| 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
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| 2 | /* |
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| 3 | * External livepatch interfaces for patch creation tooling |
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| 4 | */ |
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| 5 | |
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| 6 | #ifndef _LINUX_LIVEPATCH_EXTERNAL_H_ |
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| 7 | #define _LINUX_LIVEPATCH_EXTERNAL_H_ |
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| 8 | |
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| 9 | #include <linux/types.h> |
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| 10 | |
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| 11 | #define KLP_RELOC_SEC_PREFIX ".klp.rela." |
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| 12 | #define KLP_SYM_PREFIX ".klp.sym." |
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| 13 | |
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| 14 | #define __KLP_PRE_PATCH_PREFIX __klp_pre_patch_callback_ |
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| 15 | #define __KLP_POST_PATCH_PREFIX __klp_post_patch_callback_ |
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| 16 | #define __KLP_PRE_UNPATCH_PREFIX __klp_pre_unpatch_callback_ |
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| 17 | #define __KLP_POST_UNPATCH_PREFIX __klp_post_unpatch_callback_ |
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| 18 | |
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| 19 | #define KLP_PRE_PATCH_PREFIX __stringify(__KLP_PRE_PATCH_PREFIX) |
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| 20 | #define KLP_POST_PATCH_PREFIX __stringify(__KLP_POST_PATCH_PREFIX) |
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| 21 | #define KLP_PRE_UNPATCH_PREFIX __stringify(__KLP_PRE_UNPATCH_PREFIX) |
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| 22 | #define KLP_POST_UNPATCH_PREFIX __stringify(__KLP_POST_UNPATCH_PREFIX) |
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| 23 | |
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| 24 | struct klp_object; |
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| 25 | |
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| 26 | typedef int (*klp_pre_patch_t)(struct klp_object *obj); |
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| 27 | typedef void (*klp_post_patch_t)(struct klp_object *obj); |
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| 28 | typedef void (*klp_pre_unpatch_t)(struct klp_object *obj); |
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| 29 | typedef void (*klp_post_unpatch_t)(struct klp_object *obj); |
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| 30 | |
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| 31 | /** |
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| 32 | * struct klp_callbacks - pre/post live-(un)patch callback structure |
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| 33 | * @pre_patch: executed before code patching |
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| 34 | * @post_patch: executed after code patching |
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| 35 | * @pre_unpatch: executed before code unpatching |
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| 36 | * @post_unpatch: executed after code unpatching |
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| 37 | * @post_unpatch_enabled: flag indicating if post-unpatch callback |
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| 38 | * should run |
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| 39 | * |
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| 40 | * All callbacks are optional. Only the pre-patch callback, if provided, |
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| 41 | * will be unconditionally executed. If the parent klp_object fails to |
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| 42 | * patch for any reason, including a non-zero error status returned from |
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| 43 | * the pre-patch callback, no further callbacks will be executed. |
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| 44 | */ |
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| 45 | struct klp_callbacks { |
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| 46 | klp_pre_patch_t pre_patch; |
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| 47 | klp_post_patch_t post_patch; |
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| 48 | klp_pre_unpatch_t pre_unpatch; |
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| 49 | klp_post_unpatch_t post_unpatch; |
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| 50 | bool post_unpatch_enabled; |
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| 51 | }; |
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| 52 | |
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| 53 | /* |
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| 54 | * 'struct klp_{func,object}_ext' are compact "external" representations of |
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| 55 | * 'struct klp_{func,object}'. They are used by objtool for livepatch |
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| 56 | * generation. The structs are then read by the livepatch module and converted |
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| 57 | * to the real structs before calling klp_enable_patch(). |
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| 58 | * |
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| 59 | * TODO make these the official API for klp_enable_patch(). That should |
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| 60 | * simplify livepatch's interface as well as its data structure lifetime |
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| 61 | * management. |
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| 62 | */ |
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| 63 | struct klp_func_ext { |
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| 64 | const char *old_name; |
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| 65 | void *new_func; |
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| 66 | unsigned long sympos; |
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| 67 | }; |
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| 68 | |
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| 69 | struct klp_object_ext { |
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| 70 | const char *name; |
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| 71 | struct klp_func_ext *funcs; |
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| 72 | struct klp_callbacks callbacks; |
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| 73 | unsigned int nr_funcs; |
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| 74 | }; |
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| 75 | |
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| 76 | #endif /* _LINUX_LIVEPATCH_EXTERNAL_H_ */ |
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| 77 | |
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