Merge branch 'libbpf-stringify-error-codes-in-log-messages'

Mykyta Yatsenko says:

====================
libbpf: stringify error codes in log messages

From: Mykyta Yatsenko <yatsenko@meta.com>

Libbpf may report error in 2 ways:
 1. Numeric errno
 2. Errno's text representation, returned by strerror
Both ways may be confusing for users: numeric code requires people to
know how to find its meaning and strerror may be too generic and
unclear.

These patches modify libbpf error reporting by swapping numeric codes
and strerror with the standard short error name, for example:
"failed to attach: -22" becomes "failed to attach: -EINVAL".
====================

Link: https://patch.msgid.link/20241111212919.368971-1-mykyta.yatsenko5@gmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/tools/lib/bpf/str_error.h b/tools/lib/bpf/str_error.h
index 626d7ffb03d6..66ffebde0684 100644
--- a/tools/lib/bpf/str_error.h
+++ b/tools/lib/bpf/str_error.h
@@ -6,4 +6,11 @@
 
 char *libbpf_strerror_r(int err, char *dst, int len);
 
+/**
+ * @brief **errstr()** returns string corresponding to numeric errno
+ * @param err negative numeric errno
+ * @return pointer to string representation of the errno, that is invalidated
+ * upon the next call.
+ */
+const char *errstr(int err);
 #endif /* __LIBBPF_STR_ERROR_H */