From: Tobias Klauser <tklauser@distanz.ch>
Date: Thu, 11 Jun 2020 12:33:41 +0200
Subject: tools, bpftool: Exit on error in function codegen
Patch-mainline: v5.8-rc1
Git-commit: 2c4779eff837f1035f6f9650d246905daadd9528
References: bsc#1177028

Currently, the codegen function might fail and return an error. But its
callers continue without checking its return value. Since codegen can
fail only in the unlikely case of the system running out of memory or
the static template being malformed, just exit(-1) directly from codegen
and make it void-returning.

Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200611103341.21532-1-tklauser@distanz.ch
Acked-by: Gary Lin <glin@suse.com>
---
 tools/bpf/bpftool/gen.c |   11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -200,7 +200,7 @@ out:
 	return err;
 }
 
-static int codegen(const char *template, ...)
+static void codegen(const char *template, ...)
 {
 	const char *src, *end;
 	int skip_tabs = 0, n;
@@ -211,7 +211,7 @@ static int codegen(const char *template,
 	n = strlen(template);
 	s = malloc(n + 1);
 	if (!s)
-		return -ENOMEM;
+		exit(-1);
 	src = template;
 	dst = s;
 
@@ -225,7 +225,7 @@ static int codegen(const char *template,
 			p_err("unrecognized character at pos %td in template '%s'",
 			      src - template - 1, template);
 			free(s);
-			return -EINVAL;
+			exit(-1);
 		}
 	}
 
@@ -236,7 +236,7 @@ static int codegen(const char *template,
 				p_err("not enough tabs at pos %td in template '%s'",
 				      src - template - 1, template);
 				free(s);
-				return -EINVAL;
+				exit(-1);
 			}
 		}
 		/* trim trailing whitespace */
@@ -257,7 +257,8 @@ static int codegen(const char *template,
 	va_end(args);
 
 	free(s);
-	return n;
+	if (n)
+		exit(-1);
 }
 
 static int do_skeleton(int argc, char **argv)