Merge branch 'bpf-add-cookies-retrieval-for-perf-kprobe-multi-links'

Jiri Olsa says:

====================
bpf: Add cookies retrieval for perf/kprobe multi links

hi,
this patchset adds support to retrieve cookies from existing tracing
links that still did not support it plus changes to bpftool to display
them. It's leftover we discussed some time ago [1].

thanks,
jirka

v2 changes:
 - added review/ack tags
 - fixed memory leak [Quentin]
 - align the uapi fields properly [Yafang Shao]

[1] https://lore.kernel.org/bpf/CALOAHbAZ6=A9j3VFCLoAC_WhgQKU7injMf06=cM2sU4Hi4Sx+Q@mail.gmail.com/
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
---
====================

Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/r/20240119110505.400573-1-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 78 insertions, 16 deletions

diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c
index cb46667a6b2e..afde9d0c2ea1 100644
--- a/tools/bpf/bpftool/link.c
+++ b/tools/bpf/bpftool/link.c
@@ -249,18 +249,44 @@ static int get_prog_info(int prog_id, struct bpf_prog_info *info)
 	return err;
 }
 
-static int cmp_u64(const void *A, const void *B)
+struct addr_cookie {
+	__u64 addr;
+	__u64 cookie;
+};
+
+static int cmp_addr_cookie(const void *A, const void *B)
 {
-	const __u64 *a = A, *b = B;
+	const struct addr_cookie *a = A, *b = B;
 
-	return *a - *b;
+	if (a->addr == b->addr)
+		return 0;
+	return a->addr < b->addr ? -1 : 1;
+}
+
+static struct addr_cookie *
+get_addr_cookie_array(__u64 *addrs, __u64 *cookies, __u32 count)
+{
+	struct addr_cookie *data;
+	__u32 i;
+
+	data = calloc(count, sizeof(data[0]));
+	if (!data) {
+		p_err("mem alloc failed");
+		return NULL;
+	}
+	for (i = 0; i < count; i++) {
+		data[i].addr = addrs[i];
+		data[i].cookie = cookies[i];
+	}
+	qsort(data, count, sizeof(data[0]), cmp_addr_cookie);
+	return data;
 }
 
 static void
 show_kprobe_multi_json(struct bpf_link_info *info, json_writer_t *wtr)
 {
+	struct addr_cookie *data;
 	__u32 i, j = 0;
-	__u64 *addrs;
 
 	jsonw_bool_field(json_wtr, "retprobe",
 			 info->kprobe_multi.flags & BPF_F_KPROBE_MULTI_RETURN);
@@ -268,14 +294,20 @@ show_kprobe_multi_json(struct bpf_link_info *info, json_writer_t *wtr)
 	jsonw_uint_field(json_wtr, "missed", info->kprobe_multi.missed);
 	jsonw_name(json_wtr, "funcs");
 	jsonw_start_array(json_wtr);
-	addrs = u64_to_ptr(info->kprobe_multi.addrs);
-	qsort(addrs, info->kprobe_multi.count, sizeof(addrs[0]), cmp_u64);
+	data = get_addr_cookie_array(u64_to_ptr(info->kprobe_multi.addrs),
+				     u64_to_ptr(info->kprobe_multi.cookies),
+				     info->kprobe_multi.count);
+	if (!data)
+		return;
 
 	/* Load it once for all. */
 	if (!dd.sym_count)
 		kernel_syms_load(&dd);
+	if (!dd.sym_count)
+		goto error;
+
 	for (i = 0; i < dd.sym_count; i++) {
-		if (dd.sym_mapping[i].address != addrs[j])
+		if (dd.sym_mapping[i].address != data[j].addr)
 			continue;
 		jsonw_start_object(json_wtr);
 		jsonw_uint_field(json_wtr, "addr", dd.sym_mapping[i].address);
@@ -287,11 +319,14 @@ show_kprobe_multi_json(struct bpf_link_info *info, json_writer_t *wtr)
 		} else {
 			jsonw_string_field(json_wtr, "module", dd.sym_mapping[i].module);
 		}
+		jsonw_uint_field(json_wtr, "cookie", data[j].cookie);
 		jsonw_end_object(json_wtr);
 		if (j++ == info->kprobe_multi.count)
 			break;
 	}
 	jsonw_end_array(json_wtr);
+error:
+	free(data);
 }
 
 static __u64 *u64_to_arr(__u64 val)
@@ -334,6 +369,7 @@ show_perf_event_kprobe_json(struct bpf_link_info *info, json_writer_t *wtr)
 			   u64_to_ptr(info->perf_event.kprobe.func_name));
 	jsonw_uint_field(wtr, "offset", info->perf_event.kprobe.offset);
 	jsonw_uint_field(wtr, "missed", info->perf_event.kprobe.missed);
+	jsonw_uint_field(wtr, "cookie", info->perf_event.kprobe.cookie);
 }
 
 static void
@@ -343,6 +379,7 @@ show_perf_event_uprobe_json(struct bpf_link_info *info, json_writer_t *wtr)
 	jsonw_string_field(wtr, "file",
 			   u64_to_ptr(info->perf_event.uprobe.file_name));
 	jsonw_uint_field(wtr, "offset", info->perf_event.uprobe.offset);
+	jsonw_uint_field(wtr, "cookie", info->perf_event.uprobe.cookie);
 }
 
 static void
@@ -350,6 +387,7 @@ show_perf_event_tracepoint_json(struct bpf_link_info *info, json_writer_t *wtr)
 {
 	jsonw_string_field(wtr, "tracepoint",
 			   u64_to_ptr(info->perf_event.tracepoint.tp_name));
+	jsonw_uint_field(wtr, "cookie", info->perf_event.tracepoint.cookie);
 }
 
 static char *perf_config_hw_cache_str(__u64 config)
@@ -426,6 +464,8 @@ show_perf_event_event_json(struct bpf_link_info *info, json_writer_t *wtr)
 	else
 		jsonw_uint_field(wtr, "event_config", config);
 
+	jsonw_uint_field(wtr, "cookie", info->perf_event.event.cookie);
+
 	if (type == PERF_TYPE_HW_CACHE && perf_config)
 		free((void *)perf_config);
 }
@@ -670,8 +710,8 @@ void netfilter_dump_plain(const struct bpf_link_info *info)
 
 static void show_kprobe_multi_plain(struct bpf_link_info *info)
 {
+	struct addr_cookie *data;
 	__u32 i, j = 0;
-	__u64 *addrs;
 
 	if (!info->kprobe_multi.count)
 		return;
@@ -683,21 +723,24 @@ static void show_kprobe_multi_plain(struct bpf_link_info *info)
 	printf("func_cnt %u  ", info->kprobe_multi.count);
 	if (info->kprobe_multi.missed)
 		printf("missed %llu  ", info->kprobe_multi.missed);
-	addrs = (__u64 *)u64_to_ptr(info->kprobe_multi.addrs);
-	qsort(addrs, info->kprobe_multi.count, sizeof(__u64), cmp_u64);
+	data = get_addr_cookie_array(u64_to_ptr(info->kprobe_multi.addrs),
+				     u64_to_ptr(info->kprobe_multi.cookies),
+				     info->kprobe_multi.count);
+	if (!data)
+		return;
 
 	/* Load it once for all. */
 	if (!dd.sym_count)
 		kernel_syms_load(&dd);
 	if (!dd.sym_count)
-		return;
+		goto error;
 
-	printf("\n\t%-16s %s", "addr", "func [module]");
+	printf("\n\t%-16s %-16s %s", "addr", "cookie", "func [module]");
 	for (i = 0; i < dd.sym_count; i++) {
-		if (dd.sym_mapping[i].address != addrs[j])
+		if (dd.sym_mapping[i].address != data[j].addr)
 			continue;
-		printf("\n\t%016lx %s",
-		       dd.sym_mapping[i].address, dd.sym_mapping[i].name);
+		printf("\n\t%016lx %-16llx %s",
+		       dd.sym_mapping[i].address, data[j].cookie, dd.sym_mapping[i].name);
 		if (dd.sym_mapping[i].module[0] != '\0')
 			printf(" [%s]  ", dd.sym_mapping[i].module);
 		else
@@ -706,6 +749,8 @@ static void show_kprobe_multi_plain(struct bpf_link_info *info)
 		if (j++ == info->kprobe_multi.count)
 			break;
 	}
+error:
+	free(data);
 }
 
 static void show_uprobe_multi_plain(struct bpf_link_info *info)
@@ -754,6 +799,8 @@ static void show_perf_event_kprobe_plain(struct bpf_link_info *info)
 		printf("+%#x", info->perf_event.kprobe.offset);
 	if (info->perf_event.kprobe.missed)
 		printf("  missed %llu", info->perf_event.kprobe.missed);
+	if (info->perf_event.kprobe.cookie)
+		printf("  cookie %llu", info->perf_event.kprobe.cookie);
 	printf("  ");
 }
 
@@ -770,6 +817,8 @@ static void show_perf_event_uprobe_plain(struct bpf_link_info *info)
 	else
 		printf("\n\tuprobe ");
 	printf("%s+%#x  ", buf, info->perf_event.uprobe.offset);
+	if (info->perf_event.uprobe.cookie)
+		printf("cookie %llu  ", info->perf_event.uprobe.cookie);
 }
 
 static void show_perf_event_tracepoint_plain(struct bpf_link_info *info)
@@ -781,6 +830,8 @@ static void show_perf_event_tracepoint_plain(struct bpf_link_info *info)
 		return;
 
 	printf("\n\ttracepoint %s  ", buf);
+	if (info->perf_event.tracepoint.cookie)
+		printf("cookie %llu  ", info->perf_event.tracepoint.cookie);
 }
 
 static void show_perf_event_event_plain(struct bpf_link_info *info)
@@ -802,6 +853,9 @@ static void show_perf_event_event_plain(struct bpf_link_info *info)
 	else
 		printf("%llu  ", config);
 
+	if (info->perf_event.event.cookie)
+		printf("cookie %llu  ", info->perf_event.event.cookie);
+
 	if (type == PERF_TYPE_HW_CACHE && perf_config)
 		free((void *)perf_config);
 }
@@ -952,6 +1006,14 @@ again:
 				return -ENOMEM;
 			}
 			info.kprobe_multi.addrs = ptr_to_u64(addrs);
+			cookies = calloc(count, sizeof(__u64));
+			if (!cookies) {
+				p_err("mem alloc failed");
+				free(addrs);
+				close(fd);
+				return -ENOMEM;
+			}
+			info.kprobe_multi.cookies = ptr_to_u64(cookies);
 			goto again;
 		}
 	}
@@ -977,7 +1039,7 @@ again:
 			cookies = calloc(count, sizeof(__u64));
 			if (!cookies) {
 				p_err("mem alloc failed");
-				free(cookies);
+				free(ref_ctr_offsets);
 				free(offsets);
 				close(fd);
 				return -ENOMEM;