From: Stefano Stabellini Date: Fri, 13 May 2022 21:07:24 +0000 (-0700) Subject: xen/dt: of_property_read_string return -ENODATA when !length X-Git-Tag: archive/raspbian/4.17.0-1+rpi1^2~33^2~623 X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=d43d2b6056fc65126e8d991a11f5dec14e51754d;p=xen.git xen/dt: of_property_read_string return -ENODATA when !length 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-sstabellini@kernel.org/ Signed-off-by: Stefano Stabellini Reviewed-by: Bertrand Marquis Reviewed-by: Luca Fancellu --- 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,