netdev - [iproute PATCH v3 4/6] lib/bpf: Check return value of write()

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Message-Id: <20170824094131.2963-5-phil@nwl.cc>
Date:   Thu, 24 Aug 2017 11:41:29 +0200
From:   Phil Sutter <phil@....cc>
To:     Stephen Hemminger <stephen@...workplumber.org>
Cc:     netdev@...r.kernel.org
Subject: [iproute PATCH v3 4/6] lib/bpf: Check return value of write()

This is merely to silence the compiler warning. If write to stderr
failed, assume that printing an error message will fail as well so don't
even try.

Signed-off-by: Phil Sutter <phil@....cc>
---
 lib/bpf.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/bpf.c b/lib/bpf.c
index 1dcb261dc915f..825e071cea572 100644
--- a/lib/bpf.c
+++ b/lib/bpf.c
@@ -591,7 +591,8 @@ int bpf_trace_pipe(void)
 
 		ret = read(fd, buff, sizeof(buff) - 1);
 		if (ret > 0) {
-			write(2, buff, ret);
+			if (write(STDERR_FILENO, buff, ret) != ret)
+				return -1;
 			fflush(stderr);
 		}
 	}
-- 
2.13.1