From: Stefano Stabellini <stefano.stabell...@xilinx.com> When the length of the string is zero of_property_read_string should return -ENODATA according to the description of the function.
However, of_property_read_string doesn't check prop->length. If prop->length is zero, return -ENODATA. Without this patch the following command in u-boot: fdt set /chosen/node property-name results in of_property_read_string returning -EILSEQ when attempting to read property-name. With this patch, it returns -ENODATA as expected. This commit is a backport of: https://lore.kernel.org/xen-devel/20220416003028.1315268-1-sstabell...@kernel.org/ Signed-off-by: Stefano Stabellini <stefano.stabell...@xilinx.com> --- Changes in v5: - backport from Linux, I don't have the commit id yet so I used an LKML link instead for now --- xen/common/device_tree.c | 2 +- xen/include/xen/device_tree.h | 3 +++ 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/xen/common/device_tree.c b/xen/common/device_tree.c index 4aae281e89..0e8798bd24 100644 --- a/xen/common/device_tree.c +++ b/xen/common/device_tree.c @@ -198,7 +198,7 @@ int dt_property_read_string(const struct dt_device_node *np, if ( !pp ) return -EINVAL; - if ( !pp->value ) + if ( !pp->length ) return -ENODATA; if ( strnlen(pp->value, pp->length) >= pp->length ) return -EILSEQ; diff --git a/xen/include/xen/device_tree.h b/xen/include/xen/device_tree.h index fd6cd00b43..430a1ef445 100644 --- a/xen/include/xen/device_tree.h +++ b/xen/include/xen/device_tree.h @@ -451,6 +451,9 @@ static inline bool_t dt_property_read_bool(const struct dt_device_node *np, * doest not have value, and -EILSEQ if the string is not * null-terminated with the length of the property data. * + * Note that the empty string "" has length of 1, thus -ENODATA cannot + * be interpreted as an empty string. + * * The out_string pointer is modified only if a valid string can be decoded. */ int dt_property_read_string(const struct dt_device_node *np, -- 2.25.1
