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Diffstat (limited to 'kernel/trace/trace_probe.c')
-rw-r--r--kernel/trace/trace_probe.c177
1 files changed, 156 insertions, 21 deletions
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 93f36f8a108e..217169de0920 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -594,6 +594,8 @@ static int parse_btf_field(char *fieldname, const struct btf_type *type,
return 0;
}
+static int __store_entry_arg(struct trace_probe *tp, int argnum);
+
static int parse_btf_arg(char *varname,
struct fetch_insn **pcode, struct fetch_insn *end,
struct traceprobe_parse_context *ctx)
@@ -618,11 +620,7 @@ static int parse_btf_arg(char *varname,
return -EOPNOTSUPP;
}
- if (ctx->flags & TPARG_FL_RETURN) {
- if (strcmp(varname, "$retval") != 0) {
- trace_probe_log_err(ctx->offset, NO_BTFARG);
- return -ENOENT;
- }
+ if (ctx->flags & TPARG_FL_RETURN && !strcmp(varname, "$retval")) {
code->op = FETCH_OP_RETVAL;
/* Check whether the function return type is not void */
if (query_btf_context(ctx) == 0) {
@@ -654,11 +652,21 @@ static int parse_btf_arg(char *varname,
const char *name = btf_name_by_offset(ctx->btf, params[i].name_off);
if (name && !strcmp(name, varname)) {
- code->op = FETCH_OP_ARG;
- if (ctx->flags & TPARG_FL_TPOINT)
- code->param = i + 1;
- else
- code->param = i;
+ if (tparg_is_function_entry(ctx->flags)) {
+ code->op = FETCH_OP_ARG;
+ if (ctx->flags & TPARG_FL_TPOINT)
+ code->param = i + 1;
+ else
+ code->param = i;
+ } else if (tparg_is_function_return(ctx->flags)) {
+ code->op = FETCH_OP_EDATA;
+ ret = __store_entry_arg(ctx->tp, i);
+ if (ret < 0) {
+ /* internal error */
+ return ret;
+ }
+ code->offset = ret;
+ }
tid = params[i].type;
goto found;
}
@@ -755,6 +763,110 @@ static int check_prepare_btf_string_fetch(char *typename,
#endif
+#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
+
+static int __store_entry_arg(struct trace_probe *tp, int argnum)
+{
+ struct probe_entry_arg *earg = tp->entry_arg;
+ bool match = false;
+ int i, offset;
+
+ if (!earg) {
+ earg = kzalloc(sizeof(*tp->entry_arg), GFP_KERNEL);
+ if (!earg)
+ return -ENOMEM;
+ earg->size = 2 * tp->nr_args + 1;
+ earg->code = kcalloc(earg->size, sizeof(struct fetch_insn),
+ GFP_KERNEL);
+ if (!earg->code) {
+ kfree(earg);
+ return -ENOMEM;
+ }
+ /* Fill the code buffer with 'end' to simplify it */
+ for (i = 0; i < earg->size; i++)
+ earg->code[i].op = FETCH_OP_END;
+ tp->entry_arg = earg;
+ }
+
+ offset = 0;
+ for (i = 0; i < earg->size - 1; i++) {
+ switch (earg->code[i].op) {
+ case FETCH_OP_END:
+ earg->code[i].op = FETCH_OP_ARG;
+ earg->code[i].param = argnum;
+ earg->code[i + 1].op = FETCH_OP_ST_EDATA;
+ earg->code[i + 1].offset = offset;
+ return offset;
+ case FETCH_OP_ARG:
+ match = (earg->code[i].param == argnum);
+ break;
+ case FETCH_OP_ST_EDATA:
+ offset = earg->code[i].offset;
+ if (match)
+ return offset;
+ offset += sizeof(unsigned long);
+ break;
+ default:
+ break;
+ }
+ }
+ return -ENOSPC;
+}
+
+int traceprobe_get_entry_data_size(struct trace_probe *tp)
+{
+ struct probe_entry_arg *earg = tp->entry_arg;
+ int i, size = 0;
+
+ if (!earg)
+ return 0;
+
+ for (i = 0; i < earg->size; i++) {
+ switch (earg->code[i].op) {
+ case FETCH_OP_END:
+ goto out;
+ case FETCH_OP_ST_EDATA:
+ size = earg->code[i].offset + sizeof(unsigned long);
+ break;
+ default:
+ break;
+ }
+ }
+out:
+ return size;
+}
+
+void store_trace_entry_data(void *edata, struct trace_probe *tp, struct pt_regs *regs)
+{
+ struct probe_entry_arg *earg = tp->entry_arg;
+ unsigned long val;
+ int i;
+
+ if (!earg)
+ return;
+
+ for (i = 0; i < earg->size; i++) {
+ struct fetch_insn *code = &earg->code[i];
+
+ switch (code->op) {
+ case FETCH_OP_ARG:
+ val = regs_get_kernel_argument(regs, code->param);
+ break;
+ case FETCH_OP_ST_EDATA:
+ *(unsigned long *)((unsigned long)edata + code->offset) = val;
+ break;
+ case FETCH_OP_END:
+ goto end;
+ default:
+ break;
+ }
+ }
+end:
+ return;
+}
+NOKPROBE_SYMBOL(store_trace_entry_data)
+#endif
+
#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
/* Parse $vars. @orig_arg points '$', which syncs to @ctx->offset */
@@ -830,7 +942,7 @@ static int parse_probe_vars(char *orig_arg, const struct fetch_type *t,
#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
len = str_has_prefix(arg, "arg");
- if (len && tparg_is_function_entry(ctx->flags)) {
+ if (len) {
ret = kstrtoul(arg + len, 10, &param);
if (ret)
goto inval;
@@ -839,15 +951,29 @@ static int parse_probe_vars(char *orig_arg, const struct fetch_type *t,
err = TP_ERR_BAD_ARG_NUM;
goto inval;
}
+ param--; /* argN starts from 1, but internal arg[N] starts from 0 */
- code->op = FETCH_OP_ARG;
- code->param = (unsigned int)param - 1;
- /*
- * The tracepoint probe will probe a stub function, and the
- * first parameter of the stub is a dummy and should be ignored.
- */
- if (ctx->flags & TPARG_FL_TPOINT)
- code->param++;
+ if (tparg_is_function_entry(ctx->flags)) {
+ code->op = FETCH_OP_ARG;
+ code->param = (unsigned int)param;
+ /*
+ * The tracepoint probe will probe a stub function, and the
+ * first parameter of the stub is a dummy and should be ignored.
+ */
+ if (ctx->flags & TPARG_FL_TPOINT)
+ code->param++;
+ } else if (tparg_is_function_return(ctx->flags)) {
+ /* function entry argument access from return probe */
+ ret = __store_entry_arg(ctx->tp, param);
+ if (ret < 0) /* This error should be an internal error */
+ return ret;
+
+ code->op = FETCH_OP_EDATA;
+ code->offset = ret;
+ } else {
+ err = TP_ERR_NOFENTRY_ARGS;
+ goto inval;
+ }
return 0;
}
#endif
@@ -1037,7 +1163,8 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
break;
default:
if (isalpha(arg[0]) || arg[0] == '_') { /* BTF variable */
- if (!tparg_is_function_entry(ctx->flags)) {
+ if (!tparg_is_function_entry(ctx->flags) &&
+ !tparg_is_function_return(ctx->flags)) {
trace_probe_log_err(ctx->offset, NOSUP_BTFARG);
return -EINVAL;
}
@@ -1423,6 +1550,7 @@ int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg,
struct probe_arg *parg = &tp->args[i];
const char *body;
+ ctx->tp = tp;
body = strchr(arg, '=');
if (body) {
if (body - arg > MAX_ARG_NAME_LEN) {
@@ -1479,7 +1607,8 @@ static int argv_has_var_arg(int argc, const char *argv[], int *args_idx,
if (str_has_prefix(argv[i], "$arg")) {
trace_probe_log_set_index(i + 2);
- if (!tparg_is_function_entry(ctx->flags)) {
+ if (!tparg_is_function_entry(ctx->flags) &&
+ !tparg_is_function_return(ctx->flags)) {
trace_probe_log_err(0, NOFENTRY_ARGS);
return -EINVAL;
}
@@ -1802,6 +1931,12 @@ void trace_probe_cleanup(struct trace_probe *tp)
for (i = 0; i < tp->nr_args; i++)
traceprobe_free_probe_arg(&tp->args[i]);
+ if (tp->entry_arg) {
+ kfree(tp->entry_arg->code);
+ kfree(tp->entry_arg);
+ tp->entry_arg = NULL;
+ }
+
if (tp->event)
trace_probe_unlink(tp);
}
generated by cgit v1.2.3-70-g09d2 (git 2.48.1) at 2025-05-11 11:43:05 +0000