On Wed, Sep 20, 2023 at 9:44 AM Mirsad Goran Todorovac <mirsad.todorovac@xxxxxxxxxxxx> wrote: > > KCSAN reported hundreds of instances of data-races in ACPICA like this one: If you want to make changes in the ACPICA code, the way to do that is to submit a pull request for the upstream ACPICA project on GitHub. Then you can resend the Linux patch with a Link: tag pointing to the upstream pull request. > [ 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 <mirsad.todorovac@xxxxxxxxxxxx> > 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 <jkim@xxxxxxxxxxx> > Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > Cc: Erik Kaneda <erik.kaneda@xxxxxxxxx> > Cc: Bob Moore <robert.moore@xxxxxxxxx> > Cc: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx> > Cc: Len Brown <lenb@xxxxxxxxxx> > Cc: linux-acpi@xxxxxxxxxxxxxxx > Cc: acpica-devel@xxxxxxxxxxxxxxxxxxxxxxxxx > Signed-off-by: Mirsad Goran Todorovac <mirsad.todorovac@xxxxxxxxxxxx> > Reported-by: kernel test robot <lkp@xxxxxxxxx> > Closes: https://lore.kernel.org/oe-kbuild-all/202309201331.S2c1JL2h-lkp@xxxxxxxxx/ > --- > v1 -> v2: > Moved the declaration of 'u32 nesting_level' inside #ifdef ACPI_APPLICATION ... #endif > according to the unused variable warning of the kernel test robot. > > v1: > Preliminary RFC version of 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..1faf7dc144f0 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; > } > } > > @@ -136,6 +141,7 @@ acpi_debug_print(u32 requested_debug_level, > va_list args; > #ifdef ACPI_APPLICATION > int fill_count; > + u32 nesting_level; > #endif > > /* 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); > } > > /******************************************************************************* > -- > 2.34.1 >
