Re: [PATCH 2/6] tests/qtest/migration: Initialize buffer in probe_o_direct_support

[Philippe Mathieu-Daudé]

On 9/12/24 21:44, Fabiano Rosas wrote:
> Valgrind complains about the probe_o_direct_support() function reading
> from an uninitialized buffer. For probing O_DIRECT support we don't
> actually need to write to the file, just make sure the pwrite call
> doesn't reject the write. Still, write zeroes to the buffer to
> suppress the warning.
>
> Signed-off-by: Fabiano Rosas <farosas@suse.de>
> ---
>   tests/qtest/migration-helpers.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/tests/qtest/migration-helpers.c b/tests/qtest/migration-helpers.c
> index 3f8ba7fa8e..981910ba35 100644
> --- a/tests/qtest/migration-helpers.c
> +++ b/tests/qtest/migration-helpers.c
> @@ -496,6 +496,7 @@ bool probe_o_direct_support(const char *tmpfs)
>   
>       buf = qemu_try_memalign(len, len);
>       g_assert(buf);

(we could directly use qemu_memalign here)

> +    memset(buf, 0, len);
>   
>       ret = pwrite(fd, buf, len, offset);
>       unlink(filename);

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>