[PATCH v3 0/2] stacked overlay support

[PATCH v3 0/2] stacked overlay support

[Pantelis Antoniou]

Overlay application has a shortcoming that it is not possible
to refer to labels that were defined by a previously applied
overlay.

This patchset fixes the problem by keeping around the labels
that each overlay contains.

It is dependent on two previously submitted patches
"Introduce fdt_get_path_len() method"
"Introduce fdt_setprop_placeholder() method"

Changes since V2:
* Rework to make application faster when using target-path
* Various cosmetic fixes

Changes since V1:
* Rework to remove reliance on malloc and FDT_PATH_MAX


Pantelis Antoniou (2):
  fdt: Allow stacked overlays phandle references
  tests: Add stacked overlay tests on fdtoverlay

 libfdt/fdt_overlay.c           | 197 ++++++++++++++++++++++++++++++++++++-----
 tests/run_tests.sh             |  15 ++++
 tests/stacked_overlay_bar.dts  |  13 +++
 tests/stacked_overlay_base.dts |   6 ++
 tests/stacked_overlay_baz.dts  |  13 +++
 5 files changed, 222 insertions(+), 22 deletions(-)
 create mode 100644 tests/stacked_overlay_bar.dts
 create mode 100644 tests/stacked_overlay_base.dts
 create mode 100644 tests/stacked_overlay_baz.dts

-- 
2.1.4

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[PATCH v3 1/2] fdt: Allow stacked overlays phandle references

[Pantelis Antoniou]

This patch enables an overlay to refer to a previous overlay's
labels by performing a merge of symbol information at application
time.

In a nutshell it allows an overlay to refer to a symbol that a previous
overlay has defined. It requires both the base and all the overlays
to be compiled with the -@ command line switch so that symbol
information is included.

base.dts
--------

	/dts-v1/;
	/ {
		foo: foonode {
			foo-property;
		};
	};

	$ dtc -@ -I dts -O dtb -o base.dtb base.dts

bar.dts
-------

	/dts-v1/;
	/plugin/;
	/ {
		fragment@1 {
			target = <&foo>;
			__overlay__ {
				overlay-1-property;
				bar: barnode {
					bar-property;
				};
			};
		};
	};

	$ dtc -@ -I dts -O dtb -o bar.dtb bar.dts

baz.dts
-------

	/dts-v1/;
	/plugin/;
	/ {
		fragment@1 {
			target = <&bar>;
			__overlay__ {
				overlay-2-property;
				baz: baznode {
					baz-property;
				};
			};
		};
	};

	$ dtc -@ -I dts -O dtb -o baz.dtb baz.dts

Applying the overlays:

	$ fdtoverlay -i base.dtb -o target.dtb bar.dtb baz.dtb

Dumping:

	$ fdtdump target.dtb
	/ {
            foonode {
                overlay-1-property;
                foo-property;
                linux,phandle = <0x00000001>;
                phandle = <0x00000001>;
                barnode {
                    overlay-2-property;
                    phandle = <0x00000002>;
                    linux,phandle = <0x00000002>;
                    bar-property;
                    baznode {
                        phandle = <0x00000003>;
                        linux,phandle = <0x00000003>;
                        baz-property;
                    };
                };
            };
            __symbols__ {
                baz = "/foonode/barnode/baznode";
                bar = "/foonode/barnode";
                foo = "/foonode";
            };
	};

Signed-off-by: Pantelis Antoniou <pantelis.antoniou-OWPKS81ov/FWk0Htik3J/w@public.gmane.org>
---
 libfdt/fdt_overlay.c | 197 +++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 175 insertions(+), 22 deletions(-)

diff --git a/libfdt/fdt_overlay.c b/libfdt/fdt_overlay.c
index ceb9687..e6fe058 100644
--- a/libfdt/fdt_overlay.c
+++ b/libfdt/fdt_overlay.c
@@ -39,6 +39,7 @@ static uint32_t overlay_get_target_phandle(const void *fdto, int fragment)
  * @fdt: Base device tree blob
  * @fdto: Device tree overlay blob
  * @fragment: node offset of the fragment in the overlay
+ * @pathp: pointer which receives the path of the target (or NULL)
  *
  * overlay_get_target() retrieves the target offset in the base
  * device tree of a fragment, no matter how the actual targetting is
@@ -49,37 +50,47 @@ static uint32_t overlay_get_target_phandle(const void *fdto, int fragment)
  *      Negative error code on error
  */
 static int overlay_get_target(const void *fdt, const void *fdto,
-			      int fragment)
+			      int fragment, char const **pathp)
 {
 	uint32_t phandle;
-	const char *path;
-	int path_len;
+	const char *path = NULL;
+	int path_len = 0, ret;
 
 	/* Try first to do a phandle based lookup */
 	phandle = overlay_get_target_phandle(fdto, fragment);
 	if (phandle == (uint32_t)-1)
 		return -FDT_ERR_BADPHANDLE;
 
-	if (phandle)
-		return fdt_node_offset_by_phandle(fdt, phandle);
+	/* no phandle, try path */
+	if (!phandle) {
+		/* And then a path based lookup */
+		path = fdt_getprop(fdto, fragment, "target-path", &path_len);
+		if (path)
+			ret = fdt_path_offset(fdt, path);
+		else
+			ret = path_len;
+	} else
+		ret = fdt_node_offset_by_phandle(fdt, phandle);
 
-	/* And then a path based lookup */
-	path = fdt_getprop(fdto, fragment, "target-path", &path_len);
-	if (!path) {
-		/*
-		 * If we haven't found either a target or a
-		 * target-path property in a node that contains a
-		 * __overlay__ subnode (we wouldn't be called
-		 * otherwise), consider it a improperly written
-		 * overlay
-		 */
-		if (path_len == -FDT_ERR_NOTFOUND)
-			return -FDT_ERR_BADOVERLAY;
+	/*
+	* If we haven't found either a target or a
+	* target-path property in a node that contains a
+	* __overlay__ subnode (we wouldn't be called
+	* otherwise), consider it a improperly written
+	* overlay
+	*/
+	if (ret < 0 && path_len == -FDT_ERR_NOTFOUND)
+		ret = -FDT_ERR_BADOVERLAY;
+
+	/* return on error */
+	if (ret < 0)
+		return ret;
 
-		return path_len;
-	}
+	/* return pointer to path (if available) */
+	if (pathp)
+		*pathp = path ? path : NULL;
 
-	return fdt_path_offset(fdt, path);
+	return ret;
 }
 
 /**
@@ -590,7 +601,7 @@ static int overlay_apply_node(void *fdt, int target,
  *
  * overlay_merge() merges an overlay into its base device tree.
  *
- * This is the final step in the device tree overlay application
+ * This is the next to last step in the device tree overlay application
  * process, when all the phandles have been adjusted and resolved and
  * you just have to merge overlay into the base device tree.
  *
@@ -618,7 +629,7 @@ static int overlay_merge(void *fdt, void *fdto)
 		if (overlay < 0)
 			return overlay;
 
-		target = overlay_get_target(fdt, fdto, fragment);
+		target = overlay_get_target(fdt, fdto, fragment, NULL);
 		if (target < 0)
 			return target;
 
@@ -630,6 +641,144 @@ static int overlay_merge(void *fdt, void *fdto)
 	return 0;
 }
 
+/**
+ * overlay_symbol_update - Update the symbols of base tree after a merge
+ * @fdt: Base Device Tree blob
+ * @fdto: Device tree overlay blob
+ *
+ * overlay_symbol_update() updates the symbols of the base tree with the
+ * symbols of the applied overlay
+ *
+ * This is the last step in the device tree overlay application
+ * process, allowing the reference of overlay symbols by subsequent
+ * overlay operations.
+ *
+ * returns:
+ *      0 on success
+ *      Negative error code on failure
+ */
+static int overlay_symbol_update(void *fdt, void *fdto)
+{
+	int root_sym, ov_sym, prop, path_len, fragment, target;
+	int len, frag_name_len, ret, rel_path_len;
+	const char *s;
+	const char *path;
+	const char *name;
+	const char *frag_name;
+	const char *rel_path;
+	const char *target_path;
+	char *buf;
+	void *p;
+
+	ov_sym = fdt_subnode_offset(fdto, 0, "__symbols__");
+
+	/* if no overlay symbols exist no problem */
+	if (ov_sym < 0)
+		return 0;
+
+	root_sym = fdt_subnode_offset(fdt, 0, "__symbols__");
+
+	/* it no root symbols exist we should create them */
+	if (root_sym < 0) {
+		root_sym = fdt_add_subnode(fdt, 0, "__symbols__");
+		if (root_sym < 0)
+			return root_sym;
+	}
+
+	/* iterate over each overlay symbol */
+	fdt_for_each_property_offset(prop, fdto, ov_sym) {
+		path = fdt_getprop_by_offset(fdto, prop, &name, &path_len);
+		if (!path)
+			return path_len;
+
+		/* verify it's a string property (terminated with \0) */
+		if (path_len < 1 || path[path_len - 1] != '\0')
+			return -FDT_ERR_BADVALUE;
+
+		/* format: /<fragment-name>/__overlay__/<relative-subnode-path> */
+
+		if (*path != '/')
+			return -FDT_ERR_BADVALUE;
+
+		/* verify that no stray \0 exist in the property */
+		if (strlen(path) != path_len - 1)
+			return -FDT_ERR_BADVALUE;
+
+		/* get fragment name first */
+		s = strchr(path + 1, '/');
+		if (!s)
+			return -FDT_ERR_BADVALUE;
+
+		frag_name = path + 1;
+		frag_name_len = s - path - 1;
+
+		/* verify format; safe since "s" lies in \0 terminated prop */
+		len = strlen("/__overlay__/");
+		if (strncmp(s, "/__overlay__/", len))
+			return -FDT_ERR_NOTFOUND;
+
+		rel_path = s + len;
+		rel_path_len = strlen(rel_path);
+
+		/* find the fragment index in which the symbol lies */
+		ret = fdt_subnode_offset_namelen(fdto, 0, frag_name,
+					       frag_name_len);
+		/* not found? */
+		if (ret < 0)
+			return ret;
+		fragment = ret;
+
+		/* an __overlay__ subnode must exist */
+		ret = fdt_subnode_offset(fdto, fragment, "__overlay__");
+		if (ret < 0)
+			return ret;
+
+		/* get the target of the fragment */
+		ret = overlay_get_target(fdt, fdto, fragment, &target_path);
+		if (ret < 0)
+			return ret;
+		target = ret;
+
+		/* if we have a target path use */
+		if (!target_path) {
+			ret = fdt_get_path_len(fdt, target);
+			if (ret < 0)
+				return ret;
+			len = ret;
+		} else
+			len = strlen(target_path);
+
+		ret = fdt_setprop_placeholder(fdt, root_sym, name,
+				len + (len > 1) + rel_path_len + 1, &p);
+		if (ret < 0)
+			return ret;
+
+		/* again in case setprop_placeholder changed it */
+		ret = overlay_get_target(fdt, fdto, fragment, &target_path);
+		if (ret < 0)
+			return ret;
+		target = ret;
+
+		buf = p;
+		if (len > 1) { /* target is not root */
+			if (!target_path) {
+				ret = fdt_get_path(fdt, target, buf, len + 1);
+				if (ret < 0)
+					return ret;
+			} else
+				memcpy(buf, target_path, len + 1);
+
+		} else
+			len--;
+
+		buf[len] = '/';
+		memcpy(buf + len + 1, rel_path, rel_path_len);
+		buf[len + 1 + rel_path_len] = '\0';
+	}
+
+	return 0;
+}
+
 int fdt_overlay_apply(void *fdt, void *fdto)
 {
 	uint32_t delta = fdt_get_max_phandle(fdt);
@@ -654,6 +803,10 @@ int fdt_overlay_apply(void *fdt, void *fdto)
 	if (ret)
 		goto err;
 
+	ret = overlay_symbol_update(fdt, fdto);
+	if (ret)
+		goto err;
+
 	/*
 	 * The overlay has been damaged, erase its magic.
 	 */
-- 
2.1.4

[PATCH v3 2/2] tests: Add stacked overlay tests on fdtoverlay

[Pantelis Antoniou]

Add a stacked overlay unit test, piggybacking on fdtoverlay.

Signed-off-by: Pantelis Antoniou <pantelis.antoniou-OWPKS81ov/FWk0Htik3J/w@public.gmane.org>
---
 tests/run_tests.sh             | 15 +++++++++++++++
 tests/stacked_overlay_bar.dts  | 13 +++++++++++++
 tests/stacked_overlay_base.dts |  6 ++++++
 tests/stacked_overlay_baz.dts  | 13 +++++++++++++
 4 files changed, 47 insertions(+)
 create mode 100644 tests/stacked_overlay_bar.dts
 create mode 100644 tests/stacked_overlay_base.dts
 create mode 100644 tests/stacked_overlay_baz.dts

diff --git a/tests/run_tests.sh b/tests/run_tests.sh
index b8a2825..9e3d35d 100755
--- a/tests/run_tests.sh
+++ b/tests/run_tests.sh
@@ -791,6 +791,21 @@ fdtoverlay_tests() {
 
     # test that the new property is installed
     run_fdtoverlay_test foobar "/test-node" "test-str-property" "-ts" ${basedtb} ${targetdtb} ${overlaydtb}
+
+    stacked_base=stacked_overlay_base.dts
+    stacked_basedtb=stacked_overlay_base.fdtoverlay.test.dtb
+    stacked_bar=stacked_overlay_bar.dts
+    stacked_bardtb=stacked_overlay_bar.fdtoverlay.test.dtb
+    stacked_baz=stacked_overlay_baz.dts
+    stacked_bazdtb=stacked_overlay_baz.fdtoverlay.test.dtb
+    stacked_targetdtb=stacked_overlay_target.fdoverlay.test.dtb
+
+    run_dtc_test -@ -I dts -O dtb -o $stacked_basedtb $stacked_base
+    run_dtc_test -@ -I dts -O dtb -o $stacked_bardtb $stacked_bar
+    run_dtc_test -@ -I dts -O dtb -o $stacked_bazdtb $stacked_baz
+
+    # test that baz correctly inserted the property
+    run_fdtoverlay_test baz "/foonode/barnode/baznode" "baz-property" "-ts" ${stacked_basedtb} ${stacked_targetdtb} ${stacked_bardtb} ${stacked_bazdtb}
 }
 
 pylibfdt_tests () {
diff --git a/tests/stacked_overlay_bar.dts b/tests/stacked_overlay_bar.dts
new file mode 100644
index 0000000..c646399
--- /dev/null
+++ b/tests/stacked_overlay_bar.dts
@@ -0,0 +1,13 @@
+/dts-v1/;
+/plugin/;
+/ {
+	fragment@1 {
+		target = <&foo>;
+		__overlay__ {
+			overlay-1-property;
+			bar: barnode {
+				bar-property = "bar";
+			};
+		};
+	};
+};
diff --git a/tests/stacked_overlay_base.dts b/tests/stacked_overlay_base.dts
new file mode 100644
index 0000000..2916423
--- /dev/null
+++ b/tests/stacked_overlay_base.dts
@@ -0,0 +1,6 @@
+/dts-v1/;
+/ {
+	foo: foonode {
+		foo-property = "foo";
+	};
+};
diff --git a/tests/stacked_overlay_baz.dts b/tests/stacked_overlay_baz.dts
new file mode 100644
index 0000000..a52f0cc
--- /dev/null
+++ b/tests/stacked_overlay_baz.dts
@@ -0,0 +1,13 @@
+/dts-v1/;
+/plugin/;
+/ {
+	fragment@1 {
+		target = <&bar>;
+		__overlay__ {
+			overlay-2-property;
+			baz: baznode {
+				baz-property = "baz";
+			};
+		};
+	};
+};
-- 
2.1.4

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Re: [PATCH v3 1/2] fdt: Allow stacked overlays phandle references

[David Gibson]

[-- Attachment #1: Type: text/plain, Size: 11103 bytes --]

On Tue, Jul 25, 2017 at 08:24:35PM +0300, Pantelis Antoniou wrote:
> This patch enables an overlay to refer to a previous overlay's
> labels by performing a merge of symbol information at application
> time.
> 
> In a nutshell it allows an overlay to refer to a symbol that a previous
> overlay has defined. It requires both the base and all the overlays
> to be compiled with the -@ command line switch so that symbol
> information is included.

Sorry I've taken so long to review this spin.  There's a few nits
left, but it's very close to ready.

> 
> base.dts
> --------
> 
> 	/dts-v1/;
> 	/ {
> 		foo: foonode {
> 			foo-property;
> 		};
> 	};
> 
> 	$ dtc -@ -I dts -O dtb -o base.dtb base.dts
> 
> bar.dts
> -------
> 
> 	/dts-v1/;
> 	/plugin/;
> 	/ {
> 		fragment@1 {
> 			target = <&foo>;
> 			__overlay__ {
> 				overlay-1-property;
> 				bar: barnode {
> 					bar-property;
> 				};
> 			};
> 		};
> 	};
> 
> 	$ dtc -@ -I dts -O dtb -o bar.dtb bar.dts
> 
> baz.dts
> -------
> 
> 	/dts-v1/;
> 	/plugin/;
> 	/ {
> 		fragment@1 {
> 			target = <&bar>;
> 			__overlay__ {
> 				overlay-2-property;
> 				baz: baznode {
> 					baz-property;
> 				};
> 			};
> 		};
> 	};
> 
> 	$ dtc -@ -I dts -O dtb -o baz.dtb baz.dts
> 
> Applying the overlays:
> 
> 	$ fdtoverlay -i base.dtb -o target.dtb bar.dtb baz.dtb
> 
> Dumping:
> 
> 	$ fdtdump target.dtb
> 	/ {
>             foonode {
>                 overlay-1-property;
>                 foo-property;
>                 linux,phandle = <0x00000001>;
>                 phandle = <0x00000001>;
>                 barnode {
>                     overlay-2-property;
>                     phandle = <0x00000002>;
>                     linux,phandle = <0x00000002>;
>                     bar-property;
>                     baznode {
>                         phandle = <0x00000003>;
>                         linux,phandle = <0x00000003>;
>                         baz-property;
>                     };
>                 };
>             };
>             __symbols__ {
>                 baz = "/foonode/barnode/baznode";
>                 bar = "/foonode/barnode";
>                 foo = "/foonode";
>             };
> 	};
> 
> Signed-off-by: Pantelis Antoniou <pantelis.antoniou-OWPKS81ov/FWk0Htik3J/w@public.gmane.org>
> ---
>  libfdt/fdt_overlay.c | 197 +++++++++++++++++++++++++++++++++++++++++++++------
>  1 file changed, 175 insertions(+), 22 deletions(-)
> 
> diff --git a/libfdt/fdt_overlay.c b/libfdt/fdt_overlay.c
> index ceb9687..e6fe058 100644
> --- a/libfdt/fdt_overlay.c
> +++ b/libfdt/fdt_overlay.c
> @@ -39,6 +39,7 @@ static uint32_t overlay_get_target_phandle(const void *fdto, int fragment)
>   * @fdt: Base device tree blob
>   * @fdto: Device tree overlay blob
>   * @fragment: node offset of the fragment in the overlay
> + * @pathp: pointer which receives the path of the target (or NULL)
>   *
>   * overlay_get_target() retrieves the target offset in the base
>   * device tree of a fragment, no matter how the actual targetting is
> @@ -49,37 +50,47 @@ static uint32_t overlay_get_target_phandle(const void *fdto, int fragment)
>   *      Negative error code on error
>   */
>  static int overlay_get_target(const void *fdt, const void *fdto,
> -			      int fragment)
> +			      int fragment, char const **pathp)
>  {
>  	uint32_t phandle;
> -	const char *path;
> -	int path_len;
> +	const char *path = NULL;
> +	int path_len = 0, ret;
>  
>  	/* Try first to do a phandle based lookup */
>  	phandle = overlay_get_target_phandle(fdto, fragment);
>  	if (phandle == (uint32_t)-1)
>  		return -FDT_ERR_BADPHANDLE;
>  
> -	if (phandle)
> -		return fdt_node_offset_by_phandle(fdt, phandle);
> +	/* no phandle, try path */
> +	if (!phandle) {
> +		/* And then a path based lookup */
> +		path = fdt_getprop(fdto, fragment, "target-path", &path_len);
> +		if (path)
> +			ret = fdt_path_offset(fdt, path);
> +		else
> +			ret = path_len;
> +	} else
> +		ret = fdt_node_offset_by_phandle(fdt, phandle);
>  
> -	/* And then a path based lookup */
> -	path = fdt_getprop(fdto, fragment, "target-path", &path_len);
> -	if (!path) {
> -		/*
> -		 * If we haven't found either a target or a
> -		 * target-path property in a node that contains a
> -		 * __overlay__ subnode (we wouldn't be called
> -		 * otherwise), consider it a improperly written
> -		 * overlay
> -		 */
> -		if (path_len == -FDT_ERR_NOTFOUND)
> -			return -FDT_ERR_BADOVERLAY;
> +	/*
> +	* If we haven't found either a target or a
> +	* target-path property in a node that contains a
> +	* __overlay__ subnode (we wouldn't be called
> +	* otherwise), consider it a improperly written
> +	* overlay
> +	*/
> +	if (ret < 0 && path_len == -FDT_ERR_NOTFOUND)
> +		ret = -FDT_ERR_BADOVERLAY;
> +
> +	/* return on error */
> +	if (ret < 0)
> +		return ret;
>  
> -		return path_len;
> -	}
> +	/* return pointer to path (if available) */
> +	if (pathp)
> +		*pathp = path ? path : NULL;
>  
> -	return fdt_path_offset(fdt, path);
> +	return ret;
>  }
>  
>  /**
> @@ -590,7 +601,7 @@ static int overlay_apply_node(void *fdt, int target,
>   *
>   * overlay_merge() merges an overlay into its base device tree.
>   *
> - * This is the final step in the device tree overlay application
> + * This is the next to last step in the device tree overlay application
>   * process, when all the phandles have been adjusted and resolved and
>   * you just have to merge overlay into the base device tree.
>   *
> @@ -618,7 +629,7 @@ static int overlay_merge(void *fdt, void *fdto)
>  		if (overlay < 0)
>  			return overlay;
>  
> -		target = overlay_get_target(fdt, fdto, fragment);
> +		target = overlay_get_target(fdt, fdto, fragment, NULL);
>  		if (target < 0)
>  			return target;
>  
> @@ -630,6 +641,144 @@ static int overlay_merge(void *fdt, void *fdto)
>  	return 0;
>  }
>  
> +/**
> + * overlay_symbol_update - Update the symbols of base tree after a merge
> + * @fdt: Base Device Tree blob
> + * @fdto: Device tree overlay blob
> + *
> + * overlay_symbol_update() updates the symbols of the base tree with the
> + * symbols of the applied overlay
> + *
> + * This is the last step in the device tree overlay application
> + * process, allowing the reference of overlay symbols by subsequent
> + * overlay operations.
> + *
> + * returns:
> + *      0 on success
> + *      Negative error code on failure
> + */
> +static int overlay_symbol_update(void *fdt, void *fdto)
> +{
> +	int root_sym, ov_sym, prop, path_len, fragment, target;
> +	int len, frag_name_len, ret, rel_path_len;
> +	const char *s;
> +	const char *path;
> +	const char *name;
> +	const char *frag_name;
> +	const char *rel_path;
> +	const char *target_path;
> +	char *buf;
> +	void *p;
> +
> +	ov_sym = fdt_subnode_offset(fdto, 0, "__symbols__");
> +
> +	/* if no overlay symbols exist no problem */
> +	if (ov_sym < 0)
> +		return 0;
> +
> +	root_sym = fdt_subnode_offset(fdt, 0, "__symbols__");
> +
> +	/* it no root symbols exist we should create them */
> +	if (root_sym < 0) {
> +		root_sym = fdt_add_subnode(fdt, 0, "__symbols__");
> +		if (root_sym < 0)
> +			return root_sym;
> +	}
> +
> +	/* iterate over each overlay symbol */
> +	fdt_for_each_property_offset(prop, fdto, ov_sym) {
> +		path = fdt_getprop_by_offset(fdto, prop, &name, &path_len);
> +		if (!path)
> +			return path_len;
> +
> +		/* verify it's a string property (terminated with \0) */
> +		if (path_len < 1 || path[path_len - 1] != '\0')
> +			return -FDT_ERR_BADVALUE;

That's probably enough to be safe, but checking that memchr(path,
'\0', prop_len) points at the last byte of the property would be more
complete.

> +
> +		/* format: /<fragment-name>/__overlay__/<relative-subnode-path> */
> +
> +		if (*path != '/')
> +			return -FDT_ERR_BADVALUE;
> +
> +		/* verify that no stray \0 exist in the property */
> +		if (strlen(path) != path_len - 1)
> +			return -FDT_ERR_BADVALUE;
> +
> +		/* get fragment name first */
> +		s = strchr(path + 1, '/');
> +		if (!s)
> +			return -FDT_ERR_BADVALUE;

BADOVERLAY for these two, I think.  These values are part of the
overlay's structural information, rather than a value for direct
client consumption.

> +
> +		frag_name = path + 1;
> +		frag_name_len = s - path - 1;
> +
> +		/* verify format; safe since "s" lies in \0 terminated prop */
> +		len = strlen("/__overlay__/");
> +		if (strncmp(s, "/__overlay__/", len))

memcmp is simpler here.

> +			return -FDT_ERR_NOTFOUND;
> +
> +		rel_path = s + len;
> +		rel_path_len = strlen(rel_path);
> +
> +		/* find the fragment index in which the symbol lies */
> +		ret = fdt_subnode_offset_namelen(fdto, 0, frag_name,
> +					       frag_name_len);
> +		/* not found? */
> +		if (ret < 0)
> +			return ret;
> +		fragment = ret;
> +
> +		/* an __overlay__ subnode must exist */
> +		ret = fdt_subnode_offset(fdto, fragment, "__overlay__");
> +		if (ret < 0)
> +			return ret;
> +
> +		/* get the target of the fragment */
> +		ret = overlay_get_target(fdt, fdto, fragment, &target_path);
> +		if (ret < 0)
> +			return ret;
> +		target = ret;
> +
> +		/* if we have a target path use */
> +		if (!target_path) {
> +			ret = fdt_get_path_len(fdt, target);

Given the mess of trying to resolve the path for a phandle target,
using this is reasonable.  However, I think it should be a local
function, not exported to discourage use of a really inefficient
approach.

> +			if (ret < 0)
> +				return ret;
> +			len = ret;
> +		} else
> +			len = strlen(target_path);
> +
> +		ret = fdt_setprop_placeholder(fdt, root_sym, name,
> +				len + (len > 1) + rel_path_len + 1, &p);
> +		if (ret < 0)
> +			return ret;
> +
> +		/* again in case setprop_placeholder changed it */
> +		ret = overlay_get_target(fdt, fdto, fragment, &target_path);
> +		if (ret < 0)
> +			return ret;
> +		target = ret;
> +
> +		buf = p;
> +		if (len > 1) { /* target is not root */
> +			if (!target_path) {
> +				ret = fdt_get_path(fdt, target, buf, len + 1);
> +				if (ret < 0)
> +					return ret;
> +			} else
> +				memcpy(buf, target_path, len + 1);
> +
> +		} else
> +			len--;
> +
> +		buf[len] = '/';
> +		memcpy(buf + len + 1, rel_path, rel_path_len);
> +		buf[len + 1 + rel_path_len] = '\0';
> +	}
> +
> +	return 0;
> +}
> +
>  int fdt_overlay_apply(void *fdt, void *fdto)
>  {
>  	uint32_t delta = fdt_get_max_phandle(fdt);
> @@ -654,6 +803,10 @@ int fdt_overlay_apply(void *fdt, void *fdto)
>  	if (ret)
>  		goto err;
>  
> +	ret = overlay_symbol_update(fdt, fdto);
> +	if (ret)
> +		goto err;
> +
>  	/*
>  	 * The overlay has been damaged, erase its magic.
>  	 */

-- 
David Gibson			| 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

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Re: [PATCH v3 2/2] tests: Add stacked overlay tests on fdtoverlay

[David Gibson]

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On Tue, Jul 25, 2017 at 08:24:36PM +0300, Pantelis Antoniou wrote:
> Add a stacked overlay unit test, piggybacking on fdtoverlay.
> 
> Signed-off-by: Pantelis Antoniou <pantelis.antoniou-OWPKS81ov/FWk0Htik3J/w@public.gmane.org>
> ---
>  tests/run_tests.sh             | 15 +++++++++++++++
>  tests/stacked_overlay_bar.dts  | 13 +++++++++++++
>  tests/stacked_overlay_base.dts |  6 ++++++
>  tests/stacked_overlay_baz.dts  | 13 +++++++++++++
>  4 files changed, 47 insertions(+)
>  create mode 100644 tests/stacked_overlay_bar.dts
>  create mode 100644 tests/stacked_overlay_base.dts
>  create mode 100644 tests/stacked_overlay_baz.dts
> 
> diff --git a/tests/run_tests.sh b/tests/run_tests.sh
> index b8a2825..9e3d35d 100755
> --- a/tests/run_tests.sh
> +++ b/tests/run_tests.sh
> @@ -791,6 +791,21 @@ fdtoverlay_tests() {
>  
>      # test that the new property is installed
>      run_fdtoverlay_test foobar "/test-node" "test-str-property" "-ts" ${basedtb} ${targetdtb} ${overlaydtb}
> +
> +    stacked_base=stacked_overlay_base.dts
> +    stacked_basedtb=stacked_overlay_base.fdtoverlay.test.dtb
> +    stacked_bar=stacked_overlay_bar.dts
> +    stacked_bardtb=stacked_overlay_bar.fdtoverlay.test.dtb
> +    stacked_baz=stacked_overlay_baz.dts
> +    stacked_bazdtb=stacked_overlay_baz.fdtoverlay.test.dtb
> +    stacked_targetdtb=stacked_overlay_target.fdoverlay.test.dtb

Typo here                                       ^^^

> +
> +    run_dtc_test -@ -I dts -O dtb -o $stacked_basedtb $stacked_base
> +    run_dtc_test -@ -I dts -O dtb -o $stacked_bardtb $stacked_bar
> +    run_dtc_test -@ -I dts -O dtb -o $stacked_bazdtb $stacked_baz
> +
> +    # test that baz correctly inserted the property
> +    run_fdtoverlay_test baz "/foonode/barnode/baznode" "baz-property" "-ts" ${stacked_basedtb} ${stacked_targetdtb} ${stacked_bardtb} ${stacked_bazdtb}
>  }
>  
>  pylibfdt_tests () {
> diff --git a/tests/stacked_overlay_bar.dts b/tests/stacked_overlay_bar.dts
> new file mode 100644
> index 0000000..c646399
> --- /dev/null
> +++ b/tests/stacked_overlay_bar.dts
> @@ -0,0 +1,13 @@
> +/dts-v1/;
> +/plugin/;
> +/ {
> +	fragment@1 {
> +		target = <&foo>;
> +		__overlay__ {
> +			overlay-1-property;
> +			bar: barnode {
> +				bar-property = "bar";
> +			};
> +		};
> +	};
> +};
> diff --git a/tests/stacked_overlay_base.dts b/tests/stacked_overlay_base.dts
> new file mode 100644
> index 0000000..2916423
> --- /dev/null
> +++ b/tests/stacked_overlay_base.dts
> @@ -0,0 +1,6 @@
> +/dts-v1/;
> +/ {
> +	foo: foonode {
> +		foo-property = "foo";
> +	};
> +};
> diff --git a/tests/stacked_overlay_baz.dts b/tests/stacked_overlay_baz.dts
> new file mode 100644
> index 0000000..a52f0cc
> --- /dev/null
> +++ b/tests/stacked_overlay_baz.dts
> @@ -0,0 +1,13 @@
> +/dts-v1/;
> +/plugin/;
> +/ {
> +	fragment@1 {
> +		target = <&bar>;
> +		__overlay__ {
> +			overlay-2-property;
> +			baz: baznode {
> +				baz-property = "baz";
> +			};
> +		};
> +	};
> +};

-- 
David Gibson			| 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

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Re: [PATCH v3 2/2] tests: Add stacked overlay tests on fdtoverlay

[David Gibson]

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On Mon, Jul 31, 2017 at 11:35:30PM +1000, David Gibson wrote:
> On Tue, Jul 25, 2017 at 08:24:36PM +0300, Pantelis Antoniou wrote:
> > Add a stacked overlay unit test, piggybacking on fdtoverlay.
> > 
> > Signed-off-by: Pantelis Antoniou <pantelis.antoniou-OWPKS81ov/FWk0Htik3J/w@public.gmane.org>
> > ---
> >  tests/run_tests.sh             | 15 +++++++++++++++
> >  tests/stacked_overlay_bar.dts  | 13 +++++++++++++
> >  tests/stacked_overlay_base.dts |  6 ++++++
> >  tests/stacked_overlay_baz.dts  | 13 +++++++++++++
> >  4 files changed, 47 insertions(+)
> >  create mode 100644 tests/stacked_overlay_bar.dts
> >  create mode 100644 tests/stacked_overlay_base.dts
> >  create mode 100644 tests/stacked_overlay_baz.dts
> > 
> > diff --git a/tests/run_tests.sh b/tests/run_tests.sh
> > index b8a2825..9e3d35d 100755
> > --- a/tests/run_tests.sh
> > +++ b/tests/run_tests.sh
> > @@ -791,6 +791,21 @@ fdtoverlay_tests() {
> >  
> >      # test that the new property is installed
> >      run_fdtoverlay_test foobar "/test-node" "test-str-property" "-ts" ${basedtb} ${targetdtb} ${overlaydtb}
> > +
> > +    stacked_base=stacked_overlay_base.dts
> > +    stacked_basedtb=stacked_overlay_base.fdtoverlay.test.dtb
> > +    stacked_bar=stacked_overlay_bar.dts
> > +    stacked_bardtb=stacked_overlay_bar.fdtoverlay.test.dtb
> > +    stacked_baz=stacked_overlay_baz.dts
> > +    stacked_bazdtb=stacked_overlay_baz.fdtoverlay.test.dtb
> > +    stacked_targetdtb=stacked_overlay_target.fdoverlay.test.dtb
> 
> Typo here                                       ^^^

Apart from that,

Reviewed-by: David Gibson <david-xT8FGy+AXnRB3Ne2BGzF6laj5H9X9Tb+@public.gmane.org>


> 
> > +
> > +    run_dtc_test -@ -I dts -O dtb -o $stacked_basedtb $stacked_base
> > +    run_dtc_test -@ -I dts -O dtb -o $stacked_bardtb $stacked_bar
> > +    run_dtc_test -@ -I dts -O dtb -o $stacked_bazdtb $stacked_baz
> > +
> > +    # test that baz correctly inserted the property
> > +    run_fdtoverlay_test baz "/foonode/barnode/baznode" "baz-property" "-ts" ${stacked_basedtb} ${stacked_targetdtb} ${stacked_bardtb} ${stacked_bazdtb}
> >  }
> >  
> >  pylibfdt_tests () {
> > diff --git a/tests/stacked_overlay_bar.dts b/tests/stacked_overlay_bar.dts
> > new file mode 100644
> > index 0000000..c646399
> > --- /dev/null
> > +++ b/tests/stacked_overlay_bar.dts
> > @@ -0,0 +1,13 @@
> > +/dts-v1/;
> > +/plugin/;
> > +/ {
> > +	fragment@1 {
> > +		target = <&foo>;
> > +		__overlay__ {
> > +			overlay-1-property;
> > +			bar: barnode {
> > +				bar-property = "bar";
> > +			};
> > +		};
> > +	};
> > +};
> > diff --git a/tests/stacked_overlay_base.dts b/tests/stacked_overlay_base.dts
> > new file mode 100644
> > index 0000000..2916423
> > --- /dev/null
> > +++ b/tests/stacked_overlay_base.dts
> > @@ -0,0 +1,6 @@
> > +/dts-v1/;
> > +/ {
> > +	foo: foonode {
> > +		foo-property = "foo";
> > +	};
> > +};
> > diff --git a/tests/stacked_overlay_baz.dts b/tests/stacked_overlay_baz.dts
> > new file mode 100644
> > index 0000000..a52f0cc
> > --- /dev/null
> > +++ b/tests/stacked_overlay_baz.dts
> > @@ -0,0 +1,13 @@
> > +/dts-v1/;
> > +/plugin/;
> > +/ {
> > +	fragment@1 {
> > +		target = <&bar>;
> > +		__overlay__ {
> > +			overlay-2-property;
> > +			baz: baznode {
> > +				baz-property = "baz";
> > +			};
> > +		};
> > +	};
> > +};
> 



-- 
David Gibson			| 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

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