Mirsad Goran Todorovac , linux-acpi@vger.kernel.org, acpica-devel@lists.linuxfoundation.org, linux-kernel@vger.kernel.org Cc: Robert Moore , "Rafael J. Wysocki" , Len Brown , Jung-uk Kim , Linus Torvalds , Erik Kaneda Subject: [PATCH v1 1/1] acpica: use spinlocks to fix the data-races reported by the KCSAN Date: Wed, 20 Sep 2023 01:33:17 +0200 Message-Id: <20230919233316.11420-1-mirsad.todorovac@alu.unizg.hr> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org KCSAN reported hundreds of instances of data-races in ACPICA like this one: [ 6.994149] ================================================================== [ 6.994443] BUG: KCSAN: data-race in acpi_ut_status_exit / acpi_ut_trace [ 6.994795] write to 0xffffffffbae5a884 of 4 bytes by task 0 on cpu 2: [ 6.994944] acpi_ut_status_exit (/home/marvin/linux/kernel/torvalds2/drivers/acpi/acpica/utdebug.c:467) [ 6.994957] acpi_hw_register_read (/home/marvin/linux/kernel/torvalds2/drivers/acpi/acpica/hwregs.c:563) [ 6.994968] acpi_read_bit_register (/home/marvin/linux/kernel/torvalds2/drivers/acpi/acpica/hwxface.c:171) [ 6.994980] acpi_idle_bm_check (/home/marvin/linux/kernel/torvalds2/drivers/acpi/processor_idle.c:511) [ 6.994990] acpi_idle_enter_bm (/home/marvin/linux/kernel/torvalds2/drivers/acpi/processor_idle.c:644 (discriminator 1)) [ 6.995000] acpi_idle_enter (/home/marvin/linux/kernel/torvalds2/drivers/acpi/processor_idle.c:695) [ 6.995010] cpuidle_enter_state (/home/marvin/linux/kernel/torvalds2/drivers/cpuidle/cpuidle.c:267) [ 6.995019] cpuidle_enter (/home/marvin/linux/kernel/torvalds2/drivers/cpuidle/cpuidle.c:390) [ 6.995027] call_cpuidle (/home/marvin/linux/kernel/torvalds2/kernel/sched/idle.c:135) [ 6.995038] do_idle (/home/marvin/linux/kernel/torvalds2/kernel/sched/idle.c:219 /home/marvin/linux/kernel/torvalds2/kernel/sched/idle.c:282) [ 6.995046] cpu_startup_entry (/home/marvin/linux/kernel/torvalds2/kernel/sched/idle.c:378 (discriminator 1)) [ 6.995055] start_secondary (/home/marvin/linux/kernel/torvalds2/arch/x86/kernel/smpboot.c:210 /home/marvin/linux/kernel/torvalds2/arch/x86/kernel/smpboot.c:294) [ 6.995066] secondary_startup_64_no_verify (/home/marvin/linux/kernel/torvalds2/arch/x86/kernel/head_64.S:433) [ 6.995121] read to 0xffffffffbae5a884 of 4 bytes by task 0 on cpu 9: [ 6.995267] acpi_ut_trace (/home/marvin/linux/kernel/torvalds2/drivers/acpi/acpica/utdebug.c:263) [ 6.995279] acpi_hw_validate_io_request (/home/marvin/linux/kernel/torvalds2/drivers/acpi/acpica/hwvalid.c:101) [ 6.995291] acpi_hw_read_port (/home/marvin/linux/kernel/torvalds2/drivers/acpi/acpica/hwvalid.c:202) [ 6.995303] acpi_hw_read (/home/marvin/linux/kernel/torvalds2/drivers/acpi/acpica/hwregs.c:251) [ 6.995313] acpi_hw_register_read (/home/marvin/linux/kernel/torvalds2/drivers/acpi/acpica/hwregs.c:725 /home/marvin/linux/kernel/torvalds2/drivers/acpi/acpica/hwregs.c:499) [ 6.995325] acpi_read_bit_register (/home/marvin/linux/kernel/torvalds2/drivers/acpi/acpica/hwxface.c:171) [ 6.995336] acpi_idle_bm_check (/home/marvin/linux/kernel/torvalds2/drivers/acpi/processor_idle.c:511) [ 6.995346] acpi_idle_enter_bm (/home/marvin/linux/kernel/torvalds2/drivers/acpi/processor_idle.c:644 (discriminator 1)) [ 6.995356] acpi_idle_enter (/home/marvin/linux/kernel/torvalds2/drivers/acpi/processor_idle.c:695) [ 6.995366] cpuidle_enter_state (/home/marvin/linux/kernel/torvalds2/drivers/cpuidle/cpuidle.c:267) [ 6.995375] cpuidle_enter (/home/marvin/linux/kernel/torvalds2/drivers/cpuidle/cpuidle.c:390) [ 6.995383] call_cpuidle (/home/marvin/linux/kernel/torvalds2/kernel/sched/idle.c:135) [ 6.995394] do_idle (/home/marvin/linux/kernel/torvalds2/kernel/sched/idle.c:219 /home/marvin/linux/kernel/torvalds2/kernel/sched/idle.c:282) [ 6.995402] cpu_startup_entry (/home/marvin/linux/kernel/torvalds2/kernel/sched/idle.c:378 (discriminator 1)) [ 6.995411] start_secondary (/home/marvin/linux/kernel/torvalds2/arch/x86/kernel/smpboot.c:210 /home/marvin/linux/kernel/torvalds2/arch/x86/kernel/smpboot.c:294) [ 6.995422] secondary_startup_64_no_verify (/home/marvin/linux/kernel/torvalds2/arch/x86/kernel/head_64.S:433) [ 6.995476] value changed: 0x00000004 -> 0x00000002 [ 6.995629] Reported by Kernel Concurrency Sanitizer on: [ 6.995748] CPU: 9 PID: 0 Comm: swapper/9 Not tainted 6.6.0-rc2-kcsan-00003-g16819584c239-dirty #21 [ 6.995758] Hardware name: ASRock X670E PG Lightning/X670E PG Lightning, BIOS 1.21 04/26/2023 [ 6.995765] ================================================================== Please find the complete list at: https://domac.alu.unizg.hr/~mtodorov/linux/patches/acpica_utdebug/acpi_ut_status_exit.log.xz A number of unprotected increments: acpi_gbl_nesting_level++; and conditional statements: if (acpi_gbl_nesting_level) { acpi_gbl_nesting_level--; } no longer work in SMP environment. Proper locking like spin_lock(&acpi_utdebug_lock); acpi_gbl_nesting_level++; spin_unlock(&acpi_utdebug_lock); and spin_lock(&acpi_utdebug_lock); if (acpi_gbl_nesting_level) { acpi_gbl_nesting_level--; } spin_unlock(&acpi_utdebug_lock); makes these data-races go away. Additionally, READ_ONCE() or WRITE_ONCE() is required with the global variable acpi_gbl_nesting_level to prevent unwanted read or write reordering or other funny stuff the optmisers do. The patch eliminates KCSAN BUG warnings. Reported-by: Mirsad Goran Todorovac Fixes: 6be2d72b18649 ("ACPICA: Update for a few debug output statements") Fixes: bf9b448ef8430 ("ACPICA: Debug output: Do not emit function nesting level for kernel build.") Fixes: 6e875fa0480c1 ("ACPICA: Debugger: fix slight indentation issue") Fixes: ^1da177e4c3f4 ("Initial git repository build.") Cc: Jung-uk Kim Cc: Linus Torvalds Cc: Erik Kaneda Cc: Bob Moore Cc: "Rafael J. Wysocki" Cc: Len Brown Cc: linux-acpi@vger.kernel.org Cc: acpica-devel@lists.linuxfoundation.org Signed-off-by: Mirsad Goran Todorovac --- v1: RFC for the patch. drivers/acpi/acpica/utdebug.c | 40 ++++++++++++++++++++++++++++++----- 1 file changed, 35 insertions(+), 5 deletions(-) diff --git a/drivers/acpi/acpica/utdebug.c b/drivers/acpi/acpica/utdebug.c index c5f6c85a3a09..148f2b820c88 100644 --- a/drivers/acpi/acpica/utdebug.c +++ b/drivers/acpi/acpica/utdebug.c @@ -16,6 +16,8 @@ #define _COMPONENT ACPI_UTILITIES ACPI_MODULE_NAME("utdebug") +static DEFINE_SPINLOCK(acpi_utdebug_lock); + #ifdef ACPI_DEBUG_OUTPUT static acpi_thread_id acpi_gbl_previous_thread_id = (acpi_thread_id) 0xFFFFFFFF; static const char *acpi_gbl_function_entry_prefix = "----Entry"; @@ -60,13 +62,16 @@ void acpi_ut_init_stack_ptr_trace(void) void acpi_ut_track_stack_ptr(void) { acpi_size current_sp; + u32 nesting_level; if (¤t_sp < acpi_gbl_lowest_stack_pointer) { acpi_gbl_lowest_stack_pointer = ¤t_sp; } - if (acpi_gbl_nesting_level > acpi_gbl_deepest_nesting) { - acpi_gbl_deepest_nesting = acpi_gbl_nesting_level; + nesting_level = READ_ONCE(acpi_gbl_nesting_level); + + if (nesting_level > acpi_gbl_deepest_nesting) { + acpi_gbl_deepest_nesting = nesting_level; } } @@ -137,6 +142,7 @@ acpi_debug_print(u32 requested_debug_level, #ifdef ACPI_APPLICATION int fill_count; #endif + u32 nesting_level; /* Check if debug output enabled */ @@ -156,7 +162,7 @@ acpi_debug_print(u32 requested_debug_level, } acpi_gbl_previous_thread_id = thread_id; - acpi_gbl_nesting_level = 0; + WRITE_ONCE(acpi_gbl_nesting_level, 0); } /* @@ -176,14 +182,16 @@ acpi_debug_print(u32 requested_debug_level, acpi_os_printf("[%u] ", (u32)thread_id); } - fill_count = 48 - acpi_gbl_nesting_level - + fill_count = 48 - READ_ONCE(acpi_gbl_nesting_level) - strlen(acpi_ut_trim_function_name(function_name)); if (fill_count < 0) { fill_count = 0; } + nesting_level = READ_ONCE(acpi_gbl_nesting_level); + acpi_os_printf("[%02d] %*s", - acpi_gbl_nesting_level, acpi_gbl_nesting_level + 1, " "); + nesting_level, nesting_level + 1, " "); acpi_os_printf("%s%*s: ", acpi_ut_trim_function_name(function_name), fill_count, " "); @@ -260,7 +268,10 @@ acpi_ut_trace(u32 line_number, const char *module_name, u32 component_id) { + spin_lock(&acpi_utdebug_lock); acpi_gbl_nesting_level++; + spin_unlock(&acpi_utdebug_lock); + acpi_ut_track_stack_ptr(); /* Check if enabled up-front for performance */ @@ -298,7 +309,10 @@ acpi_ut_trace_ptr(u32 line_number, u32 component_id, const void *pointer) { + spin_lock(&acpi_utdebug_lock); acpi_gbl_nesting_level++; + spin_unlock(&acpi_utdebug_lock); + acpi_ut_track_stack_ptr(); /* Check if enabled up-front for performance */ @@ -334,7 +348,10 @@ acpi_ut_trace_str(u32 line_number, const char *module_name, u32 component_id, const char *string) { + spin_lock(&acpi_utdebug_lock); acpi_gbl_nesting_level++; + spin_unlock(&acpi_utdebug_lock); + acpi_ut_track_stack_ptr(); /* Check if enabled up-front for performance */ @@ -370,7 +387,10 @@ acpi_ut_trace_u32(u32 line_number, const char *module_name, u32 component_id, u32 integer) { + spin_lock(&acpi_utdebug_lock); acpi_gbl_nesting_level++; + spin_unlock(&acpi_utdebug_lock); + acpi_ut_track_stack_ptr(); /* Check if enabled up-front for performance */ @@ -414,9 +434,11 @@ acpi_ut_exit(u32 line_number, acpi_gbl_function_exit_prefix); } + spin_lock(&acpi_utdebug_lock); if (acpi_gbl_nesting_level) { acpi_gbl_nesting_level--; } + spin_unlock(&acpi_utdebug_lock); } ACPI_EXPORT_SYMBOL(acpi_ut_exit) @@ -463,9 +485,11 @@ acpi_ut_status_exit(u32 line_number, } } + spin_lock(&acpi_utdebug_lock); if (acpi_gbl_nesting_level) { acpi_gbl_nesting_level--; } + spin_unlock(&acpi_utdebug_lock); } ACPI_EXPORT_SYMBOL(acpi_ut_status_exit) @@ -502,9 +526,11 @@ acpi_ut_value_exit(u32 line_number, ACPI_FORMAT_UINT64(value)); } + spin_lock(&acpi_utdebug_lock); if (acpi_gbl_nesting_level) { acpi_gbl_nesting_level--; } + spin_unlock(&acpi_utdebug_lock); } ACPI_EXPORT_SYMBOL(acpi_ut_value_exit) @@ -540,9 +566,11 @@ acpi_ut_ptr_exit(u32 line_number, acpi_gbl_function_exit_prefix, ptr); } + spin_lock(&acpi_utdebug_lock); if (acpi_gbl_nesting_level) { acpi_gbl_nesting_level--; } + spin_unlock(&acpi_utdebug_lock); } /******************************************************************************* @@ -577,9 +605,11 @@ acpi_ut_str_exit(u32 line_number, acpi_gbl_function_exit_prefix, string); } + spin_lock(&acpi_utdebug_lock); if (acpi_gbl_nesting_level) { acpi_gbl_nesting_level--; } + spin_unlock(&acpi_utdebug_lock); } /*******************************************************************************