| Message ID | 20190727193414.11371-1-martin.blumenstingl@googlemail.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | cb6b0a393c4a6d43e29ef476d19313c5fef8b6c7 |
| Headers | show |
| Series | [v2] nvmem: meson-mx-efuse: allow reading data smaller than word_size | expand |
On 27/07/2019 21:34, Martin Blumenstingl wrote: > 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, > Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
On 27/07/2019 20:34, Martin Blumenstingl wrote: > 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> > --- Applied Thanks, Srini
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,
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(-)