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7fde14d705
when acpi=off is provided in bootarg, kernel crash with [ 1.252739] BUG: kernel NULL pointer dereference, address: 0000000000000018 [ 1.258308] Call Trace: [ 1.258490] ? acpi_walk_namespace+0x147/0x147 [ 1.258770] acpi_get_devices+0xe4/0x137 [ 1.258921] ? drm_core_init+0xc0/0xc0 [drm] [ 1.259108] detect_thinkpad_privacy_screen+0x5e/0xa8 [drm] [ 1.259337] drm_privacy_screen_lookup_init+0xe/0xe85 [drm] The reason is that acpi_walk_namespace expects acpi related stuff initialized but in fact it wouldn't when acpi is set to off. In this case we should honor acpi=off in detect_thinkpad_privacy_screen(). Signed-off-by: Tong Zhang <ztong0001@gmail.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220123091004.763775-1-ztong0001@gmail.com
89 lines
2.1 KiB
C
89 lines
2.1 KiB
C
// SPDX-License-Identifier: MIT
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/*
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* Copyright (C) 2020 Red Hat, Inc.
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*
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* Authors:
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* Hans de Goede <hdegoede@redhat.com>
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*/
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#include <linux/acpi.h>
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#include <drm/drm_privacy_screen_machine.h>
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#ifdef CONFIG_X86
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static struct drm_privacy_screen_lookup arch_lookup;
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struct arch_init_data {
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struct drm_privacy_screen_lookup lookup;
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bool (*detect)(void);
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};
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#if IS_ENABLED(CONFIG_THINKPAD_ACPI)
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static acpi_status __init acpi_set_handle(acpi_handle handle, u32 level,
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void *context, void **return_value)
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{
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*(acpi_handle *)return_value = handle;
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return AE_CTRL_TERMINATE;
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}
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static bool __init detect_thinkpad_privacy_screen(void)
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{
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union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
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struct acpi_object_list args = { .count = 1, .pointer = &obj, };
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acpi_handle ec_handle = NULL;
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unsigned long long output;
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acpi_status status;
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if (acpi_disabled)
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return false;
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/* Get embedded-controller handle */
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status = acpi_get_devices("PNP0C09", acpi_set_handle, NULL, &ec_handle);
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if (ACPI_FAILURE(status) || !ec_handle)
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return false;
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/* And call the privacy-screen get-status method */
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status = acpi_evaluate_integer(ec_handle, "HKEY.GSSS", &args, &output);
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if (ACPI_FAILURE(status))
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return false;
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return (output & 0x10000) ? true : false;
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}
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#endif
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static const struct arch_init_data arch_init_data[] __initconst = {
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#if IS_ENABLED(CONFIG_THINKPAD_ACPI)
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{
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.lookup = {
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.dev_id = NULL,
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.con_id = NULL,
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.provider = "privacy_screen-thinkpad_acpi",
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},
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.detect = detect_thinkpad_privacy_screen,
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},
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#endif
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};
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void __init drm_privacy_screen_lookup_init(void)
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{
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int i;
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for (i = 0; i < ARRAY_SIZE(arch_init_data); i++) {
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if (!arch_init_data[i].detect())
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continue;
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pr_info("Found '%s' privacy-screen provider\n",
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arch_init_data[i].lookup.provider);
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/* Make a copy because arch_init_data is __initconst */
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arch_lookup = arch_init_data[i].lookup;
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drm_privacy_screen_lookup_add(&arch_lookup);
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break;
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}
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}
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void drm_privacy_screen_lookup_exit(void)
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{
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if (arch_lookup.provider)
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drm_privacy_screen_lookup_remove(&arch_lookup);
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}
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#endif /* ifdef CONFIG_X86 */
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