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1ecbd7170d
Default value of pcc_subspace_idx is -1.
Make sure to check pcc_subspace_idx before using the same as array index.
This will avoid following KASAN warnings too.
[ 15.113449] ==================================================================
[ 15.116983] BUG: KASAN: global-out-of-bounds in cppc_get_perf_caps+0xf3/0x3b0
[ 15.116983] Read of size 8 at addr ffffffffb9a5c0d8 by task swapper/0/1
[ 15.116983] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.15.0-rc2+ #2
[ 15.116983] Hardware name: Dell Inc. OptiPlex 7040/0Y7WYT, BIOS 1.2.8 01/26/2016
[ 15.116983] Call Trace:
[ 15.116983] dump_stack+0x7c/0xbb
[ 15.116983] print_address_description+0x1df/0x290
[ 15.116983] kasan_report+0x28a/0x370
[ 15.116983] ? cppc_get_perf_caps+0xf3/0x3b0
[ 15.116983] cppc_get_perf_caps+0xf3/0x3b0
[ 15.116983] ? cpc_read+0x210/0x210
[ 15.116983] ? __rdmsr_on_cpu+0x90/0x90
[ 15.116983] ? rdmsrl_on_cpu+0xa9/0xe0
[ 15.116983] ? rdmsr_on_cpu+0x100/0x100
[ 15.116983] ? wrmsrl_on_cpu+0x9c/0xd0
[ 15.116983] ? wrmsrl_on_cpu+0x9c/0xd0
[ 15.116983] ? wrmsr_on_cpu+0xe0/0xe0
[ 15.116983] __intel_pstate_cpu_init.part.16+0x3a2/0x530
[ 15.116983] ? intel_pstate_init_cpu+0x197/0x390
[ 15.116983] ? show_no_turbo+0xe0/0xe0
[ 15.116983] ? __lockdep_init_map+0xa0/0x290
[ 15.116983] intel_pstate_cpu_init+0x30/0x60
[ 15.116983] cpufreq_online+0x155/0xac0
[ 15.116983] cpufreq_add_dev+0x9b/0xb0
[ 15.116983] subsys_interface_register+0x1ae/0x290
[ 15.116983] ? bus_unregister_notifier+0x40/0x40
[ 15.116983] ? mark_held_locks+0x83/0xb0
[ 15.116983] ? _raw_write_unlock_irqrestore+0x32/0x60
[ 15.116983] ? intel_pstate_setup+0xc/0x104
[ 15.116983] ? intel_pstate_setup+0xc/0x104
[ 15.116983] ? cpufreq_register_driver+0x1ce/0x2b0
[ 15.116983] cpufreq_register_driver+0x1ce/0x2b0
[ 15.116983] ? intel_pstate_setup+0x104/0x104
[ 15.116983] intel_pstate_register_driver+0x3a/0xa0
[ 15.116983] intel_pstate_init+0x3c4/0x434
[ 15.116983] ? intel_pstate_setup+0x104/0x104
[ 15.116983] ? intel_pstate_setup+0x104/0x104
[ 15.116983] do_one_initcall+0x9c/0x206
[ 15.116983] ? parameq+0xa0/0xa0
[ 15.116983] ? initcall_blacklisted+0x150/0x150
[ 15.116983] ? lock_downgrade+0x2c0/0x2c0
[ 15.116983] kernel_init_freeable+0x327/0x3f0
[ 15.116983] ? start_kernel+0x612/0x612
[ 15.116983] ? _raw_spin_unlock_irq+0x29/0x40
[ 15.116983] ? finish_task_switch+0xdd/0x320
[ 15.116983] ? finish_task_switch+0x8e/0x320
[ 15.116983] ? rest_init+0xd0/0xd0
[ 15.116983] kernel_init+0xf/0x11a
[ 15.116983] ? rest_init+0xd0/0xd0
[ 15.116983] ret_from_fork+0x24/0x30
[ 15.116983] The buggy address belongs to the variable:
[ 15.116983] __key.36299+0x38/0x40
[ 15.116983] Memory state around the buggy address:
[ 15.116983] ffffffffb9a5bf80: fa fa fa fa 00 fa fa fa fa fa fa fa 00 fa fa fa
[ 15.116983] ffffffffb9a5c000: fa fa fa fa 00 fa fa fa fa fa fa fa 00 fa fa fa
[ 15.116983] >ffffffffb9a5c080: fa fa fa fa 00 fa fa fa fa fa fa fa 00 00 00 00
[ 15.116983] ^
[ 15.116983] ffffffffb9a5c100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 15.116983] ffffffffb9a5c180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 15.116983] ==================================================================
Fixes: 85b1407bf6 (ACPI / CPPC: Make CPPC ACPI driver aware of PCC subspace IDs)
Reported-by: Changbin Du <changbin.du@intel.com>
Signed-off-by: George Cherian <george.cherian@cavium.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.