perf tools: Fix copyfile_offset update of output offset

[ Upstream commit fa1195ccc0af2d121abe0fe266a1caee8c265eea ]

We need to increase output offset in each iteration, not decrease it as
we currently do.

I guess we were lucky to finish in most cases in first iteration, so the
bug never showed. However it shows a lot when working with big (~4GB)
size data.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: 9c9f5a2f1944 ("perf tools: Introduce copyfile_offset() function")
Link: http://lkml.kernel.org/r/20180109133923.25406-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index 3687b720327ac8ac4b0492cc2d814adbdc20a3ab..cc57c246eadea3be29d9707339a16141e8be118b 100644 (file)
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -196,7 +196,7 @@ int copyfile_offset(int ifd, loff_t off_in, int ofd, loff_t off_out, u64 size)
 
                size -= ret;
                off_in += ret;
-               off_out -= ret;
+               off_out += ret;
        }
        munmap(ptr, off_in + size);