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device property: export code duplicating array of property entries
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When augmenting ACPI-enumerated devices with additional property data based
on DMI info, a module has often several potential property sets, with only
one being active on a given box. In order to save memory it should be
possible to mark everything and __initdata or __initconst, execute DMI
match early, and duplicate relevant properties. Then kernel will discard
the rest of them.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Dmitry Torokhov authored and Rafael J. Wysocki committed Feb 7, 2017
1 parent 9426998 commit 2d479e1
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Showing 2 changed files with 134 additions and 65 deletions.
194 changes: 129 additions & 65 deletions drivers/base/property.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -682,77 +682,64 @@ int fwnode_property_match_string(struct fwnode_handle *fwnode,
}
EXPORT_SYMBOL_GPL(fwnode_property_match_string);

/**
* pset_free_set - releases memory allocated for copied property set
* @pset: Property set to release
*
* Function takes previously copied property set and releases all the
* memory allocated to it.
*/
static void pset_free_set(struct property_set *pset)
static int property_copy_string_array(struct property_entry *dst,
const struct property_entry *src)
{
const struct property_entry *prop;
size_t i, nval;
char **d;
size_t nval = src->length / sizeof(*d);
int i;

if (!pset)
return;
d = kcalloc(nval, sizeof(*d), GFP_KERNEL);
if (!d)
return -ENOMEM;

for (prop = pset->properties; prop->name; prop++) {
if (prop->is_array) {
if (prop->is_string && prop->pointer.str) {
nval = prop->length / sizeof(const char *);
for (i = 0; i < nval; i++)
kfree(prop->pointer.str[i]);
}
kfree(prop->pointer.raw_data);
} else if (prop->is_string) {
kfree(prop->value.str);
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;
}
kfree(prop->name);
}

kfree(pset->properties);
kfree(pset);
dst->pointer.raw_data = d;
return 0;
}

static int pset_copy_entry(struct property_entry *dst,
const struct property_entry *src)
static int property_entry_copy_data(struct property_entry *dst,
const struct property_entry *src)
{
const char * const *s;
char **d;
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 *);
d = kcalloc(nval, sizeof(const char *), GFP_KERNEL);
if (!d)
return -ENOMEM;

dst->pointer.raw_data = d;
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;
}
Expand All @@ -762,6 +749,95 @@ static int pset_copy_entry(struct property_entry *dst,
dst->is_string = src->is_string;

return 0;

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

static void property_entry_free_data(const struct property_entry *p)
{
size_t i, nval;

if (p->is_array) {
if (p->is_string && p->pointer.str) {
nval = p->length / sizeof(const char *);
for (i = 0; i < nval; i++)
kfree(p->pointer.str[i]);
}
kfree(p->pointer.raw_data);
} else if (p->is_string) {
kfree(p->value.str);
}
kfree(p->name);
}

/**
* property_entries_dup - duplicate array of properties
* @properties: array of properties to copy
*
* This function creates a deep copy of the given NULL-terminated array
* of property entries.
*/
struct property_entry *
property_entries_dup(const struct property_entry *properties)
{
struct property_entry *p;
int i, n = 0;

while (properties[n].name)
n++;

p = kcalloc(n + 1, sizeof(*p), GFP_KERNEL);
if (!p)
return ERR_PTR(-ENOMEM);

for (i = 0; i < n; i++) {
int ret = property_entry_copy_data(&p[i], &properties[i]);
if (ret) {
while (--i >= 0)
property_entry_free_data(&p[i]);
kfree(p);
return ERR_PTR(ret);
}
}

return p;
}
EXPORT_SYMBOL_GPL(property_entries_dup);

/**
* property_entries_free - free previously allocated array of properties
* @properties: array of properties to destroy
*
* This function frees given NULL-terminated array of property entries,
* along with their data.
*/
void property_entries_free(const struct property_entry *properties)
{
const struct property_entry *p;

for (p = properties; p->name; p++)
property_entry_free_data(p);

kfree(properties);
}
EXPORT_SYMBOL_GPL(property_entries_free);

/**
* pset_free_set - releases memory allocated for copied property set
* @pset: Property set to release
*
* Function takes previously copied property set and releases all the
* memory allocated to it.
*/
static void pset_free_set(struct property_set *pset)
{
if (!pset)
return;

property_entries_free(pset->properties);
kfree(pset);
}

/**
Expand All @@ -776,32 +852,20 @@ static int pset_copy_entry(struct property_entry *dst,
*/
static struct property_set *pset_copy_set(const struct property_set *pset)
{
struct property_entry *props;
struct property_entry *properties;
struct property_set *p;
size_t i, n = 0;

p = kzalloc(sizeof(*p), GFP_KERNEL);
if (!p)
return ERR_PTR(-ENOMEM);

while (pset->properties[n].name)
n++;

p->properties = props = kcalloc(n + 1, sizeof(*props), GFP_KERNEL);
if (!p->properties) {
properties = property_entries_dup(pset->properties);
if (IS_ERR(properties)) {
kfree(p);
return ERR_PTR(-ENOMEM);
}

for (i = 0; i < n; i++) {
int ret = pset_copy_entry(&props[i],
&pset->properties[i]);
if (ret) {
pset_free_set(p);
return ERR_PTR(ret);
}
return ERR_CAST(properties);
}

p->properties = properties;
return p;
}

Expand Down
5 changes: 5 additions & 0 deletions include/linux/property.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -241,6 +241,11 @@ struct property_entry {
.name = _name_, \
}

struct property_entry *
property_entries_dup(const struct property_entry *properties);

void property_entries_free(const struct property_entry *properties);

int device_add_properties(struct device *dev,
const struct property_entry *properties);
void device_remove_properties(struct device *dev);
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