a8a4f0467d
When booting with CONFIG_CFI_CLANG, there are numerous violations when accessing the files under /sys/devices/pci0000:00/0000:00:02.0/drm/card0/gt/gt0: $ cd /sys/devices/pci0000:00/0000:00:02.0/drm/card0/gt/gt0 $ grep . * id:0 punit_req_freq_mhz:350 rc6_enable:1 rc6_residency_ms:214934 rps_act_freq_mhz:1300 rps_boost_freq_mhz:1300 rps_cur_freq_mhz:350 rps_max_freq_mhz:1300 rps_min_freq_mhz:350 rps_RP0_freq_mhz:1300 rps_RP1_freq_mhz:350 rps_RPn_freq_mhz:350 throttle_reason_pl1:0 throttle_reason_pl2:0 throttle_reason_pl4:0 throttle_reason_prochot:0 throttle_reason_ratl:0 throttle_reason_status:0 throttle_reason_thermal:0 throttle_reason_vr_tdc:0 throttle_reason_vr_thermalert:0 $ sudo dmesg &| grep "CFI failure at" [ 214.595903] CFI failure at kobj_attr_show+0x19/0x30 (target: id_show+0x0/0x70 [i915]; expected type: 0xc527b809) [ 214.596064] CFI failure at kobj_attr_show+0x19/0x30 (target: punit_req_freq_mhz_show+0x0/0x40 [i915]; expected type: 0xc527b809) [ 214.596407] CFI failure at kobj_attr_show+0x19/0x30 (target: rc6_enable_show+0x0/0x40 [i915]; expected type: 0xc527b809) [ 214.596528] CFI failure at kobj_attr_show+0x19/0x30 (target: rc6_residency_ms_show+0x0/0x270 [i915]; expected type: 0xc527b809) [ 214.596682] CFI failure at kobj_attr_show+0x19/0x30 (target: act_freq_mhz_show+0x0/0xe0 [i915]; expected type: 0xc527b809) [ 214.596792] CFI failure at kobj_attr_show+0x19/0x30 (target: boost_freq_mhz_show+0x0/0xe0 [i915]; expected type: 0xc527b809) [ 214.596893] CFI failure at kobj_attr_show+0x19/0x30 (target: cur_freq_mhz_show+0x0/0xe0 [i915]; expected type: 0xc527b809) [ 214.596996] CFI failure at kobj_attr_show+0x19/0x30 (target: max_freq_mhz_show+0x0/0xe0 [i915]; expected type: 0xc527b809) [ 214.597099] CFI failure at kobj_attr_show+0x19/0x30 (target: min_freq_mhz_show+0x0/0xe0 [i915]; expected type: 0xc527b809) [ 214.597198] CFI failure at kobj_attr_show+0x19/0x30 (target: RP0_freq_mhz_show+0x0/0xe0 [i915]; expected type: 0xc527b809) [ 214.597301] CFI failure at kobj_attr_show+0x19/0x30 (target: RP1_freq_mhz_show+0x0/0xe0 [i915]; expected type: 0xc527b809) [ 214.597405] CFI failure at kobj_attr_show+0x19/0x30 (target: RPn_freq_mhz_show+0x0/0xe0 [i915]; expected type: 0xc527b809) [ 214.597538] CFI failure at kobj_attr_show+0x19/0x30 (target: throttle_reason_bool_show+0x0/0x50 [i915]; expected type: 0xc527b809) [ 214.597701] CFI failure at kobj_attr_show+0x19/0x30 (target: throttle_reason_bool_show+0x0/0x50 [i915]; expected type: 0xc527b809) [ 214.597836] CFI failure at kobj_attr_show+0x19/0x30 (target: throttle_reason_bool_show+0x0/0x50 [i915]; expected type: 0xc527b809) [ 214.597952] CFI failure at kobj_attr_show+0x19/0x30 (target: throttle_reason_bool_show+0x0/0x50 [i915]; expected type: 0xc527b809) [ 214.598071] CFI failure at kobj_attr_show+0x19/0x30 (target: throttle_reason_bool_show+0x0/0x50 [i915]; expected type: 0xc527b809) [ 214.598177] CFI failure at kobj_attr_show+0x19/0x30 (target: throttle_reason_bool_show+0x0/0x50 [i915]; expected type: 0xc527b809) [ 214.598307] CFI failure at kobj_attr_show+0x19/0x30 (target: throttle_reason_bool_show+0x0/0x50 [i915]; expected type: 0xc527b809) [ 214.598439] CFI failure at kobj_attr_show+0x19/0x30 (target: throttle_reason_bool_show+0x0/0x50 [i915]; expected type: 0xc527b809) [ 214.598542] CFI failure at kobj_attr_show+0x19/0x30 (target: throttle_reason_bool_show+0x0/0x50 [i915]; expected type: 0xc527b809) With kCFI, indirect calls are validated against their expected type versus actual type and failures occur when the two types do not match. The ultimate issue is that these sysfs functions are expecting to be called via dev_attr_show() but they may also be called via kobj_attr_show(), as certain files are created under two different kobjects that have two different sysfs_ops in intel_gt_sysfs_register(), hence the warnings above. When accessing the gt_ files under /sys/devices/pci0000:00/0000:00:02.0/drm/card0, which are using the same sysfs functions, there are no violations, meaning the functions are being called with the proper type. To make everything work properly, adjust certain functions to match the type of the ->show() and ->store() members in 'struct kobj_attribute'. Add a macro to generate functions for that can be called via both dev_attr_{show,store}() or kobj_attr_{show,store}() so that they can be called through both kobject locations without violating kCFI and adjust the attribute groups to account for this. Link: https://github.com/ClangBuiltLinux/linux/issues/1716 Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com> Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20221013205909.1282545-1-nathan@kernel.org
32 lines
721 B
C
32 lines
721 B
C
/* SPDX-License-Identifier: MIT */
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/*
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* Copyright © 2022 Intel Corporation
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*/
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#ifndef __SYSFS_GT_H__
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#define __SYSFS_GT_H__
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#include <linux/ctype.h>
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#include <linux/kobject.h>
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#include "i915_gem.h" /* GEM_BUG_ON() */
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#include "intel_gt_types.h"
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struct intel_gt;
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bool is_object_gt(struct kobject *kobj);
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struct drm_i915_private *kobj_to_i915(struct kobject *kobj);
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static inline struct intel_gt *kobj_to_gt(struct kobject *kobj)
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{
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return container_of(kobj, struct intel_gt, sysfs_gt);
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}
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void intel_gt_sysfs_register(struct intel_gt *gt);
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void intel_gt_sysfs_unregister(struct intel_gt *gt);
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struct intel_gt *intel_gt_sysfs_get_drvdata(struct kobject *kobj,
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const char *name);
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#endif /* SYSFS_GT_H */
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