[PATCH v2 0/4] libfdt: Add namelen variants for setprop

[PATCH v2 0/4] libfdt: Add namelen variants for setprop

[Ayush Singh]

Helper functions to setproperty with length of property name similar to
getprop_namelen variants.

This patch series was originally part of overlay-path patch series [0].

[0]: https://lore.kernel.org/devicetree-compiler/6b2dba90-3c52-4933-88f3-b47f96dc7710@beagleboard.org/T/#t

Signed-off-by: Ayush Singh <ayush@beagleboard.org>

---
Changes in v2:
- Rename fdt_setprop_namelen_placeholder() to
  fdt_setprop_placeholder_namelen().
- Some formatting changes in fdt_resize_property_().
- Add trailers.
- Link to v1: https://lore.kernel.org/r/20241203-setprop-namelen-v1-0-d1ea333fbd6c@beagleboard.org

---
Ayush Singh (4):
      libfdt: add fdt_get_property_namelen_w()
      libfdt_internal: fdt_find_string_len_()
      libfdt: Add fdt_setprop_namelen()
      libfdt: Add fdt_setprop_namelen_string()

 libfdt/fdt.c             |   8 ++--
 libfdt/fdt_rw.c          |  41 +++++++++-------
 libfdt/libfdt.h          | 120 +++++++++++++++++++++++++++++++++++++++++++++--
 libfdt/libfdt_internal.h |  11 ++++-
 libfdt/version.lds       |   2 +
 5 files changed, 156 insertions(+), 26 deletions(-)
---
base-commit: 6f183c7d9246bde8f05d2edbc31fdd497c4a8702
change-id: 20241203-setprop-namelen-a94f7f057acf

Best regards,
-- 
Ayush Singh <ayush@beagleboard.org>

[PATCH v2 1/4] libfdt: add fdt_get_property_namelen_w()

[Ayush Singh]

Similar to the non-namelen variant, it is implemented in terms of
fdt_get_property_namelen()

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Ayush Singh <ayush@beagleboard.org>
---
 libfdt/libfdt.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/libfdt/libfdt.h b/libfdt/libfdt.h
index 2e182ea3314d44f30e5362ad1ca62431c0bf663b..7d0c252a34970f4ca841935f8088410a3970127a 100644
--- a/libfdt/libfdt.h
+++ b/libfdt/libfdt.h
@@ -712,6 +712,13 @@ const struct fdt_property *fdt_get_property_namelen(const void *fdt,
 						    int nodeoffset,
 						    const char *name,
 						    int namelen, int *lenp);
+static inline struct fdt_property *
+fdt_get_property_namelen_w(void *fdt, int nodeoffset, const char *name,
+			   int namelen, int *lenp)
+{
+	return (struct fdt_property *)(uintptr_t)fdt_get_property_namelen(
+		fdt, nodeoffset, name, namelen, lenp);
+}
 #endif
 
 /**

-- 
2.47.1

[PATCH v2 2/4] libfdt_internal: fdt_find_string_len_()

[Ayush Singh]

Allow specifying string length to `fdt_find_string_`.
fdt_find_string_() now internally uses this function.

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Ayush Singh <ayush@beagleboard.org>
---
 libfdt/fdt.c             |  8 ++++----
 libfdt/libfdt_internal.h | 11 ++++++++++-
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/libfdt/fdt.c b/libfdt/fdt.c
index 20c6415b9ced113d9fcce25b69007a6b0f9e68e7..95f644c31f9431eb597b6f683741ff9be375cebf 100644
--- a/libfdt/fdt.c
+++ b/libfdt/fdt.c
@@ -312,14 +312,14 @@ int fdt_next_subnode(const void *fdt, int offset)
 	return offset;
 }
 
-const char *fdt_find_string_(const char *strtab, int tabsize, const char *s)
+const char *fdt_find_string_len_(const char *strtab, int tabsize, const char *s,
+				 int slen)
 {
-	int len = strlen(s) + 1;
-	const char *last = strtab + tabsize - len;
+	const char *last = strtab + tabsize - (slen + 1);
 	const char *p;
 
 	for (p = strtab; p <= last; p++)
-		if (memcmp(p, s, len) == 0)
+		if (memcmp(p, s, slen) == 0 && p[slen] == '\0')
 			return p;
 	return NULL;
 }
diff --git a/libfdt/libfdt_internal.h b/libfdt/libfdt_internal.h
index 16bda1906a7b335519b9f748d1be6110de551e79..1fd35f364e9af15df19ae5b8b7231584804e96a4 100644
--- a/libfdt/libfdt_internal.h
+++ b/libfdt/libfdt_internal.h
@@ -6,6 +6,7 @@
  * Copyright (C) 2006 David Gibson, IBM Corporation.
  */
 #include <fdt.h>
+#include <string.h>
 
 #define FDT_ALIGN(x, a)		(((x) + (a) - 1) & ~((a) - 1))
 #define FDT_TAGALIGN(x)		(FDT_ALIGN((x), FDT_TAGSIZE))
@@ -20,7 +21,15 @@ int32_t fdt_ro_probe_(const void *fdt);
 
 int fdt_check_node_offset_(const void *fdt, int offset);
 int fdt_check_prop_offset_(const void *fdt, int offset);
-const char *fdt_find_string_(const char *strtab, int tabsize, const char *s);
+
+const char *fdt_find_string_len_(const char *strtab, int tabsize, const char *s,
+				 int s_len);
+static inline const char *fdt_find_string_(const char *strtab, int tabsize,
+					   const char *s)
+{
+	return fdt_find_string_len_(strtab, tabsize, s, strlen(s));
+}
+
 int fdt_node_end_offset_(void *fdt, int nodeoffset);
 
 static inline const void *fdt_offset_ptr_(const void *fdt, int offset)

-- 
2.47.1

[PATCH v2 3/4] libfdt: Add fdt_setprop_namelen()

[Ayush Singh]

Allow specifying name length in setprop similar to
`fdt_get_property_namelen` functions.

Signed-off-by: Ayush Singh <ayush@beagleboard.org>
---
 libfdt/fdt_rw.c    | 41 +++++++++++++++------------
 libfdt/libfdt.h    | 81 +++++++++++++++++++++++++++++++++++++++++++++++++++---
 libfdt/version.lds |  2 ++
 3 files changed, 103 insertions(+), 21 deletions(-)

diff --git a/libfdt/fdt_rw.c b/libfdt/fdt_rw.c
index 3621d3651d3f4bd82b7af66c60d023e3139add03..7475cafce071307796d7944ff8278aa5597d0812 100644
--- a/libfdt/fdt_rw.c
+++ b/libfdt/fdt_rw.c
@@ -124,31 +124,33 @@ static int fdt_splice_string_(void *fdt, int newlen)
  *	allocated. Ignored if can_assume(NO_ROLLBACK)
  * @return offset of string in the string table (whether found or added)
  */
-static int fdt_find_add_string_(void *fdt, const char *s, int *allocated)
+static int fdt_find_add_string_(void *fdt, const char *s, int slen,
+				int *allocated)
 {
 	char *strtab = (char *)fdt + fdt_off_dt_strings(fdt);
 	const char *p;
 	char *new;
-	int len = strlen(s) + 1;
 	int err;
 
 	if (!can_assume(NO_ROLLBACK))
 		*allocated = 0;
 
-	p = fdt_find_string_(strtab, fdt_size_dt_strings(fdt), s);
+	p = fdt_find_string_len_(strtab, fdt_size_dt_strings(fdt), s, slen);
 	if (p)
 		/* found it */
 		return (p - strtab);
 
 	new = strtab + fdt_size_dt_strings(fdt);
-	err = fdt_splice_string_(fdt, len);
+	err = fdt_splice_string_(fdt, slen + 1);
 	if (err)
 		return err;
 
 	if (!can_assume(NO_ROLLBACK))
 		*allocated = 1;
 
-	memcpy(new, s, len);
+	memcpy(new, s, slen);
+	new[slen] = '\0';
+
 	return (new - strtab);
 }
 
@@ -181,13 +183,15 @@ int fdt_del_mem_rsv(void *fdt, int n)
 	return fdt_splice_mem_rsv_(fdt, re, 1, 0);
 }
 
-static int fdt_resize_property_(void *fdt, int nodeoffset, const char *name,
+static int fdt_resize_property_(void *fdt, int nodeoffset,
+				const char *name, int namelen,
 				int len, struct fdt_property **prop)
 {
 	int oldlen;
 	int err;
 
-	*prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
+	*prop = fdt_get_property_namelen_w(fdt, nodeoffset, name, namelen,
+					   &oldlen);
 	if (!*prop)
 		return oldlen;
 
@@ -200,7 +204,7 @@ static int fdt_resize_property_(void *fdt, int nodeoffset, const char *name,
 }
 
 static int fdt_add_property_(void *fdt, int nodeoffset, const char *name,
-			     int len, struct fdt_property **prop)
+			     int namelen, int len, struct fdt_property **prop)
 {
 	int proplen;
 	int nextoffset;
@@ -211,7 +215,7 @@ static int fdt_add_property_(void *fdt, int nodeoffset, const char *name,
 	if ((nextoffset = fdt_check_node_offset_(fdt, nodeoffset)) < 0)
 		return nextoffset;
 
-	namestroff = fdt_find_add_string_(fdt, name, &allocated);
+	namestroff = fdt_find_add_string_(fdt, name, namelen, &allocated);
 	if (namestroff < 0)
 		return namestroff;
 
@@ -255,17 +259,18 @@ int fdt_set_name(void *fdt, int nodeoffset, const char *name)
 	return 0;
 }
 
-int fdt_setprop_placeholder(void *fdt, int nodeoffset, const char *name,
-			    int len, void **prop_data)
+int fdt_setprop_placeholder_namelen(void *fdt, int nodeoffset, const char *name,
+				    int namelen, int len, void **prop_data)
 {
 	struct fdt_property *prop;
 	int err;
 
 	FDT_RW_PROBE(fdt);
 
-	err = fdt_resize_property_(fdt, nodeoffset, name, len, &prop);
+	err = fdt_resize_property_(fdt, nodeoffset, name, namelen, len, &prop);
 	if (err == -FDT_ERR_NOTFOUND)
-		err = fdt_add_property_(fdt, nodeoffset, name, len, &prop);
+		err = fdt_add_property_(fdt, nodeoffset, name, namelen, len,
+					&prop);
 	if (err)
 		return err;
 
@@ -273,13 +278,14 @@ int fdt_setprop_placeholder(void *fdt, int nodeoffset, const char *name,
 	return 0;
 }
 
-int fdt_setprop(void *fdt, int nodeoffset, const char *name,
-		const void *val, int len)
+int fdt_setprop_namelen(void *fdt, int nodeoffset, const char *name,
+			int namelen, const void *val, int len)
 {
 	void *prop_data;
 	int err;
 
-	err = fdt_setprop_placeholder(fdt, nodeoffset, name, len, &prop_data);
+	err = fdt_setprop_placeholder_namelen(fdt, nodeoffset, name, namelen,
+					      len, &prop_data);
 	if (err)
 		return err;
 
@@ -307,7 +313,8 @@ int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
 		prop->len = cpu_to_fdt32(newlen);
 		memcpy(prop->data + oldlen, val, len);
 	} else {
-		err = fdt_add_property_(fdt, nodeoffset, name, len, &prop);
+		err = fdt_add_property_(fdt, nodeoffset, name, strlen(name),
+					len, &prop);
 		if (err)
 			return err;
 		memcpy(prop->data, val, len);
diff --git a/libfdt/libfdt.h b/libfdt/libfdt.h
index 7d0c252a34970f4ca841935f8088410a3970127a..127f41a45f40d13e307949e27f3f1b4fbf34fa2c 100644
--- a/libfdt/libfdt.h
+++ b/libfdt/libfdt.h
@@ -1666,6 +1666,38 @@ int fdt_del_mem_rsv(void *fdt, int n);
  */
 int fdt_set_name(void *fdt, int nodeoffset, const char *name);
 
+/**
+ * fdt_setprop_namelen - create or change a property
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node whose property to change
+ * @name: name of the property to change
+ * @namelen: length of the name
+ * @val: pointer to data to set the property value to
+ * @len: length of the property value
+ *
+ * fdt_setprop_namelen() sets the value of the named property in the given
+ * node to the given value and length, creating the property if it
+ * does not already exist.
+ *
+ * This function may insert or delete data from the blob, and will
+ * therefore change the offsets of some existing nodes.
+ *
+ * returns:
+ *	0, on success
+ *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
+ *		contain the new property value
+ *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ *	-FDT_ERR_BADLAYOUT,
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE,
+ *	-FDT_ERR_BADLAYOUT,
+ *	-FDT_ERR_TRUNCATED, standard meanings
+ */
+int fdt_setprop_namelen(void *fdt, int nodeoffset, const char *name,
+			int namelen, const void *val, int len);
+
 /**
  * fdt_setprop - create or change a property
  * @fdt: pointer to the device tree blob
@@ -1694,8 +1726,44 @@ int fdt_set_name(void *fdt, int nodeoffset, const char *name);
  *	-FDT_ERR_BADLAYOUT,
  *	-FDT_ERR_TRUNCATED, standard meanings
  */
-int fdt_setprop(void *fdt, int nodeoffset, const char *name,
-		const void *val, int len);
+static inline int fdt_setprop(void *fdt, int nodeoffset, const char *name,
+			      const void *val, int len)
+{
+	return fdt_setprop_namelen(fdt, nodeoffset, name, strlen(name), val,
+				   len);
+}
+
+/**
+ * fdt_setprop_placeholder_namelen - allocate space for a property
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node whose property to change
+ * @name: name of the property to change
+ * @namelen: length of the name
+ * @len: length of the property value
+ * @prop_data: return pointer to property data
+ *
+ * fdt_setprop_placeholder_namelen() allocates the named property in the given node.
+ * If the property exists it is resized. In either case a pointer to the
+ * property data is returned.
+ *
+ * This function may insert or delete data from the blob, and will
+ * therefore change the offsets of some existing nodes.
+ *
+ * returns:
+ *	0, on success
+ *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
+ *		contain the new property value
+ *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ *	-FDT_ERR_BADLAYOUT,
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE,
+ *	-FDT_ERR_BADLAYOUT,
+ *	-FDT_ERR_TRUNCATED, standard meanings
+ */
+int fdt_setprop_placeholder_namelen(void *fdt, int nodeoffset, const char *name,
+				    int namelen, int len, void **prop_data);
 
 /**
  * fdt_setprop_placeholder - allocate space for a property
@@ -1725,8 +1793,13 @@ int fdt_setprop(void *fdt, int nodeoffset, const char *name,
  *	-FDT_ERR_BADLAYOUT,
  *	-FDT_ERR_TRUNCATED, standard meanings
  */
-int fdt_setprop_placeholder(void *fdt, int nodeoffset, const char *name,
-			    int len, void **prop_data);
+static inline int fdt_setprop_placeholder(void *fdt, int nodeoffset,
+					  const char *name, int len,
+					  void **prop_data)
+{
+	return fdt_setprop_placeholder_namelen(fdt, nodeoffset, name,
+					       strlen(name), len, prop_data);
+}
 
 /**
  * fdt_setprop_u32 - set a property to a 32-bit integer
diff --git a/libfdt/version.lds b/libfdt/version.lds
index 989cd89f1051ce59255a3b3e60493be4e5e985cc..cbfef546de6c7dd2b26a5298be46687be9779233 100644
--- a/libfdt/version.lds
+++ b/libfdt/version.lds
@@ -43,6 +43,7 @@ LIBFDT_1.2 {
 		fdt_add_mem_rsv;
 		fdt_del_mem_rsv;
 		fdt_set_name;
+		fdt_setprop_namelen;
 		fdt_setprop;
 		fdt_delprop;
 		fdt_add_subnode_namelen;
@@ -71,6 +72,7 @@ LIBFDT_1.2 {
 		fdt_find_max_phandle;
 		fdt_generate_phandle;
 		fdt_check_full;
+		fdt_setprop_placeholder_namelen;
 		fdt_setprop_placeholder;
 		fdt_property_placeholder;
 		fdt_header_size_;

-- 
2.47.1

[PATCH v2 4/4] libfdt: Add fdt_setprop_namelen_string()

[Ayush Singh]

Macro using fdt_setprop_namelen() internally similar to
`fdt_setprop_string()`.

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Ayush Singh <ayush@beagleboard.org>
---
 libfdt/libfdt.h | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/libfdt/libfdt.h b/libfdt/libfdt.h
index 127f41a45f40d13e307949e27f3f1b4fbf34fa2c..f2675b12f674b2221273d666d51b8e31f9b4dfbe 100644
--- a/libfdt/libfdt.h
+++ b/libfdt/libfdt.h
@@ -1919,6 +1919,38 @@ static inline int fdt_setprop_cell(void *fdt, int nodeoffset, const char *name,
 #define fdt_setprop_string(fdt, nodeoffset, name, str) \
 	fdt_setprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
 
+/**
+ * fdt_setprop_namelen_string - set a property to a string value
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node whose property to change
+ * @name: name of the property to change
+ * @namelen: number of characters of name to consider
+ * @str: string value for the property
+ *
+ * fdt_setprop_namelen_string() sets the value of the named property in the
+ * given node to the given string value (using the length of the
+ * string to determine the new length of the property), or creates a
+ * new property with that value if it does not already exist.
+ *
+ * This function may insert or delete data from the blob, and will
+ * therefore change the offsets of some existing nodes.
+ *
+ * returns:
+ *	0, on success
+ *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
+ *		contain the new property value
+ *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ *	-FDT_ERR_BADLAYOUT,
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE,
+ *	-FDT_ERR_BADLAYOUT,
+ *	-FDT_ERR_TRUNCATED, standard meanings
+ */
+#define fdt_setprop_namelen_string(fdt, nodeoffset, name, namelen, str)    \
+	fdt_setprop_namelen((fdt), (nodeoffset), (name), (namelen), (str), \
+			    strlen(str) + 1)
 
 /**
  * fdt_setprop_empty - set a property to an empty value

-- 
2.47.1

Re: [PATCH v2 0/4] libfdt: Add namelen variants for setprop

[David Gibson]

[-- Attachment #1: Type: text/plain, Size: 1604 bytes --]

On Thu, Dec 05, 2024 at 10:21:02AM +0530, Ayush Singh wrote:
> Helper functions to setproperty with length of property name similar to
> getprop_namelen variants.
> 
> This patch series was originally part of overlay-path patch series [0].
> 
> [0]: https://lore.kernel.org/devicetree-compiler/6b2dba90-3c52-4933-88f3-b47f96dc7710@beagleboard.org/T/#t
> 
> Signed-off-by: Ayush Singh <ayush@beagleboard.org>

Merged, thanks.

> 
> ---
> Changes in v2:
> - Rename fdt_setprop_namelen_placeholder() to
>   fdt_setprop_placeholder_namelen().
> - Some formatting changes in fdt_resize_property_().
> - Add trailers.
> - Link to v1: https://lore.kernel.org/r/20241203-setprop-namelen-v1-0-d1ea333fbd6c@beagleboard.org
> 
> ---
> Ayush Singh (4):
>       libfdt: add fdt_get_property_namelen_w()
>       libfdt_internal: fdt_find_string_len_()
>       libfdt: Add fdt_setprop_namelen()
>       libfdt: Add fdt_setprop_namelen_string()
> 
>  libfdt/fdt.c             |   8 ++--
>  libfdt/fdt_rw.c          |  41 +++++++++-------
>  libfdt/libfdt.h          | 120 +++++++++++++++++++++++++++++++++++++++++++++--
>  libfdt/libfdt_internal.h |  11 ++++-
>  libfdt/version.lds       |   2 +
>  5 files changed, 156 insertions(+), 26 deletions(-)
> ---
> base-commit: 6f183c7d9246bde8f05d2edbc31fdd497c4a8702
> change-id: 20241203-setprop-namelen-a94f7f057acf
> 
> Best regards,

-- 
David Gibson (he or they)	| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you, not the other way
				| around.
http://www.ozlabs.org/~dgibson

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]