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b2eb3e67ee
A bug was introduced during unification of setting CAP_SMP_T_SWCOORD for
the _PDC and _OSC methods.
The third u32 in the buffer is never cleared before setting bits on it.
The memory is not guaranteed to be zero as it was allocated by kmalloc()
instead of kzalloc().
Fix this by initializing the third u32 in the buffer to 0.
Fixes: b9e8d0168a ("ACPI: processor: Set CAP_SMP_T_SWCOORD in arch_acpi_set_proc_cap_bits()")
Signed-off-by: Michal Wilczynski <michal.wilczynski@intel.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
120 lines
2.5 KiB
C
120 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2005 Intel Corporation
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* Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
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*
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* Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
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* - Added _PDC for platforms with Intel CPUs
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*/
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#define pr_fmt(fmt) "ACPI: " fmt
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#include <linux/slab.h>
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#include <linux/acpi.h>
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#include <acpi/processor.h>
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#include "internal.h"
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static void acpi_set_pdc_bits(u32 *buf)
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{
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buf[0] = ACPI_PDC_REVISION_ID;
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buf[1] = 1;
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buf[2] = 0;
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/* Twiddle arch-specific bits needed for _PDC */
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arch_acpi_set_proc_cap_bits(&buf[2]);
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}
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static struct acpi_object_list *acpi_processor_alloc_pdc(void)
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{
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struct acpi_object_list *obj_list;
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union acpi_object *obj;
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u32 *buf;
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/* allocate and initialize pdc. It will be used later. */
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obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL);
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if (!obj_list)
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goto out;
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obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
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if (!obj) {
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kfree(obj_list);
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goto out;
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}
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buf = kmalloc(12, GFP_KERNEL);
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if (!buf) {
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kfree(obj);
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kfree(obj_list);
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goto out;
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}
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acpi_set_pdc_bits(buf);
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obj->type = ACPI_TYPE_BUFFER;
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obj->buffer.length = 12;
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obj->buffer.pointer = (u8 *) buf;
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obj_list->count = 1;
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obj_list->pointer = obj;
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return obj_list;
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out:
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pr_err("Memory allocation error\n");
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return NULL;
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}
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/*
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* _PDC is required for a BIOS-OS handshake for most of the newer
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* ACPI processor features.
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*/
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static acpi_status
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acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in)
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{
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acpi_status status = AE_OK;
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status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL);
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if (ACPI_FAILURE(status))
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acpi_handle_debug(handle,
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"Could not evaluate _PDC, using legacy perf control\n");
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return status;
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}
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void acpi_processor_set_pdc(acpi_handle handle)
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{
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struct acpi_object_list *obj_list;
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if (arch_has_acpi_pdc() == false)
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return;
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obj_list = acpi_processor_alloc_pdc();
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if (!obj_list)
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return;
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acpi_processor_eval_pdc(handle, obj_list);
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kfree(obj_list->pointer->buffer.pointer);
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kfree(obj_list->pointer);
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kfree(obj_list);
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}
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static acpi_status __init
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early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
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{
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if (processor_physically_present(handle) == false)
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return AE_OK;
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acpi_processor_set_pdc(handle);
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return AE_OK;
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}
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void __init acpi_early_processor_set_pdc(void)
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{
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acpi_proc_quirk_mwait_check();
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acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
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ACPI_UINT32_MAX,
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early_init_pdc, NULL, NULL, NULL);
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acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, early_init_pdc, NULL, NULL);
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}
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