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SubjectRe: [PATCH 20/73] perf machine: Null-terminate version char array upon fgets(/proc/version) error
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Thank you Arnaldo for signing my patch.

I think we should use version 4 of my patch and return NULL instead of null-terminating for efficiency.

Thanks,

Donald

> On May 17, 2019, at 3:35 PM, Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
>
> From: Donald Yandt <donald.yandt@gmail.com>
>
> If fgets() fails due to any other error besides end-of-file, the version
> char array may not even be null-terminated.
>
> Signed-off-by: Donald Yandt <donald.yandt@gmail.com>
> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
> Cc: Avi Kivity <avi@scylladb.com>
> Cc: Jiri Olsa <jolsa@redhat.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com>
> Fixes: a1645ce12adb ("perf: 'perf kvm' tool for monitoring guest performance from host")
> Link: http://lkml.kernel.org/r/20190514110100.22019-1-donald.yandt@gmail.com
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> ---
> tools/perf/util/machine.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
> index 3c520baa198c..28a9541c4835 100644
> --- a/tools/perf/util/machine.c
> +++ b/tools/perf/util/machine.c
> @@ -1234,8 +1234,9 @@ static char *get_kernel_version(const char *root_dir)
> if (!file)
> return NULL;
>
> - version[0] = '\0';
> tmp = fgets(version, sizeof(version), file);
> + if (!tmp)
> + *version = '\0';
> fclose(file);
>
> name = strstr(version, prefix);
> --
> 2.20.1
>

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