1 /* SPDX-License-Identifier: GPL-2.0 */
3 * Traceprobe fetch helper inlines
6 static nokprobe_inline void
7 fetch_store_raw(unsigned long val, struct fetch_insn *code, void *buf)
14 *(u16 *)buf = (u16)val;
17 *(u32 *)buf = (u32)val;
21 *(u64 *)buf = (u64)val;
24 *(unsigned long *)buf = val;
28 static nokprobe_inline void
29 fetch_apply_bitfield(struct fetch_insn *code, void *buf)
31 switch (code->basesize) {
33 *(u8 *)buf <<= code->lshift;
34 *(u8 *)buf >>= code->rshift;
37 *(u16 *)buf <<= code->lshift;
38 *(u16 *)buf >>= code->rshift;
41 *(u32 *)buf <<= code->lshift;
42 *(u32 *)buf >>= code->rshift;
45 *(u64 *)buf <<= code->lshift;
46 *(u64 *)buf >>= code->rshift;
52 * These functions must be defined for each callsite.
53 * Return consumed dynamic data size (>= 0), or error (< 0).
54 * If dest is NULL, don't store result and return required dynamic data size.
57 process_fetch_insn(struct fetch_insn *code, void *rec,
58 void *dest, void *base);
59 static nokprobe_inline int fetch_store_strlen(unsigned long addr);
60 static nokprobe_inline int
61 fetch_store_string(unsigned long addr, void *dest, void *base);
62 static nokprobe_inline int fetch_store_strlen_user(unsigned long addr);
63 static nokprobe_inline int
64 fetch_store_string_user(unsigned long addr, void *dest, void *base);
65 static nokprobe_inline int
66 probe_mem_read(void *dest, void *src, size_t size);
67 static nokprobe_inline int
68 probe_mem_read_user(void *dest, void *src, size_t size);
70 static nokprobe_inline int
71 fetch_store_symstrlen(unsigned long addr)
73 char namebuf[KSYM_SYMBOL_LEN];
76 ret = sprint_symbol(namebuf, addr);
84 * Fetch a null-terminated symbol string + offset. Caller MUST set *(u32 *)buf
85 * with max length and relative data location.
87 static nokprobe_inline int
88 fetch_store_symstring(unsigned long addr, void *dest, void *base)
90 int maxlen = get_loc_len(*(u32 *)dest);
93 if (unlikely(!maxlen))
96 __dest = get_loc_data(dest, base);
98 return sprint_symbol(__dest, addr);
101 /* common part of process_fetch_insn*/
102 static nokprobe_inline int
103 process_common_fetch_insn(struct fetch_insn *code, unsigned long *val)
107 *val = code->immediate;
110 *val = (unsigned long)current->comm;
113 *val = (unsigned long)code->data;
121 /* From the 2nd stage, routine is same */
122 static nokprobe_inline int
123 process_fetch_insn_bottom(struct fetch_insn *code, unsigned long val,
124 void *dest, void *base)
126 struct fetch_insn *s3 = NULL;
127 int total = 0, ret = 0, i = 0;
129 unsigned long lval = val;
132 /* 2nd stage: dereference memory if needed */
134 if (code->op == FETCH_OP_DEREF) {
136 ret = probe_mem_read(&val, (void *)val + code->offset,
138 } else if (code->op == FETCH_OP_UDEREF) {
140 ret = probe_mem_read_user(&val,
141 (void *)val + code->offset, sizeof(val));
151 /* 3rd stage: store value to buffer */
152 if (unlikely(!dest)) {
154 case FETCH_OP_ST_STRING:
155 ret = fetch_store_strlen(val + code->offset);
158 case FETCH_OP_ST_USTRING:
159 ret = fetch_store_strlen_user(val + code->offset);
162 case FETCH_OP_ST_SYMSTR:
163 ret = fetch_store_symstrlen(val + code->offset);
172 case FETCH_OP_ST_RAW:
173 fetch_store_raw(val, code, dest);
175 case FETCH_OP_ST_MEM:
176 probe_mem_read(dest, (void *)val + code->offset, code->size);
178 case FETCH_OP_ST_UMEM:
179 probe_mem_read_user(dest, (void *)val + code->offset, code->size);
181 case FETCH_OP_ST_STRING:
183 ret = fetch_store_string(val + code->offset, dest, base);
185 case FETCH_OP_ST_USTRING:
187 ret = fetch_store_string_user(val + code->offset, dest, base);
189 case FETCH_OP_ST_SYMSTR:
191 ret = fetch_store_symstring(val + code->offset, dest, base);
198 /* 4th stage: modify stored value if needed */
199 if (code->op == FETCH_OP_MOD_BF) {
200 fetch_apply_bitfield(code, dest);
205 /* the last stage: Loop on array */
206 if (code->op == FETCH_OP_LP_ARRAY) {
210 if (++i < code->param) {
212 if (s3->op != FETCH_OP_ST_STRING &&
213 s3->op != FETCH_OP_ST_USTRING) {
219 val = lval + sizeof(char *);
222 *(u32 *)dest = update_data_loc(loc, ret);
230 return code->op == FETCH_OP_END ? ret : -EILSEQ;
233 /* Sum up total data length for dynamic arrays (strings) */
234 static nokprobe_inline int
235 __get_data_size(struct trace_probe *tp, struct pt_regs *regs)
237 struct probe_arg *arg;
240 for (i = 0; i < tp->nr_args; i++) {
242 if (unlikely(arg->dynamic)) {
243 len = process_fetch_insn(arg->code, regs, NULL, NULL);
252 /* Store the value of each argument */
253 static nokprobe_inline void
254 store_trace_args(void *data, struct trace_probe *tp, void *rec,
255 int header_size, int maxlen)
257 struct probe_arg *arg;
258 void *base = data - header_size;
259 void *dyndata = data + tp->size;
260 u32 *dl; /* Data location */
263 for (i = 0; i < tp->nr_args; i++) {
265 dl = data + arg->offset;
266 /* Point the dynamic data area if needed */
267 if (unlikely(arg->dynamic))
268 *dl = make_data_loc(maxlen, dyndata - base);
269 ret = process_fetch_insn(arg->code, rec, dl, base);
270 if (arg->dynamic && likely(ret > 0)) {