xref: /xnu-11417.101.15/osfmk/kern/trap_telemetry.h (revision e3723e1f17661b24996789d8afc084c0c3303b26)
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28 
29 #ifndef _TRAP_TELEMETRY_H_
30 #define _TRAP_TELEMETRY_H_
31 
32 #include <stdint.h>
33 #include <stdbool.h>
34 #include <sys/cdefs.h>
35 #include <mach/mach_types.h>
36 #include <kern/thread.h>
37 
38 __BEGIN_DECLS
39 #if XNU_KERNEL_PRIVATE
40 __enum_decl(trap_telemetry_ca_event_t, uint8_t, {
41 	/** Do not report this event to CoreAnalytics. */
42 	TRAP_TELEMETRY_CA_EVENT_NONE = 0,
43 
44 	TRAP_TELEMETRY_CA_EVENT_KERNEL_BRK = 1,
45 
46 	TRAP_TELEMETRY_CA_EVENT_INTERNAL = 2,
47 
48 	/** Used for validation, keep this value last. */
49 	TRAP_TELEMETRY_CA_EVENT_COUNT,
50 });
51 
52 typedef struct {
53 	uint8_t
54 	/**
55 	 * The event to use when reporting to CoreAnalytics.
56 	 * Encodings specified by trap_telemetry_ca_event_t.
57 	 */
58 	    telemetry_ca_event:2,
59 
60 	/**
61 	 * Should the trap only be reported once per fault PC, per boot?
62 	 *
63 	 * This should be set for traps which may fire very often in order to avoid
64 	 * overwhelming Core Analytics.
65 	 *
66 	 * Note, however, that unsetting this option does not guarantee all traps
67 	 * will be reported. Repeated traps at the same location within quick
68 	 * succession will, for example, only be reported once for performance
69 	 * reasons. Additionally, trap telemetry events may be dropped/fail at any
70 	 * time due to internal conditions.
71 	 */
72 	    report_once_per_site:1;
73 } trap_telemetry_options_s;
74 
75 __enum_decl(trap_telemetry_type_t, uint32_t, {
76 	/* These show up in telemetry, do not renumber */
77 	TRAP_TELEMETRY_TYPE_KERNEL_BRK_KASAN     = 0,     /* <unrecoverable> KASan violation traps */
78 	TRAP_TELEMETRY_TYPE_KERNEL_BRK_PTRAUTH   = 1,     /* <unrecoverable> Pointer Auth failure traps */
79 	TRAP_TELEMETRY_TYPE_KERNEL_BRK_CLANG     = 2,     /* <unrecoverable> Clang sanitizer traps */
80 	TRAP_TELEMETRY_TYPE_KERNEL_BRK_LIBCXX    = 3,     /* <unrecoverable> Libc++ abort trap*/
81 	TRAP_TELEMETRY_TYPE_KERNEL_BRK_TELEMETRY = 4,     /* <  recoverable> Soft telemetry collection traps */
82 	TRAP_TELEMETRY_TYPE_KERNEL_BRK_XNU       = 5,     /* <??recoverable> XNU defined traps */
83 
84 	/* Failure conditions which may eventually turn into hard errors */
85 	TRAP_TELEMETRY_TYPE_KERNEL_SOFT_ERROR    = 6,
86 	TRAP_TELEMETRY_TYPE_SPTM_SOFT_ERROR      = 7,
87 
88 	TRAP_TELEMETRY_TYPE_KERNEL_BRK_TEST      = ~0u,   /* Development only */
89 });
90 
91 /**
92  * Report a trap with a given type and code originating from the fault location
93  * in SAVED_STATE.
94  *
95  * Returns true if the event was submitted (or duped) and false on error.
96  */
97 extern bool
98 trap_telemetry_report_exception(
99 	trap_telemetry_type_t trap_type,
100 	uint64_t trap_code,
101 	trap_telemetry_options_s options,
102 	void *saved_state);
103 
104 /**
105  * Perform a simulated trap of a given type and code.
106  * Fault PC and backtrace will begin at the call site of this function.
107  *
108  * Returns true if the event was submitted (or duped) and false on error.
109  */
110 extern bool
111 trap_telemetry_report_simulated_trap(
112 	trap_telemetry_type_t trap_type,
113 	uint64_t trap_code,
114 	trap_telemetry_options_s options);
115 
116 /**
117  * Perform a simulated trap of a given type and code, with given fault PC and
118  * backtrace.
119  *
120  * Only up to TRAP_TELEMETRY_BT_FRAMES frames of backtrace will be used.
121  *
122  * Returns true if the event was submitted (or duped) and false on error.
123  */
124 extern bool
125 trap_telemetry_report_simulated_trap_with_backtrace(
126 	trap_telemetry_type_t trap_type,
127 	uint64_t trap_code,
128 	trap_telemetry_options_s options,
129 	uintptr_t fault_pc,
130 	uintptr_t *frames,
131 	size_t frames_valid_count);
132 
133 /** Initialize the trap telemetry module */
134 extern void
135 trap_telemetry_init(void);
136 
137 /* ~* Breakpoint Telemetry Helpers *~ */
138 
139 enum kernel_brk_trap_comment {
140 	/* CLANG (reserved)       : [0x0000 ~ 0x00FF] <Intel only> */
141 	CLANG_X86_TRAP_START           = 0x0000,
142 	CLANG_X86_TRAP_BOUND_CHK       = 0x0019, /* bound check fatal trap */
143 	CLANG_X86_TRAP_END             = 0x00FF,
144 
145 	/* LIBCXX                 : [0x0800 ~ 0x0800] */
146 	LIBCXX_TRAP_START              = 0x0800,
147 	LIBCXX_TRAP_ABORT              = 0x0800, /* libcxx abort() in libcxx_support/stdlib.h */
148 	LIBCXX_TRAP_END                = 0x0800,
149 
150 	/* KASAN (kasan-tbi.h)    : [0x0900 ~ 0x093F] <ARM only> */
151 
152 	/* CLANG (reserved)       : [0x5500 ~ 0x55FF] <ARM only> */
153 	CLANG_ARM_TRAP_START           = 0x5500,
154 	CLANG_ARM_TRAP_BOUND_CHK       = 0x5519, /* bound check fatal trap */
155 	CLANG_ARM_TRAP_END             = 0x55FF,
156 
157 	/* Software defined       : [0xB000 ~ 0xBFFF] */
158 	XNU_HARD_TRAP_START            = 0xB000,
159 	XNU_HARD_TRAP_ASSERT_FAILURE   = 0xBFFC, /* backend for assert() */
160 	XNU_HARD_TRAP_SAFE_UNLINK      = 0xBFFD, /* queue safe unlinking traps */
161 	XNU_HARD_TRAP_STRING_CHK       = 0xBFFE, /* read traps in string.h */
162 	XNU_HARD_TRAP_END              = 0xBFFF,
163 
164 	/* PTRAUTH (sleh.c)       : [0xC470 ~ 0xC473] <ARM only> */
165 
166 	/* TELEMETRY              : [0xFF00 ~ 0xFFFE] */
167 	XNU_SOFT_TRAP_START            = 0xFF00,
168 	UBSAN_SOFT_TRAP_SIGNED_OF      = 0xFF00, /* ubsan minimal signed overflow*/
169 	CLANG_SOFT_TRAP_BOUND_CHK      = 0xFF19, /* ml_bound_chk_soft_trap */
170 	XNU_SOFT_TRAP_STRING_CHK       = 0xFFFE, /* read traps in string.h */
171 	XNU_SOFT_TRAP_END              = 0xFFFE,
172 
173 	/* TEST */
174 	TEST_RECOVERABLE_SOFT_TRAP     = 0xFFFF, /* development only */
175 };
176 
177 typedef struct {
178 	uint8_t
179 	/** Can this breakpoint be recovered from? */
180 	    recoverable : 1,
181 	/** Should this breakpoint be reported to trap telemetry? */
182 	    enable_trap_telemetry : 1;
183 	/** If recoverable, the telemetry options  */
184 	trap_telemetry_options_s telemetry_options;
185 } brk_telemetry_options_s;
186 
187 /** Default configuration for fatal breakpoints */
188 #define BRK_TELEMETRY_OPTIONS_FATAL_DEFAULT \
189 	(brk_telemetry_options_s) { \
190 	    .recoverable = false, \
191 	    .enable_trap_telemetry = false, \
192 	/* ignored when trap telemetry disabled, but zero init anyways */ \
193 	    .telemetry_options = {0}, \
194 	}
195 
196 /** Default configuration for recoverable breakpoints */
197 #define BRK_TELEMETRY_OPTIONS_RECOVERABLE_DEFAULT(enable_telemetry) \
198 	(brk_telemetry_options_s) { \
199 	    .recoverable = true, \
200 	    .enable_trap_telemetry = (enable_telemetry), \
201 	    .telemetry_options = { \
202 	        .telemetry_ca_event = TRAP_TELEMETRY_CA_EVENT_KERNEL_BRK, \
203 	/* Different backtraces may be useful, so report all */ \
204 	        .report_once_per_site = false, \
205 	    }, \
206 	}
207 
208 typedef struct kernel_brk_descriptor {
209 	trap_telemetry_type_t    type;
210 	uint16_t                 base;
211 	uint16_t                 max;
212 	brk_telemetry_options_s  options;
213 
214 	const char *(*handle_breakpoint)(void *states, uint16_t comment);
215 } *kernel_brk_descriptor_t;
216 
217 extern struct kernel_brk_descriptor brk_descriptors[]
218 __SECTION_START_SYM("__DATA_CONST", "__brk_desc");
219 
220 extern struct kernel_brk_descriptor brk_descriptors_end[]
221 __SECTION_END_SYM("__DATA_CONST", "__brk_desc");
222 
223 #define KERNEL_BRK_DESCRIPTOR_DEFINE(name, ...) \
224 __PLACE_IN_SECTION("__DATA_CONST,__brk_desc") \
225 static const struct kernel_brk_descriptor name = { __VA_ARGS__ };
226 
227 const static inline struct kernel_brk_descriptor *
find_brk_descriptor_by_comment(uint16_t comment)228 find_brk_descriptor_by_comment(uint16_t comment)
229 {
230 	for (kernel_brk_descriptor_t des = brk_descriptors; des < brk_descriptors_end; des++) {
231 		if (comment >= des->base && comment <= des->max) {
232 			return des;
233 		}
234 	}
235 
236 	return NULL;
237 }
238 
239 /* ~* Kernel Soft Error Telemetry Helpers *~ */
240 
241 __enum_decl(trap_telemetry_kernel_soft_error_code_t, uint64_t, {
242 	/* Do not renumber entries -- IDs are used in telemetry */
243 	TRAP_TELEMETRY_KERNEL_SOFT_ERROR_VM_KERNEL_MAX_ALLOC_SIZE = 0,
244 });
245 
246 /**
247  * Report a kernel soft error CODE with a backtrace originating at this
248  * function's call site.
249  *
250  * If REPORT_ONCE_PER_SITE is true, events will be deduplicated by call site
251  * address and only the first instance at a given site will be reported. For the
252  * call site address to be meaningful, this function must be inlined (hence the
253  * always_inline attribute).
254  */
255 __unused
256 __attribute__((always_inline))
257 static void
trap_telemetry_report_kernel_soft_error(trap_telemetry_kernel_soft_error_code_t code,bool report_once_per_site)258 trap_telemetry_report_kernel_soft_error(
259 	trap_telemetry_kernel_soft_error_code_t code,
260 	bool report_once_per_site)
261 {
262 	trap_telemetry_report_simulated_trap(
263 		TRAP_TELEMETRY_TYPE_KERNEL_SOFT_ERROR,
264 		(uint64_t)code,
265 		(trap_telemetry_options_s) {
266 		.telemetry_ca_event = TRAP_TELEMETRY_CA_EVENT_INTERNAL,
267 		.report_once_per_site = report_once_per_site
268 	});
269 }
270 
271 #endif /* XNU_KERNEL_PRIVATE */
272 
273 __END_DECLS
274 
275 #endif /* _TRAP_TELEMETRY_H_  */
276