[PATCH v2 44/45] dm: core: Allow copying ofnode property data when writing
Simon Glass
sjg at chromium.org
Wed Sep 7 04:27:32 CEST 2022
At present ofnode_write_prop() is inconsistent between livetree and
flattree, in that livetree requires the caller to ensure the property
value is stable (e.g. in rodata or allocated) but flattree does not, since
it makes a copy.
This makes the API call a bit painful to use, since the caller must do
different things depending on OF_LIVE.
Add a new 'copy' argument which tells the function to make a copy if
needed. Add some tests to cover this behaviour.
Signed-off-by: Simon Glass <sjg at chromium.org>
---
(no changes since v1)
doc/develop/driver-model/livetree.rst | 2 +
drivers/core/ofnode.c | 29 +++++++++----
include/dm/ofnode.h | 12 ++++--
test/dm/ofnode.c | 62 ++++++++++++++++++++++++++-
4 files changed, 92 insertions(+), 13 deletions(-)
diff --git a/doc/develop/driver-model/livetree.rst b/doc/develop/driver-model/livetree.rst
index 65b88f854eb..55aa3eac929 100644
--- a/doc/develop/driver-model/livetree.rst
+++ b/doc/develop/driver-model/livetree.rst
@@ -325,3 +325,5 @@ Live tree support was introduced in U-Boot 2017.07. Some possible enhancements
are:
- support for livetree in SPL and before relocation (if desired)
+- freeing leaked memory caused by writing new nodes / property values to the
+ livetree (ofnode_write_prop())
diff --git a/drivers/core/ofnode.c b/drivers/core/ofnode.c
index 1f477322d5d..51a16537b0d 100644
--- a/drivers/core/ofnode.c
+++ b/drivers/core/ofnode.c
@@ -1322,15 +1322,27 @@ ofnode ofnode_by_prop_value(ofnode from, const char *propname,
}
int ofnode_write_prop(ofnode node, const char *propname, const void *value,
- int len)
+ int len, bool copy)
{
- if (of_live_active())
- return of_write_prop(ofnode_to_np(node), propname, len, value);
- else
+ if (of_live_active()) {
+ void *newval;
+ int ret;
+
+ if (copy) {
+ newval = malloc(len);
+ if (!newval)
+ return log_ret(-ENOMEM);
+ memcpy(newval, value, len);
+ value = newval;
+ }
+ ret = of_write_prop(ofnode_to_np(node), propname, len, value);
+ if (ret && copy)
+ free(newval);
+ return ret;
+ } else {
return fdt_setprop(ofnode_to_fdt(node), ofnode_to_offset(node),
propname, value, len);
-
- return 0;
+ }
}
int ofnode_write_string(ofnode node, const char *propname, const char *value)
@@ -1339,7 +1351,8 @@ int ofnode_write_string(ofnode node, const char *propname, const char *value)
debug("%s: %s = %s", __func__, propname, value);
- return ofnode_write_prop(node, propname, value, strlen(value) + 1);
+ return ofnode_write_prop(node, propname, value, strlen(value) + 1,
+ false);
}
int ofnode_write_u32(ofnode node, const char *propname, u32 value)
@@ -1354,7 +1367,7 @@ int ofnode_write_u32(ofnode node, const char *propname, u32 value)
return -ENOMEM;
*val = cpu_to_fdt32(value);
- return ofnode_write_prop(node, propname, val, sizeof(value));
+ return ofnode_write_prop(node, propname, val, sizeof(value), false);
}
int ofnode_set_enabled(ofnode node, bool value)
diff --git a/include/dm/ofnode.h b/include/dm/ofnode.h
index 113dd15afe3..c7d61e94121 100644
--- a/include/dm/ofnode.h
+++ b/include/dm/ofnode.h
@@ -1310,19 +1310,23 @@ int ofnode_device_is_compatible(ofnode node, const char *compat);
/**
* ofnode_write_prop() - Set a property of a ofnode
*
- * Note that the value passed to the function is *not* allocated by the
- * function itself, but must be allocated by the caller if necessary. However
- * it does allocate memory for the property struct and name.
+ * Note that if @copy is false, the value passed to the function is *not*
+ * allocated by the function itself, but must be allocated by the caller if
+ * necessary. However it does allocate memory for the property struct and name.
*
* @node: The node for whose property should be set
* @propname: The name of the property to set
* @value: The new value of the property (must be valid prior to calling
* the function)
* @len: The length of the new value of the property
+ * @copy: true to allocate memory for the value. This only has any effect with
+ * live tree, since flat tree handles this automatically. It allows a
+ * node's value to be written to the tree, without requiring that the
+ * caller allocate it
* Return: 0 if successful, -ve on error
*/
int ofnode_write_prop(ofnode node, const char *propname, const void *value,
- int len);
+ int len, bool copy);
/**
* ofnode_write_string() - Set a string property of a ofnode
diff --git a/test/dm/ofnode.c b/test/dm/ofnode.c
index 0912a53099d..69ffba06534 100644
--- a/test/dm/ofnode.c
+++ b/test/dm/ofnode.c
@@ -822,7 +822,8 @@ static int dm_test_ofnode_livetree_writing(struct unit_test_state *uts)
ut_asserteq_64(FDT_ADDR_T_NONE, dev_read_addr(dev));
/* reg = 0x42, size = 0x100 */
ut_assertok(ofnode_write_prop(node, "reg",
- "\x00\x00\x00\x42\x00\x00\x01\x00", 8));
+ "\x00\x00\x00\x42\x00\x00\x01\x00", 8,
+ false));
ut_asserteq(0x42, dev_read_addr(dev));
/* Test disabling devices */
@@ -838,6 +839,65 @@ static int dm_test_ofnode_livetree_writing(struct unit_test_state *uts)
DM_TEST(dm_test_ofnode_livetree_writing,
UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);
+static int check_write_prop(struct unit_test_state *uts, ofnode node)
+{
+ char prop[] = "middle-name";
+ char name[10];
+ int len;
+
+ strcpy(name, "cecil");
+ len = strlen(name) + 1;
+ ut_assertok(ofnode_write_prop(node, prop, name, len, false));
+ ut_asserteq_str(name, ofnode_read_string(node, prop));
+
+ /* change the underlying value, this should mess up the live tree */
+ strcpy(name, "tony");
+ if (of_live_active()) {
+ ut_asserteq_str(name, ofnode_read_string(node, prop));
+ } else {
+ ut_asserteq_str("cecil", ofnode_read_string(node, prop));
+ }
+
+ /* try again, this time copying the property */
+ strcpy(name, "mary");
+ ut_assertok(ofnode_write_prop(node, prop, name, len, true));
+ ut_asserteq_str(name, ofnode_read_string(node, prop));
+ strcpy(name, "leah");
+
+ /* both flattree and livetree behave the same */
+ ut_asserteq_str("mary", ofnode_read_string(node, prop));
+
+ return 0;
+}
+
+/* writing the tree with and without copying the property */
+static int dm_test_ofnode_write_copy(struct unit_test_state *uts)
+{
+ ofnode node;
+
+ node = ofnode_path("/a-test");
+ ut_assertok(check_write_prop(uts, node));
+
+ return 0;
+}
+DM_TEST(dm_test_ofnode_write_copy, UT_TESTF_SCAN_FDT);
+
+static int dm_test_ofnode_write_copy_ot(struct unit_test_state *uts)
+{
+ oftree otree = get_other_oftree(uts);
+ ofnode node, check_node;
+
+ node = oftree_path(otree, "/node");
+ ut_assertok(check_write_prop(uts, node));
+
+ /* make sure the control FDT is not touched */
+ check_node = ofnode_path("/node");
+ ut_assertnull(ofnode_read_string(check_node, "middle-name"));
+
+ return 0;
+}
+DM_TEST(dm_test_ofnode_write_copy_ot, UT_TESTF_OTHER_FDT);
+
static int dm_test_ofnode_u32(struct unit_test_state *uts)
{
ofnode node;
--
2.37.2.789.g6183377224-goog
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