in decimal ('s' and 'u') or hexadecimal ('x'). Without type casting, 'x32'
or 'x64' is used depends on the architecture (e.g. x86-32 uses x32, and
x86-64 uses x64).
+These value types can be an array. To record array data, you can add '[N]'
+(where N is a fixed number, less than 64) to the base type.
+E.g. 'x16[4]' means an array of x16 (2bytes hex) with 4 elements.
+Note that the array can be applied to memory type fetchargs, you can not
+apply it to registers/stack-entries etc. (for example, '$stack1:x8[8]' is
+wrong, but '+8($stack):x8[8]' is OK.)
String type is a special type, which fetches a "null-terminated" string from
kernel space. This means it will fail and store NULL if the string container
has been paged out.
+The string array type is a bit different from other types. For other base
+types, <base-type>[1] is equal to <base-type> (e.g. +0(%di):x32[1] is same
+as +0(%di):x32.) But string[1] is not equal to string. The string type itself
+represents "char array", but string array type represents "char * array".
+So, for example, +0(%di):string[1] is equal to +0(+0(%di)):string.
Bitfield is another special type, which takes 3 parameters, bit-width, bit-
offset, and container-size (usually 32). The syntax is::
int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
struct probe_arg *parg, bool is_return, bool is_kprobe)
{
- struct fetch_insn *code, *tmp = NULL;
- const char *t;
- int ret;
+ struct fetch_insn *code, *scode, *tmp = NULL;
+ char *t, *t2;
+ int ret, len;
if (strlen(arg) > MAX_ARGSTR_LEN) {
pr_info("Argument is too long.: %s\n", arg);
pr_info("Failed to allocate memory for command '%s'.\n", arg);
return -ENOMEM;
}
- t = strchr(parg->comm, ':');
+ t = strchr(arg, ':');
if (t) {
- arg[t - parg->comm] = '\0';
- t++;
+ *t = '\0';
+ t2 = strchr(++t, '[');
+ if (t2) {
+ *t2 = '\0';
+ parg->count = simple_strtoul(t2 + 1, &t2, 0);
+ if (strcmp(t2, "]") || parg->count == 0)
+ return -EINVAL;
+ if (parg->count > MAX_ARRAY_LEN)
+ return -E2BIG;
+ }
}
/*
* The default type of $comm should be "string", and it can't be
* dereferenced.
*/
if (!t && strcmp(arg, "$comm") == 0)
- t = "string";
- parg->type = find_fetch_type(t);
+ parg->type = find_fetch_type("string");
+ else
+ parg->type = find_fetch_type(t);
if (!parg->type) {
pr_info("Unsupported type: %s\n", t);
return -EINVAL;
}
parg->offset = *size;
- *size += parg->type->size;
+ *size += parg->type->size * (parg->count ?: 1);
+
+ if (parg->count) {
+ len = strlen(parg->type->fmttype) + 6;
+ parg->fmt = kmalloc(len, GFP_KERNEL);
+ if (!parg->fmt)
+ return -ENOMEM;
+ snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
+ parg->count);
+ }
code = tmp = kzalloc(sizeof(*code) * FETCH_INSN_MAX, GFP_KERNEL);
if (!code)
ret = -EINVAL;
goto fail;
}
- /* Since IMM or COMM must be the 1st insn, this is safe */
- if (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM)
+ if (code->op != FETCH_OP_DEREF || parg->count) {
+ /*
+ * IMM and COMM is pointing actual address, those must
+ * be kept, and if parg->count != 0, this is an array
+ * of string pointers instead of string address itself.
+ */
code++;
+ if (code->op != FETCH_OP_NOP) {
+ ret = -E2BIG;
+ goto fail;
+ }
+ }
code->op = FETCH_OP_ST_STRING; /* In DEREF case, replace it */
+ code->size = parg->type->size;
parg->dynamic = true;
} else if (code->op == FETCH_OP_DEREF) {
code->op = FETCH_OP_ST_MEM;
code->op = FETCH_OP_ST_RAW;
code->size = parg->type->size;
}
+ scode = code;
/* Modify operation */
if (t != NULL) {
ret = __parse_bitfield_probe_arg(t, parg->type, &code);
if (ret)
goto fail;
}
+ /* Loop(Array) operation */
+ if (parg->count) {
+ if (scode->op != FETCH_OP_ST_MEM &&
+ scode->op != FETCH_OP_ST_STRING) {
+ pr_info("array only accepts memory or address\n");
+ ret = -EINVAL;
+ goto fail;
+ }
+ code++;
+ if (code->op != FETCH_OP_NOP) {
+ ret = -E2BIG;
+ goto fail;
+ }
+ code->op = FETCH_OP_LP_ARRAY;
+ code->param = parg->count;
+ }
code++;
code->op = FETCH_OP_END;
kfree(arg->code);
kfree(arg->name);
kfree(arg->comm);
+ kfree(arg->fmt);
}
+/* When len=0, we just calculate the needed length */
+#define LEN_OR_ZERO (len ? len - pos : 0)
static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,
bool is_return)
{
- int i;
+ struct probe_arg *parg;
+ int i, j;
int pos = 0;
-
const char *fmt, *arg;
if (!is_return) {
arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
}
- /* When len=0, we just calculate the needed length */
-#define LEN_OR_ZERO (len ? len - pos : 0)
-
pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
for (i = 0; i < tp->nr_args; i++) {
- pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s",
- tp->args[i].name, tp->args[i].type->fmt);
+ parg = tp->args + i;
+ pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name);
+ if (parg->count) {
+ pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s",
+ parg->type->fmt);
+ for (j = 1; j < parg->count; j++)
+ pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s",
+ parg->type->fmt);
+ pos += snprintf(buf + pos, LEN_OR_ZERO, "}");
+ } else
+ pos += snprintf(buf + pos, LEN_OR_ZERO, "%s",
+ parg->type->fmt);
}
pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
for (i = 0; i < tp->nr_args; i++) {
- if (strcmp(tp->args[i].type->name, "string") == 0)
+ parg = tp->args + i;
+ if (parg->count) {
+ if (strcmp(parg->type->name, "string") == 0)
+ fmt = ", __get_str(%s[%d])";
+ else
+ fmt = ", REC->%s[%d]";
+ for (j = 0; j < parg->count; j++)
+ pos += snprintf(buf + pos, LEN_OR_ZERO,
+ fmt, parg->name, j);
+ } else {
+ if (strcmp(parg->type->name, "string") == 0)
+ fmt = ", __get_str(%s)";
+ else
+ fmt = ", REC->%s";
pos += snprintf(buf + pos, LEN_OR_ZERO,
- ", __get_str(%s)",
- tp->args[i].name);
- else
- pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
- tp->args[i].name);
+ fmt, parg->name);
+ }
}
-#undef LEN_OR_ZERO
-
/* return the length of print_fmt */
return pos;
}
+#undef LEN_OR_ZERO
int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return)
{
/* Set argument names as fields */
for (i = 0; i < tp->nr_args; i++) {
struct probe_arg *parg = &tp->args[i];
-
- ret = trace_define_field(event_call, parg->type->fmttype,
- parg->name,
- offset + parg->offset,
- parg->type->size,
+ const char *fmt = parg->type->fmttype;
+ int size = parg->type->size;
+
+ if (parg->fmt)
+ fmt = parg->fmt;
+ if (parg->count)
+ size *= parg->count;
+ ret = trace_define_field(event_call, fmt, parg->name,
+ offset + parg->offset, size,
parg->type->is_signed,
FILTER_OTHER);
if (ret)
#define MAX_TRACE_ARGS 128
#define MAX_ARGSTR_LEN 63
+#define MAX_ARRAY_LEN 64
#define MAX_STRING_SIZE PATH_MAX
/* Reserved field names */
return (u8 *)ent + get_loc_offs(*dl);
}
+static nokprobe_inline u32 update_data_loc(u32 loc, int consumed)
+{
+ u32 maxlen = get_loc_len(loc);
+ u32 offset = get_loc_offs(loc);
+
+ return make_data_loc(maxlen - consumed, offset + consumed);
+}
+
/* Printing function type */
typedef int (*print_type_func_t)(struct trace_seq *, void *, void *);
FETCH_OP_ST_STRING, /* String: .offset, .size */
// Stage 4 (modify) op
FETCH_OP_MOD_BF, /* Bitfield: .basesize, .lshift, .rshift */
+ // Stage 5 (loop) op
+ FETCH_OP_LP_ARRAY, /* Array: .param = loop count */
FETCH_OP_END,
};
_ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, atype)
#define ASSIGN_FETCH_TYPE_END {}
+#define MAX_ARRAY_LEN 64
#ifdef CONFIG_KPROBE_EVENTS
bool trace_kprobe_on_func_entry(struct trace_event_call *call);
struct fetch_insn *code;
bool dynamic;/* Dynamic array (string) is used */
unsigned int offset; /* Offset from argument entry */
+ unsigned int count; /* Array count */
const char *name; /* Name of this argument */
const char *comm; /* Command of this argument */
+ char *fmt; /* Format string if needed */
const struct fetch_type *type; /* Type of this argument */
};
process_fetch_insn_bottom(struct fetch_insn *code, unsigned long val,
void *dest, void *base)
{
- int ret = 0;
+ struct fetch_insn *s3 = NULL;
+ int total = 0, ret = 0, i = 0;
+ u32 loc = 0;
+ unsigned long lval = val;
+stage2:
/* 2nd stage: dereference memory if needed */
while (code->op == FETCH_OP_DEREF) {
+ lval = val;
ret = probe_mem_read(&val, (void *)val + code->offset,
sizeof(val));
if (ret)
code++;
}
+ s3 = code;
+stage3:
/* 3rd stage: store value to buffer */
if (unlikely(!dest)) {
- if (code->op == FETCH_OP_ST_STRING)
- return fetch_store_strlen(val + code->offset);
- else
+ if (code->op == FETCH_OP_ST_STRING) {
+ ret += fetch_store_strlen(val + code->offset);
+ code++;
+ goto array;
+ } else
return -EILSEQ;
}
probe_mem_read(dest, (void *)val + code->offset, code->size);
break;
case FETCH_OP_ST_STRING:
+ loc = *(u32 *)dest;
ret = fetch_store_string(val + code->offset, dest, base);
break;
default:
code++;
}
+array:
+ /* the last stage: Loop on array */
+ if (code->op == FETCH_OP_LP_ARRAY) {
+ total += ret;
+ if (++i < code->param) {
+ code = s3;
+ if (s3->op != FETCH_OP_ST_STRING) {
+ dest += s3->size;
+ val += s3->size;
+ goto stage3;
+ }
+ code--;
+ val = lval + sizeof(char *);
+ if (dest) {
+ dest += sizeof(u32);
+ *(u32 *)dest = update_data_loc(loc, ret);
+ }
+ goto stage2;
+ }
+ code++;
+ ret = total;
+ }
+
return code->op == FETCH_OP_END ? ret : -EILSEQ;
}
print_probe_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
u8 *data, void *field)
{
- int i;
+ void *p;
+ int i, j;
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;
+ struct probe_arg *a = args + i;
+
+ trace_seq_printf(s, " %s=", a->name);
+ if (likely(!a->count)) {
+ if (!a->type->print(s, data + a->offset, field))
+ return -ENOMEM;
+ continue;
+ }
+ trace_seq_putc(s, '{');
+ p = data + a->offset;
+ for (j = 0; j < a->count; j++) {
+ if (!a->type->print(s, p, field))
+ return -ENOMEM;
+ trace_seq_putc(s, j == a->count - 1 ? '}' : ',');
+ p += a->type->size;
+ }
}
return 0;
}
projects / thirdparty / kernel / stable.git / commitdiff
