From: Quentin Monnet <quentin.monnet@netronome.com>
Date: Tue, 19 Nov 2019 11:17:06 +0000
Subject: tools, bpftool: Fix warning on ignored return value for 'read'
Patch-mainline: v5.5-rc1
Git-commit: a0f17cc6665c80ab2765f9244c41ec127821f343
References: bsc#1177028
When building bpftool, a warning was introduced by commit a94364603610
("bpftool: Allow to read btf as raw data"), because the return value
from a call to 'read()' is ignored. Let's address it.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191119111706.22440-1-quentin.monnet@netronome.com
Acked-by: Gary Lin <glin@suse.com>
---
tools/bpf/bpftool/btf.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/tools/bpf/bpftool/btf.c
+++ b/tools/bpf/bpftool/btf.c
@@ -428,15 +428,15 @@ exit_close:
static bool is_btf_raw(const char *file)
{
__u16 magic = 0;
- int fd;
+ int fd, nb_read;
fd = open(file, O_RDONLY);
if (fd < 0)
return false;
- read(fd, &magic, sizeof(magic));
+ nb_read = read(fd, &magic, sizeof(magic));
close(fd);
- return magic == BTF_MAGIC;
+ return nb_read == sizeof(magic) && magic == BTF_MAGIC;
}
static int do_dump(int argc, char **argv)