Use the relatively new scope based kfree() cleanup to simplify error
handling. Doing so reduces the chances of memory leaks and simplifies
error paths by avoiding the need for goto statements.
Signed-off-by: Rob Herring <[email protected]>
---
drivers/of/base.c | 34 ++++++++--------------------------
drivers/of/dynamic.c | 11 ++++-------
drivers/of/resolver.c | 35 +++++++++++++----------------------
3 files changed, 25 insertions(+), 55 deletions(-)
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 8856c67c466a..20603d3c9931 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -16,6 +16,7 @@
#define pr_fmt(fmt) "OF: " fmt
+#include <linux/cleanup.h>
#include <linux/console.h>
#include <linux/ctype.h>
#include <linux/cpu.h>
@@ -1393,8 +1394,10 @@ int of_parse_phandle_with_args_map(const struct device_node *np,
const char *stem_name,
int index, struct of_phandle_args *out_args)
{
- char *cells_name, *map_name = NULL, *mask_name = NULL;
- char *pass_name = NULL;
+ char *cells_name __free(kfree) = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
+ char *map_name __free(kfree) = kasprintf(GFP_KERNEL, "%s-map", stem_name);
+ char *mask_name __free(kfree) = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
+ char *pass_name __free(kfree) = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
struct device_node *cur, *new = NULL;
const __be32 *map, *mask, *pass;
static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = cpu_to_be32(~0) };
@@ -1407,27 +1410,13 @@ int of_parse_phandle_with_args_map(const struct device_node *np,
if (index < 0)
return -EINVAL;
- cells_name = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
- if (!cells_name)
+ if (!cells_name || !map_name || !mask_name || !pass_name)
return -ENOMEM;
- ret = -ENOMEM;
- map_name = kasprintf(GFP_KERNEL, "%s-map", stem_name);
- if (!map_name)
- goto free;
-
- mask_name = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
- if (!mask_name)
- goto free;
-
- pass_name = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
- if (!pass_name)
- goto free;
-
ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index,
out_args);
if (ret)
- goto free;
+ return ret;
/* Get the #<list>-cells property */
cur = out_args->np;
@@ -1444,8 +1433,7 @@ int of_parse_phandle_with_args_map(const struct device_node *np,
/* Get the <list>-map property */
map = of_get_property(cur, map_name, &map_len);
if (!map) {
- ret = 0;
- goto free;
+ return 0;
}
map_len /= sizeof(u32);
@@ -1521,12 +1509,6 @@ int of_parse_phandle_with_args_map(const struct device_node *np,
put:
of_node_put(cur);
of_node_put(new);
-free:
- kfree(mask_name);
- kfree(map_name);
- kfree(cells_name);
- kfree(pass_name);
-
return ret;
}
EXPORT_SYMBOL(of_parse_phandle_with_args_map);
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index af7c57a7a25d..43f4e2c93bd2 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -9,6 +9,7 @@
#define pr_fmt(fmt) "OF: " fmt
+#include <linux/cleanup.h>
#include <linux/of.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
@@ -1019,10 +1020,9 @@ int of_changeset_add_prop_u32_array(struct of_changeset *ocs,
const u32 *array, size_t sz)
{
struct property prop;
- __be32 *val;
- int i, ret;
+ __be32 *val __free(kfree) = kcalloc(sz, sizeof(__be32), GFP_KERNEL);
+ int i;
- val = kcalloc(sz, sizeof(__be32), GFP_KERNEL);
if (!val)
return -ENOMEM;
@@ -1032,9 +1032,6 @@ int of_changeset_add_prop_u32_array(struct of_changeset *ocs,
prop.length = sizeof(u32) * sz;
prop.value = (void *)val;
- ret = of_changeset_add_prop_helper(ocs, np, &prop);
- kfree(val);
-
- return ret;
+ return of_changeset_add_prop_helper(ocs, np, &prop);
}
EXPORT_SYMBOL_GPL(of_changeset_add_prop_u32_array);
diff --git a/drivers/of/resolver.c b/drivers/of/resolver.c
index b278ab4338ce..2780928764a4 100644
--- a/drivers/of/resolver.c
+++ b/drivers/of/resolver.c
@@ -8,6 +8,7 @@
#define pr_fmt(fmt) "OF: resolver: " fmt
+#include <linux/cleanup.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
@@ -74,11 +75,11 @@ static int update_usages_of_a_phandle_reference(struct device_node *overlay,
{
struct device_node *refnode;
struct property *prop;
- char *value, *cur, *end, *node_path, *prop_name, *s;
+ char *value __free(kfree) = kmemdup(prop_fixup->value, prop_fixup->length, GFP_KERNEL);
+ char *cur, *end, *node_path, *prop_name, *s;
int offset, len;
int err = 0;
- value = kmemdup(prop_fixup->value, prop_fixup->length, GFP_KERNEL);
if (!value)
return -ENOMEM;
@@ -89,23 +90,19 @@ static int update_usages_of_a_phandle_reference(struct device_node *overlay,
node_path = cur;
s = strchr(cur, ':');
- if (!s) {
- err = -EINVAL;
- goto err_fail;
- }
+ if (!s)
+ return -EINVAL;
*s++ = '\0';
prop_name = s;
s = strchr(s, ':');
- if (!s) {
- err = -EINVAL;
- goto err_fail;
- }
+ if (!s)
+ return -EINVAL;
*s++ = '\0';
err = kstrtoint(s, 10, &offset);
if (err)
- goto err_fail;
+ return err;
refnode = __of_find_node_by_full_path(of_node_get(overlay), node_path);
if (!refnode)
@@ -117,22 +114,16 @@ static int update_usages_of_a_phandle_reference(struct device_node *overlay,
}
of_node_put(refnode);
- if (!prop) {
- err = -ENOENT;
- goto err_fail;
- }
+ if (!prop)
+ return -ENOENT;
- if (offset < 0 || offset + sizeof(__be32) > prop->length) {
- err = -EINVAL;
- goto err_fail;
- }
+ if (offset < 0 || offset + sizeof(__be32) > prop->length)
+ return -EINVAL;
*(__be32 *)(prop->value + offset) = cpu_to_be32(phandle);
}
-err_fail:
- kfree(value);
- return err;
+ return 0;
}
/* compare nodes taking into account that 'name' strips out the @ part */
--
2.43.0
On Thu, Apr 4, 2024 at 7:15 AM Rob Herring <[email protected]> wrote:
>
> Use the relatively new scope based kfree() cleanup to simplify error
> handling. Doing so reduces the chances of memory leaks and simplifies
> error paths by avoiding the need for goto statements.
>
> Signed-off-by: Rob Herring <[email protected]>
> ---
> drivers/of/base.c | 34 ++++++++--------------------------
> drivers/of/dynamic.c | 11 ++++-------
> drivers/of/resolver.c | 35 +++++++++++++----------------------
> 3 files changed, 25 insertions(+), 55 deletions(-)
>
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 8856c67c466a..20603d3c9931 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -16,6 +16,7 @@
>
> #define pr_fmt(fmt) "OF: " fmt
>
> +#include <linux/cleanup.h>
> #include <linux/console.h>
> #include <linux/ctype.h>
> #include <linux/cpu.h>
> @@ -1393,8 +1394,10 @@ int of_parse_phandle_with_args_map(const struct device_node *np,
> const char *stem_name,
> int index, struct of_phandle_args *out_args)
> {
> - char *cells_name, *map_name = NULL, *mask_name = NULL;
> - char *pass_name = NULL;
> + char *cells_name __free(kfree) = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
> + char *map_name __free(kfree) = kasprintf(GFP_KERNEL, "%s-map", stem_name);
> + char *mask_name __free(kfree) = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
> + char *pass_name __free(kfree) = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
With the scoped stuff, do these function calls need to be in the same
line we are defining these variables? If not, I'd rather that the
calls remain where they were. It feels like a lote to visually parse
and take in from a readability perspective.
> struct device_node *cur, *new = NULL;
> const __be32 *map, *mask, *pass;
> static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = cpu_to_be32(~0) };
> @@ -1407,27 +1410,13 @@ int of_parse_phandle_with_args_map(const struct device_node *np,
> if (index < 0)
> return -EINVAL;
>
> - cells_name = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
> - if (!cells_name)
> + if (!cells_name || !map_name || !mask_name || !pass_name)
> return -ENOMEM;
>
> - ret = -ENOMEM;
> - map_name = kasprintf(GFP_KERNEL, "%s-map", stem_name);
> - if (!map_name)
> - goto free;
> -
> - mask_name = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
> - if (!mask_name)
> - goto free;
> -
> - pass_name = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
> - if (!pass_name)
> - goto free;
> -
> ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index,
> out_args);
> if (ret)
> - goto free;
> + return ret;
>
> /* Get the #<list>-cells property */
> cur = out_args->np;
> @@ -1444,8 +1433,7 @@ int of_parse_phandle_with_args_map(const struct device_node *np,
> /* Get the <list>-map property */
> map = of_get_property(cur, map_name, &map_len);
> if (!map) {
> - ret = 0;
> - goto free;
> + return 0;
> }
> map_len /= sizeof(u32);
>
> @@ -1521,12 +1509,6 @@ int of_parse_phandle_with_args_map(const struct device_node *np,
> put:
> of_node_put(cur);
> of_node_put(new);
> -free:
> - kfree(mask_name);
> - kfree(map_name);
> - kfree(cells_name);
> - kfree(pass_name);
> -
> return ret;
> }
> EXPORT_SYMBOL(of_parse_phandle_with_args_map);
> diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
> index af7c57a7a25d..43f4e2c93bd2 100644
> --- a/drivers/of/dynamic.c
> +++ b/drivers/of/dynamic.c
> @@ -9,6 +9,7 @@
>
> #define pr_fmt(fmt) "OF: " fmt
>
> +#include <linux/cleanup.h>
> #include <linux/of.h>
> #include <linux/spinlock.h>
> #include <linux/slab.h>
> @@ -1019,10 +1020,9 @@ int of_changeset_add_prop_u32_array(struct of_changeset *ocs,
> const u32 *array, size_t sz)
> {
> struct property prop;
> - __be32 *val;
> - int i, ret;
> + __be32 *val __free(kfree) = kcalloc(sz, sizeof(__be32), GFP_KERNEL);
> + int i;
>
> - val = kcalloc(sz, sizeof(__be32), GFP_KERNEL);
> if (!val)
> return -ENOMEM;
>
> @@ -1032,9 +1032,6 @@ int of_changeset_add_prop_u32_array(struct of_changeset *ocs,
> prop.length = sizeof(u32) * sz;
> prop.value = (void *)val;
>
> - ret = of_changeset_add_prop_helper(ocs, np, &prop);
> - kfree(val);
> -
> - return ret;
> + return of_changeset_add_prop_helper(ocs, np, &prop);
> }
> EXPORT_SYMBOL_GPL(of_changeset_add_prop_u32_array);
> diff --git a/drivers/of/resolver.c b/drivers/of/resolver.c
> index b278ab4338ce..2780928764a4 100644
> --- a/drivers/of/resolver.c
> +++ b/drivers/of/resolver.c
> @@ -8,6 +8,7 @@
>
> #define pr_fmt(fmt) "OF: resolver: " fmt
>
> +#include <linux/cleanup.h>
> #include <linux/kernel.h>
> #include <linux/module.h>
> #include <linux/of.h>
> @@ -74,11 +75,11 @@ static int update_usages_of_a_phandle_reference(struct device_node *overlay,
> {
> struct device_node *refnode;
> struct property *prop;
> - char *value, *cur, *end, *node_path, *prop_name, *s;
> + char *value __free(kfree) = kmemdup(prop_fixup->value, prop_fixup->length, GFP_KERNEL);
> + char *cur, *end, *node_path, *prop_name, *s;
> int offset, len;
> int err = 0;
>
> - value = kmemdup(prop_fixup->value, prop_fixup->length, GFP_KERNEL);
> if (!value)
> return -ENOMEM;
>
> @@ -89,23 +90,19 @@ static int update_usages_of_a_phandle_reference(struct device_node *overlay,
>
> node_path = cur;
> s = strchr(cur, ':');
> - if (!s) {
> - err = -EINVAL;
> - goto err_fail;
> - }
> + if (!s)
> + return -EINVAL;
> *s++ = '\0';
>
> prop_name = s;
> s = strchr(s, ':');
> - if (!s) {
> - err = -EINVAL;
> - goto err_fail;
> - }
> + if (!s)
> + return -EINVAL;
> *s++ = '\0';
>
> err = kstrtoint(s, 10, &offset);
> if (err)
> - goto err_fail;
> + return err;
>
> refnode = __of_find_node_by_full_path(of_node_get(overlay), node_path);
> if (!refnode)
> @@ -117,22 +114,16 @@ static int update_usages_of_a_phandle_reference(struct device_node *overlay,
> }
> of_node_put(refnode);
>
> - if (!prop) {
> - err = -ENOENT;
> - goto err_fail;
> - }
> + if (!prop)
> + return -ENOENT;
>
> - if (offset < 0 || offset + sizeof(__be32) > prop->length) {
> - err = -EINVAL;
> - goto err_fail;
> - }
> + if (offset < 0 || offset + sizeof(__be32) > prop->length)
> + return -EINVAL;
>
> *(__be32 *)(prop->value + offset) = cpu_to_be32(phandle);
> }
>
> -err_fail:
> - kfree(value);
> - return err;
> + return 0;
> }
>
> /* compare nodes taking into account that 'name' strips out the @ part */
Reviewed-by: Saravana Kannan <[email protected]>
-Saravana
On Thu, Apr 4, 2024 at 6:16 PM Saravana Kannan <[email protected]> wrote:
>
> On Thu, Apr 4, 2024 at 7:15 AM Rob Herring <[email protected]> wrote:
> >
> > Use the relatively new scope based kfree() cleanup to simplify error
> > handling. Doing so reduces the chances of memory leaks and simplifies
> > error paths by avoiding the need for goto statements.
> >
> > Signed-off-by: Rob Herring <[email protected]>
> > ---
> > drivers/of/base.c | 34 ++++++++--------------------------
> > drivers/of/dynamic.c | 11 ++++-------
> > drivers/of/resolver.c | 35 +++++++++++++----------------------
> > 3 files changed, 25 insertions(+), 55 deletions(-)
> >
> > diff --git a/drivers/of/base.c b/drivers/of/base.c
> > index 8856c67c466a..20603d3c9931 100644
> > --- a/drivers/of/base.c
> > +++ b/drivers/of/base.c
> > @@ -16,6 +16,7 @@
> >
> > #define pr_fmt(fmt) "OF: " fmt
> >
> > +#include <linux/cleanup.h>
> > #include <linux/console.h>
> > #include <linux/ctype.h>
> > #include <linux/cpu.h>
> > @@ -1393,8 +1394,10 @@ int of_parse_phandle_with_args_map(const struct device_node *np,
> > const char *stem_name,
> > int index, struct of_phandle_args *out_args)
> > {
> > - char *cells_name, *map_name = NULL, *mask_name = NULL;
> > - char *pass_name = NULL;
> > + char *cells_name __free(kfree) = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
> > + char *map_name __free(kfree) = kasprintf(GFP_KERNEL, "%s-map", stem_name);
> > + char *mask_name __free(kfree) = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
> > + char *pass_name __free(kfree) = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
>
> With the scoped stuff, do these function calls need to be in the same
> line we are defining these variables? If not, I'd rather that the
> calls remain where they were. It feels like a lote to visually parse
> and take in from a readability perspective.
They don't have to be, but if you don't want to get yelled at by the
chief penguin, then yes, they should be together. See the discussions
on adding the scoped iterators. But with the C99 adoption, we can move
the declaration to where the assignment was original.
Rob
On Fri, Apr 5, 2024 at 5:44 AM Rob Herring <[email protected]> wrote:
>
> On Thu, Apr 4, 2024 at 6:16 PM Saravana Kannan <[email protected]> wrote:
> >
> > On Thu, Apr 4, 2024 at 7:15 AM Rob Herring <[email protected]> wrote:
> > >
> > > Use the relatively new scope based kfree() cleanup to simplify error
> > > handling. Doing so reduces the chances of memory leaks and simplifies
> > > error paths by avoiding the need for goto statements.
> > >
> > > Signed-off-by: Rob Herring <[email protected]>
> > > ---
> > > drivers/of/base.c | 34 ++++++++--------------------------
> > > drivers/of/dynamic.c | 11 ++++-------
> > > drivers/of/resolver.c | 35 +++++++++++++----------------------
> > > 3 files changed, 25 insertions(+), 55 deletions(-)
> > >
> > > diff --git a/drivers/of/base.c b/drivers/of/base.c
> > > index 8856c67c466a..20603d3c9931 100644
> > > --- a/drivers/of/base.c
> > > +++ b/drivers/of/base.c
> > > @@ -16,6 +16,7 @@
> > >
> > > #define pr_fmt(fmt) "OF: " fmt
> > >
> > > +#include <linux/cleanup.h>
> > > #include <linux/console.h>
> > > #include <linux/ctype.h>
> > > #include <linux/cpu.h>
> > > @@ -1393,8 +1394,10 @@ int of_parse_phandle_with_args_map(const struct device_node *np,
> > > const char *stem_name,
> > > int index, struct of_phandle_args *out_args)
> > > {
> > > - char *cells_name, *map_name = NULL, *mask_name = NULL;
> > > - char *pass_name = NULL;
> > > + char *cells_name __free(kfree) = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
> > > + char *map_name __free(kfree) = kasprintf(GFP_KERNEL, "%s-map", stem_name);
> > > + char *mask_name __free(kfree) = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
> > > + char *pass_name __free(kfree) = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
> >
> > With the scoped stuff, do these function calls need to be in the same
> > line we are defining these variables? If not, I'd rather that the
> > calls remain where they were. It feels like a lote to visually parse
> > and take in from a readability perspective.
>
> They don't have to be, but if you don't want to get yelled at by the
> chief penguin, then yes, they should be together. See the discussions
> on adding the scoped iterators. But with the C99 adoption, we can move
> the declaration to where the assignment was original.
Thanks for the context and the link in the other email.
Review-by without reservations.
-Saravana
On Thu, 04 Apr 2024 09:15:11 -0500
Rob Herring <[email protected]> wrote:
> Use the relatively new scope based kfree() cleanup to simplify error
> handling. Doing so reduces the chances of memory leaks and simplifies
> error paths by avoiding the need for goto statements.
>
> Signed-off-by: Rob Herring <[email protected]>
Reviewed-by: Jonathan Cameron <[email protected]>