Retsnoop improvements for LBR, stitched stacks, and interim stacks

src/env.c

@@ -119,6 +119,7 @@ static const struct argp_option opts[] = {
 	  "Only emit stacks that took at least a given amount of milliseconds" },
 	{ "success-stacks", 'S', "VALUE", OPTION_ARG_OPTIONAL,
 	  "Specify whether emitting non-erroring (successful) call stacks is allowed" },
+	{ "interim-stacks", 'I', NULL, 0, "Emit incomplete interim call stacks" },
 	{ "allow-errors", 'x', "ERROR", 0,
 	  "Record stacks only with specified errors (e.g., EINVAL, EFAULT, etc.; also accepts special 'any' value)" },
 	{ "deny-errors", 'X', "ERROR", 0, "Ignore stacks that have specified errors" },
@@ -614,6 +615,9 @@ static error_t parse_arg(int key, char *arg, struct argp_state *state)
 		}
 		env.emit_success_stacks = val;
 		break;
+	case 'I':
+		env.emit_interim_stacks = true;
+		break;
 	case 'M':
 		if (env.attach_mode != ATTACH_DEFAULT) {
 			fprintf(stderr, "Can't specify -M, -K or -F simultaneously, pick one.\n");

src/env.h

@@ -119,6 +119,7 @@ struct env {
 	 * -1 forces unsuccessful stacks only capture;
 	 */
 	int emit_success_stacks;
+	bool emit_interim_stacks;
 
 	int allow_error_cnt;
 	bool has_allow_error_filter;

src/fnargs.c

@@ -405,7 +405,7 @@ static void fmt_capture_item(struct fmt_buf *b, const struct btf *btf,
 			    btf_data_dump_printf, b, &opts);
 	if (err == -E2BIG) {
 		/* truncated data */
-		bnappendf(b, "\u2026");
+		bnappendf(b, UNICODE_HELLIP);
 	} else if (err < 0) {
 		/* unexpected error */
 		const char *errstr = err_to_str(err);
@@ -456,7 +456,7 @@ void emit_fnargs_data(FILE *f, struct stack_item *s,
 		if (env.args_fmt_mode == ARGS_FMT_COMPACT)
 			fprintf(f, "%s", i == 0 ? "" : " ");
 		else /* emit Unicode's slightly smaller-sized '>' as a marker of an argument */
-			fprintf(f, "\n%*.s\u203A ", indent_shift, "");
+			fprintf(f, "\n%*.s%s ", indent_shift, "", UNICODE_RANGLEQUOT);
 		if (fn_args->btf) {
 			if (is_vararg)
 				fprintf(f, "vararg%d%s=%s", i - vararg_start_idx, sep, sep);
@@ -564,7 +564,7 @@ void emit_ctxargs_data(FILE *f, struct stack_item *s, int indent_shift,
 		if (env.args_fmt_mode == ARGS_FMT_COMPACT)
 			fprintf(f, "%s", i == 0 ? "" : " ");
 		else /* emit Unicode's slightly smaller-sized '>' as a marker of an argument */
-			fprintf(f, "\n%*.s\u203A ", indent_shift, "");
+			fprintf(f, "\n%*.s%s ", indent_shift, "", UNICODE_RANGLEQUOT);
 
 		if (info->btf) {
 			fprintf(f, "%s%s=%s", spec->name, sep, sep);
@@ -902,7 +902,7 @@ static int prepare_tp_ctx_specs(int probe_id,
 		return err;
 	}
 
-	trace_fn_sym = ksyms__map_addr(ksyms, kmem_skel->bss->value);
+	trace_fn_sym = ksyms__map_addr(ksyms, kmem_skel->bss->value, KSYM_FUNC);
 	if (!trace_fn_sym) {
 		elog("Failed to resolve 0x%lx to `__bpf_trace_<class>` symbol for tracepoint '%s:%s'!\n",
 		     kmem_skel->bss->value, inj->tp.category, inj->tp.name);

src/ksyms.c

@@ -83,8 +83,12 @@ static int ksym_by_addr_cmp(const void *p1, const void *p2)
 {
 	const struct ksym *s1 = p1, *s2 = p2;
 
+	if (s1->kind != s2->kind)
+		return s1->kind < s2->kind ? -1 : 1;
+
 	if (s1->addr == s2->addr)
 		return strcmp(s1->name, s2->name);
+
 	return s1->addr < s2->addr ? -1 : 1;
 }
 
@@ -210,24 +214,36 @@ void ksyms__free(struct ksyms *ksyms)
 }
 
 const struct ksym *ksyms__map_addr(const struct ksyms *ksyms,
-				   unsigned long addr)
+				   unsigned long addr,
+				   enum ksym_kind kind)
 {
 	int start = 0, end = ksyms->syms_sz - 1, mid;
+	const struct ksym *ksym;
 	unsigned long sym_addr;
+	enum ksym_kind sym_kind;
+
+	if (kind != KSYM_FUNC && kind != KSYM_DATA)
+		return NULL;
 
 	/* find largest sym_addr <= addr using binary search */
 	while (start < end) {
 		mid = start + (end - start + 1) / 2;
-		sym_addr = ksyms->syms_by_addr[mid].addr;
+		ksym = &ksyms->syms_by_addr[mid];
+		sym_addr = ksym->addr;
+		sym_kind = ksym->kind;
 
-		if (sym_addr <= addr)
+		if (sym_kind < kind || (sym_kind == kind && sym_addr <= addr))
 			start = mid;
 		else
 			end = mid - 1;
 	}
 
-	if (start == end && ksyms->syms_by_addr[start].addr <= addr)
-		return &ksyms->syms_by_addr[start];
+	if (start == end) {
+		ksym = &ksyms->syms_by_addr[start];
+		if (ksym->kind == kind && ksym->addr <= addr)
+			return ksym;
+	}
+
 	return NULL;
 }
 

src/ksyms.h

@@ -21,7 +21,7 @@ struct ksyms;
 struct ksyms *ksyms__load(void);
 void ksyms__free(struct ksyms *ksyms);
 const struct ksym *ksyms__map_addr(const struct ksyms *ksyms,
-				   unsigned long addr);
+				   unsigned long addr, enum ksym_kind kind);
 const struct ksym *ksyms__get_symbol(const struct ksyms *ksyms,
 				     const char *name, const char *module,
 				     enum ksym_kind kind);