[PATCH v4 3/4] device property: constify property arrays values

Dmitry Torokhov
2017-02-02T16:39:22Z

From: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Data that is fed into property arrays should not be modified, so let's mark
relevant pointers as const. This will allow us making source arrays as
const/__initconst.

Also fix memory leaks on errors in property_entry_copy().

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---

Not sending the rest of the series as to not clutter mailing lists too
much...

drivers/base/property.c | 66 +++++++++++++++++++++++++++++++---------------
include/linux/property.h | 12 ++++----
2 files changed, 51 insertions(+), 27 deletions(-)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index edc09854520b..09fb9757e086 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -682,44 +682,64 @@ int fwnode_property_match_string(struct fwnode_handle *fwnode,
}
EXPORT_SYMBOL_GPL(fwnode_property_match_string);

+static int property_copy_string_array(struct property_entry *dst,
+ const struct property_entry *src)
+{
+ char **d;
+ size_t nval = src->length / sizeof(*d);
+ size_t i;
+
+ d = kcalloc(nval, sizeof(*d), GFP_KERNEL);
+ if (!d)
+ return -ENOMEM;
+
+ for (i = 0; i < nval; i++) {
+ d[i] = kstrdup(src->pointer.str[i], GFP_KERNEL);
+ if (!d[i] && src->pointer.str[i]) {
+ while (--i >= 0)
+ kfree(d[i]);
+ kfree(d);
+ return -ENOMEM;
+ }
+ }
+
+ dst->pointer.str = (void *)d;
+ return 0;
+}
+
static int property_entry_copy(struct property_entry *dst,
const struct property_entry *src)
{
- const char **d, **s;
- size_t i, nval;
+ int error;

dst->name = kstrdup(src->name, GFP_KERNEL);
if (!dst->name)
return -ENOMEM;

if (src->is_array) {
- if (!src->length)
- return -ENODATA;
+ if (!src->length) {
+ error = -ENODATA;
+ goto out_free_name;
+ }

if (src->is_string) {
- nval = src->length / sizeof(const char *);
- dst->pointer.str = kcalloc(nval, sizeof(const char *),
- GFP_KERNEL);
- if (!dst->pointer.str)
- return -ENOMEM;
-
- d = dst->pointer.str;
- s = src->pointer.str;
- for (i = 0; i < nval; i++) {
- d[i] = kstrdup(s[i], GFP_KERNEL);
- if (!d[i] && s[i])
- return -ENOMEM;
- }
+ error = property_copy_string_array(dst, src);
+ if (error)
+ goto out_free_name;
} else {
dst->pointer.raw_data = kmemdup(src->pointer.raw_data,
src->length, GFP_KERNEL);
- if (!dst->pointer.raw_data)
- return -ENOMEM;
+ if (!dst->pointer.raw_data) {
+ error = -ENOMEM;
+ goto out_free_name;
+ }
}
} else if (src->is_string) {
dst->value.str = kstrdup(src->value.str, GFP_KERNEL);
- if (!dst->value.str && src->value.str)
- return -ENOMEM;
+ if (!dst->value.str && src->value.str) {
+ error = -ENOMEM;
+ goto out_free_name;
+ }
} else {
dst->value.raw_data = src->value.raw_data;
}
@@ -729,6 +749,10 @@ static int property_entry_copy(struct property_entry *dst,
dst->is_string = src->is_string;

return 0;
+
+out_free_name:
+ kfree(dst->name);
+ return error;
}

/**
diff --git a/include/linux/property.h b/include/linux/property.h
index 5746e9927016..64e3a9c6d95f 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -160,12 +160,12 @@ struct property_entry {
bool is_string;
union {
union {
- void *raw_data;
- u8 *u8_data;
- u16 *u16_data;
- u32 *u32_data;
- u64 *u64_data;
- const char **str;
+ const void *raw_data;
+ const u8 *u8_data;
+ const u16 *u16_data;
+ const u32 *u32_data;
+ const u64 *u64_data;
+ const char * const *str;
} pointer;
union {
unsigned long long raw_data;