Merging upstream version 1.31.0.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

2 files changed, 165 insertions, 19 deletions

diff --git a/libnetdata/ebpf/ebpf.c b/libnetdata/ebpf/ebpf.c
index 8619ae26..1f71f6a2 100644
--- a/libnetdata/ebpf/ebpf.c
+++ b/libnetdata/ebpf/ebpf.c
@@ -295,25 +295,112 @@ static int select_file(char *name, const char *program, size_t length, int mode,
     return ret;
 }
 
-struct bpf_link **ebpf_load_program(char *plugins_dir, ebpf_module_t *em, char *kernel_string, struct bpf_object **obj, int *map_fd)
+void ebpf_update_pid_table(ebpf_local_maps_t *pid, ebpf_module_t *em)
+{
+    pid->user_input = em->pid_map_size;
+}
+
+void ebpf_update_map_sizes(struct bpf_object *program, ebpf_module_t *em)
+{
+    struct bpf_map *map;
+    ebpf_local_maps_t *maps = em->maps;
+    if (!maps)
+        return;
+
+    bpf_map__for_each(map, program)
+    {
+        const char *map_name = bpf_map__name(map);
+        int i = 0; ;
+        while (maps[i].name) {
+            ebpf_local_maps_t *w = &maps[i];
+            if (w->user_input != w->internal_input && !strcmp(w->name, map_name)) {
+#ifdef NETDATA_INTERNAL_CHECKS
+                info("Changing map %s from size %u to %u ", map_name, w->internal_input, w->user_input);
+#endif
+                bpf_map__resize(map, w->user_input);
+            }
+            i++;
+        }
+    }
+}
+
+size_t ebpf_count_programs(struct bpf_object *obj)
+{
+    size_t tot = 0;
+    struct bpf_program *prog;
+    bpf_object__for_each_program(prog, obj)
+    {
+        tot++;
+    }
+
+    return tot;
+}
+
+static ebpf_specify_name_t *ebpf_find_names(ebpf_specify_name_t *names, const char *prog_name)
+{
+    size_t i = 0;
+    while (names[i].program_name) {
+        if (!strcmp(prog_name, names[i].program_name))
+            return &names[i];
+
+        i++;
+    }
+
+    return NULL;
+}
+
+static struct bpf_link **ebpf_attach_programs(struct bpf_object *obj, size_t length, ebpf_specify_name_t *names)
+{
+    struct bpf_link **links = callocz(length , sizeof(struct bpf_link *));
+    size_t i = 0;
+    struct bpf_program *prog;
+    bpf_object__for_each_program(prog, obj)
+    {
+        links[i] = bpf_program__attach(prog);
+        if (libbpf_get_error(links[i]) && names) {
+            const char *name = bpf_program__name(prog);
+            ebpf_specify_name_t *w = ebpf_find_names(names, name);
+            if (w) {
+                enum bpf_prog_type type = bpf_program__get_type(prog);
+                if (type == BPF_PROG_TYPE_KPROBE)
+                    links[i] = bpf_program__attach_kprobe(prog, w->retprobe, w->optional);
+            }
+        }
+
+        if (libbpf_get_error(links[i])) {
+            links[i] = NULL;
+        }
+
+        i++;
+    }
+
+    return links;
+}
+
+struct bpf_link **ebpf_load_program(char *plugins_dir, ebpf_module_t *em, char *kernel_string,
+                                    struct bpf_object **obj, int *map_fd)
 {
     char lpath[4096];
     char lname[128];
-    int prog_fd;
 
     int test = select_file(lname, em->thread_name, (size_t)127, em->mode, kernel_string);
     if (test < 0 || test > 127)
         return NULL;
 
     snprintf(lpath, 4096, "%s/ebpf.d/%s", plugins_dir, lname);
-    // We are using BPF_PROG_TYPE_UNSPEC instead a specific type for bpf_prog_load to define the type
-    // according the eBPF program loaded
-    if (bpf_prog_load(lpath, BPF_PROG_TYPE_UNSPEC, obj, &prog_fd)) {
-        em->enabled = CONFIG_BOOLEAN_NO;
-        info("Cannot load program: %s", lpath);
+    *obj = bpf_object__open_file(lpath, NULL);
+    if (libbpf_get_error(obj)) {
+        error("Cannot open BPF object %s", lpath);
+        bpf_object__close(*obj);
+        return NULL;
+    }
+
+    ebpf_update_map_sizes(*obj, em);
+
+    if (bpf_object__load(*obj)) {
+        error("ERROR: loading BPF object file failed %s\n", lpath);
+        bpf_object__close(*obj);
         return NULL;
-    } else {
-        info("The eBPF program %s was loaded with success.", em->thread_name);
     }
 
     struct bpf_map *map;
@@ -324,16 +411,53 @@ struct bpf_link **ebpf_load_program(char *plugins_dir, ebpf_module_t *em, char *
         i++;
     }
 
-    struct bpf_program *prog;
-    struct bpf_link **links = callocz(NETDATA_MAX_PROBES , sizeof(struct bpf_link *));
-    i = 0;
-    bpf_object__for_each_program(prog, *obj)
-    {
-        links[i] = bpf_program__attach(prog);
-        i++;
+    size_t count_programs =  ebpf_count_programs(*obj);
+
+    return ebpf_attach_programs(*obj, count_programs, em->names);
+}
+
+static char *ebpf_update_name(char *search)
+{
+    char filename[FILENAME_MAX + 1];
+    char *ret = NULL;
+    snprintfz(filename, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, NETDATA_KALLSYMS);
+    procfile *ff = procfile_open(filename, " \t", PROCFILE_FLAG_DEFAULT);
+    if(unlikely(!ff)) {
+        error("Cannot open %s%s", netdata_configured_host_prefix, NETDATA_KALLSYMS);
+        return ret;
     }
 
-    return links;
+    ff = procfile_readall(ff);
+    if(unlikely(!ff))
+        return ret;
+
+    unsigned long i, lines = procfile_lines(ff);
+    size_t length = strlen(search);
+    for(i = 0; i < lines ; i++) {
+        char *cmp = procfile_lineword(ff, i,2);;
+        if (!strncmp(search, cmp, length)) {
+            ret = strdupz(cmp);
+            break;
+        }
+    }
+
+    procfile_close(ff);
+
+    return ret;
+}
+
+void ebpf_update_names(ebpf_specify_name_t *opt, ebpf_module_t *em)
+{
+    int mode = em->mode;
+    em->names = opt;
+
+    size_t i = 0;
+    while (opt[i].program_name) {
+        opt[i].retprobe = (mode == MODE_RETURN);
+        opt[i].optional = ebpf_update_name(opt[i].function_to_attach);
+
+        i++;
+    }
 }
 
 //----------------------------------------------------------------------------------------------------------------------
@@ -368,6 +492,9 @@ void ebpf_update_module_using_config(ebpf_module_t *modules, struct config *cfg)
 
     modules->apps_charts = appconfig_get_boolean(cfg, EBPF_GLOBAL_SECTION, EBPF_CFG_APPLICATION,
                                                  CONFIG_BOOLEAN_YES);
+
+    modules->pid_map_size = (uint32_t)appconfig_get_number(cfg, EBPF_GLOBAL_SECTION, EBPF_CFG_PID_SIZE,
+                                                           modules->pid_map_size);
 }
 
 
diff --git a/libnetdata/ebpf/ebpf.h b/libnetdata/ebpf/ebpf.h
index ac3a1a2f..bc55d959 100644
--- a/libnetdata/ebpf/ebpf.h
+++ b/libnetdata/ebpf/ebpf.h
@@ -7,6 +7,7 @@
 #include <bpf/libbpf.h>
 
 #define NETDATA_DEBUGFS "/sys/kernel/debug/tracing/"
+#define NETDATA_KALLSYMS "/proc/kallsyms"
 
 // Config files
 #define EBPF_GLOBAL_SECTION "global"
@@ -15,6 +16,7 @@
 #define EBPF_CFG_LOAD_MODE_RETURN "return"
 
 #define EBPF_CFG_UPDATE_EVERY "update every"
+#define EBPF_CFG_PID_SIZE "pid table size"
 #define EBPF_CFG_APPLICATION "apps"
 
 /**
@@ -95,6 +97,21 @@ typedef enum {
     MODE_ENTRY       // This attaches kprobe when the function is called
 } netdata_run_mode_t;
 
+#define ND_EBPF_DEFAULT_PID_SIZE 32768U
+
+typedef struct ebpf_local_maps {
+    char *name;
+    uint32_t internal_input;
+    uint32_t user_input;
+} ebpf_local_maps_t;
+
+typedef struct ebpf_specify_name {
+    char *program_name;
+    char *function_to_attach;
+    char *optional;
+    bool retprobe;
+} ebpf_specify_name_t;
+
 typedef struct ebpf_module {
     const char *thread_name;
     const char *config_name;
@@ -107,10 +124,11 @@ typedef struct ebpf_module {
     uint32_t thread_id;
     int optional;
     void (*apps_routine)(struct ebpf_module *em, void *ptr);
+    ebpf_local_maps_t *maps;
+    ebpf_specify_name_t *names;
+    uint32_t pid_map_size;
 } ebpf_module_t;
 
-#define NETDATA_MAX_PROBES 64
-
 extern int get_kernel_version(char *out, int size);
 extern int get_redhat_release();
 extern int has_condition_to_run(int version);
@@ -126,5 +144,6 @@ extern void ebpf_mount_config_name(char *filename, size_t length, char *path, ch
 extern int ebpf_load_config(struct config *config, char *filename);
 extern void ebpf_update_module_using_config(ebpf_module_t *modules, struct config *cfg);
 extern void ebpf_update_module(ebpf_module_t *em, struct config *cfg, char *cfg_file);
+extern void ebpf_update_names(ebpf_specify_name_t *opt, ebpf_module_t *em);
 
 #endif /* NETDATA_EBPF_H */