Messages in this thread Patch in this message | | | From | Martin Blumenstingl <> | Subject | [PATCH v2] nvmem: meson-mx-efuse: allow reading data smaller than word_size | Date | Sat, 27 Jul 2019 21:34:14 +0200 |
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Some Amlogic boards store the Ethernet MAC address inside the eFuse. The Ethernet MAC address uses 6 bytes. The existing logic in meson_mx_efuse_read() would write beyond the end of the data buffer when trying to read data with a size that is not aligned to word_size (4 bytes on Meson8, Meson8b and Meson8m2).
Calculate the remaining data to copy inside meson_mx_efuse_read() so reading 6 bytes doesn't write beyond the end of the data buffer.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> --- Changes since v1: - switch from min() to min_t() to get rid of a compiler warning
drivers/nvmem/meson-mx-efuse.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/nvmem/meson-mx-efuse.c b/drivers/nvmem/meson-mx-efuse.c index 2976aef87c82..e8fc0baa09e7 100644 --- a/drivers/nvmem/meson-mx-efuse.c +++ b/drivers/nvmem/meson-mx-efuse.c @@ -155,7 +155,8 @@ static int meson_mx_efuse_read(void *context, unsigned int offset, if (err) break; - memcpy(buf + i, &tmp, efuse->config.word_size); + memcpy(buf + i, &tmp, + min_t(size_t, bytes - i, efuse->config.word_size)); } meson_mx_efuse_mask_bits(efuse, MESON_MX_EFUSE_CNTL1, -- 2.22.0
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