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authorMykyta Yatsenko <yatsenko@meta.com>2024-05-24 14:18:40 +0100
committerAndrii Nakryiko <andrii@kernel.org>2024-05-28 16:25:06 -0700
commiteb4e7726279a344c82e3c23be396bcfd0a4d5669 (patch)
tree4aca2e5c18389f01ec9919e13ea4f728792b474b /tools/lib
parent4b3529edbb8ff069d762c6947e055e10c1748170 (diff)
libbpf: Configure log verbosity with env variable
Configure logging verbosity by setting LIBBPF_LOG_LEVEL environment variable, which is applied only to default logger. Once user set their custom logging callback, it is up to them to handle filtering. Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20240524131840.114289-1-yatsenko@meta.com
Diffstat (limited to 'tools/lib')
-rw-r--r--tools/lib/bpf/libbpf.c25
-rw-r--r--tools/lib/bpf/libbpf.h5
2 files changed, 28 insertions, 2 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 5401f2df463d..d1627a2ca30b 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -229,7 +229,30 @@ static const char * const prog_type_name[] = {
static int __base_pr(enum libbpf_print_level level, const char *format,
va_list args)
{
- if (level == LIBBPF_DEBUG)
+ const char *env_var = "LIBBPF_LOG_LEVEL";
+ static enum libbpf_print_level min_level = LIBBPF_INFO;
+ static bool initialized;
+
+ if (!initialized) {
+ char *verbosity;
+
+ initialized = true;
+ verbosity = getenv(env_var);
+ if (verbosity) {
+ if (strcasecmp(verbosity, "warn") == 0)
+ min_level = LIBBPF_WARN;
+ else if (strcasecmp(verbosity, "debug") == 0)
+ min_level = LIBBPF_DEBUG;
+ else if (strcasecmp(verbosity, "info") == 0)
+ min_level = LIBBPF_INFO;
+ else
+ fprintf(stderr, "libbpf: unrecognized '%s' envvar value: '%s', should be one of 'warn', 'debug', or 'info'.\n",
+ env_var, verbosity);
+ }
+ }
+
+ /* if too verbose, skip logging */
+ if (level > min_level)
return 0;
return vfprintf(stderr, format, args);
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index c3f77d9260fe..26e4e35528c5 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -98,7 +98,10 @@ typedef int (*libbpf_print_fn_t)(enum libbpf_print_level level,
/**
* @brief **libbpf_set_print()** sets user-provided log callback function to
- * be used for libbpf warnings and informational messages.
+ * be used for libbpf warnings and informational messages. If the user callback
+ * is not set, messages are logged to stderr by default. The verbosity of these
+ * messages can be controlled by setting the environment variable
+ * LIBBPF_LOG_LEVEL to either warn, info, or debug.
* @param fn The log print function. If NULL, libbpf won't print anything.
* @return Pointer to old print function.
*