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path: root/kernel/trace/trace_probe.c
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Diffstat (limited to 'kernel/trace/trace_probe.c')
-rw-r--r--kernel/trace/trace_probe.c174
1 files changed, 148 insertions, 26 deletions
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 25e8f5408efc..2333e5446c9f 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -331,6 +331,19 @@ static int parse_trace_event_arg(char *arg, struct fetch_insn *code,
return -ENOENT;
}
+static int parse_trace_event(char *arg, struct fetch_insn *code,
+ struct traceprobe_parse_context *ctx)
+{
+ int ret;
+
+ if (code->data)
+ return -EFAULT;
+ ret = parse_trace_event_arg(arg, code, ctx);
+ if (!ret)
+ return 0;
+ return -EINVAL;
+}
+
#ifdef CONFIG_PROBE_EVENTS_BTF_ARGS
static u32 btf_type_int(const struct btf_type *t)
@@ -375,11 +388,16 @@ static bool btf_type_is_char_array(struct btf *btf, const struct btf_type *type)
&& BTF_INT_BITS(intdata) == 8;
}
+static struct btf *ctx_btf(struct traceprobe_parse_context *ctx)
+{
+ return ctx->struct_btf ? : ctx->btf;
+}
+
static int check_prepare_btf_string_fetch(char *typename,
struct fetch_insn **pcode,
struct traceprobe_parse_context *ctx)
{
- struct btf *btf = ctx->btf;
+ struct btf *btf = ctx_btf(ctx);
if (!btf || !ctx->last_type)
return 0;
@@ -505,6 +523,15 @@ static int query_btf_context(struct traceprobe_parse_context *ctx)
return 0;
}
+static void clear_struct_btf(struct traceprobe_parse_context *ctx)
+{
+ if (ctx->struct_btf) {
+ btf_put(ctx->struct_btf);
+ ctx->struct_btf = NULL;
+ ctx->last_struct = NULL;
+ }
+}
+
static void clear_btf_context(struct traceprobe_parse_context *ctx)
{
if (ctx->btf) {
@@ -553,22 +580,29 @@ static int parse_btf_field(char *fieldname, const struct btf_type *type,
struct fetch_insn *code = *pcode;
const struct btf_member *field;
u32 bitoffs, anon_offs;
+ bool is_struct = ctx->struct_btf != NULL;
+ struct btf *btf = ctx_btf(ctx);
char *next;
int is_ptr;
s32 tid;
do {
- /* Outer loop for solving arrow operator ('->') */
- if (BTF_INFO_KIND(type->info) != BTF_KIND_PTR) {
- trace_probe_log_err(ctx->offset, NO_PTR_STRCT);
- return -EINVAL;
- }
- /* Convert a struct pointer type to a struct type */
- type = btf_type_skip_modifiers(ctx->btf, type->type, &tid);
- if (!type) {
- trace_probe_log_err(ctx->offset, BAD_BTF_TID);
- return -EINVAL;
+ if (!is_struct) {
+ /* Outer loop for solving arrow operator ('->') */
+ if (BTF_INFO_KIND(type->info) != BTF_KIND_PTR) {
+ trace_probe_log_err(ctx->offset, NO_PTR_STRCT);
+ return -EINVAL;
+ }
+
+ /* Convert a struct pointer type to a struct type */
+ type = btf_type_skip_modifiers(btf, type->type, &tid);
+ if (!type) {
+ trace_probe_log_err(ctx->offset, BAD_BTF_TID);
+ return -EINVAL;
+ }
}
+ /* Only the first type can skip being a pointer */
+ is_struct = false;
bitoffs = 0;
do {
@@ -579,7 +613,7 @@ static int parse_btf_field(char *fieldname, const struct btf_type *type,
return is_ptr;
anon_offs = 0;
- field = btf_find_struct_member(ctx->btf, type, fieldname,
+ field = btf_find_struct_member(btf, type, fieldname,
&anon_offs);
if (IS_ERR(field)) {
trace_probe_log_err(ctx->offset, BAD_BTF_TID);
@@ -601,7 +635,7 @@ static int parse_btf_field(char *fieldname, const struct btf_type *type,
ctx->last_bitsize = 0;
}
- type = btf_type_skip_modifiers(ctx->btf, field->type, &tid);
+ type = btf_type_skip_modifiers(btf, field->type, &tid);
if (!type) {
trace_probe_log_err(ctx->offset, BAD_BTF_TID);
return -EINVAL;
@@ -639,7 +673,7 @@ static int parse_btf_arg(char *varname,
int i, is_ptr, ret;
u32 tid;
- if (WARN_ON_ONCE(!ctx->funcname))
+ if (!ctx->funcname && !(ctx->flags & TPARG_FL_TEVENT))
return -EINVAL;
is_ptr = split_next_field(varname, &field, ctx);
@@ -652,6 +686,19 @@ static int parse_btf_arg(char *varname,
return -EOPNOTSUPP;
}
+ if (ctx->flags & TPARG_FL_TEVENT) {
+ ret = parse_trace_event(varname, code, ctx);
+ if (ret < 0) {
+ trace_probe_log_err(ctx->offset, BAD_ATTACH_ARG);
+ return ret;
+ }
+ /* TEVENT is only here via a typecast */
+ if (WARN_ON_ONCE(ctx->struct_btf == NULL))
+ return -EINVAL;
+ type = ctx->last_struct;
+ goto found_type;
+ }
+
if (ctx->flags & TPARG_FL_RETURN && !strcmp(varname, "$retval")) {
code->op = FETCH_OP_RETVAL;
/* Check whether the function return type is not void */
@@ -708,6 +755,7 @@ static int parse_btf_arg(char *varname,
found:
type = btf_type_skip_modifiers(ctx->btf, tid, &tid);
+found_type:
if (!type) {
trace_probe_log_err(ctx->offset, BAD_BTF_TID);
return -EINVAL;
@@ -726,7 +774,7 @@ found:
static const struct fetch_type *find_fetch_type_from_btf_type(
struct traceprobe_parse_context *ctx)
{
- struct btf *btf = ctx->btf;
+ struct btf *btf = ctx_btf(ctx);
const char *typestr = NULL;
if (btf && ctx->last_type)
@@ -757,7 +805,67 @@ static int parse_btf_bitfield(struct fetch_insn **pcode,
return 0;
}
-#else
+static int query_btf_struct(const char *sname, struct traceprobe_parse_context *ctx)
+{
+ struct btf *btf = NULL;
+ int id;
+
+ /* A struct_btf should only be used by a single argument */
+ if (WARN_ON_ONCE(ctx->struct_btf)) {
+ btf_put(ctx->struct_btf);
+ ctx->struct_btf = NULL;
+ }
+
+ id = bpf_find_btf_id(sname, BTF_KIND_STRUCT, &btf);
+ if (id < 0)
+ return id;
+ ctx->struct_btf = btf;
+ ctx->last_struct = btf_type_by_id(ctx->struct_btf, id);
+ return 0;
+}
+
+static int handle_typecast(char *arg, struct fetch_insn **pcode,
+ struct fetch_insn *end,
+ struct traceprobe_parse_context *ctx)
+{
+ char *tmp;
+ int ret;
+
+ /* Currently this only works for eprobes */
+ if (!(ctx->flags & TPARG_FL_TEVENT)) {
+ trace_probe_log_err(ctx->offset, TYPECAST_NOT_EVENT);
+ return -EINVAL;
+ }
+
+ tmp = strchr(arg, ')');
+ if (!tmp) {
+ trace_probe_log_err(ctx->offset + strlen(arg),
+ DEREF_OPEN_BRACE);
+ return -EINVAL;
+ }
+ *tmp = '\0';
+ ret = query_btf_struct(arg + 1, ctx);
+ *tmp = ')';
+
+ if (ret < 0) {
+ trace_probe_log_err(ctx->offset + 1, NO_PTR_STRCT);
+ return -EINVAL;
+ }
+
+ tmp++;
+
+ ctx->offset += tmp - arg;
+ ret = parse_btf_arg(tmp, pcode, end, ctx);
+ return ret;
+}
+
+#else /* !CONFIG_PROBE_EVENTS_BTF_ARGS */
+
+static void clear_struct_btf(struct traceprobe_parse_context *ctx)
+{
+ ctx->struct_btf = NULL;
+}
+
static void clear_btf_context(struct traceprobe_parse_context *ctx)
{
ctx->btf = NULL;
@@ -793,7 +901,15 @@ static int check_prepare_btf_string_fetch(char *typename,
return 0;
}
-#endif
+static int handle_typecast(char *arg, struct fetch_insn **pcode,
+ struct fetch_insn *end,
+ struct traceprobe_parse_context *ctx)
+{
+ trace_probe_log_err(ctx->offset, NOSUP_BTFARG);
+ return -EOPNOTSUPP;
+}
+
+#endif /* CONFIG_PROBE_EVENTS_BTF_ARGS */
#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
@@ -953,16 +1069,15 @@ static int parse_probe_vars(char *orig_arg, const struct fetch_type *t,
int len;
if (ctx->flags & TPARG_FL_TEVENT) {
- if (code->data)
- return -EFAULT;
- ret = parse_trace_event_arg(arg, code, ctx);
- if (!ret)
- return 0;
- if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) {
- code->op = FETCH_OP_COMM;
- return 0;
+ if (parse_trace_event(arg, code, ctx) < 0) {
+ /* 'comm' should be checked after field parsing. */
+ if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) {
+ code->op = FETCH_OP_COMM;
+ return 0;
+ }
+ goto inval;
}
- goto inval;
+ return 0;
}
if (str_has_prefix(arg, "retval")) {
@@ -1133,6 +1248,7 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
code->op = FETCH_OP_FOFFS;
code->immediate = (unsigned long)offset; // imm64?
+ offset = 0;
} else {
/* uprobes don't support symbols */
if (!(ctx->flags & TPARG_FL_KERNEL)) {
@@ -1229,6 +1345,9 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
code->op = FETCH_OP_IMM;
}
break;
+ case '(':
+ ret = handle_typecast(arg, pcode, end, ctx);
+ break;
default:
if (isalpha(arg[0]) || arg[0] == '_') { /* BTF variable */
if (!tparg_is_function_entry(ctx->flags) &&
@@ -1561,6 +1680,9 @@ fail:
}
kfree(tmp);
+ /* struct_btf should not be passed to other arguments */
+ clear_struct_btf(ctx);
+
return ret;
}
generated by cgit v1.2.3 (git 2.25.1) at 2026-07-25 13:59:01 +0000