libbpf-tools: Add verbose option to ksnoop

Support verbose mode and set custom libbpf print callback
in ksnoop.

Signed-off-by: Hengqi Chen <chenhengqi@outlook.com>

diff --git a/libbpf-tools/ksnoop.c b/libbpf-tools/ksnoop.c
index 496bc2e0b74b469aa0340b38a04d5b160bace85b..69c58403bbe35af73bbe85ae1786ae2222c027ca 100644 (file)
--- a/libbpf-tools/ksnoop.c
+++ b/libbpf-tools/ksnoop.c
@@ -33,6 +33,7 @@ enum log_level {
 };
 
 static enum log_level log_level = WARN;
+static bool verbose = false;
 
 static __u32 filter_pid;
 static bool stack_mode;
@@ -70,7 +71,7 @@ static int cmd_help(int argc, char **argv)
                "       FUNC    := { name | name(ARG[,ARG]*) }\n"
                "       ARG     := { arg | arg [PRED] | arg->member [PRED] }\n"
                "       PRED    := { == | != | > | >= | < | <=  value }\n"
-               "       OPTIONS := { {-d|--debug} | {-V|--version} |\n"
+               "       OPTIONS := { {-d|--debug} | {-v|--verbose} | {-V|--version} |\n"
                "                    {-p|--pid filter_pid}|\n"
                "                    {-P|--pages nr_pages} }\n"
                "                    {-s|--stack}\n",
@@ -251,7 +252,7 @@ static int get_func_btf(struct btf *btf, struct func *func)
        return 0;
 }
 
-int predicate_to_value(char *predicate, struct value *val)
+static int predicate_to_value(char *predicate, struct value *val)
 {
        char pred[MAX_STR];
        long v;
@@ -946,9 +947,10 @@ static int cmd_select(int argc, char **argv)
        return cmd_trace(argc, argv);
 }
 
-static int print_all_levels(enum libbpf_print_level level,
-                const char *format, va_list args)
+static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)
 {
+       if (level == LIBBPF_DEBUG && !verbose)
+               return 0;
        return vfprintf(stderr, format, args);
 }
 
@@ -956,6 +958,7 @@ int main(int argc, char *argv[])
 {
        static const struct option options[] = {
                { "debug",      no_argument,            NULL,   'd' },
+               { "verbose",    no_argument,            NULL,   'v' },
                { "help",       no_argument,            NULL,   'h' },
                { "version",    no_argument,            NULL,   'V' },
                { "pages",      required_argument,      NULL,   'P' },
@@ -966,11 +969,15 @@ int main(int argc, char *argv[])
 
        bin_name = argv[0];
 
-       while ((opt = getopt_long(argc, argv, "dhp:P:sV", options,
+       while ((opt = getopt_long(argc, argv, "dvhp:P:sV", options,
                                  NULL)) >= 0) {
                switch (opt) {
                case 'd':
-                       libbpf_set_print(print_all_levels);
+                       verbose = true;
+                       log_level = DEBUG;
+                       break;
+               case 'v':
+                       verbose = true;
                        log_level = DEBUG;
                        break;
                case 'h':
@@ -999,6 +1006,7 @@ int main(int argc, char *argv[])
                usage();
 
        libbpf_set_strict_mode(LIBBPF_STRICT_ALL);
+       libbpf_set_print(libbpf_print_fn);
 
        return cmd_select(argc, argv);
 }