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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Traceprobe fetch helper inlines
*/
static nokprobe_inline void
fetch_store_raw(unsigned long val, struct fetch_insn *code, void *buf)
{
switch (code->size) {
case 1:
*(u8 *)buf = (u8)val;
break;
case 2:
*(u16 *)buf = (u16)val;
break;
case 4:
*(u32 *)buf = (u32)val;
break;
case 8:
//TBD: 32bit signed
*(u64 *)buf = (u64)val;
break;
default:
*(unsigned long *)buf = val;
}
}
static nokprobe_inline void
fetch_apply_bitfield(struct fetch_insn *code, void *buf)
{
switch (code->basesize) {
case 1:
*(u8 *)buf <<= code->lshift;
*(u8 *)buf >>= code->rshift;
break;
case 2:
*(u16 *)buf <<= code->lshift;
*(u16 *)buf >>= code->rshift;
break;
case 4:
*(u32 *)buf <<= code->lshift;
*(u32 *)buf >>= code->rshift;
break;
case 8:
*(u64 *)buf <<= code->lshift;
*(u64 *)buf >>= code->rshift;
break;
}
}
/*
* These functions must be defined for each callsite.
* Return consumed dynamic data size (>= 0), or error (< 0).
* If dest is NULL, don't store result and return required dynamic data size.
*/
static int
process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs,
void *dest, void *base);
static nokprobe_inline int fetch_store_strlen(unsigned long addr);
static nokprobe_inline int
fetch_store_string(unsigned long addr, void *dest, void *base);
static nokprobe_inline int
probe_mem_read(void *dest, void *src, size_t size);
/* From the 2nd stage, routine is same */
static nokprobe_inline int
process_fetch_insn_bottom(struct fetch_insn *code, unsigned long val,
void *dest, void *base)
{
int ret = 0;
/* 2nd stage: dereference memory if needed */
while (code->op == FETCH_OP_DEREF) {
ret = probe_mem_read(&val, (void *)val + code->offset,
sizeof(val));
if (ret)
return ret;
code++;
}
/* 3rd stage: store value to buffer */
if (unlikely(!dest)) {
if (code->op == FETCH_OP_ST_STRING)
return fetch_store_strlen(val + code->offset);
else
return -EILSEQ;
}
switch (code->op) {
case FETCH_OP_ST_RAW:
fetch_store_raw(val, code, dest);
break;
case FETCH_OP_ST_MEM:
probe_mem_read(dest, (void *)val + code->offset, code->size);
break;
case FETCH_OP_ST_STRING:
ret = fetch_store_string(val + code->offset, dest, base);
break;
default:
return -EILSEQ;
}
code++;
/* 4th stage: modify stored value if needed */
if (code->op == FETCH_OP_MOD_BF) {
fetch_apply_bitfield(code, dest);
code++;
}
return code->op == FETCH_OP_END ? ret : -EILSEQ;
}
/* Sum up total data length for dynamic arraies (strings) */
static nokprobe_inline int
__get_data_size(struct trace_probe *tp, struct pt_regs *regs)
{
struct probe_arg *arg;
int i, len, ret = 0;
for (i = 0; i < tp->nr_args; i++) {
arg = tp->args + i;
if (unlikely(arg->dynamic)) {
len = process_fetch_insn(arg->code, regs, NULL, NULL);
if (len > 0)
ret += len;
}
}
return ret;
}
/* Store the value of each argument */
static nokprobe_inline void
store_trace_args(void *data, struct trace_probe *tp, struct pt_regs *regs,
int header_size, int maxlen)
{
struct probe_arg *arg;
void *base = data - header_size;
void *dyndata = data + tp->size;
u32 *dl; /* Data location */
int ret, i;
for (i = 0; i < tp->nr_args; i++) {
arg = tp->args + i;
dl = data + arg->offset;
/* Point the dynamic data area if needed */
if (unlikely(arg->dynamic))
*dl = make_data_loc(maxlen, dyndata - base);
ret = process_fetch_insn(arg->code, regs, dl, base);
if (unlikely(ret < 0 && arg->dynamic))
*dl = make_data_loc(0, dyndata - base);
else
dyndata += ret;
}
}
static inline int
print_probe_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
u8 *data, void *field)
{
int i;
for (i = 0; i < nr_args; i++) {
trace_seq_printf(s, " %s=", args[i].name);
if (!args[i].type->print(s, data + args[i].offset, field))
return -ENOMEM;
}
return 0;
}
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