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generated by cgit v1.2.3-54-g00ecf (git 2.39.0) at 2025-02-04 20:47:07 +0000
1. When it is invoked from the OS boot stage, the ACPICA mutex may not have been initialized yet and so acpi_ut_acquire_mutex()/acpi_ut_release_mutex() are not invoked in these code paths: acpi_initialize_tables acpi_tb_parse_root_table acpi_tb_install_standard_table (4 invocations) acpi_install_table acpi_tb_install_standard_table 2. When it is invoked during the runtime, ACPICA mutex is used as appropriate: acpi_ex_load_op acpi_tb_install_and_load_table acpi_tb_install_standard_table acpi_load_table acpi_tb_install_and_load_table acpi_tb_install_standard_table The mutex is now used in acpi_tb_install_and_load_table(), while it actually should be in acpi_tb_install_standard_table(). This introduces another problem in acpi_tb_install_standard_table() where acpi_gbl_table_handler is invoked from and the lock contexts are thus not consistent for the table handlers. This triggers a regression when acpi_get_table()/acpi_put_table() start to hold table mutex during runtime. The regression is noticed by LKP as new errors reported by ACPICA mutex debugging facility. [ 2.043693] ACPI Error: Mutex [ACPI_MTX_Tables] already acquired by this thread [497483776] (20160930/utmutex-254) [ 2.054084] ACPI Error: Mutex [0x2] is not acquired, cannot release (20160930/utmutex-326) And it triggers a deadlock: [ 247.066214] INFO: task swapper/0:1 blocked for more than 120 seconds. ... [ 247.091271] Call Trace: ... [ 247.121523] down_timeout+0x47/0x50 [ 247.125065] acpi_os_wait_semaphore+0x47/0x62 [ 247.129475] acpi_ut_acquire_mutex+0x43/0x81 [ 247.133798] acpi_get_table+0x2d/0x84 [ 247.137513] acpi_table_attr_init+0xcd/0x100 [ 247.146590] acpi_sysfs_table_handler+0x5d/0xb8 [ 247.151174] acpi_bus_table_handler+0x23/0x2a [ 247.155583] acpi_tb_install_standard_table+0xe0/0x213 [ 247.164489] acpi_tb_install_and_load_table+0x3a/0x82 [ 247.169592] acpi_ex_load_op+0x194/0x201 ... [ 247.200108] acpi_ns_evaluate+0x1bb/0x247 [ 247.204170] acpi_evaluate_object+0x178/0x274 [ 247.213249] acpi_processor_set_pdc+0x154/0x17b ... The table mutex is held in acpi_tb_install_and_load_table() and is re-visited by acpi_get_table(). Noticing that the early mutex requirement actually belongs to the OSL layer and has already been handled in acpi_os_wait_semaphore()/acpi_os_signal_semaphore(), the regression canbe fixed by removing this hidden logic from the ACPICA core to the OS-specific code. Fixes: 174cc7187e6f ("ACPICA: Tables: Back port acpi_get_table_with_size() and early_acpi_os_unmap_memory() from Linux kernel") Reported-and-tested-by: Tomi Sarvela <tomi.p.sarvela@intel.com> Reported-by: Ye Xiaolong <xiaolong.ye@intel.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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